diff --git a/CMakeLists.txt b/CMakeLists.txt new file mode 100644 index 0000000..969a94d --- /dev/null +++ b/CMakeLists.txt @@ -0,0 +1,58 @@ +project(bc7enc) + +cmake_minimum_required(VERSION 2.8) +option(BUILD_X64 "build 64-bit" TRUE) + +message("Initial BUILD_X64=${BUILD_X64}") +message("Initial CMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}") + +if( NOT CMAKE_BUILD_TYPE ) + set( CMAKE_BUILD_TYPE Release ) +endif( NOT CMAKE_BUILD_TYPE ) + +message( ${PROJECT_NAME} " build type: " ${CMAKE_BUILD_TYPE} ) + +if (BUILD_X64) + message("Building 64-bit") +else() + message("Building 32-bit") +endif(BUILD_X64) + +if (NOT MSVC) +set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g") +set(CMAKE_C_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g") + +set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}") +set(CMAKE_C_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}") +endif() + +# -fno-strict-aliasing shouldn't be necessary, it's here because that is what MSVC uses by default and that's what I've tested with the most. +if (NOT MSVC) + set(GCC_COMPILE_FLAGS "-fno-strict-aliasing -Wall -Wextra") + if (NOT BUILD_X64) + set(GCC_COMPILE_FLAGS "${GCC_COMPILE_FLAGS} -m32") + endif() +endif() + +set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${GCC_COMPILE_FLAGS}") +set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} ${GCC_COMPILE_FLAGS}") +set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} ${GCC_COMPILE_FLAGS} -D_DEBUG") + +set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${GCC_COMPILE_FLAGS}") +set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} ${GCC_COMPILE_FLAGS}") +set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} ${GCC_COMPILE_FLAGS} -D_DEBUG") + +set (BC7ENC_SRC_LIST ${COMMON_SRC_LIST} + bc7enc.cpp + lodepng.cpp + bc7decomp.c + bc7enc16.c + ) + +add_executable(bc7enc ${BC7ENC_SRC_LIST}) + +if (NOT MSVC) + target_link_libraries(bc7enc m) +endif() + + diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..6c93a9d --- /dev/null +++ b/LICENSE @@ -0,0 +1,76 @@ +bc7enc16.c/.h is available under 2 licenses -- choose whichever you prefer: + +ALTERNATIVE A for bc7enc.c/.h - MIT License +Copyright(c) 2018 Richard Geldreich, Jr. +Permission is hereby granted, free of charge, to any person obtaining a copy of +this software and associated documentation files(the "Software"), to deal in +the Software without restriction, including without limitation the rights to +use, copy, modify, merge, publish, distribute, sublicense, and / or sell copies +of the Software, and to permit persons to whom the Software is furnished to do +so, subject to the following conditions : +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. +------------------------------------------------------------------------------ +ALTERNATIVE B for bc7enc.c/.h - Public Domain(www.unlicense.org) +This is free and unencumbered software released into the public domain. +Anyone is free to copy, modify, publish, use, compile, sell, or distribute this +software, either in source code form or as a compiled binary, for any purpose, +commercial or non - commercial, and by any means. +In jurisdictions that recognize copyright laws, the author or authors of this +software dedicate any and all copyright interest in the software to the public +domain.We make this dedication for the benefit of the public at large and to +the detriment of our heirs and successors.We intend this dedication to be an +overt act of relinquishment in perpetuity of all present and future rights to +this software under copyright law. +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE +AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +------------------------------------------------------------------------------ + +bc7decomp.c/.h: Copyright (c) 2015 Harm Hanemaaijer +Permission to use, copy, modify, and/or distribute this software for any +purpose with or without fee is hereby granted, provided that the above +copyright notice and this permission notice appear in all copies. +THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +------------------------------------------------------------------------------ + +LodePNG version 20161127 + +Copyright (c) 2005-2016 Lode Vandevenne + +This software is provided 'as-is', without any express or implied +warranty. In no event will the authors be held liable for any damages +arising from the use of this software. + +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it +freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + + 3. This notice may not be removed or altered from any source + distribution. + \ No newline at end of file diff --git a/README b/README new file mode 100644 index 0000000..d41f8a6 --- /dev/null +++ b/README @@ -0,0 +1,11 @@ +bc7enc16 - Fast, single source file BC7/BPTC GPU texture encoder with perceptual colorspace metric support + + + +Supports modes 1 and 6. This is a strong opaque texture encoder, with basic +support for alpha channels (using mode 6). If alpha is highly correlated +compared to RGB, or it's relatively simple (think straightforward masks where +lots of blocks are either all-transparent or all-opaque), it should work great. +For complex alpha channels more modes (such as 4,5 or maybe 7) are necessary. + + diff --git a/bc7decomp.c b/bc7decomp.c new file mode 100644 index 0000000..0693332 --- /dev/null +++ b/bc7decomp.c @@ -0,0 +1,808 @@ +/* +Copyright (c) 2015 Harm Hanemaaijer +Permission to use, copy, modify, and/or distribute this software for any +purpose with or without fee is hereby granted, provided that the above +copyright notice and this permission notice appear in all copies. +THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +// Modified by Rich Geldreich 4/26/18- fixed bugs in detexBlock128ExtractBits() and FullyDecodeEndpoints(), +// compared vs. DirectXTex'c BC7 decoder for correctness. + +#include +#include +#include +#include +#include "bc7decomp.h" + +// Integer division using look-up tables, used by BC1/2/3 and RGTC (BC4/5) +// decompression. + +typedef struct { + uint64_t data0; + uint64_t data1; + int index; +} detexBlock128; + +uint32_t detexBlock128ExtractBits(detexBlock128 *block, int nu_bits) { + uint32_t value = 0; + for (int i = 0; i < nu_bits; i++) { + if (block->index < 64) { + int shift = block->index - i; + if (shift < 0) + value |= (block->data0 & ((uint64_t)1 << block->index)) << (-shift); + else + value |= (block->data0 & ((uint64_t)1 << block->index)) >> shift; + } + else { + int shift = ((block->index - 64) - i); + if (shift < 0) + value |= (block->data1 & ((uint64_t)1 << (block->index - 64))) << (-shift); + else + value |= (block->data1 & ((uint64_t)1 << (block->index - 64))) >> shift; + } + block->index++; + } + // if (block->index > 128) + // printf("Block overflow (%d)\n", block->index); + return value; +} + +static DETEX_INLINE_ONLY uint32_t detexPixel32GetR8(uint32_t pixel) { + return pixel & 0xFF; +} + +static DETEX_INLINE_ONLY uint32_t detexPixel32GetG8(uint32_t pixel) { + return (pixel & 0xFF00) >> 8; +} + +static DETEX_INLINE_ONLY uint32_t detexPixel32GetB8(uint32_t pixel) { + return (pixel & 0xFF0000) >> 16; +} + +static DETEX_INLINE_ONLY uint32_t detexPixel32GetA8(uint32_t pixel) { + return (pixel & 0xFF000000) >> 24; +} + +static DETEX_INLINE_ONLY uint32_t detexPack32R8(int r) { + return (uint32_t)r; +} + +static DETEX_INLINE_ONLY uint32_t detexPack32G8(int g) { + return (uint32_t)g << 8; +} + +static DETEX_INLINE_ONLY uint32_t detexPack32B8(int b) { + return (uint32_t)b << 16; +} + +static DETEX_INLINE_ONLY uint32_t detexPack32A8(int a) { + return (uint32_t)a << 24; +} + +static DETEX_INLINE_ONLY uint32_t detexPack32RGBA8(int r, int g, int b, int a) { + return (uint32_t)r | ((uint32_t)g << 8) | ((uint32_t)b << 16) | + ((uint32_t)a << 24); +} + +uint32_t detexBlock128ExtractBits(detexBlock128 *block, int nu_bits); + +/* Return bitfield from bit0 to bit1 from 64-bit bitstring. */ +static DETEX_INLINE_ONLY uint32_t detexGetBits64(uint64_t data, int bit0, int bit1) { + uint64_t mask; + if (bit1 == 63) + mask = UINT64_MAX; + else + mask = ((uint64_t)1 << (bit1 + 1)) - 1; + + return (uint32_t)((data & mask) >> bit0); +} + +const uint8_t detex_bptc_table_P2[64 * 16] = { + 0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1, + 0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1, + 0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1, + 0,0,0,1,0,0,1,1,0,0,1,1,0,1,1,1, + 0,0,0,0,0,0,0,1,0,0,0,1,0,0,1,1, + 0,0,1,1,0,1,1,1,0,1,1,1,1,1,1,1, + 0,0,0,1,0,0,1,1,0,1,1,1,1,1,1,1, + 0,0,0,0,0,0,0,1,0,0,1,1,0,1,1,1, + 0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,1, + 0,0,1,1,0,1,1,1,1,1,1,1,1,1,1,1, + 0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1, + 0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1, + 0,0,0,1,0,1,1,1,1,1,1,1,1,1,1,1, + 0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1, + 0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1, + 0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1, + 0,0,0,0,1,0,0,0,1,1,1,0,1,1,1,1, + 0,1,1,1,0,0,0,1,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,1,0,0,0,1,1,1,0, + 0,1,1,1,0,0,1,1,0,0,0,1,0,0,0,0, + 0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0, + 0,0,0,0,1,0,0,0,1,1,0,0,1,1,1,0, + 0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0, + 0,1,1,1,0,0,1,1,0,0,1,1,0,0,0,1, + 0,0,1,1,0,0,0,1,0,0,0,1,0,0,0,0, + 0,0,0,0,1,0,0,0,1,0,0,0,1,1,0,0, + 0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0, + 0,0,1,1,0,1,1,0,0,1,1,0,1,1,0,0, + 0,0,0,1,0,1,1,1,1,1,1,0,1,0,0,0, + 0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0, + 0,1,1,1,0,0,0,1,1,0,0,0,1,1,1,0, + 0,0,1,1,1,0,0,1,1,0,0,1,1,1,0,0, + 0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1, + 0,0,0,0,1,1,1,1,0,0,0,0,1,1,1,1, + 0,1,0,1,1,0,1,0,0,1,0,1,1,0,1,0, + 0,0,1,1,0,0,1,1,1,1,0,0,1,1,0,0, + 0,0,1,1,1,1,0,0,0,0,1,1,1,1,0,0, + 0,1,0,1,0,1,0,1,1,0,1,0,1,0,1,0, + 0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1, + 0,1,0,1,1,0,1,0,1,0,1,0,0,1,0,1, + 0,1,1,1,0,0,1,1,1,1,0,0,1,1,1,0, + 0,0,0,1,0,0,1,1,1,1,0,0,1,0,0,0, + 0,0,1,1,0,0,1,0,0,1,0,0,1,1,0,0, + 0,0,1,1,1,0,1,1,1,1,0,1,1,1,0,0, + 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0, + 0,0,1,1,1,1,0,0,1,1,0,0,0,0,1,1, + 0,1,1,0,0,1,1,0,1,0,0,1,1,0,0,1, + 0,0,0,0,0,1,1,0,0,1,1,0,0,0,0,0, + 0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,0, + 0,0,1,0,0,1,1,1,0,0,1,0,0,0,0,0, + 0,0,0,0,0,0,1,0,0,1,1,1,0,0,1,0, + 0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,0, + 0,1,1,0,1,1,0,0,1,0,0,1,0,0,1,1, + 0,0,1,1,0,1,1,0,1,1,0,0,1,0,0,1, + 0,1,1,0,0,0,1,1,1,0,0,1,1,1,0,0, + 0,0,1,1,1,0,0,1,1,1,0,0,0,1,1,0, + 0,1,1,0,1,1,0,0,1,1,0,0,1,0,0,1, + 0,1,1,0,0,0,1,1,0,0,1,1,1,0,0,1, + 0,1,1,1,1,1,1,0,1,0,0,0,0,0,0,1, + 0,0,0,1,1,0,0,0,1,1,1,0,0,1,1,1, + 0,0,0,0,1,1,1,1,0,0,1,1,0,0,1,1, + 0,0,1,1,0,0,1,1,1,1,1,1,0,0,0,0, + 0,0,1,0,0,0,1,0,1,1,1,0,1,1,1,0, + 0,1,0,0,0,1,0,0,0,1,1,1,0,1,1,1 +}; + +const uint8_t detex_bptc_table_P3[64 * 16] = { + 0,0,1,1,0,0,1,1,0,2,2,1,2,2,2,2, + 0,0,0,1,0,0,1,1,2,2,1,1,2,2,2,1, + 0,0,0,0,2,0,0,1,2,2,1,1,2,2,1,1, + 0,2,2,2,0,0,2,2,0,0,1,1,0,1,1,1, + 0,0,0,0,0,0,0,0,1,1,2,2,1,1,2,2, + 0,0,1,1,0,0,1,1,0,0,2,2,0,0,2,2, + 0,0,2,2,0,0,2,2,1,1,1,1,1,1,1,1, + 0,0,1,1,0,0,1,1,2,2,1,1,2,2,1,1, + 0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2, + 0,0,0,0,1,1,1,1,1,1,1,1,2,2,2,2, + 0,0,0,0,1,1,1,1,2,2,2,2,2,2,2,2, + 0,0,1,2,0,0,1,2,0,0,1,2,0,0,1,2, + 0,1,1,2,0,1,1,2,0,1,1,2,0,1,1,2, + 0,1,2,2,0,1,2,2,0,1,2,2,0,1,2,2, + 0,0,1,1,0,1,1,2,1,1,2,2,1,2,2,2, + 0,0,1,1,2,0,0,1,2,2,0,0,2,2,2,0, + 0,0,0,1,0,0,1,1,0,1,1,2,1,1,2,2, + 0,1,1,1,0,0,1,1,2,0,0,1,2,2,0,0, + 0,0,0,0,1,1,2,2,1,1,2,2,1,1,2,2, + 0,0,2,2,0,0,2,2,0,0,2,2,1,1,1,1, + 0,1,1,1,0,1,1,1,0,2,2,2,0,2,2,2, + 0,0,0,1,0,0,0,1,2,2,2,1,2,2,2,1, + 0,0,0,0,0,0,1,1,0,1,2,2,0,1,2,2, + 0,0,0,0,1,1,0,0,2,2,1,0,2,2,1,0, + 0,1,2,2,0,1,2,2,0,0,1,1,0,0,0,0, + 0,0,1,2,0,0,1,2,1,1,2,2,2,2,2,2, + 0,1,1,0,1,2,2,1,1,2,2,1,0,1,1,0, + 0,0,0,0,0,1,1,0,1,2,2,1,1,2,2,1, + 0,0,2,2,1,1,0,2,1,1,0,2,0,0,2,2, + 0,1,1,0,0,1,1,0,2,0,0,2,2,2,2,2, + 0,0,1,1,0,1,2,2,0,1,2,2,0,0,1,1, + 0,0,0,0,2,0,0,0,2,2,1,1,2,2,2,1, + 0,0,0,0,0,0,0,2,1,1,2,2,1,2,2,2, + 0,2,2,2,0,0,2,2,0,0,1,2,0,0,1,1, + 0,0,1,1,0,0,1,2,0,0,2,2,0,2,2,2, + 0,1,2,0,0,1,2,0,0,1,2,0,0,1,2,0, + 0,0,0,0,1,1,1,1,2,2,2,2,0,0,0,0, + 0,1,2,0,1,2,0,1,2,0,1,2,0,1,2,0, + 0,1,2,0,2,0,1,2,1,2,0,1,0,1,2,0, + 0,0,1,1,2,2,0,0,1,1,2,2,0,0,1,1, + 0,0,1,1,1,1,2,2,2,2,0,0,0,0,1,1, + 0,1,0,1,0,1,0,1,2,2,2,2,2,2,2,2, + 0,0,0,0,0,0,0,0,2,1,2,1,2,1,2,1, + 0,0,2,2,1,1,2,2,0,0,2,2,1,1,2,2, + 0,0,2,2,0,0,1,1,0,0,2,2,0,0,1,1, + 0,2,2,0,1,2,2,1,0,2,2,0,1,2,2,1, + 0,1,0,1,2,2,2,2,2,2,2,2,0,1,0,1, + 0,0,0,0,2,1,2,1,2,1,2,1,2,1,2,1, + 0,1,0,1,0,1,0,1,0,1,0,1,2,2,2,2, + 0,2,2,2,0,1,1,1,0,2,2,2,0,1,1,1, + 0,0,0,2,1,1,1,2,0,0,0,2,1,1,1,2, + 0,0,0,0,2,1,1,2,2,1,1,2,2,1,1,2, + 0,2,2,2,0,1,1,1,0,1,1,1,0,2,2,2, + 0,0,0,2,1,1,1,2,1,1,1,2,0,0,0,2, + 0,1,1,0,0,1,1,0,0,1,1,0,2,2,2,2, + 0,0,0,0,0,0,0,0,2,1,1,2,2,1,1,2, + 0,1,1,0,0,1,1,0,2,2,2,2,2,2,2,2, + 0,0,2,2,0,0,1,1,0,0,1,1,0,0,2,2, + 0,0,2,2,1,1,2,2,1,1,2,2,0,0,2,2, + 0,0,0,0,0,0,0,0,0,0,0,0,2,1,1,2, + 0,0,0,2,0,0,0,1,0,0,0,2,0,0,0,1, + 0,2,2,2,1,2,2,2,0,2,2,2,1,2,2,2, + 0,1,0,1,2,2,2,2,2,2,2,2,2,2,2,2, + 0,1,1,1,2,0,1,1,2,2,0,1,2,2,2,0, +}; + +const uint8_t detex_bptc_table_anchor_index_second_subset[64] = { + 15,15,15,15,15,15,15,15, + 15,15,15,15,15,15,15,15, + 15, 2, 8, 2, 2, 8, 8,15, + 2, 8, 2, 2, 8, 8, 2, 2, + 15,15, 6, 8, 2, 8,15,15, + 2, 8, 2, 2, 2,15,15, 6, + 6, 2, 6, 8,15,15, 2, 2, + 15,15,15,15,15, 2, 2,15 +}; + +const uint8_t detex_bptc_table_anchor_index_second_subset_of_three[64] = { + 3, 3,15,15, 8, 3,15,15, + 8, 8, 6, 6, 6, 5, 3, 3, + 3, 3, 8,15, 3, 3, 6,10, + 5, 8, 8, 6, 8, 5,15,15, + 8,15, 3, 5, 6,10, 8,15, + 15, 3,15, 5,15,15,15,15, + 3,15, 5, 5, 5, 8, 5,10, + 5,10, 8,13,15,12, 3, 3 +}; + +const uint8_t detex_bptc_table_anchor_index_third_subset[64] = { + 15, 8, 8, 3,15,15, 3, 8, + 15,15,15,15,15,15,15, 8, + 15, 8,15, 3,15, 8,15, 8, + 3,15, 6,10,15,15,10, 8, + 15, 3,15,10,10, 8, 9,10, + 6,15, 8,15, 3, 6, 6, 8, + 15, 3,15,15,15,15,15,15, + 15,15,15,15, 3,15,15, 8 +}; + +const uint16_t detex_bptc_table_aWeight2[4] = { + 0, 21, 43, 64 +}; + +const uint16_t detex_bptc_table_aWeight3[8] = { + 0, 9, 18, 27, 37, 46, 55, 64 +}; + +const uint16_t detex_bptc_table_aWeight4[16] = { + 0, 4, 9, 13, 17, 21, 26, 30, + 34, 38, 43, 47, 51, 55, 60, 64 +}; + + + +// BPTC mode layout: +// +// Number of subsets = { 3, 2, 3, 2, 1, 1, 1, 2 }; +// Partition bits = { 4, 6, 6, 6, 0, 0, 0, 6 }; +// Rotation bits = { 0, 0, 0, 0, 2, 2, 0, 0 }; +// Mode 4 has one index selection bit. +// +// #subsets color alpha before color index after color index after After Index +// alpha pbits bits (*) +// Mode 0 3 4 0 1 + 4 = 5 5 + 6 * 3 * 4 = 77 77 + 6 = 83 + 48 - 3 = 128 +// Mode 1 2 6 0 2 + 6 = 8 8 + 4 * 3 * 6 = 80 80 + 2 = 82 + 48 - 2 = 128 +// Mode 2 3 5 0 3 + 6 = 9 9 + 6 * 3 * 5 = 99 99 99 + 32 - 3 = 128 +// Mode 3 2 7 0 4 + 6 = 10 10 + 4 * 3 * 7 = 94 94 + 4 = 98 + 32 - 2 = 128 +// Mode 4 1 5 6 5 + 2 + 1 = 8 8 + 2 * 3 * 5 = 38 37 + 2 * 6 = 50 50 + 80 - 2 = 128 +// Mode 5 1 7 8 6 + 2 = 8 8 + 2 * 3 * 7 = 50 50 + 2 * 8 = 66 66 + 64 - 2 = 128 +// Mode 6 1 7 7 7 7 + 2 * 3 * 7 = 49 49 + 2 * 7 = 63 + 2 = 65 + 64 - 1 = 128 +// Mode 7 2 5 5 8 + 6 = 14 14 + 4 * 3 * 5 = 74 74 + 4 * 5 = 94 + 4 = 98 + 32 - 2 = 128 +// +// (*) For formats without alpha, the number of index bits is reduced by #subsets anchor bits. +// For formats with alpha, the number of index bits is reduced by 2 * #subsets by the anchor bits. + + +static const uint8_t color_precision_table[8] = { 4, 6, 5, 7, 5, 7, 7, 5 }; + +// Note: precision includes P-bits! +static const uint8_t color_precision_plus_pbit_table[8] = { 5, 7, 5, 8, 5, 7, 8, 6 }; + +static DETEX_INLINE_ONLY uint8_t GetColorComponentPrecision(int mode) { + return color_precision_table[mode]; +} + +static DETEX_INLINE_ONLY uint8_t GetColorComponentPrecisionPlusPbit(int mode) { + return color_precision_plus_pbit_table[mode]; +} + +static const int8_t alpha_precision_table[8] = { 0, 0, 0, 0, 6, 8, 7, 5 }; + +// Note: precision include P-bits! +static const uint8_t alpha_precision_plus_pbit_table[8] = { 0, 0, 0, 0, 6, 8, 8, 6 }; + +static DETEX_INLINE_ONLY uint8_t GetAlphaComponentPrecision(int mode) { + return alpha_precision_table[mode]; +} + +static DETEX_INLINE_ONLY uint8_t GetAlphaComponentPrecisionPlusPbit(int mode) { + return alpha_precision_plus_pbit_table[mode]; +} + +static const int8_t components_in_qword0_table[8] = { 2, -1, 1, 1, 3, 3, 3, 2 }; + +/* Extract endpoint colors. */ +static void ExtractEndpoints(int mode, int nu_subsets, detexBlock128 * DETEX_RESTRICT block, + uint8_t * DETEX_RESTRICT endpoint_array) { + // Optimized version avoiding the use of block_extract_bits(). + int components_in_qword0 = components_in_qword0_table[mode]; + uint64_t data = block->data0 >> block->index; + uint8_t precision = GetColorComponentPrecision(mode); + uint8_t mask = (1 << precision) - 1; + int total_bits_per_component = nu_subsets * 2 * precision; + for (int i = 0; i < components_in_qword0; i++) // For each color component. + for (int j = 0; j < nu_subsets; j++) // For each subset. + for (int k = 0; k < 2; k++) { // For each endpoint. + endpoint_array[j * 8 + k * 4 + i] = data & mask; + data >>= precision; + } + block->index += components_in_qword0 * total_bits_per_component; + if (components_in_qword0 < 3) { + // Handle the color component that crosses the boundary between data0 and data1 + data = block->data0 >> block->index; + data |= block->data1 << (64 - block->index); + int i = components_in_qword0; + for (int j = 0; j < nu_subsets; j++) // For each subset. + for (int k = 0; k < 2; k++) { // For each endpoint. + endpoint_array[j * 8 + k * 4 + i] = data & mask; + data >>= precision; + } + block->index += total_bits_per_component; + } + if (components_in_qword0 < 2) { + // Handle the color component that is wholly in data1. + data = block->data1 >> (block->index - 64); + int i = 2; + for (int j = 0; j < nu_subsets; j++) // For each subset. + for (int k = 0; k < 2; k++) { // For each endpoint. + endpoint_array[j * 8 + k * 4 + i] = data & mask; + data >>= precision; + } + block->index += total_bits_per_component; + } + // Alpha component. + if (GetAlphaComponentPrecision(mode) > 0) { + // For mode 7, the alpha data is wholly in data1. + // For modes 4 and 6, the alpha data is wholly in data0. + // For mode 5, the alpha data is in data0 and data1. + if (mode == 7) + data = block->data1 >> (block->index - 64); + else if (mode == 5) + data = (block->data0 >> block->index) | ((block->data1 & 0x3) << 14); + else + data = block->data0 >> block->index; + uint8_t alpha_precision = GetAlphaComponentPrecision(mode); + uint8_t mask = (1 << alpha_precision) - 1; + for (int j = 0; j < nu_subsets; j++) + for (int k = 0; k < 2; k++) { // For each endpoint. + endpoint_array[j * 8 + k * 4 + 3] = data & mask; + data >>= alpha_precision; + } + block->index += nu_subsets * 2 * alpha_precision; + } +} + +static const uint8_t mode_has_p_bits[8] = { 1, 1, 0, 1, 0, 0, 1, 1 }; + +static void FullyDecodeEndpoints(uint8_t * DETEX_RESTRICT endpoint_array, int nu_subsets, + int mode, detexBlock128 * DETEX_RESTRICT block) { + if (mode_has_p_bits[mode]) { + // Mode 1 (shared P-bits) handled elsewhere. + // Extract end-point P-bits. + uint32_t bits; + if (block->index < 64) + { + bits = (uint32_t)(block->data0 >> block->index); + if ((block->index + nu_subsets * 2) > 64) + { + bits |= (block->data1 << (64 - block->index)); + } + } + else + bits = (uint32_t)(block->data1 >> (block->index - 64)); + for (int i = 0; i < nu_subsets * 2; i++) { + endpoint_array[i * 4 + 0] <<= 1; + endpoint_array[i * 4 + 1] <<= 1; + endpoint_array[i * 4 + 2] <<= 1; + endpoint_array[i * 4 + 3] <<= 1; + endpoint_array[i * 4 + 0] |= (bits & 1); + endpoint_array[i * 4 + 1] |= (bits & 1); + endpoint_array[i * 4 + 2] |= (bits & 1); + endpoint_array[i * 4 + 3] |= (bits & 1); + bits >>= 1; + } + block->index += nu_subsets * 2; + } + int color_prec = GetColorComponentPrecisionPlusPbit(mode); + int alpha_prec = GetAlphaComponentPrecisionPlusPbit(mode); + for (int i = 0; i < nu_subsets * 2; i++) { + // Color_component_precision & alpha_component_precision includes pbit + // left shift endpoint components so that their MSB lies in bit 7 + endpoint_array[i * 4 + 0] <<= (8 - color_prec); + endpoint_array[i * 4 + 1] <<= (8 - color_prec); + endpoint_array[i * 4 + 2] <<= (8 - color_prec); + endpoint_array[i * 4 + 3] <<= (8 - alpha_prec); + + // Replicate each component's MSB into the LSBs revealed by the left-shift operation above. + endpoint_array[i * 4 + 0] |= (endpoint_array[i * 4 + 0] >> color_prec); + endpoint_array[i * 4 + 1] |= (endpoint_array[i * 4 + 1] >> color_prec); + endpoint_array[i * 4 + 2] |= (endpoint_array[i * 4 + 2] >> color_prec); + endpoint_array[i * 4 + 3] |= (endpoint_array[i * 4 + 3] >> alpha_prec); + } + if (mode <= 3) { + for (int i = 0; i < nu_subsets * 2; i++) + endpoint_array[i * 4 + 3] = 0xFF; + } +} + +static uint8_t Interpolate(uint8_t e0, uint8_t e1, uint8_t index, uint8_t indexprecision) { + if (indexprecision == 2) + return (uint8_t)(((64 - detex_bptc_table_aWeight2[index]) * (uint16_t)e0 + + detex_bptc_table_aWeight2[index] * (uint16_t)e1 + 32) >> 6); + else + if (indexprecision == 3) + return (uint8_t)(((64 - detex_bptc_table_aWeight3[index]) * (uint16_t)e0 + + detex_bptc_table_aWeight3[index] * (uint16_t)e1 + 32) >> 6); + else // indexprecision == 4 + return (uint8_t)(((64 - detex_bptc_table_aWeight4[index]) * (uint16_t)e0 + + detex_bptc_table_aWeight4[index] * (uint16_t)e1 + 32) >> 6); +} + +static const uint8_t bptc_color_index_bitcount[8] = { 3, 3, 2, 2, 2, 2, 4, 2 }; + +static DETEX_INLINE_ONLY int GetColorIndexBitcount(int mode, int index_selection_bit) { + // If the index selection bit is set for mode 4, return 3, otherwise 2. + return bptc_color_index_bitcount[mode] + index_selection_bit; +} + +static uint8_t bptc_alpha_index_bitcount[8] = { 3, 3, 2, 2, 3, 2, 4, 2 }; + +static DETEX_INLINE_ONLY int GetAlphaIndexBitcount(int mode, int index_selection_bit) { + // If the index selection bit is set for mode 4, return 2, otherwise 3. + return bptc_alpha_index_bitcount[mode] - index_selection_bit; +} + +static const uint8_t bptc_NS[8] = { 3, 2, 3, 2, 1, 1, 1, 2 }; + +static DETEX_INLINE_ONLY int GetNumberOfSubsets(int mode) { + return bptc_NS[mode]; +} + +static const uint8_t PB[8] = { 4, 6, 6, 6, 0, 0, 0, 6 }; + +static DETEX_INLINE_ONLY int GetNumberOfPartitionBits(int mode) { + return PB[mode]; +} + +static const uint8_t RB[8] = { 0, 0, 0, 0, 2, 2, 0, 0 }; + +static DETEX_INLINE_ONLY int GetNumberOfRotationBits(int mode) { + return RB[mode]; +} + +// Functions to extract parameters. */ + +static int ExtractMode(detexBlock128 *block) { + for (int i = 0; i < 8; i++) + if (block->data0 & ((uint64_t)1 << i)) { + block->index = i + 1; + return i; + } + // Illegal. + return -1; +} + +static DETEX_INLINE_ONLY int ExtractPartitionSetID(detexBlock128 *block, int mode) { + return detexBlock128ExtractBits(block, GetNumberOfPartitionBits(mode)); +} + +static DETEX_INLINE_ONLY int GetPartitionIndex(int nu_subsets, int partition_set_id, int i) { + if (nu_subsets == 1) + return 0; + if (nu_subsets == 2) + return detex_bptc_table_P2[partition_set_id * 16 + i]; + return detex_bptc_table_P3[partition_set_id * 16 + i]; +} + +static DETEX_INLINE_ONLY int ExtractRotationBits(detexBlock128 *block, int mode) { + return detexBlock128ExtractBits(block, GetNumberOfRotationBits(mode)); +} + +static DETEX_INLINE_ONLY int GetAnchorIndex(int partition_set_id, int partition, int nu_subsets) { + if (partition == 0) + return 0; + if (nu_subsets == 2) + return detex_bptc_table_anchor_index_second_subset[partition_set_id]; + if (partition == 1) + return detex_bptc_table_anchor_index_second_subset_of_three[partition_set_id]; + return detex_bptc_table_anchor_index_third_subset[partition_set_id]; +} + +static const uint8_t IB[8] = { 3, 3, 2, 2, 2, 2, 4, 2 }; +static const uint8_t IB2[8] = { 0, 0, 0, 0, 3, 2, 0, 0 }; +static const uint8_t mode_has_partition_bits[8] = { 1, 1, 1, 1, 0, 0, 0, 1 }; + +/* Decompress a 128-bit 4x4 pixel texture block compressed using BPTC mode 1. */ + +static bool DecompressBlockBPTCMode1(detexBlock128 * DETEX_RESTRICT block, + uint8_t * DETEX_RESTRICT pixel_buffer) { + uint64_t data0 = block->data0; + uint64_t data1 = block->data1; + int partition_set_id = detexGetBits64(data0, 2, 7); + uint8_t endpoint[2 * 2 * 3]; // 2 subsets. + endpoint[0] = detexGetBits64(data0, 8, 13); // red, subset 0, endpoint 0 + endpoint[3] = detexGetBits64(data0, 14, 19); // red, subset 0, endpoint 1 + endpoint[6] = detexGetBits64(data0, 20, 25); // red, subset 1, endpoint 0 + endpoint[9] = detexGetBits64(data0, 26, 31); // red, subset 1, endpoint 1 + endpoint[1] = detexGetBits64(data0, 32, 37); // green, subset 0, endpoint 0 + endpoint[4] = detexGetBits64(data0, 38, 43); // green, subset 0, endpoint 1 + endpoint[7] = detexGetBits64(data0, 44, 49); // green, subset 1, endpoint 0 + endpoint[10] = detexGetBits64(data0, 50, 55); // green, subset 1, endpoint 1 + endpoint[2] = detexGetBits64(data0, 56, 61); // blue, subset 0, endpoint 0 + endpoint[5] = detexGetBits64(data0, 62, 63) // blue, subset 0, endpoint 1 + | (detexGetBits64(data1, 0, 3) << 2); + endpoint[8] = detexGetBits64(data1, 4, 9); // blue, subset 1, endpoint 0 + endpoint[11] = detexGetBits64(data1, 10, 15); // blue, subset 1, endpoint 1 + // Decode endpoints. + for (int i = 0; i < 2 * 2; i++) { + //component-wise left-shift + endpoint[i * 3 + 0] <<= 2; + endpoint[i * 3 + 1] <<= 2; + endpoint[i * 3 + 2] <<= 2; + } + // P-bit is shared. + uint8_t pbit_zero = detexGetBits64(data1, 16, 16) << 1; + uint8_t pbit_one = detexGetBits64(data1, 17, 17) << 1; + // RGB only pbits for mode 1, one for each subset. + for (int j = 0; j < 3; j++) { + endpoint[0 * 3 + j] |= pbit_zero; + endpoint[1 * 3 + j] |= pbit_zero; + endpoint[2 * 3 + j] |= pbit_one; + endpoint[3 * 3 + j] |= pbit_one; + } + for (int i = 0; i < 2 * 2; i++) { + // Replicate each component's MSB into the LSB. + endpoint[i * 3 + 0] |= endpoint[i * 3 + 0] >> 7; + endpoint[i * 3 + 1] |= endpoint[i * 3 + 1] >> 7; + endpoint[i * 3 + 2] |= endpoint[i * 3 + 2] >> 7; + } + + uint8_t subset_index[16]; + for (int i = 0; i < 16; i++) + // subset_index[i] is a number from 0 to 1. + subset_index[i] = detex_bptc_table_P2[partition_set_id * 16 + i]; + uint8_t anchor_index[2]; + anchor_index[0] = 0; + anchor_index[1] = detex_bptc_table_anchor_index_second_subset[partition_set_id]; + uint8_t color_index[16]; + // Extract primary index bits. + data1 >>= 18; + for (int i = 0; i < 16; i++) + if (i == anchor_index[subset_index[i]]) { + // Highest bit is zero. + color_index[i] = data1 & 3; // Get two bits. + data1 >>= 2; + } + else { + color_index[i] = data1 & 7; // Get three bits. + data1 >>= 3; + } + uint32_t *pixel32_buffer = (uint32_t *)pixel_buffer; + for (int i = 0; i < 16; i++) { + uint8_t endpoint_start[3]; + uint8_t endpoint_end[3]; + for (int j = 0; j < 3; j++) { + endpoint_start[j] = endpoint[2 * subset_index[i] * 3 + j]; + endpoint_end[j] = endpoint[(2 * subset_index[i] + 1) * 3 + j]; + } + uint32_t output; + output = detexPack32R8(Interpolate(endpoint_start[0], endpoint_end[0], color_index[i], 3)); + output |= detexPack32G8(Interpolate(endpoint_start[1], endpoint_end[1], color_index[i], 3)); + output |= detexPack32B8(Interpolate(endpoint_start[2], endpoint_end[2], color_index[i], 3)); + output |= detexPack32A8(0xFF); + pixel32_buffer[i] = output; + } + return true; +} + +/* Decompress a 128-bit 4x4 pixel texture block compressed using the BPTC */ +/* (BC7) format. */ +bool detexDecompressBlockBPTC(const uint8_t * DETEX_RESTRICT bitstring, uint32_t mode_mask, + uint32_t flags, uint8_t * DETEX_RESTRICT pixel_buffer) { + detexBlock128 block; + block.data0 = *(uint64_t *)&bitstring[0]; + block.data1 = *(uint64_t *)&bitstring[8]; + block.index = 0; + int mode = ExtractMode(&block); + if (mode == -1) + return 0; + // Allow compression tied to specific modes (according to mode_mask). + if (!(mode_mask & ((int)1 << mode))) + return 0; + if (mode >= 4 && (flags & DETEX_DECOMPRESS_FLAG_OPAQUE_ONLY)) + return 0; + if (mode < 4 && (flags & DETEX_DECOMPRESS_FLAG_NON_OPAQUE_ONLY)) + return 0; + if (mode == 1) + return DecompressBlockBPTCMode1(&block, pixel_buffer); + + int nu_subsets = 1; + int partition_set_id = 0; + if (mode_has_partition_bits[mode]) { + nu_subsets = GetNumberOfSubsets(mode); + partition_set_id = ExtractPartitionSetID(&block, mode); + } + int rotation = ExtractRotationBits(&block, mode); + int index_selection_bit = 0; + if (mode == 4) + index_selection_bit = detexBlock128ExtractBits(&block, 1); + + int alpha_index_bitcount = GetAlphaIndexBitcount(mode, index_selection_bit); + int color_index_bitcount = GetColorIndexBitcount(mode, index_selection_bit); + + uint8_t endpoint_array[3 * 2 * 4]; // Max. 3 subsets. + ExtractEndpoints(mode, nu_subsets, &block, endpoint_array); + FullyDecodeEndpoints(endpoint_array, nu_subsets, mode, &block); + + uint8_t subset_index[16]; + for (int i = 0; i < 16; i++) + // subset_index[i] is a number from 0 to 2, or 0 to 1, or 0 depending on the number of subsets. + subset_index[i] = GetPartitionIndex(nu_subsets, partition_set_id, i); + uint8_t anchor_index[4] = { 0, 0, 0, 0 }; // Only need max. 3 elements. + for (int i = 0; i < nu_subsets; i++) + anchor_index[i] = GetAnchorIndex(partition_set_id, i, nu_subsets); + uint8_t color_index[16]; + uint8_t alpha_index[16]; + memset(color_index, 0, sizeof(color_index)); + memset(alpha_index, 0, sizeof(alpha_index)); + // Extract primary index bits. + uint64_t data1; + if (block.index >= 64) { + // Because the index bits are all in the second 64-bit word, there is no need to use + // block_extract_bits(). + // This implies the mode is not 4. + data1 = block.data1 >> (block.index - 64); + uint8_t mask1 = (1 << IB[mode]) - 1; + uint8_t mask2 = (1 << (IB[mode] - 1)) - 1; + for (int i = 0; i < 16; i++) + if (i == anchor_index[subset_index[i]]) { + // Highest bit is zero. + color_index[i] = data1 & mask2; + data1 >>= IB[mode] - 1; + alpha_index[i] = color_index[i]; + } + else { + color_index[i] = data1 & mask1; + data1 >>= IB[mode]; + alpha_index[i] = color_index[i]; + } + } + else { // Implies mode 4. + // Because the bits cross the 64-bit word boundary, we have to be careful. + // Block index is 50 at this point. + uint64_t data = block.data0 >> 50; + data |= block.data1 << 14; + for (int i = 0; i < 16; i++) + if (i == anchor_index[subset_index[i]]) { + // Highest bit is zero. + if (index_selection_bit) { // Implies mode == 4. + alpha_index[i] = data & 0x1; + data >>= 1; + } + else { + color_index[i] = data & 0x1; + data >>= 1; + } + } + else { + if (index_selection_bit) { // Implies mode == 4. + alpha_index[i] = data & 0x3; + data >>= 2; + } + else { + color_index[i] = data & 0x3; + data >>= 2; + } + } + // Block index is 81 at this point. + data1 = block.data1 >> (81 - 64); + } + // Extract secondary index bits. + if (IB2[mode] > 0) { + uint8_t mask1 = (1 << IB2[mode]) - 1; + uint8_t mask2 = (1 << (IB2[mode] - 1)) - 1; + for (int i = 0; i < 16; i++) + if (i == anchor_index[subset_index[i]]) { + // Highest bit is zero. + if (index_selection_bit) { + color_index[i] = data1 & 0x3; + data1 >>= 2; + } + else { + // alpha_index[i] = block_extract_bits(&block, IB2[mode] - 1); + alpha_index[i] = data1 & mask2; + data1 >>= IB2[mode] - 1; + } + } + else { + if (index_selection_bit) { + color_index[i] = data1 & 0x7; + data1 >>= 3; + } + else { + // alpha_index[i] = block_extract_bits(&block, IB2[mode]); + alpha_index[i] = data1 & mask1; + data1 >>= IB2[mode]; + } + } + } + + uint32_t *pixel32_buffer = (uint32_t *)pixel_buffer; + for (int i = 0; i < 16; i++) { + uint8_t endpoint_start[4]; + uint8_t endpoint_end[4]; + for (int j = 0; j < 4; j++) { + endpoint_start[j] = endpoint_array[2 * subset_index[i] * 4 + j]; + endpoint_end[j] = endpoint_array[(2 * subset_index[i] + 1) * 4 + j]; + } + + uint32_t output = 0; + output = detexPack32R8(Interpolate(endpoint_start[0], endpoint_end[0], color_index[i], color_index_bitcount)); + output |= detexPack32G8(Interpolate(endpoint_start[1], endpoint_end[1], color_index[i], color_index_bitcount)); + output |= detexPack32B8(Interpolate(endpoint_start[2], endpoint_end[2], color_index[i], color_index_bitcount)); + output |= detexPack32A8(Interpolate(endpoint_start[3], endpoint_end[3], alpha_index[i], alpha_index_bitcount)); + + if (rotation > 0) { + if (rotation == 1) + output = detexPack32RGBA8(detexPixel32GetA8(output), detexPixel32GetG8(output), + detexPixel32GetB8(output), detexPixel32GetR8(output)); + else + if (rotation == 2) + output = detexPack32RGBA8(detexPixel32GetR8(output), detexPixel32GetA8(output), + detexPixel32GetB8(output), detexPixel32GetG8(output)); + else // rotation == 3 + output = detexPack32RGBA8(detexPixel32GetR8(output), detexPixel32GetG8(output), + detexPixel32GetA8(output), detexPixel32GetB8(output)); + } + pixel32_buffer[i] = output; + } + return true; +} + +/* Return the internal mode of the BPTC block. */ +uint32_t detexGetModeBPTC(const uint8_t *bitstring) { + detexBlock128 block; + block.data0 = *(uint64_t *)&bitstring[0]; + block.data1 = *(uint64_t *)&bitstring[8]; + block.index = 0; + int mode = ExtractMode(&block); + return mode; +} + +void detexSetModeBPTC(uint8_t *bitstring, uint32_t mode, uint32_t flags, + uint32_t *colors) { + // Mode 0 starts with 1 + // Mode 1 starts with 01 + // ... + // Mode 7 starts with 00000001 + int bit = 0x1 << mode; + bitstring[0] &= ~(bit - 1); + bitstring[0] |= bit; + return; +} + diff --git a/bc7decomp.h b/bc7decomp.h new file mode 100644 index 0000000..1ade732 --- /dev/null +++ b/bc7decomp.h @@ -0,0 +1,34 @@ +#pragma once + +#ifdef _MSC_VER +#define DETEX_INLINE_ONLY __forceinline +#define DETEX_RESTRICT __restrict +#else +#define DETEX_INLINE_ONLY +#define DETEX_RESTRICT +#endif + +enum { + /* Function returns false (invalid block) when the compressed block */ + /* is in a format not allowed to be generated by an encoder. */ + DETEX_DECOMPRESS_FLAG_ENCODE = 0x1, + /* For compression formats that have opaque and non-opaque modes, */ + /* return false (invalid block) when the compressed block is encoded */ + /* using a non-opaque mode. */ + DETEX_DECOMPRESS_FLAG_OPAQUE_ONLY = 0x2, + /* For compression formats that have opaque and non-opaque modes, */ + /* return false (invalid block) when the compressed block is encoded */ + /* using an opaque mode. */ + DETEX_DECOMPRESS_FLAG_NON_OPAQUE_ONLY = 0x4, +}; + +#ifdef __cplusplus +extern "C" { +#endif + +bool detexDecompressBlockBPTC(const uint8_t * DETEX_RESTRICT bitstring, uint32_t mode_mask, + uint32_t flags, uint8_t * DETEX_RESTRICT pixel_buffer); + +#ifdef __cplusplus +} +#endif diff --git a/bc7enc.cpp b/bc7enc.cpp new file mode 100644 index 0000000..f912c56 --- /dev/null +++ b/bc7enc.cpp @@ -0,0 +1,634 @@ +// bc7enc.cpp - bc7enc17.c command line example/test app +#include +#include +#include +#include +#include +#include +#include + +#include "bc7enc16.h" +#include "lodepng.h" +#include "dds_defs.h" +#include "bc7decomp.h" + +template inline T clamp(T v, T l, T h) { if (v < l) v = l; else if (v > h) v = h; return v; } +inline int iabs(int i) { if (i < 0) i = -i; return i; } + +static int print_usage() +{ + fprintf(stderr, "bc7enc\n"); + fprintf(stderr, "Reads PNG files (with or without alpha channels) and packs them to BC7/BPTC using modes 1 and 6.\n"); + fprintf(stderr, "This tool works best with opaque images, or on images with relatively simple alpha channels.\n"); + fprintf(stderr, "By default, a DX10 DDS file and a unpacked PNG file will be written to the source file's directory with the .dds/_unpacked.png/_unpacked_alpha.png suffixes.\n\n"); + fprintf(stderr, "Usage: bc7enc [-apng_filename] [-l] [-uX] [-aX] [-g] [-y] input_filename.png [compressed_output.dds] [unpacked_output.png]\n"); + fprintf(stderr, "-apng_filename Load G channel of PNG file into alpha channel of source image\n"); + fprintf(stderr, "-l Use linear colorspace metrics instead of perceptual\n"); + fprintf(stderr, "-uX Higher quality levels, X ranges from [0,4], higher=slower\n"); + fprintf(stderr, "-pX Scan X partitions in mode 1, X ranges from [0,64], use 0 to disable mode 1 entirely (faster)\n"); + fprintf(stderr, "-g Don't write an unpacked output PNG file\n"); + fprintf(stderr, "-y Flip source image along Y axis before packing\n"); + + return EXIT_FAILURE; +} + +struct color_quad_u8 +{ + uint8_t m_c[4]; + + inline color_quad_u8(uint8_t r, uint8_t g, uint8_t b, uint8_t a) + { + set(r, g, b, a); + } + + inline color_quad_u8(uint8_t y = 0, uint8_t a = 255) + { + set(y, a); + } + + inline color_quad_u8 &set(uint8_t y, uint8_t a = 255) + { + m_c[0] = y; + m_c[1] = y; + m_c[2] = y; + m_c[3] = a; + return *this; + } + + inline color_quad_u8 &set(uint8_t r, uint8_t g, uint8_t b, uint8_t a) + { + m_c[0] = r; + m_c[1] = g; + m_c[2] = b; + m_c[3] = a; + return *this; + } + + inline uint8_t &operator[] (uint32_t i) { assert(i < 4); return m_c[i]; } + inline uint8_t operator[] (uint32_t i) const { assert(i < 4); return m_c[i]; } + + inline int get_luma() const { return (13938U * m_c[0] + 46869U * m_c[1] + 4729U * m_c[2] + 32768U) >> 16U; } // REC709 weightings +}; +typedef std::vector color_quad_u8_vec; + +class image_u8 +{ +public: + image_u8() : + m_width(0), m_height(0) + { + } + + image_u8(uint32_t width, uint32_t height) : + m_width(width), m_height(height) + { + m_pixels.resize(width * height); + } + + inline const color_quad_u8_vec &get_pixels() const { return m_pixels; } + inline color_quad_u8_vec &get_pixels() { return m_pixels; } + + inline uint32_t width() const { return m_width; } + inline uint32_t height() const { return m_height; } + inline uint32_t total_pixels() const { return m_width * m_height; } + + inline color_quad_u8 &operator()(uint32_t x, uint32_t y) { assert(x < m_width && y < m_height); return m_pixels[x + m_width * y]; } + inline const color_quad_u8 &operator()(uint32_t x, uint32_t y) const { assert(x < m_width && y < m_height); return m_pixels[x + m_width * y]; } + + image_u8& clear() + { + m_width = m_height = 0; + m_pixels.clear(); + return *this; + } + + image_u8& init(uint32_t width, uint32_t height) + { + clear(); + + m_width = width; + m_height = height; + m_pixels.resize(width * height); + return *this; + } + + image_u8& set_all(const color_quad_u8 &p) + { + for (uint32_t i = 0; i < m_pixels.size(); i++) + m_pixels[i] = p; + return *this; + } + + image_u8& crop(uint32_t new_width, uint32_t new_height) + { + if ((m_width == new_width) && (m_height == new_height)) + return *this; + + image_u8 new_image(new_width, new_height); + + const uint32_t w = std::min(m_width, new_width); + const uint32_t h = std::min(m_height, new_height); + + for (uint32_t y = 0; y < h; y++) + for (uint32_t x = 0; x < w; x++) + new_image(x, y) = (*this)(x, y); + + return swap(new_image); + } + + image_u8 &swap(image_u8 &other) + { + std::swap(m_width, other.m_width); + std::swap(m_height, other.m_height); + std::swap(m_pixels, other.m_pixels); + return *this; + } + + inline void get_block(uint32_t bx, uint32_t by, uint32_t width, uint32_t height, color_quad_u8 *pPixels) + { + assert((bx * width + width) <= m_width); + assert((by * height + height) <= m_height); + + for (uint32_t y = 0; y < height; y++) + memcpy(pPixels + y * width, &(*this)(bx * width, by * height + y), width * sizeof(color_quad_u8)); + } + + inline void set_block(uint32_t bx, uint32_t by, uint32_t width, uint32_t height, const color_quad_u8 *pPixels) + { + assert((bx * width + width) <= m_width); + assert((by * height + height) <= m_height); + + for (uint32_t y = 0; y < height; y++) + memcpy(&(*this)(bx * width, by * height + y), pPixels + y * width, width * sizeof(color_quad_u8)); + } + + image_u8 &swizzle(uint32_t r, uint32_t g, uint32_t b, uint32_t a) + { + assert((r | g | b | a) <= 3); + for (uint32_t y = 0; y < m_height; y++) + { + for (uint32_t x = 0; x < m_width; x++) + { + color_quad_u8 tmp((*this)(x, y)); + (*this)(x, y).set(tmp[r], tmp[g], tmp[b], tmp[a]); + } + } + + return *this; + } + +private: + color_quad_u8_vec m_pixels; + uint32_t m_width, m_height; +}; + +static bool load_png(const char *pFilename, image_u8 &img) +{ + img.clear(); + + std::vector pixels; + unsigned int w = 0, h = 0; + unsigned int e = lodepng::decode(pixels, w, h, pFilename); + if (e != 0) + { + fprintf(stderr, "Failed loading PNG file %s\n", pFilename); + return false; + } + + img.init(w, h); + memcpy(&img.get_pixels()[0], &pixels[0], w * h * sizeof(uint32_t)); + + return true; +} + +static bool save_png(const char *pFilename, const image_u8 &img, bool save_alpha) +{ + const uint32_t w = img.width(); + const uint32_t h = img.height(); + + std::vector pixels; + if (save_alpha) + { + pixels.resize(w * h * sizeof(color_quad_u8)); + memcpy(&pixels[0], &img.get_pixels()[0], w * h * sizeof(color_quad_u8)); + } + else + { + pixels.resize(w * h * 3); + unsigned char *pDst = &pixels[0]; + for (uint32_t y = 0; y < h; y++) + for (uint32_t x = 0; x < w; x++, pDst += 3) + pDst[0] = img(x, y)[0], pDst[1] = img(x, y)[1], pDst[2] = img(x, y)[2]; + } + + return lodepng::encode(pFilename, pixels, w, h, save_alpha ? LCT_RGBA : LCT_RGB) == 0; +} + +class image_metrics +{ +public: + double m_max, m_mean, m_mean_squared, m_root_mean_squared, m_peak_snr; + + image_metrics() + { + clear(); + } + + void clear() + { + memset(this, 0, sizeof(*this)); + } + + void compute(const image_u8 &a, const image_u8 &b, uint32_t first_channel, uint32_t num_channels) + { + const bool average_component_error = true; + + const uint32_t width = std::min(a.width(), b.width()); + const uint32_t height = std::min(a.height(), b.height()); + + assert((first_channel < 4U) && (first_channel + num_channels <= 4U)); + + // Histogram approach originally due to Charles Bloom. + double hist[256]; + memset(hist, 0, sizeof(hist)); + + for (uint32_t y = 0; y < height; y++) + { + for (uint32_t x = 0; x < width; x++) + { + const color_quad_u8 &ca = a(x, y); + const color_quad_u8 &cb = b(x, y); + + if (!num_channels) + hist[iabs(ca.get_luma() - cb.get_luma())]++; + else + { + for (uint32_t c = 0; c < num_channels; c++) + hist[iabs(ca[first_channel + c] - cb[first_channel + c])]++; + } + } + } + + m_max = 0; + double sum = 0.0f, sum2 = 0.0f; + for (uint32_t i = 0; i < 256; i++) + { + if (!hist[i]) + continue; + + m_max = std::max(m_max, i); + + double x = i * hist[i]; + + sum += x; + sum2 += i * x; + } + + // See http://richg42.blogspot.com/2016/09/how-to-compute-psnr-from-old-berkeley.html + double total_values = width * height; + + if (average_component_error) + total_values *= clamp(num_channels, 1, 4); + + m_mean = clamp(sum / total_values, 0.0f, 255.0f); + m_mean_squared = clamp(sum2 / total_values, 0.0f, 255.0f * 255.0f); + + m_root_mean_squared = sqrt(m_mean_squared); + + if (!m_root_mean_squared) + m_peak_snr = 1e+10f; + else + m_peak_snr = clamp(log10(255.0f / m_root_mean_squared) * 20.0f, 0.0f, 500.0f); + } +}; + +struct bc7_block +{ + uint64_t m_vals[2]; +}; + +typedef std::vector bc7_block_vec; + +static bool save_bc7_dds(const char *pFilename, uint32_t width, uint32_t height, const bc7_block *pBlocks, bool srgb) +{ + FILE *pFile = NULL; + fopen_s(&pFile, pFilename, "wb"); + if (!pFile) + { + fprintf(stderr, "Failed creating file %s!\n", pFilename); + return false; + } + + fwrite("DDS ", 4, 1, pFile); + + DDSURFACEDESC2 desc; + memset(&desc, 0, sizeof(desc)); + + desc.dwSize = sizeof(desc); + desc.dwFlags = DDSD_WIDTH | DDSD_HEIGHT | DDSD_PIXELFORMAT | DDSD_CAPS; + + desc.dwWidth = width; + desc.dwHeight = height; + + desc.ddsCaps.dwCaps = DDSCAPS_TEXTURE; + desc.ddpfPixelFormat.dwSize = sizeof(desc.ddpfPixelFormat); + + desc.ddpfPixelFormat.dwFlags |= DDPF_FOURCC; + + desc.ddpfPixelFormat.dwFourCC = (uint32_t)PIXEL_FMT_FOURCC('D', 'X', '1', '0'); + desc.ddpfPixelFormat.dwRGBBitCount = 0; + + const uint32_t pixel_format_bpp = 8; + + desc.lPitch = (((desc.dwWidth + 3) & ~3) * ((desc.dwHeight + 3) & ~3) * pixel_format_bpp) >> 3; + desc.dwFlags |= DDSD_LINEARSIZE; + + fwrite(&desc, sizeof(desc), 1, pFile); + + DDS_HEADER_DXT10 hdr10; + memset(&hdr10, 0, sizeof(hdr10)); + + hdr10.dxgiFormat = srgb ? DXGI_FORMAT_BC7_UNORM_SRGB : DXGI_FORMAT_BC7_UNORM; + hdr10.resourceDimension = D3D10_RESOURCE_DIMENSION_TEXTURE2D; + hdr10.arraySize = 1; + + fwrite(&hdr10, sizeof(hdr10), 1, pFile); + + fwrite(pBlocks, desc.lPitch, 1, pFile); + + if (fclose(pFile) == EOF) + { + fprintf(stderr, "Failed writing to DDS file %s!\n", pFilename); + return false; + } + + return true; +} + +static void strip_extension(std::string &s) +{ + for (int32_t i = (int32_t)s.size() - 1; i >= 0; i--) + { + if (s[i] == '.') + { + s.resize(i); + break; + } + } +} + +int main(int argc, char *argv[]) +{ + if (argc < 2) + return print_usage(); + + std::string src_filename; + std::string src_alpha_filename; + std::string dds_output_filename; + std::string png_output_filename; + std::string png_alpha_output_filename; + int uber_level = 0; + int max_partitions_to_scan = BC7ENC16_MAX_PARTITIONS1; + bool perceptual = true; + bool no_output_png = false; + bool y_flip = false; + + for (int i = 1; i < argc; i++) + { + const char *pArg = argv[i]; + if (pArg[0] == '-') + { + switch (pArg[1]) + { + case 'y': + { + y_flip = true; + break; + } + case 'a': + { + src_alpha_filename = pArg + 2; + break; + } + case 'u': + { + uber_level = atoi(pArg + 2); + if ((uber_level < 0) || (uber_level > BC7ENC16_MAX_UBER_LEVEL)) + { + fprintf(stderr, "Invalid argument: %s\n", pArg); + return EXIT_FAILURE; + } + break; + + } + case 'g': + { + no_output_png = true; + break; + } + case 'l': + { + perceptual = false; + break; + } + case 'p': + { + max_partitions_to_scan = atoi(pArg + 2); + if ((max_partitions_to_scan < 0) || (max_partitions_to_scan > BC7ENC16_MAX_PARTITIONS1)) + { + fprintf(stderr, "Invalid argument: %s\n", pArg); + return EXIT_FAILURE; + } + break; + } + default: + { + fprintf(stderr, "Invalid argument: %s\n", pArg); + return EXIT_FAILURE; + } + } + } + else + { + if (!src_filename.size()) + src_filename = pArg; + else if (!dds_output_filename.size()) + dds_output_filename = pArg; + else if (!png_output_filename.size()) + png_output_filename = pArg; + else + { + fprintf(stderr, "Invalid argument: %s\n", pArg); + return EXIT_FAILURE; + } + } + } + + if (!src_filename.size()) + { + fprintf(stderr, "No source filename specified!\n"); + return EXIT_FAILURE; + } + + if (!dds_output_filename.size()) + { + dds_output_filename = src_filename; + strip_extension(dds_output_filename); + dds_output_filename += ".dds"; + } + + if (!png_output_filename.size()) + { + png_output_filename = src_filename; + strip_extension(png_output_filename); + png_output_filename += "_unpacked.png"; + } + + png_alpha_output_filename = png_output_filename; + strip_extension(png_alpha_output_filename); + png_alpha_output_filename += "_unpacked_alpha.png"; + + image_u8 source_image; + if (!load_png(src_filename.c_str(), source_image)) + return EXIT_FAILURE; + + printf("Source image: %s %ux%u\n", src_filename.c_str(), source_image.width(), source_image.height()); + + if (src_alpha_filename.size()) + { + image_u8 source_alpha_image; + if (!load_png(src_alpha_filename.c_str(), source_alpha_image)) + return EXIT_FAILURE; + + printf("Source alpha image: %s %ux%u\n", src_alpha_filename.c_str(), source_alpha_image.width(), source_alpha_image.height()); + + const uint32_t w = std::min(source_alpha_image.width(), source_image.width()); + const uint32_t h = std::min(source_alpha_image.height(), source_image.height()); + + for (uint32_t y = 0; y < h; y++) + for (uint32_t x = 0; x < w; x++) + source_image(x, y)[3] = source_alpha_image(x, y)[1]; + } + + const uint32_t orig_width = source_image.width(); + const uint32_t orig_height = source_image.height(); + + if (y_flip) + { + image_u8 temp; + temp.init(orig_width, orig_height); + + for (uint32_t y = 0; y < orig_height; y++) + for (uint32_t x = 0; x < orig_width; x++) + temp(x, (orig_height - 1) - y) = source_image(x, y); + + temp.swap(source_image); + } + + source_image.crop((source_image.width() + 3) & ~3, (source_image.height() + 3) & ~3); + + const uint32_t blocks_x = source_image.width() / 4; + const uint32_t blocks_y = source_image.height() / 4; + + bc7_block_vec packed_image(blocks_x * blocks_y); + + bc7enc16_compress_block_params pack_params; + bc7enc16_compress_block_params_init(&pack_params); + if (!perceptual) + bc7enc16_compress_block_params_init_linear_weights(&pack_params); + pack_params.m_max_partitions_mode1 = max_partitions_to_scan; + pack_params.m_uber_level = uber_level; + + printf("Max mode 1 partitions: %u, uber level: %u, perceptual: %u\n", pack_params.m_max_partitions_mode1, pack_params.m_uber_level, perceptual); + + bc7enc16_compress_block_init(); + + bool has_alpha = false; + + clock_t start_t = clock(); + for (uint32_t by = 0; by < blocks_y; by++) + { + for (uint32_t bx = 0; bx < blocks_x; bx++) + { + color_quad_u8 pixels[16]; + + source_image.get_block(bx, by, 4, 4, pixels); + + bc7_block *pBlock = &packed_image[bx + by * blocks_x]; + + if (bc7enc16_compress_block(pBlock, pixels, &pack_params)) + has_alpha = true; + } + + if ((by & 63) == 0) + printf("."); + } + + clock_t end_t = clock(); + + printf("\nTotal time: %f secs\n", (double)(end_t - start_t) / CLOCKS_PER_SEC); + + if (has_alpha) + printf("Source image had an alpha channel.\n"); + + bool failed = false; + if (!save_bc7_dds(dds_output_filename.c_str(), orig_width, orig_height, &packed_image[0], perceptual)) + failed = true; + else + printf("Wrote DDS file %s\n", dds_output_filename.c_str()); + + if ((!no_output_png) && (png_output_filename.size())) + { + image_u8 unpacked_image(source_image.width(), source_image.height()); + + for (uint32_t by = 0; by < blocks_y; by++) + { + for (uint32_t bx = 0; bx < blocks_x; bx++) + { + bc7_block *pBlock = &packed_image[bx + by * blocks_x]; + + color_quad_u8 unpacked_pixels[16]; + detexDecompressBlockBPTC((const uint8_t *)pBlock, UINT32_MAX, 0, (uint8_t *)unpacked_pixels); + + unpacked_image.set_block(bx, by, 4, 4, unpacked_pixels); + } + } + + image_metrics y_metrics; + y_metrics.compute(source_image, unpacked_image, 0, 0); + printf("Luma Max error: %3.0f RMSE: %f PSNR %03.02f dB\n", y_metrics.m_max, y_metrics.m_root_mean_squared, y_metrics.m_peak_snr); + + image_metrics rgb_metrics; + rgb_metrics.compute(source_image, unpacked_image, 0, 3); + printf("RGB Max error: %3.0f RMSE: %f PSNR %03.02f dB\n", rgb_metrics.m_max, rgb_metrics.m_root_mean_squared, rgb_metrics.m_peak_snr); + + image_metrics rgba_metrics; + rgba_metrics.compute(source_image, unpacked_image, 0, 4); + printf("RGBA Max error: %3.0f RMSE: %f PSNR %03.02f dB\n", rgba_metrics.m_max, rgba_metrics.m_root_mean_squared, rgba_metrics.m_peak_snr); + + image_metrics a_metrics; + a_metrics.compute(source_image, unpacked_image, 3, 1); + printf("Alpha Max error: %3.0f RMSE: %f PSNR %03.02f dB\n", a_metrics.m_max, a_metrics.m_root_mean_squared, a_metrics.m_peak_snr); + + if (!save_png(png_output_filename.c_str(), unpacked_image, false)) + failed = true; + else + printf("Wrote PNG file %s\n", png_output_filename.c_str()); + + //if ((png_alpha_output_filename.size()) && (has_alpha)) + if (png_alpha_output_filename.size()) + { + image_u8 unpacked_image_alpha(unpacked_image); + for (uint32_t y = 0; y < unpacked_image_alpha.height(); y++) + for (uint32_t x = 0; x < unpacked_image_alpha.width(); x++) + unpacked_image_alpha(x, y).set(unpacked_image_alpha(x, y)[3], 255); + + if (!save_png(png_alpha_output_filename.c_str(), unpacked_image_alpha, false)) + failed = true; + else + printf("Wrote PNG file %s\n", png_alpha_output_filename.c_str()); + } + } + + return failed ? EXIT_FAILURE : EXIT_SUCCESS; +} diff --git a/bc7enc16.c b/bc7enc16.c new file mode 100644 index 0000000..fce7e76 --- /dev/null +++ b/bc7enc16.c @@ -0,0 +1,1413 @@ +// File: bc7enc16.c - Richard Geldreich, Jr. 4/2018 - MIT license or public domain (see end of file) +#include "bc7enc16.h" +#include +#include +#include + +// Helpers +static inline int32_t clampi(int32_t value, int32_t low, int32_t high) { if (value < low) value = low; else if (value > high) value = high; return value; } +static inline float clampf(float value, float low, float high) { if (value < low) value = low; else if (value > high) value = high; return value; } +static inline float saturate(float value) { return clampf(value, 0, 1.0f); } +static inline uint8_t minimumub(uint8_t a, uint8_t b) { return (a < b) ? a : b; } +static inline uint32_t minimumu(uint32_t a, uint32_t b) { return (a < b) ? a : b; } +static inline float minimumf(float a, float b) { return (a < b) ? a : b; } +static inline uint8_t maximumub(uint8_t a, uint8_t b) { return (a > b) ? a : b; } +static inline uint32_t maximumu(uint32_t a, uint32_t b) { return (a > b) ? a : b; } +static inline float maximumf(float a, float b) { return (a > b) ? a : b; } +static inline int squarei(int i) { return i * i; } +static inline float squaref(float i) { return i * i; } + +typedef struct { uint8_t m_c[4]; } color_quad_u8; +typedef struct { float m_c[4]; } vec4F; + +static inline color_quad_u8 *color_quad_u8_set_clamped(color_quad_u8 *pRes, int32_t r, int32_t g, int32_t b, int32_t a) { pRes->m_c[0] = (uint8_t)clampi(r, 0, 255); pRes->m_c[1] = (uint8_t)clampi(g, 0, 255); pRes->m_c[2] = (uint8_t)clampi(b, 0, 255); pRes->m_c[3] = (uint8_t)clampi(a, 0, 255); return pRes; } +static inline color_quad_u8 *color_quad_u8_set(color_quad_u8 *pRes, int32_t r, int32_t g, int32_t b, int32_t a) { assert((uint32_t)(r | g | b | a) <= 255); pRes->m_c[0] = (uint8_t)r; pRes->m_c[1] = (uint8_t)g; pRes->m_c[2] = (uint8_t)b; pRes->m_c[3] = (uint8_t)a; return pRes; } +static inline bc7enc16_bool color_quad_u8_notequals(const color_quad_u8 *pLHS, const color_quad_u8 *pRHS) { return (pLHS->m_c[0] != pRHS->m_c[0]) || (pLHS->m_c[1] != pRHS->m_c[1]) || (pLHS->m_c[2] != pRHS->m_c[2]) || (pLHS->m_c[3] != pRHS->m_c[3]); } +static inline vec4F *vec4F_set_scalar(vec4F *pV, float x) { pV->m_c[0] = x; pV->m_c[1] = x; pV->m_c[2] = x; pV->m_c[3] = x; return pV; } +static inline vec4F *vec4F_set(vec4F *pV, float x, float y, float z, float w) { pV->m_c[0] = x; pV->m_c[1] = y; pV->m_c[2] = z; pV->m_c[3] = w; return pV; } +static inline vec4F *vec4F_saturate_in_place(vec4F *pV) { pV->m_c[0] = saturate(pV->m_c[0]); pV->m_c[1] = saturate(pV->m_c[1]); pV->m_c[2] = saturate(pV->m_c[2]); pV->m_c[3] = saturate(pV->m_c[3]); return pV; } +static inline vec4F vec4F_saturate(const vec4F *pV) { vec4F res; res.m_c[0] = saturate(pV->m_c[0]); res.m_c[1] = saturate(pV->m_c[1]); res.m_c[2] = saturate(pV->m_c[2]); res.m_c[3] = saturate(pV->m_c[3]); return res; } +static inline vec4F vec4F_from_color(const color_quad_u8 *pC) { vec4F res; vec4F_set(&res, pC->m_c[0], pC->m_c[1], pC->m_c[2], pC->m_c[3]); return res; } +static inline vec4F vec4F_add(const vec4F *pLHS, const vec4F *pRHS) { vec4F res; vec4F_set(&res, pLHS->m_c[0] + pRHS->m_c[0], pLHS->m_c[1] + pRHS->m_c[1], pLHS->m_c[2] + pRHS->m_c[2], pLHS->m_c[3] + pRHS->m_c[3]); return res; } +static inline vec4F vec4F_sub(const vec4F *pLHS, const vec4F *pRHS) { vec4F res; vec4F_set(&res, pLHS->m_c[0] - pRHS->m_c[0], pLHS->m_c[1] - pRHS->m_c[1], pLHS->m_c[2] - pRHS->m_c[2], pLHS->m_c[3] - pRHS->m_c[3]); return res; } +static inline float vec4F_dot(const vec4F *pLHS, const vec4F *pRHS) { return pLHS->m_c[0] * pRHS->m_c[0] + pLHS->m_c[1] * pRHS->m_c[1] + pLHS->m_c[2] * pRHS->m_c[2] + pLHS->m_c[3] * pRHS->m_c[3]; } +static inline vec4F vec4F_mul(const vec4F *pLHS, float s) { vec4F res; vec4F_set(&res, pLHS->m_c[0] * s, pLHS->m_c[1] * s, pLHS->m_c[2] * s, pLHS->m_c[3] * s); return res; } +static inline vec4F *vec4F_normalize_in_place(vec4F *pV) { float s = pV->m_c[0] * pV->m_c[0] + pV->m_c[1] * pV->m_c[1] + pV->m_c[2] * pV->m_c[2] + pV->m_c[3] * pV->m_c[3]; if (s != 0.0f) { s = 1.0f / sqrtf(s); pV->m_c[0] *= s; pV->m_c[1] *= s; pV->m_c[2] *= s; pV->m_c[3] *= s; } return pV; } + +// Various BC7 tables +static const uint32_t g_bc7_weights3[8] = { 0, 9, 18, 27, 37, 46, 55, 64 }; +static const uint32_t g_bc7_weights4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 }; +// Precomputed weight constants used during least fit determination. For each entry in g_bc7_weights[]: w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w +static const float g_bc7_weights3x[8 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 0.019775f, 0.120850f, 0.738525f, 0.140625f, 0.079102f, 0.202148f, 0.516602f, 0.281250f, 0.177979f, 0.243896f, 0.334229f, 0.421875f, 0.334229f, 0.243896f, 0.177979f, 0.578125f, 0.516602f, 0.202148f, + 0.079102f, 0.718750f, 0.738525f, 0.120850f, 0.019775f, 0.859375f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; +static const float g_bc7_weights4x[16 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 0.003906f, 0.058594f, 0.878906f, 0.062500f, 0.019775f, 0.120850f, 0.738525f, 0.140625f, 0.041260f, 0.161865f, 0.635010f, 0.203125f, 0.070557f, 0.195068f, 0.539307f, 0.265625f, 0.107666f, 0.220459f, + 0.451416f, 0.328125f, 0.165039f, 0.241211f, 0.352539f, 0.406250f, 0.219727f, 0.249023f, 0.282227f, 0.468750f, 0.282227f, 0.249023f, 0.219727f, 0.531250f, 0.352539f, 0.241211f, 0.165039f, 0.593750f, 0.451416f, 0.220459f, 0.107666f, 0.671875f, 0.539307f, 0.195068f, 0.070557f, 0.734375f, + 0.635010f, 0.161865f, 0.041260f, 0.796875f, 0.738525f, 0.120850f, 0.019775f, 0.859375f, 0.878906f, 0.058594f, 0.003906f, 0.937500f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; +static const uint8_t g_bc7_partition1[16] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }; +static const uint8_t g_bc7_partition2[64 * 16] = +{ + 0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1, 0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,1, 0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1, 0,0,0,1,0,0,1,1,0,0,1,1,0,1,1,1, 0,0,0,0,0,0,0,1,0,0,0,1,0,0,1,1, 0,0,1,1,0,1,1,1,0,1,1,1,1,1,1,1, 0,0,0,1,0,0,1,1,0,1,1,1,1,1,1,1, 0,0,0,0,0,0,0,1,0,0,1,1,0,1,1,1, + 0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,1, 0,0,1,1,0,1,1,1,1,1,1,1,1,1,1,1, 0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1, 0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1, 0,0,0,1,0,1,1,1,1,1,1,1,1,1,1,1, 0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1, 0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1, 0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1, + 0,0,0,0,1,0,0,0,1,1,1,0,1,1,1,1, 0,1,1,1,0,0,0,1,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,1,0,0,0,1,1,1,0, 0,1,1,1,0,0,1,1,0,0,0,1,0,0,0,0, 0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0, 0,0,0,0,1,0,0,0,1,1,0,0,1,1,1,0, 0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0, 0,1,1,1,0,0,1,1,0,0,1,1,0,0,0,1, + 0,0,1,1,0,0,0,1,0,0,0,1,0,0,0,0, 0,0,0,0,1,0,0,0,1,0,0,0,1,1,0,0, 0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0, 0,0,1,1,0,1,1,0,0,1,1,0,1,1,0,0, 0,0,0,1,0,1,1,1,1,1,1,0,1,0,0,0, 0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0, 0,1,1,1,0,0,0,1,1,0,0,0,1,1,1,0, 0,0,1,1,1,0,0,1,1,0,0,1,1,1,0,0, + 0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1, 0,0,0,0,1,1,1,1,0,0,0,0,1,1,1,1, 0,1,0,1,1,0,1,0,0,1,0,1,1,0,1,0, 0,0,1,1,0,0,1,1,1,1,0,0,1,1,0,0, 0,0,1,1,1,1,0,0,0,0,1,1,1,1,0,0, 0,1,0,1,0,1,0,1,1,0,1,0,1,0,1,0, 0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1, 0,1,0,1,1,0,1,0,1,0,1,0,0,1,0,1, + 0,1,1,1,0,0,1,1,1,1,0,0,1,1,1,0, 0,0,0,1,0,0,1,1,1,1,0,0,1,0,0,0, 0,0,1,1,0,0,1,0,0,1,0,0,1,1,0,0, 0,0,1,1,1,0,1,1,1,1,0,1,1,1,0,0, 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0, 0,0,1,1,1,1,0,0,1,1,0,0,0,0,1,1, 0,1,1,0,0,1,1,0,1,0,0,1,1,0,0,1, 0,0,0,0,0,1,1,0,0,1,1,0,0,0,0,0, + 0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,0, 0,0,1,0,0,1,1,1,0,0,1,0,0,0,0,0, 0,0,0,0,0,0,1,0,0,1,1,1,0,0,1,0, 0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,0, 0,1,1,0,1,1,0,0,1,0,0,1,0,0,1,1, 0,0,1,1,0,1,1,0,1,1,0,0,1,0,0,1, 0,1,1,0,0,0,1,1,1,0,0,1,1,1,0,0, 0,0,1,1,1,0,0,1,1,1,0,0,0,1,1,0, + 0,1,1,0,1,1,0,0,1,1,0,0,1,0,0,1, 0,1,1,0,0,0,1,1,0,0,1,1,1,0,0,1, 0,1,1,1,1,1,1,0,1,0,0,0,0,0,0,1, 0,0,0,1,1,0,0,0,1,1,1,0,0,1,1,1, 0,0,0,0,1,1,1,1,0,0,1,1,0,0,1,1, 0,0,1,1,0,0,1,1,1,1,1,1,0,0,0,0, 0,0,1,0,0,0,1,0,1,1,1,0,1,1,1,0, 0,1,0,0,0,1,0,0,0,1,1,1,0,1,1,1 +}; +static const uint8_t g_bc7_table_anchor_index_second_subset[64] = { 15,15,15,15,15,15,15,15, 15,15,15,15,15,15,15,15, 15, 2, 8, 2, 2, 8, 8,15, 2, 8, 2, 2, 8, 8, 2, 2, 15,15, 6, 8, 2, 8,15,15, 2, 8, 2, 2, 2,15,15, 6, 6, 2, 6, 8,15,15, 2, 2, 15,15,15,15,15, 2, 2,15 }; +static const uint8_t g_bc7_num_subsets[8] = { 3, 2, 3, 2, 1, 1, 1, 2 }; +static const uint8_t g_bc7_partition_bits[8] = { 4, 6, 6, 6, 0, 0, 0, 6 }; +static const uint8_t g_bc7_color_index_bitcount[8] = { 3, 3, 2, 2, 2, 2, 4, 2 }; +static int get_bc7_color_index_size(int mode, int index_selection_bit) { return g_bc7_color_index_bitcount[mode] + index_selection_bit; } +static const uint8_t g_bc7_mode_has_p_bits[8] = { 1, 1, 0, 1, 0, 0, 1, 1 }; +static const uint8_t g_bc7_mode_has_shared_p_bits[8] = { 0, 1, 0, 0, 0, 0, 0, 0 }; +static const uint8_t g_bc7_color_precision_table[8] = { 4, 6, 5, 7, 5, 7, 7, 5 }; +static const int8_t g_bc7_alpha_precision_table[8] = { 0, 0, 0, 0, 6, 8, 7, 5 }; + +typedef struct { uint16_t m_error; uint8_t m_lo; uint8_t m_hi; } endpoint_err; + +static endpoint_err g_bc7_mode_1_optimal_endpoints[256][2]; // [c][pbit] +static const uint32_t BC7ENC16_MODE_1_OPTIMAL_INDEX = 2; + +// Initialize the lookup table used for optimal single color compression in mode 1. Must be called before encoding. +void bc7enc16_compress_block_init() +{ + for (int c = 0; c < 256; c++) + { + for (uint32_t lp = 0; lp < 2; lp++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 64; l++) + { + uint32_t low = ((l << 1) | lp) << 1; + low |= (low >> 7); + for (uint32_t h = 0; h < 64; h++) + { + uint32_t high = ((h << 1) | lp) << 1; + high |= (high >> 7); + const int k = (low * (64 - g_bc7_weights3[BC7ENC16_MODE_1_OPTIMAL_INDEX]) + high * g_bc7_weights3[BC7ENC16_MODE_1_OPTIMAL_INDEX] + 32) >> 6; + const int err = (k - c) * (k - c); + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + g_bc7_mode_1_optimal_endpoints[c][lp] = best; + } // lp + } // c +} + +static void compute_least_squares_endpoints_rgba(uint32_t N, const uint8_t *pSelectors, const vec4F *pSelector_weights, vec4F *pXl, vec4F *pXh, const color_quad_u8 *pColors) +{ + // Least squares using normal equations: http://www.cs.cornell.edu/~bindel/class/cs3220-s12/notes/lec10.pdf + // I did this in matrix form first, expanded out all the ops, then optimized it a bit. + float z00 = 0.0f, z01 = 0.0f, z10 = 0.0f, z11 = 0.0f; + float q00_r = 0.0f, q10_r = 0.0f, t_r = 0.0f; + float q00_g = 0.0f, q10_g = 0.0f, t_g = 0.0f; + float q00_b = 0.0f, q10_b = 0.0f, t_b = 0.0f; + float q00_a = 0.0f, q10_a = 0.0f, t_a = 0.0f; + for (uint32_t i = 0; i < N; i++) + { + const uint32_t sel = pSelectors[i]; + z00 += pSelector_weights[sel].m_c[0]; + z10 += pSelector_weights[sel].m_c[1]; + z11 += pSelector_weights[sel].m_c[2]; + float w = pSelector_weights[sel].m_c[3]; + q00_r += w * pColors[i].m_c[0]; t_r += pColors[i].m_c[0]; + q00_g += w * pColors[i].m_c[1]; t_g += pColors[i].m_c[1]; + q00_b += w * pColors[i].m_c[2]; t_b += pColors[i].m_c[2]; + q00_a += w * pColors[i].m_c[3]; t_a += pColors[i].m_c[3]; + } + + q10_r = t_r - q00_r; + q10_g = t_g - q00_g; + q10_b = t_b - q00_b; + q10_a = t_a - q00_a; + + z01 = z10; + + float det = z00 * z11 - z01 * z10; + if (det != 0.0f) + det = 1.0f / det; + + float iz00, iz01, iz10, iz11; + iz00 = z11 * det; + iz01 = -z01 * det; + iz10 = -z10 * det; + iz11 = z00 * det; + + pXl->m_c[0] = (float)(iz00 * q00_r + iz01 * q10_r); pXh->m_c[0] = (float)(iz10 * q00_r + iz11 * q10_r); + pXl->m_c[1] = (float)(iz00 * q00_g + iz01 * q10_g); pXh->m_c[1] = (float)(iz10 * q00_g + iz11 * q10_g); + pXl->m_c[2] = (float)(iz00 * q00_b + iz01 * q10_b); pXh->m_c[2] = (float)(iz10 * q00_b + iz11 * q10_b); + pXl->m_c[3] = (float)(iz00 * q00_a + iz01 * q10_a); pXh->m_c[3] = (float)(iz10 * q00_a + iz11 * q10_a); +} + +static void compute_least_squares_endpoints_rgb(uint32_t N, const uint8_t *pSelectors, const vec4F *pSelector_weights, vec4F *pXl, vec4F *pXh, const color_quad_u8 *pColors) +{ + float z00 = 0.0f, z01 = 0.0f, z10 = 0.0f, z11 = 0.0f; + float q00_r = 0.0f, q10_r = 0.0f, t_r = 0.0f; + float q00_g = 0.0f, q10_g = 0.0f, t_g = 0.0f; + float q00_b = 0.0f, q10_b = 0.0f, t_b = 0.0f; + for (uint32_t i = 0; i < N; i++) + { + const uint32_t sel = pSelectors[i]; + z00 += pSelector_weights[sel].m_c[0]; + z10 += pSelector_weights[sel].m_c[1]; + z11 += pSelector_weights[sel].m_c[2]; + float w = pSelector_weights[sel].m_c[3]; + q00_r += w * pColors[i].m_c[0]; t_r += pColors[i].m_c[0]; + q00_g += w * pColors[i].m_c[1]; t_g += pColors[i].m_c[1]; + q00_b += w * pColors[i].m_c[2]; t_b += pColors[i].m_c[2]; + } + + q10_r = t_r - q00_r; + q10_g = t_g - q00_g; + q10_b = t_b - q00_b; + + z01 = z10; + + float det = z00 * z11 - z01 * z10; + if (det != 0.0f) + det = 1.0f / det; + + float iz00, iz01, iz10, iz11; + iz00 = z11 * det; + iz01 = -z01 * det; + iz10 = -z10 * det; + iz11 = z00 * det; + + pXl->m_c[0] = (float)(iz00 * q00_r + iz01 * q10_r); pXh->m_c[0] = (float)(iz10 * q00_r + iz11 * q10_r); + pXl->m_c[1] = (float)(iz00 * q00_g + iz01 * q10_g); pXh->m_c[1] = (float)(iz10 * q00_g + iz11 * q10_g); + pXl->m_c[2] = (float)(iz00 * q00_b + iz01 * q10_b); pXh->m_c[2] = (float)(iz10 * q00_b + iz11 * q10_b); + pXl->m_c[3] = 255.0f; pXh->m_c[3] = 255.0f; +} + +typedef struct +{ + uint32_t m_num_pixels; + const color_quad_u8 *m_pPixels; + uint32_t m_num_selector_weights; + const uint32_t *m_pSelector_weights; + const vec4F *m_pSelector_weightsx; + uint32_t m_comp_bits; + uint32_t m_weights[4]; + bc7enc16_bool m_has_alpha; + bc7enc16_bool m_has_pbits; + bc7enc16_bool m_endpoints_share_pbit; + bc7enc16_bool m_perceptual; +} color_cell_compressor_params; + +typedef struct +{ + uint64_t m_best_overall_err; + color_quad_u8 m_low_endpoint; + color_quad_u8 m_high_endpoint; + uint32_t m_pbits[2]; + uint8_t *m_pSelectors; + uint8_t *m_pSelectors_temp; +} color_cell_compressor_results; + +static inline color_quad_u8 scale_color(const color_quad_u8 *pC, const color_cell_compressor_params *pParams) +{ + color_quad_u8 results; + + const uint32_t n = pParams->m_comp_bits + (pParams->m_has_pbits ? 1 : 0); + assert((n >= 4) && (n <= 8)); + + for (uint32_t i = 0; i < 4; i++) + { + uint32_t v = pC->m_c[i] << (8 - n); + v |= (v >> n); + assert(v <= 255); + results.m_c[i] = (uint8_t)(v); + } + + return results; +} + +static inline uint64_t compute_color_distance_rgb(const color_quad_u8 *pE1, const color_quad_u8 *pE2, bc7enc16_bool perceptual, const uint32_t weights[4]) +{ + int dr, dg, db; + + if (perceptual) + { + const int l1 = pE1->m_c[0] * 109 + pE1->m_c[1] * 366 + pE1->m_c[2] * 37; + const int cr1 = ((int)pE1->m_c[0] << 9) - l1; + const int cb1 = ((int)pE1->m_c[2] << 9) - l1; + const int l2 = pE2->m_c[0] * 109 + pE2->m_c[1] * 366 + pE2->m_c[2] * 37; + const int cr2 = ((int)pE2->m_c[0] << 9) - l2; + const int cb2 = ((int)pE2->m_c[2] << 9) - l2; + dr = (l1 - l2) >> 8; + dg = (cr1 - cr2) >> 8; + db = (cb1 - cb2) >> 8; + } + else + { + dr = (int)pE1->m_c[0] - (int)pE2->m_c[0]; + dg = (int)pE1->m_c[1] - (int)pE2->m_c[1]; + db = (int)pE1->m_c[2] - (int)pE2->m_c[2]; + } + + return weights[0] * (uint32_t)(dr * dr) + weights[1] * (uint32_t)(dg * dg) + weights[2] * (uint32_t)(db * db); +} + +static inline uint64_t compute_color_distance_rgba(const color_quad_u8 *pE1, const color_quad_u8 *pE2, bc7enc16_bool perceptual, const uint32_t weights[4]) +{ + int da = (int)pE1->m_c[3] - (int)pE2->m_c[3]; + return compute_color_distance_rgb(pE1, pE2, perceptual, weights) + (weights[3] * (uint32_t)(da * da)); +} + +static uint64_t pack_mode1_to_one_color(const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, uint32_t r, uint32_t g, uint32_t b, uint8_t *pSelectors) +{ + uint32_t best_err = UINT_MAX; + uint32_t best_p = 0; + + for (uint32_t p = 0; p < 2; p++) + { + uint32_t err = g_bc7_mode_1_optimal_endpoints[r][p].m_error + g_bc7_mode_1_optimal_endpoints[g][p].m_error + g_bc7_mode_1_optimal_endpoints[b][p].m_error; + if (err < best_err) + { + best_err = err; + best_p = p; + } + } + + const endpoint_err *pEr = &g_bc7_mode_1_optimal_endpoints[r][best_p]; + const endpoint_err *pEg = &g_bc7_mode_1_optimal_endpoints[g][best_p]; + const endpoint_err *pEb = &g_bc7_mode_1_optimal_endpoints[b][best_p]; + + color_quad_u8_set(&pResults->m_low_endpoint, pEr->m_lo, pEg->m_lo, pEb->m_lo, 0); + color_quad_u8_set(&pResults->m_high_endpoint, pEr->m_hi, pEg->m_hi, pEb->m_hi, 0); + pResults->m_pbits[0] = best_p; + pResults->m_pbits[1] = 0; + + memset(pSelectors, BC7ENC16_MODE_1_OPTIMAL_INDEX, pParams->m_num_pixels); + + color_quad_u8 p; + for (uint32_t i = 0; i < 3; i++) + { + uint32_t low = ((pResults->m_low_endpoint.m_c[i] << 1) | pResults->m_pbits[0]) << 1; + low |= (low >> 7); + + uint32_t high = ((pResults->m_high_endpoint.m_c[i] << 1) | pResults->m_pbits[0]) << 1; + high |= (high >> 7); + + p.m_c[i] = (uint8_t)((low * (64 - g_bc7_weights3[BC7ENC16_MODE_1_OPTIMAL_INDEX]) + high * g_bc7_weights3[BC7ENC16_MODE_1_OPTIMAL_INDEX] + 32) >> 6); + } + p.m_c[3] = 255; + + uint64_t total_err = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + total_err += compute_color_distance_rgb(&p, &pParams->m_pPixels[i], pParams->m_perceptual, pParams->m_weights); + + pResults->m_best_overall_err = total_err; + + return total_err; +} + +static uint64_t evaluate_solution(const color_quad_u8 *pLow, const color_quad_u8 *pHigh, const uint32_t pbits[2], const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults) +{ + color_quad_u8 quantMinColor = *pLow; + color_quad_u8 quantMaxColor = *pHigh; + + if (pParams->m_has_pbits) + { + uint32_t minPBit, maxPBit; + + if (pParams->m_endpoints_share_pbit) + maxPBit = minPBit = pbits[0]; + else + { + minPBit = pbits[0]; + maxPBit = pbits[1]; + } + + quantMinColor.m_c[0] = (uint8_t)((pLow->m_c[0] << 1) | minPBit); + quantMinColor.m_c[1] = (uint8_t)((pLow->m_c[1] << 1) | minPBit); + quantMinColor.m_c[2] = (uint8_t)((pLow->m_c[2] << 1) | minPBit); + quantMinColor.m_c[3] = (uint8_t)((pLow->m_c[3] << 1) | minPBit); + + quantMaxColor.m_c[0] = (uint8_t)((pHigh->m_c[0] << 1) | maxPBit); + quantMaxColor.m_c[1] = (uint8_t)((pHigh->m_c[1] << 1) | maxPBit); + quantMaxColor.m_c[2] = (uint8_t)((pHigh->m_c[2] << 1) | maxPBit); + quantMaxColor.m_c[3] = (uint8_t)((pHigh->m_c[3] << 1) | maxPBit); + } + + color_quad_u8 actualMinColor = scale_color(&quantMinColor, pParams); + color_quad_u8 actualMaxColor = scale_color(&quantMaxColor, pParams); + + const uint32_t N = pParams->m_num_selector_weights; + + color_quad_u8 weightedColors[16]; + weightedColors[0] = actualMinColor; + weightedColors[N - 1] = actualMaxColor; + + const uint32_t nc = pParams->m_has_alpha ? 4 : 3; + for (uint32_t i = 1; i < (N - 1); i++) + for (uint32_t j = 0; j < nc; j++) + weightedColors[i].m_c[j] = (uint8_t)((actualMinColor.m_c[j] * (64 - pParams->m_pSelector_weights[i]) + actualMaxColor.m_c[j] * pParams->m_pSelector_weights[i] + 32) >> 6); + + const int lr = actualMinColor.m_c[0]; + const int lg = actualMinColor.m_c[1]; + const int lb = actualMinColor.m_c[2]; + const int dr = actualMaxColor.m_c[0] - lr; + const int dg = actualMaxColor.m_c[1] - lg; + const int db = actualMaxColor.m_c[2] - lb; + + uint64_t total_err = 0; + + if (!pParams->m_perceptual) + { + if (pParams->m_has_alpha) + { + const int la = actualMinColor.m_c[3]; + const int da = actualMaxColor.m_c[3] - la; + + const float f = N / (float)(squarei(dr) + squarei(dg) + squarei(db) + squarei(da) + .00000125f); + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + const color_quad_u8 *pC = &pParams->m_pPixels[i]; + int r = pC->m_c[0]; + int g = pC->m_c[1]; + int b = pC->m_c[2]; + int a = pC->m_c[3]; + + int best_sel = (int)((float)((r - lr) * dr + (g - lg) * dg + (b - lb) * db + (a - la) * da) * f + .5f); + best_sel = clampi(best_sel, 1, N - 1); + + uint64_t err0 = compute_color_distance_rgba(&weightedColors[best_sel - 1], pC, BC7ENC16_FALSE, pParams->m_weights); + uint64_t err1 = compute_color_distance_rgba(&weightedColors[best_sel], pC, BC7ENC16_FALSE, pParams->m_weights); + + if (err1 > err0) + { + err1 = err0; + --best_sel; + } + total_err += err1; + + pResults->m_pSelectors_temp[i] = (uint8_t)best_sel; + } + } + else + { + const float f = N / (float)(squarei(dr) + squarei(dg) + squarei(db) + .00000125f); + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + const color_quad_u8 *pC = &pParams->m_pPixels[i]; + int r = pC->m_c[0]; + int g = pC->m_c[1]; + int b = pC->m_c[2]; + + int sel = (int)((float)((r - lr) * dr + (g - lg) * dg + (b - lb) * db) * f + .5f); + sel = clampi(sel, 1, N - 1); + + uint64_t err0 = compute_color_distance_rgb(&weightedColors[sel - 1], pC, BC7ENC16_FALSE, pParams->m_weights); + uint64_t err1 = compute_color_distance_rgb(&weightedColors[sel], pC, BC7ENC16_FALSE, pParams->m_weights); + + int best_sel = sel; + uint64_t best_err = err1; + if (err0 < best_err) + { + best_err = err0; + best_sel = sel - 1; + } + + total_err += best_err; + + pResults->m_pSelectors_temp[i] = (uint8_t)best_sel; + } + } + } + else + { + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint64_t best_err = UINT64_MAX; + uint32_t best_sel = 0; + + if (pParams->m_has_alpha) + { + for (uint32_t j = 0; j < N; j++) + { + uint64_t err = compute_color_distance_rgba(&weightedColors[j], &pParams->m_pPixels[i], BC7ENC16_TRUE, pParams->m_weights); + if (err < best_err) + { + best_err = err; + best_sel = j; + } + } + } + else + { + for (uint32_t j = 0; j < N; j++) + { + uint64_t err = compute_color_distance_rgb(&weightedColors[j], &pParams->m_pPixels[i], BC7ENC16_TRUE, pParams->m_weights); + if (err < best_err) + { + best_err = err; + best_sel = j; + } + } + } + + total_err += best_err; + + pResults->m_pSelectors_temp[i] = (uint8_t)best_sel; + } + } + + if (total_err < pResults->m_best_overall_err) + { + pResults->m_best_overall_err = total_err; + + pResults->m_low_endpoint = *pLow; + pResults->m_high_endpoint = *pHigh; + + pResults->m_pbits[0] = pbits[0]; + pResults->m_pbits[1] = pbits[1]; + + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + } + + return total_err; +} + +static void fixDegenerateEndpoints(uint32_t mode, color_quad_u8 *pTrialMinColor, color_quad_u8 *pTrialMaxColor, const vec4F *pXl, const vec4F *pXh, uint32_t iscale) +{ + if (mode == 1) + { + // fix degenerate case where the input collapses to a single colorspace voxel, and we loose all freedom (test with grayscale ramps) + for (uint32_t i = 0; i < 3; i++) + { + if (pTrialMinColor->m_c[i] == pTrialMaxColor->m_c[i]) + { + if (fabs(pXl->m_c[i] - pXh->m_c[i]) > 0.0f) + { + if (pTrialMinColor->m_c[i] > (iscale >> 1)) + { + if (pTrialMinColor->m_c[i] > 0) + pTrialMinColor->m_c[i]--; + else + if (pTrialMaxColor->m_c[i] < iscale) + pTrialMaxColor->m_c[i]++; + } + else + { + if (pTrialMaxColor->m_c[i] < iscale) + pTrialMaxColor->m_c[i]++; + else if (pTrialMinColor->m_c[i] > 0) + pTrialMinColor->m_c[i]--; + } + } + } + } + } +} + +static uint64_t find_optimal_solution(uint32_t mode, vec4F xl, vec4F xh, const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults) +{ + vec4F_saturate_in_place(&xl); vec4F_saturate_in_place(&xh); + + if (pParams->m_has_pbits) + { + const int iscalep = (1 << (pParams->m_comp_bits + 1)) - 1; + const float scalep = (float)iscalep; + + const int32_t totalComps = pParams->m_has_alpha ? 4 : 3; + + uint32_t best_pbits[2]; + color_quad_u8 bestMinColor, bestMaxColor; + + if (!pParams->m_endpoints_share_pbit) + { + float best_err0 = 1e+9; + float best_err1 = 1e+9; + + for (int p = 0; p < 2; p++) + { + color_quad_u8 xMinColor, xMaxColor; + + // Notes: The pbit controls which quantization intervals are selected. + // total_levels=2^(comp_bits+1), where comp_bits=4 for mode 0, etc. + // pbit 0: v=(b*2)/(total_levels-1), pbit 1: v=(b*2+1)/(total_levels-1) where b is the component bin from [0,total_levels/2-1] and v is the [0,1] component value + // rearranging you get for pbit 0: b=floor(v*(total_levels-1)/2+.5) + // rearranging you get for pbit 1: b=floor((v*(total_levels-1)-1)/2+.5) + for (uint32_t c = 0; c < 4; c++) + { + xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + } + + color_quad_u8 scaledLow = scale_color(&xMinColor, pParams); + color_quad_u8 scaledHigh = scale_color(&xMaxColor, pParams); + + float err0 = 0, err1 = 0; + for (int i = 0; i < totalComps; i++) + { + err0 += squaref(scaledLow.m_c[i] - xl.m_c[i] * 255.0f); + err1 += squaref(scaledHigh.m_c[i] - xh.m_c[i] * 255.0f); + } + + if (err0 < best_err0) + { + best_err0 = err0; + best_pbits[0] = p; + + bestMinColor.m_c[0] = xMinColor.m_c[0] >> 1; + bestMinColor.m_c[1] = xMinColor.m_c[1] >> 1; + bestMinColor.m_c[2] = xMinColor.m_c[2] >> 1; + bestMinColor.m_c[3] = xMinColor.m_c[3] >> 1; + } + + if (err1 < best_err1) + { + best_err1 = err1; + best_pbits[1] = p; + + bestMaxColor.m_c[0] = xMaxColor.m_c[0] >> 1; + bestMaxColor.m_c[1] = xMaxColor.m_c[1] >> 1; + bestMaxColor.m_c[2] = xMaxColor.m_c[2] >> 1; + bestMaxColor.m_c[3] = xMaxColor.m_c[3] >> 1; + } + } + } + else + { + // Endpoints share pbits + float best_err = 1e+9; + + for (int p = 0; p < 2; p++) + { + color_quad_u8 xMinColor, xMaxColor; + for (uint32_t c = 0; c < 4; c++) + { + xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + } + + color_quad_u8 scaledLow = scale_color(&xMinColor, pParams); + color_quad_u8 scaledHigh = scale_color(&xMaxColor, pParams); + + float err = 0; + for (int i = 0; i < totalComps; i++) + err += squaref((scaledLow.m_c[i] / 255.0f) - xl.m_c[i]) + squaref((scaledHigh.m_c[i] / 255.0f) - xh.m_c[i]); + + if (err < best_err) + { + best_err = err; + best_pbits[0] = p; + best_pbits[1] = p; + for (uint32_t j = 0; j < 4; j++) + { + bestMinColor.m_c[j] = xMinColor.m_c[j] >> 1; + bestMaxColor.m_c[j] = xMaxColor.m_c[j] >> 1; + } + } + } + } + + fixDegenerateEndpoints(mode, &bestMinColor, &bestMaxColor, &xl, &xh, iscalep >> 1); + + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&bestMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&bestMaxColor, &pResults->m_high_endpoint) || (best_pbits[0] != pResults->m_pbits[0]) || (best_pbits[1] != pResults->m_pbits[1])) + evaluate_solution(&bestMinColor, &bestMaxColor, best_pbits, pParams, pResults); + } + else + { + const int iscale = (1 << pParams->m_comp_bits) - 1; + const float scale = (float)iscale; + + color_quad_u8 trialMinColor, trialMaxColor; + color_quad_u8_set_clamped(&trialMinColor, (int)(xl.m_c[0] * scale + .5f), (int)(xl.m_c[1] * scale + .5f), (int)(xl.m_c[2] * scale + .5f), (int)(xl.m_c[3] * scale + .5f)); + color_quad_u8_set_clamped(&trialMaxColor, (int)(xh.m_c[0] * scale + .5f), (int)(xh.m_c[1] * scale + .5f), (int)(xh.m_c[2] * scale + .5f), (int)(xh.m_c[3] * scale + .5f)); + + fixDegenerateEndpoints(mode, &trialMinColor, &trialMaxColor, &xl, &xh, iscale); + + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&trialMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&trialMaxColor, &pResults->m_high_endpoint)) + evaluate_solution(&trialMinColor, &trialMaxColor, pResults->m_pbits, pParams, pResults); + } + + return pResults->m_best_overall_err; +} + +static uint64_t color_cell_compression(uint32_t mode, const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, const bc7enc16_compress_block_params *pComp_params) +{ + assert((mode == 6) || (!pParams->m_has_alpha)); + + pResults->m_best_overall_err = UINT64_MAX; + + // If the partition's colors are all the same in mode 1, then just pack them as a single color. + if (mode == 1) + { + const uint32_t cr = pParams->m_pPixels[0].m_c[0], cg = pParams->m_pPixels[0].m_c[1], cb = pParams->m_pPixels[0].m_c[2]; + + bc7enc16_bool allSame = BC7ENC16_TRUE; + for (uint32_t i = 1; i < pParams->m_num_pixels; i++) + { + if ((cr != pParams->m_pPixels[i].m_c[0]) || (cg != pParams->m_pPixels[i].m_c[1]) || (cb != pParams->m_pPixels[i].m_c[2])) + { + allSame = BC7ENC16_FALSE; + break; + } + } + + if (allSame) + return pack_mode1_to_one_color(pParams, pResults, cr, cg, cb, pResults->m_pSelectors); + } + + // Compute partition's mean color and principle axis. + vec4F meanColor, axis; + vec4F_set_scalar(&meanColor, 0.0f); + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + vec4F color = vec4F_from_color(&pParams->m_pPixels[i]); + meanColor = vec4F_add(&meanColor, &color); + } + + vec4F meanColorScaled = vec4F_mul(&meanColor, 1.0f / (float)(pParams->m_num_pixels)); + + meanColor = vec4F_mul(&meanColor, 1.0f / (float)(pParams->m_num_pixels * 255.0f)); + vec4F_saturate_in_place(&meanColor); + + if (pParams->m_has_alpha) + { + // Use incremental PCA for RGBA PCA, because it's simple. + vec4F_set_scalar(&axis, 0.0f); + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + vec4F color = vec4F_from_color(&pParams->m_pPixels[i]); + color = vec4F_sub(&color, &meanColorScaled); + vec4F a = vec4F_mul(&color, color.m_c[0]); + vec4F b = vec4F_mul(&color, color.m_c[1]); + vec4F c = vec4F_mul(&color, color.m_c[2]); + vec4F d = vec4F_mul(&color, color.m_c[3]); + vec4F n = i ? axis : color; + vec4F_normalize_in_place(&n); + axis.m_c[0] += vec4F_dot(&a, &n); + axis.m_c[1] += vec4F_dot(&b, &n); + axis.m_c[2] += vec4F_dot(&c, &n); + axis.m_c[3] += vec4F_dot(&d, &n); + } + vec4F_normalize_in_place(&axis); + } + else + { + // Use covar technique for RGB PCA, because it doesn't require per-pixel normalization. + float cov[6] = { 0, 0, 0, 0, 0, 0 }; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + const color_quad_u8 *pV = &pParams->m_pPixels[i]; + float r = pV->m_c[0] - meanColorScaled.m_c[0]; + float g = pV->m_c[1] - meanColorScaled.m_c[1]; + float b = pV->m_c[2] - meanColorScaled.m_c[2]; + cov[0] += r*r; cov[1] += r*g; cov[2] += r*b; cov[3] += g*g; cov[4] += g*b; cov[5] += b*b; + } + + float vfr = .9f, vfg = 1.0f, vfb = .7f; + for (uint32_t iter = 0; iter < 3; iter++) + { + float r = vfr*cov[0] + vfg*cov[1] + vfb*cov[2]; + float g = vfr*cov[1] + vfg*cov[3] + vfb*cov[4]; + float b = vfr*cov[2] + vfg*cov[4] + vfb*cov[5]; + + float m = maximumf(maximumf(fabsf(r), fabsf(g)), fabsf(b)); + if (m > 1e-10f) + { + m = 1.0f / m; + r *= m; g *= m; b *= m; + } + + vfr = r; vfg = g; vfb = b; + } + + float len = vfr*vfr + vfg*vfg + vfb*vfb; + if (len < 1e-10f) + vec4F_set_scalar(&axis, 0.0f); + else + { + len = 1.0f / sqrtf(len); + vfr *= len; vfg *= len; vfb *= len; + vec4F_set(&axis, vfr, vfg, vfb, 0); + } + } + + if (vec4F_dot(&axis, &axis) < .5f) + { + if (pParams->m_perceptual) + vec4F_set(&axis, .213f, .715f, .072f, pParams->m_has_alpha ? .715f : 0); + else + vec4F_set(&axis, 1.0f, 1.0f, 1.0f, pParams->m_has_alpha ? 1.0f : 0); + vec4F_normalize_in_place(&axis); + } + + float l = 1e+9f, h = -1e+9f; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + vec4F color = vec4F_from_color(&pParams->m_pPixels[i]); + + vec4F q = vec4F_sub(&color, &meanColorScaled); + float d = vec4F_dot(&q, &axis); + + l = minimumf(l, d); + h = maximumf(h, d); + } + + l *= (1.0f / 255.0f); + h *= (1.0f / 255.0f); + + vec4F b0 = vec4F_mul(&axis, l); + vec4F b1 = vec4F_mul(&axis, h); + vec4F c0 = vec4F_add(&meanColor, &b0); + vec4F c1 = vec4F_add(&meanColor, &b1); + vec4F minColor = vec4F_saturate(&c0); + vec4F maxColor = vec4F_saturate(&c1); + + vec4F whiteVec; + vec4F_set_scalar(&whiteVec, 1.0f); + if (vec4F_dot(&minColor, &whiteVec) > vec4F_dot(&maxColor, &whiteVec)) + { + vec4F temp = minColor; + minColor = maxColor; + maxColor = temp; + } + // First find a solution using the block's PCA. + if (!find_optimal_solution(mode, minColor, maxColor, pParams, pResults)) + return 0; + + if (pComp_params->m_try_least_squares) + { + // Now try to refine the solution using least squares by computing the optimal endpoints from the current selectors. + vec4F xl, xh; + vec4F_set_scalar(&xl, 0.0f); + vec4F_set_scalar(&xh, 0.0f); + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, pResults->m_pSelectors, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, pResults->m_pSelectors, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + } + + if (pComp_params->m_uber_level > 0) + { + // In uber level 1, try varying the selectors a little, somewhat like cluster fit would. First try incrementing the minimum selectors, + // then try decrementing the selectrors, then try both. + uint8_t selectors_temp[16], selectors_temp1[16]; + memcpy(selectors_temp, pResults->m_pSelectors, pParams->m_num_pixels); + + const int max_selector = pParams->m_num_selector_weights - 1; + + uint32_t min_sel = 16; + uint32_t max_sel = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + min_sel = minimumu(min_sel, sel); + max_sel = maximumu(max_sel, sel); + } + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + if ((sel == min_sel) && (sel < (pParams->m_num_selector_weights - 1))) + sel++; + selectors_temp1[i] = (uint8_t)sel; + } + + vec4F xl, xh; + vec4F_set_scalar(&xl, 0.0f); + vec4F_set_scalar(&xh, 0.0f); + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + if ((sel == max_sel) && (sel > 0)) + sel--; + selectors_temp1[i] = (uint8_t)sel; + } + + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + if ((sel == min_sel) && (sel < (pParams->m_num_selector_weights - 1))) + sel++; + else if ((sel == max_sel) && (sel > 0)) + sel--; + selectors_temp1[i] = (uint8_t)sel; + } + + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + + // In uber levels 2+, try taking more advantage of endpoint extrapolation by scaling the selectors in one direction or another. + const uint32_t uber_err_thresh = (pParams->m_num_pixels * 56) >> 4; + if ((pComp_params->m_uber_level >= 2) && (pResults->m_best_overall_err > uber_err_thresh)) + { + const int Q = (pComp_params->m_uber_level >= 4) ? (pComp_params->m_uber_level - 2) : 1; + for (int ly = -Q; ly <= 1; ly++) + { + for (int hy = max_selector - 1; hy <= (max_selector + Q); hy++) + { + if ((ly == 0) && (hy == max_selector)) + continue; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + selectors_temp1[i] = (uint8_t)clampf(floorf((float)max_selector * ((float)selectors_temp[i] - (float)ly) / ((float)hy - (float)ly) + .5f), 0, (float)max_selector); + + //vec4F xl, xh; + vec4F_set_scalar(&xl, 0.0f); + vec4F_set_scalar(&xh, 0.0f); + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + } + } + } + } + + if (mode == 1) + { + // Try encoding the partition as a single color by using the optimal singe colors tables to encode the block to its mean. + color_cell_compressor_results avg_results = *pResults; + const uint32_t r = (int)(.5f + meanColor.m_c[0] * 255.0f), g = (int)(.5f + meanColor.m_c[1] * 255.0f), b = (int)(.5f + meanColor.m_c[2] * 255.0f); + uint64_t avg_err = pack_mode1_to_one_color(pParams, &avg_results, r, g, b, pResults->m_pSelectors_temp); + if (avg_err < pResults->m_best_overall_err) + { + *pResults = avg_results; + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + pResults->m_best_overall_err = avg_err; + } + } + + return pResults->m_best_overall_err; +} + +static uint64_t color_cell_compression_est(uint32_t num_pixels, const color_quad_u8 *pPixels, bc7enc16_bool perceptual, uint32_t pweights[4], uint64_t best_err_so_far) +{ + // Find RGB bounds as an approximation of the block's principle axis + uint32_t lr = 255, lg = 255, lb = 255; + uint32_t hr = 0, hg = 0, hb = 0; + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8 *pC = &pPixels[i]; + if (pC->m_c[0] < lr) lr = pC->m_c[0]; + if (pC->m_c[1] < lg) lg = pC->m_c[1]; + if (pC->m_c[2] < lb) lb = pC->m_c[2]; + if (pC->m_c[0] > hr) hr = pC->m_c[0]; + if (pC->m_c[1] > hg) hg = pC->m_c[1]; + if (pC->m_c[2] > hb) hb = pC->m_c[2]; + } + + color_quad_u8 lowColor; color_quad_u8_set(&lowColor, lr, lg, lb, 0); + color_quad_u8 highColor; color_quad_u8_set(&highColor, hr, hg, hb, 0); + + // Place endpoints at bbox diagonals and compute interpolated colors + const uint32_t N = 8; + color_quad_u8 weightedColors[8]; + + weightedColors[0] = lowColor; + weightedColors[N - 1] = highColor; + for (uint32_t i = 1; i < (N - 1); i++) + { + weightedColors[i].m_c[0] = (uint8_t)((lowColor.m_c[0] * (64 - g_bc7_weights3[i]) + highColor.m_c[0] * g_bc7_weights3[i] + 32) >> 6); + weightedColors[i].m_c[1] = (uint8_t)((lowColor.m_c[1] * (64 - g_bc7_weights3[i]) + highColor.m_c[1] * g_bc7_weights3[i] + 32) >> 6); + weightedColors[i].m_c[2] = (uint8_t)((lowColor.m_c[2] * (64 - g_bc7_weights3[i]) + highColor.m_c[2] * g_bc7_weights3[i] + 32) >> 6); + } + + // Compute dots and thresholds + const int ar = highColor.m_c[0] - lowColor.m_c[0]; + const int ag = highColor.m_c[1] - lowColor.m_c[1]; + const int ab = highColor.m_c[2] - lowColor.m_c[2]; + + int dots[8]; + for (uint32_t i = 0; i < N; i++) + dots[i] = weightedColors[i].m_c[0] * ar + weightedColors[i].m_c[1] * ag + weightedColors[i].m_c[2] * ab; + + int thresh[8 - 1]; + for (uint32_t i = 0; i < (N - 1); i++) + thresh[i] = (dots[i] + dots[i + 1] + 1) >> 1; + + uint64_t total_err = 0; + if (perceptual) + { + // Transform block's interpolated colors to YCbCr + int l1[8], cr1[8], cb1[8]; + for (int j = 0; j < 8; j++) + { + const color_quad_u8 *pE1 = &weightedColors[j]; + l1[j] = pE1->m_c[0] * 109 + pE1->m_c[1] * 366 + pE1->m_c[2] * 37; + cr1[j] = ((int)pE1->m_c[0] << 9) - l1[j]; + cb1[j] = ((int)pE1->m_c[2] << 9) - l1[j]; + } + + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8 *pC = &pPixels[i]; + + int d = ar * pC->m_c[0] + ag * pC->m_c[1] + ab * pC->m_c[2]; + + // Find approximate selector + uint32_t s = 0; + if (d >= thresh[6]) + s = 7; + else if (d >= thresh[5]) + s = 6; + else if (d >= thresh[4]) + s = 5; + else if (d >= thresh[3]) + s = 4; + else if (d >= thresh[2]) + s = 3; + else if (d >= thresh[1]) + s = 2; + else if (d >= thresh[0]) + s = 1; + + // Compute error + const int l2 = pC->m_c[0] * 109 + pC->m_c[1] * 366 + pC->m_c[2] * 37; + const int cr2 = ((int)pC->m_c[0] << 9) - l2; + const int cb2 = ((int)pC->m_c[2] << 9) - l2; + + const int dl = (l1[s] - l2) >> 8; + const int dcr = (cr1[s] - cr2) >> 8; + const int dcb = (cb1[s] - cb2) >> 8; + + int ie = (pweights[0] * dl * dl) + (pweights[1] * dcr * dcr) + (pweights[2] * dcb * dcb); + + total_err += ie; + if (total_err > best_err_so_far) + break; + } + } + else + { + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8 *pC = &pPixels[i]; + + int d = ar * pC->m_c[0] + ag * pC->m_c[1] + ab * pC->m_c[2]; + + // Find approximate selector + uint32_t s = 0; + if (d >= thresh[6]) + s = 7; + else if (d >= thresh[5]) + s = 6; + else if (d >= thresh[4]) + s = 5; + else if (d >= thresh[3]) + s = 4; + else if (d >= thresh[2]) + s = 3; + else if (d >= thresh[1]) + s = 2; + else if (d >= thresh[0]) + s = 1; + + // Compute error + const color_quad_u8 *pE1 = &weightedColors[s]; + + int dr = (int)pE1->m_c[0] - (int)pC->m_c[0]; + int dg = (int)pE1->m_c[1] - (int)pC->m_c[1]; + int db = (int)pE1->m_c[2] - (int)pC->m_c[2]; + + total_err += pweights[0] * (dr * dr) + pweights[1] * (dg * dg) + pweights[2] * (db * db); + if (total_err > best_err_so_far) + break; + } + } + + return total_err; +} + +// Estimate the partition used by mode 1. This scans through each partition and computes an approximate error for each. +static uint32_t estimate_partition(const color_quad_u8 *pPixels, const bc7enc16_compress_block_params *pComp_params, uint32_t pweights[4]) +{ + const uint32_t total_partitions = minimumu(pComp_params->m_max_partitions_mode1, BC7ENC16_MAX_PARTITIONS1); + if (total_partitions <= 1) + return 0; + + uint64_t best_err = UINT64_MAX; + uint32_t best_partition = 0; + + for (uint32_t partition = 0; (partition < total_partitions) && (best_err > 0); partition++) + { + const uint8_t *pPartition = &g_bc7_partition2[partition * 16]; + + color_quad_u8 subset_colors[2][16]; + uint32_t subset_total_colors[2] = { 0, 0 }; + for (uint32_t index = 0; index < 16; index++) + subset_colors[pPartition[index]][subset_total_colors[pPartition[index]]++] = pPixels[index]; + + uint64_t total_subset_err = 0; + for (uint32_t subset = 0; (subset < 2) && (total_subset_err < best_err); subset++) + total_subset_err += color_cell_compression_est(subset_total_colors[subset], &subset_colors[subset][0], pComp_params->m_perceptual, pweights, best_err); + + if (total_subset_err < best_err) + { + best_err = total_subset_err; + best_partition = partition; + } + + } // partition + + return best_partition; +} + +static void set_block_bits(uint8_t *pBytes, uint32_t val, uint32_t num_bits, uint32_t *pCur_ofs) +{ + assert((num_bits <= 32) && (val < (1ULL << num_bits))); + while (num_bits) + { + const uint32_t n = minimumu(8 - (*pCur_ofs & 7), num_bits); + pBytes[*pCur_ofs >> 3] |= (uint8_t)(val << (*pCur_ofs & 7)); + val >>= n; + num_bits -= n; + *pCur_ofs += n; + } + assert(*pCur_ofs <= 128); +} + +typedef struct +{ + uint32_t m_mode; + uint32_t m_partition; + uint8_t m_selectors[16]; + color_quad_u8 m_low[2]; + color_quad_u8 m_high[2]; + uint32_t m_pbits[2][2]; +} bc7_optimization_results; + +static void encode_bc7_block(void *pBlock, const bc7_optimization_results *pResults) +{ + const uint32_t best_mode = pResults->m_mode; + const uint32_t total_subsets = g_bc7_num_subsets[best_mode]; + const uint32_t total_partitions = 1 << g_bc7_partition_bits[best_mode]; + const uint8_t *pPartition = (total_subsets == 2) ? &g_bc7_partition2[pResults->m_partition * 16] : &g_bc7_partition1[0]; + + uint8_t color_selectors[16]; + memcpy(color_selectors, pResults->m_selectors, 16); + + color_quad_u8 low[2], high[2]; + memcpy(low, pResults->m_low, sizeof(low)); + memcpy(high, pResults->m_high, sizeof(high)); + + uint32_t pbits[2][2]; + memcpy(pbits, pResults->m_pbits, sizeof(pbits)); + + int anchor[2] = { -1, -1 }; + + for (uint32_t k = 0; k < total_subsets; k++) + { + const uint32_t anchor_index = k ? g_bc7_table_anchor_index_second_subset[pResults->m_partition] : 0; + anchor[k] = anchor_index; + + const uint32_t color_index_bits = get_bc7_color_index_size(best_mode, 0); + const uint32_t num_color_indices = 1 << color_index_bits; + + if (color_selectors[anchor_index] & (num_color_indices >> 1)) + { + for (uint32_t i = 0; i < 16; i++) + if (pPartition[i] == k) + color_selectors[i] = (uint8_t)((num_color_indices - 1) - color_selectors[i]); + + color_quad_u8 tmp = low[k]; + low[k] = high[k]; + high[k] = tmp; + + if (!g_bc7_mode_has_shared_p_bits[best_mode]) + { + uint32_t t = pbits[k][0]; + pbits[k][0] = pbits[k][1]; + pbits[k][1] = t; + } + } + } + + uint8_t *pBlock_bytes = (uint8_t *)(pBlock); + memset(pBlock_bytes, 0, BC7ENC16_BLOCK_SIZE); + + uint32_t cur_bit_ofs = 0; + set_block_bits(pBlock_bytes, 1 << best_mode, best_mode + 1, &cur_bit_ofs); + + if (total_partitions > 1) + set_block_bits(pBlock_bytes, pResults->m_partition, 6, &cur_bit_ofs); + + const uint32_t total_comps = (best_mode >= 4) ? 4 : 3; + for (uint32_t comp = 0; comp < total_comps; comp++) + { + for (uint32_t subset = 0; subset < total_subsets; subset++) + { + set_block_bits(pBlock_bytes, low[subset].m_c[comp], (comp == 3) ? g_bc7_alpha_precision_table[best_mode] : g_bc7_color_precision_table[best_mode], &cur_bit_ofs); + set_block_bits(pBlock_bytes, high[subset].m_c[comp], (comp == 3) ? g_bc7_alpha_precision_table[best_mode] : g_bc7_color_precision_table[best_mode], &cur_bit_ofs); + } + } + + for (uint32_t subset = 0; subset < total_subsets; subset++) + { + set_block_bits(pBlock_bytes, pbits[subset][0], 1, &cur_bit_ofs); + if (!g_bc7_mode_has_shared_p_bits[best_mode]) + set_block_bits(pBlock_bytes, pbits[subset][1], 1, &cur_bit_ofs); + } + + for (int idx = 0; idx < 16; idx++) + { + uint32_t n = get_bc7_color_index_size(best_mode, 0); + if ((idx == anchor[0]) || (idx == anchor[1])) + n--; + set_block_bits(pBlock_bytes, color_selectors[idx], n, &cur_bit_ofs); + } + + assert(cur_bit_ofs == 128); +} + +static void handle_alpha_block(void *pBlock, const color_quad_u8 *pPixels, const bc7enc16_compress_block_params *pComp_params, color_cell_compressor_params *pParams) +{ + color_cell_compressor_results results6; + + pParams->m_pSelector_weights = g_bc7_weights4; + pParams->m_pSelector_weightsx = (const vec4F *)g_bc7_weights4x; + pParams->m_num_selector_weights = 16; + pParams->m_comp_bits = 7; + pParams->m_has_pbits = BC7ENC16_TRUE; + pParams->m_has_alpha = BC7ENC16_TRUE; + pParams->m_perceptual = pComp_params->m_perceptual; + pParams->m_num_pixels = 16; + pParams->m_pPixels = pPixels; + + bc7_optimization_results opt_results; + results6.m_pSelectors = opt_results.m_selectors; + + uint8_t selectors_temp[16]; + results6.m_pSelectors_temp = selectors_temp; + + color_cell_compression(6, pParams, &results6, pComp_params); + + opt_results.m_mode = 6; + opt_results.m_partition = 0; + opt_results.m_low[0] = results6.m_low_endpoint; + opt_results.m_high[0] = results6.m_high_endpoint; + opt_results.m_pbits[0][0] = results6.m_pbits[0]; + opt_results.m_pbits[0][1] = results6.m_pbits[1]; + + encode_bc7_block(pBlock, &opt_results); +} + +static void handle_opaque_block(void *pBlock, const color_quad_u8 *pPixels, const bc7enc16_compress_block_params *pComp_params, color_cell_compressor_params *pParams) +{ + uint8_t selectors_temp[16]; + + // Mode 6 + bc7_optimization_results opt_results; + + pParams->m_pSelector_weights = g_bc7_weights4; + pParams->m_pSelector_weightsx = (const vec4F *)g_bc7_weights4x; + pParams->m_num_selector_weights = 16; + pParams->m_comp_bits = 7; + pParams->m_has_pbits = BC7ENC16_TRUE; + pParams->m_endpoints_share_pbit = BC7ENC16_FALSE; + pParams->m_perceptual = pComp_params->m_perceptual; + pParams->m_num_pixels = 16; + pParams->m_pPixels = pPixels; + pParams->m_has_alpha = BC7ENC16_FALSE; + + color_cell_compressor_results results6; + results6.m_pSelectors = opt_results.m_selectors; + results6.m_pSelectors_temp = selectors_temp; + + uint64_t best_err = color_cell_compression(6, pParams, &results6, pComp_params); + + opt_results.m_mode = 6; + opt_results.m_partition = 0; + opt_results.m_low[0] = results6.m_low_endpoint; + opt_results.m_high[0] = results6.m_high_endpoint; + opt_results.m_pbits[0][0] = results6.m_pbits[0]; + opt_results.m_pbits[0][1] = results6.m_pbits[1]; + + // Mode 1 + if ((best_err > 0) && (pComp_params->m_max_partitions_mode1 > 0)) + { + const uint32_t trial_partition = estimate_partition(pPixels, pComp_params, pParams->m_weights); + + pParams->m_pSelector_weights = g_bc7_weights3; + pParams->m_pSelector_weightsx = (const vec4F *)g_bc7_weights3x; + pParams->m_num_selector_weights = 8; + pParams->m_comp_bits = 6; + pParams->m_has_pbits = BC7ENC16_TRUE; + pParams->m_endpoints_share_pbit = BC7ENC16_TRUE; + + const uint8_t *pPartition = &g_bc7_partition2[trial_partition * 16]; + + color_quad_u8 subset_colors[2][16]; + + uint32_t subset_total_colors1[2] = { 0, 0 }; + + uint8_t subset_pixel_index1[2][16]; + uint8_t subset_selectors1[2][16]; + color_cell_compressor_results subset_results1[2]; + + for (uint32_t idx = 0; idx < 16; idx++) + { + const uint32_t p = pPartition[idx]; + subset_colors[p][subset_total_colors1[p]] = pPixels[idx]; + subset_pixel_index1[p][subset_total_colors1[p]] = (uint8_t)idx; + subset_total_colors1[p]++; + } + + uint64_t trial_err = 0; + for (uint32_t subset = 0; subset < 2; subset++) + { + pParams->m_num_pixels = subset_total_colors1[subset]; + pParams->m_pPixels = &subset_colors[subset][0]; + + color_cell_compressor_results *pResults = &subset_results1[subset]; + pResults->m_pSelectors = &subset_selectors1[subset][0]; + pResults->m_pSelectors_temp = selectors_temp; + uint64_t err = color_cell_compression(1, pParams, pResults, pComp_params); + trial_err += err; + if (trial_err > best_err) + break; + + } // subset + + if (trial_err < best_err) + { + best_err = trial_err; + opt_results.m_mode = 1; + opt_results.m_partition = trial_partition; + for (uint32_t subset = 0; subset < 2; subset++) + { + for (uint32_t i = 0; i < subset_total_colors1[subset]; i++) + opt_results.m_selectors[subset_pixel_index1[subset][i]] = subset_selectors1[subset][i]; + opt_results.m_low[subset] = subset_results1[subset].m_low_endpoint; + opt_results.m_high[subset] = subset_results1[subset].m_high_endpoint; + opt_results.m_pbits[subset][0] = subset_results1[subset].m_pbits[0]; + } + } + } + + encode_bc7_block(pBlock, &opt_results); +} + +bc7enc16_bool bc7enc16_compress_block(void *pBlock, const void *pPixelsRGBA, const bc7enc16_compress_block_params *pComp_params) +{ + assert(g_bc7_mode_1_optimal_endpoints[255][0].m_hi != 0); + + const color_quad_u8 *pPixels = (const color_quad_u8 *)(pPixelsRGBA); + + color_cell_compressor_params params; + if (pComp_params->m_perceptual) + { + // https://en.wikipedia.org/wiki/YCbCr#ITU-R_BT.709_conversion + const float pr_weight = (.5f / (1.0f - .2126f)) * (.5f / (1.0f - .2126f)); + const float pb_weight = (.5f / (1.0f - .0722f)) * (.5f / (1.0f - .0722f)); + params.m_weights[0] = (int)(pComp_params->m_weights[0] * 4.0f); + params.m_weights[1] = (int)(pComp_params->m_weights[1] * 4.0f * pr_weight); + params.m_weights[2] = (int)(pComp_params->m_weights[2] * 4.0f * pb_weight); + params.m_weights[3] = pComp_params->m_weights[3] * 4; + } + else + memcpy(params.m_weights, pComp_params->m_weights, sizeof(params.m_weights)); + + for (uint32_t i = 0; i < 16; i++) + { + if (pPixels[i].m_c[3] < 255) + { + handle_alpha_block(pBlock, pPixels, pComp_params, ¶ms); + return BC7ENC16_TRUE; + } + } + handle_opaque_block(pBlock, pPixels, pComp_params, ¶ms); + return BC7ENC16_FALSE; +} + +/* +------------------------------------------------------------------------------ +This software is available under 2 licenses -- choose whichever you prefer. +------------------------------------------------------------------------------ +ALTERNATIVE A - MIT License +Copyright(c) 2018 Richard Geldreich, Jr. +Permission is hereby granted, free of charge, to any person obtaining a copy of +this software and associated documentation files(the "Software"), to deal in +the Software without restriction, including without limitation the rights to +use, copy, modify, merge, publish, distribute, sublicense, and / or sell copies +of the Software, and to permit persons to whom the Software is furnished to do +so, subject to the following conditions : +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. +------------------------------------------------------------------------------ +ALTERNATIVE B - Public Domain(www.unlicense.org) +This is free and unencumbered software released into the public domain. +Anyone is free to copy, modify, publish, use, compile, sell, or distribute this +software, either in source code form or as a compiled binary, for any purpose, +commercial or non - commercial, and by any means. +In jurisdictions that recognize copyright laws, the author or authors of this +software dedicate any and all copyright interest in the software to the public +domain.We make this dedication for the benefit of the public at large and to +the detriment of our heirs and successors.We intend this dedication to be an +overt act of relinquishment in perpetuity of all present and future rights to +this software under copyright law. +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE +AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +------------------------------------------------------------------------------ +*/ diff --git a/bc7enc16.h b/bc7enc16.h new file mode 100644 index 0000000..6383c69 --- /dev/null +++ b/bc7enc16.h @@ -0,0 +1,62 @@ +// File: bc7enc16.h - Richard Geldreich, Jr. - MIT license or public domain (see end of bc7enc16.c) +#include +#include + +#ifdef __cplusplus +extern "C" { +#endif + +#define BC7ENC16_BLOCK_SIZE (16) +#define BC7ENC16_MAX_PARTITIONS1 (64) +#define BC7ENC16_MAX_UBER_LEVEL (4) + +typedef uint8_t bc7enc16_bool; +#define BC7ENC16_TRUE (1) +#define BC7ENC16_FALSE (0) + +typedef struct +{ + uint32_t m_max_partitions_mode1; + uint32_t m_weights[4]; + uint32_t m_uber_level; + bc7enc16_bool m_perceptual; + bc7enc16_bool m_try_least_squares; +} bc7enc16_compress_block_params; + +inline void bc7enc16_compress_block_params_init_linear_weights(bc7enc16_compress_block_params *p) +{ + p->m_perceptual = BC7ENC16_FALSE; + p->m_weights[0] = 1; + p->m_weights[1] = 1; + p->m_weights[2] = 1; + p->m_weights[3] = 1; +} + +inline void bc7enc16_compress_block_params_init_perceptual_weights(bc7enc16_compress_block_params *p) +{ + p->m_perceptual = BC7ENC16_TRUE; + p->m_weights[0] = 128; + p->m_weights[1] = 64; + p->m_weights[2] = 16; + p->m_weights[3] = 32; +} + +inline void bc7enc16_compress_block_params_init(bc7enc16_compress_block_params *p) +{ + p->m_max_partitions_mode1 = BC7ENC16_MAX_PARTITIONS1; + p->m_try_least_squares = BC7ENC16_TRUE; + p->m_uber_level = 0; + bc7enc16_compress_block_params_init_perceptual_weights(p); +} + +// bc7enc16_compress_block_init() MUST be called before calling bc7enc16_compress_block() (or you'll get artifacts). +void bc7enc16_compress_block_init(); + +// Packs a single block of 16x16 RGBA pixels (R first in memory) to 128-bit BC7 block pBlock, using either mode 1 and/or 6. +// Alpha blocks will always use mode 6, and by default opaque blocks will use either modes 1 or 6. +// Returns BC7ENC16_TRUE if the block had any pixels with alpha < 255, otherwise it return BC7ENC16_FALSE. (This is not an error code - a block is always encoded.) +bc7enc16_bool bc7enc16_compress_block(void *pBlock, const void *pPixelsRGBA, const bc7enc16_compress_block_params *pComp_params); + +#ifdef __cplusplus +} +#endif diff --git a/dds_defs.h b/dds_defs.h new file mode 100644 index 0000000..0c6d164 --- /dev/null +++ b/dds_defs.h @@ -0,0 +1,286 @@ +// File: dds_defs.h +// DX9 .DDS file header definitions. +#pragma once + +#define PIXEL_FMT_FOURCC(a, b, c, d) ((a) | ((b) << 8U) | ((c) << 16U) | ((d) << 24U)) + +enum pixel_format +{ + PIXEL_FMT_INVALID = 0, + + PIXEL_FMT_DXT1 = PIXEL_FMT_FOURCC('D', 'X', 'T', '1'), + PIXEL_FMT_DXT2 = PIXEL_FMT_FOURCC('D', 'X', 'T', '2'), + PIXEL_FMT_DXT3 = PIXEL_FMT_FOURCC('D', 'X', 'T', '3'), + PIXEL_FMT_DXT4 = PIXEL_FMT_FOURCC('D', 'X', 'T', '4'), + PIXEL_FMT_DXT5 = PIXEL_FMT_FOURCC('D', 'X', 'T', '5'), + PIXEL_FMT_3DC = PIXEL_FMT_FOURCC('A', 'T', 'I', '2'), // DXN_YX + PIXEL_FMT_DXN = PIXEL_FMT_FOURCC('A', '2', 'X', 'Y'), // DXN_XY + PIXEL_FMT_DXT5A = PIXEL_FMT_FOURCC('A', 'T', 'I', '1'), // ATI1N, http://developer.amd.com/media/gpu_assets/Radeon_X1x00_Programming_Guide.pdf + + // Non-standard formats (some of these are supported by ATI's Compressonator) + PIXEL_FMT_DXT5_CCxY = PIXEL_FMT_FOURCC('C', 'C', 'x', 'Y'), + PIXEL_FMT_DXT5_xGxR = PIXEL_FMT_FOURCC('x', 'G', 'x', 'R'), + PIXEL_FMT_DXT5_xGBR = PIXEL_FMT_FOURCC('x', 'G', 'B', 'R'), + PIXEL_FMT_DXT5_AGBR = PIXEL_FMT_FOURCC('A', 'G', 'B', 'R'), + + PIXEL_FMT_DXT1A = PIXEL_FMT_FOURCC('D', 'X', '1', 'A'), + PIXEL_FMT_ETC1 = PIXEL_FMT_FOURCC('E', 'T', 'C', '1'), + + PIXEL_FMT_R8G8B8 = PIXEL_FMT_FOURCC('R', 'G', 'B', 'x'), + PIXEL_FMT_L8 = PIXEL_FMT_FOURCC('L', 'x', 'x', 'x'), + PIXEL_FMT_A8 = PIXEL_FMT_FOURCC('x', 'x', 'x', 'A'), + PIXEL_FMT_A8L8 = PIXEL_FMT_FOURCC('L', 'x', 'x', 'A'), + PIXEL_FMT_A8R8G8B8 = PIXEL_FMT_FOURCC('R', 'G', 'B', 'A') +}; + +const uint32_t cDDSMaxImageDimensions = 8192U; + +// Total size of header is sizeof(uint32)+cDDSSizeofDDSurfaceDesc2; +const uint32_t cDDSSizeofDDSurfaceDesc2 = 124; + +// "DDS " +const uint32_t cDDSFileSignature = 0x20534444; + +struct DDCOLORKEY +{ + uint32_t dwUnused0; + uint32_t dwUnused1; +}; + +struct DDPIXELFORMAT +{ + uint32_t dwSize; + uint32_t dwFlags; + uint32_t dwFourCC; + uint32_t dwRGBBitCount; // ATI compressonator will place a FOURCC code here for swizzled/cooked DXTn formats + uint32_t dwRBitMask; + uint32_t dwGBitMask; + uint32_t dwBBitMask; + uint32_t dwRGBAlphaBitMask; +}; + +struct DDSCAPS2 +{ + uint32_t dwCaps; + uint32_t dwCaps2; + uint32_t dwCaps3; + uint32_t dwCaps4; +}; + +struct DDSURFACEDESC2 +{ + uint32_t dwSize; + uint32_t dwFlags; + uint32_t dwHeight; + uint32_t dwWidth; + union + { + int32_t lPitch; + uint32_t dwLinearSize; + }; + uint32_t dwBackBufferCount; + uint32_t dwMipMapCount; + uint32_t dwAlphaBitDepth; + uint32_t dwUnused0; + uint32_t lpSurface; + DDCOLORKEY unused0; + DDCOLORKEY unused1; + DDCOLORKEY unused2; + DDCOLORKEY unused3; + DDPIXELFORMAT ddpfPixelFormat; + DDSCAPS2 ddsCaps; + uint32_t dwUnused1; +}; + +const uint32_t DDSD_CAPS = 0x00000001; +const uint32_t DDSD_HEIGHT = 0x00000002; +const uint32_t DDSD_WIDTH = 0x00000004; +const uint32_t DDSD_PITCH = 0x00000008; + +const uint32_t DDSD_BACKBUFFERCOUNT = 0x00000020; +const uint32_t DDSD_ZBUFFERBITDEPTH = 0x00000040; +const uint32_t DDSD_ALPHABITDEPTH = 0x00000080; + +const uint32_t DDSD_LPSURFACE = 0x00000800; + +const uint32_t DDSD_PIXELFORMAT = 0x00001000; +const uint32_t DDSD_CKDESTOVERLAY = 0x00002000; +const uint32_t DDSD_CKDESTBLT = 0x00004000; +const uint32_t DDSD_CKSRCOVERLAY = 0x00008000; + +const uint32_t DDSD_CKSRCBLT = 0x00010000; +const uint32_t DDSD_MIPMAPCOUNT = 0x00020000; +const uint32_t DDSD_REFRESHRATE = 0x00040000; +const uint32_t DDSD_LINEARSIZE = 0x00080000; + +const uint32_t DDSD_TEXTURESTAGE = 0x00100000; +const uint32_t DDSD_FVF = 0x00200000; +const uint32_t DDSD_SRCVBHANDLE = 0x00400000; +const uint32_t DDSD_DEPTH = 0x00800000; + +const uint32_t DDSD_ALL = 0x00fff9ee; + +const uint32_t DDPF_ALPHAPIXELS = 0x00000001; +const uint32_t DDPF_ALPHA = 0x00000002; +const uint32_t DDPF_FOURCC = 0x00000004; +const uint32_t DDPF_PALETTEINDEXED8 = 0x00000020; +const uint32_t DDPF_RGB = 0x00000040; +const uint32_t DDPF_LUMINANCE = 0x00020000; + +const uint32_t DDSCAPS_COMPLEX = 0x00000008; +const uint32_t DDSCAPS_TEXTURE = 0x00001000; +const uint32_t DDSCAPS_MIPMAP = 0x00400000; + +const uint32_t DDSCAPS2_CUBEMAP = 0x00000200; +const uint32_t DDSCAPS2_CUBEMAP_POSITIVEX = 0x00000400; +const uint32_t DDSCAPS2_CUBEMAP_NEGATIVEX = 0x00000800; + +const uint32_t DDSCAPS2_CUBEMAP_POSITIVEY = 0x00001000; +const uint32_t DDSCAPS2_CUBEMAP_NEGATIVEY = 0x00002000; +const uint32_t DDSCAPS2_CUBEMAP_POSITIVEZ = 0x00004000; +const uint32_t DDSCAPS2_CUBEMAP_NEGATIVEZ = 0x00008000; + +const uint32_t DDSCAPS2_VOLUME = 0x00200000; + +typedef enum DXGI_FORMAT +{ + DXGI_FORMAT_UNKNOWN = 0, + DXGI_FORMAT_R32G32B32A32_TYPELESS = 1, + DXGI_FORMAT_R32G32B32A32_FLOAT = 2, + DXGI_FORMAT_R32G32B32A32_UINT = 3, + DXGI_FORMAT_R32G32B32A32_SINT = 4, + DXGI_FORMAT_R32G32B32_TYPELESS = 5, + DXGI_FORMAT_R32G32B32_FLOAT = 6, + DXGI_FORMAT_R32G32B32_UINT = 7, + DXGI_FORMAT_R32G32B32_SINT = 8, + DXGI_FORMAT_R16G16B16A16_TYPELESS = 9, + DXGI_FORMAT_R16G16B16A16_FLOAT = 10, + DXGI_FORMAT_R16G16B16A16_UNORM = 11, + DXGI_FORMAT_R16G16B16A16_UINT = 12, + DXGI_FORMAT_R16G16B16A16_SNORM = 13, + DXGI_FORMAT_R16G16B16A16_SINT = 14, + DXGI_FORMAT_R32G32_TYPELESS = 15, + DXGI_FORMAT_R32G32_FLOAT = 16, + DXGI_FORMAT_R32G32_UINT = 17, + DXGI_FORMAT_R32G32_SINT = 18, + DXGI_FORMAT_R32G8X24_TYPELESS = 19, + DXGI_FORMAT_D32_FLOAT_S8X24_UINT = 20, + DXGI_FORMAT_R32_FLOAT_X8X24_TYPELESS = 21, + DXGI_FORMAT_X32_TYPELESS_G8X24_UINT = 22, + DXGI_FORMAT_R10G10B10A2_TYPELESS = 23, + DXGI_FORMAT_R10G10B10A2_UNORM = 24, + DXGI_FORMAT_R10G10B10A2_UINT = 25, + DXGI_FORMAT_R11G11B10_FLOAT = 26, + DXGI_FORMAT_R8G8B8A8_TYPELESS = 27, + DXGI_FORMAT_R8G8B8A8_UNORM = 28, + DXGI_FORMAT_R8G8B8A8_UNORM_SRGB = 29, + DXGI_FORMAT_R8G8B8A8_UINT = 30, + DXGI_FORMAT_R8G8B8A8_SNORM = 31, + DXGI_FORMAT_R8G8B8A8_SINT = 32, + DXGI_FORMAT_R16G16_TYPELESS = 33, + DXGI_FORMAT_R16G16_FLOAT = 34, + DXGI_FORMAT_R16G16_UNORM = 35, + DXGI_FORMAT_R16G16_UINT = 36, + DXGI_FORMAT_R16G16_SNORM = 37, + DXGI_FORMAT_R16G16_SINT = 38, + DXGI_FORMAT_R32_TYPELESS = 39, + DXGI_FORMAT_D32_FLOAT = 40, + DXGI_FORMAT_R32_FLOAT = 41, + DXGI_FORMAT_R32_UINT = 42, + DXGI_FORMAT_R32_SINT = 43, + DXGI_FORMAT_R24G8_TYPELESS = 44, + DXGI_FORMAT_D24_UNORM_S8_UINT = 45, + DXGI_FORMAT_R24_UNORM_X8_TYPELESS = 46, + DXGI_FORMAT_X24_TYPELESS_G8_UINT = 47, + DXGI_FORMAT_R8G8_TYPELESS = 48, + DXGI_FORMAT_R8G8_UNORM = 49, + DXGI_FORMAT_R8G8_UINT = 50, + DXGI_FORMAT_R8G8_SNORM = 51, + DXGI_FORMAT_R8G8_SINT = 52, + DXGI_FORMAT_R16_TYPELESS = 53, + DXGI_FORMAT_R16_FLOAT = 54, + DXGI_FORMAT_D16_UNORM = 55, + DXGI_FORMAT_R16_UNORM = 56, + DXGI_FORMAT_R16_UINT = 57, + DXGI_FORMAT_R16_SNORM = 58, + DXGI_FORMAT_R16_SINT = 59, + DXGI_FORMAT_R8_TYPELESS = 60, + DXGI_FORMAT_R8_UNORM = 61, + DXGI_FORMAT_R8_UINT = 62, + DXGI_FORMAT_R8_SNORM = 63, + DXGI_FORMAT_R8_SINT = 64, + DXGI_FORMAT_A8_UNORM = 65, + DXGI_FORMAT_R1_UNORM = 66, + DXGI_FORMAT_R9G9B9E5_SHAREDEXP = 67, + DXGI_FORMAT_R8G8_B8G8_UNORM = 68, + DXGI_FORMAT_G8R8_G8B8_UNORM = 69, + DXGI_FORMAT_BC1_TYPELESS = 70, + DXGI_FORMAT_BC1_UNORM = 71, + DXGI_FORMAT_BC1_UNORM_SRGB = 72, + DXGI_FORMAT_BC2_TYPELESS = 73, + DXGI_FORMAT_BC2_UNORM = 74, + DXGI_FORMAT_BC2_UNORM_SRGB = 75, + DXGI_FORMAT_BC3_TYPELESS = 76, + DXGI_FORMAT_BC3_UNORM = 77, + DXGI_FORMAT_BC3_UNORM_SRGB = 78, + DXGI_FORMAT_BC4_TYPELESS = 79, + DXGI_FORMAT_BC4_UNORM = 80, + DXGI_FORMAT_BC4_SNORM = 81, + DXGI_FORMAT_BC5_TYPELESS = 82, + DXGI_FORMAT_BC5_UNORM = 83, + DXGI_FORMAT_BC5_SNORM = 84, + DXGI_FORMAT_B5G6R5_UNORM = 85, + DXGI_FORMAT_B5G5R5A1_UNORM = 86, + DXGI_FORMAT_B8G8R8A8_UNORM = 87, + DXGI_FORMAT_B8G8R8X8_UNORM = 88, + DXGI_FORMAT_R10G10B10_XR_BIAS_A2_UNORM = 89, + DXGI_FORMAT_B8G8R8A8_TYPELESS = 90, + DXGI_FORMAT_B8G8R8A8_UNORM_SRGB = 91, + DXGI_FORMAT_B8G8R8X8_TYPELESS = 92, + DXGI_FORMAT_B8G8R8X8_UNORM_SRGB = 93, + DXGI_FORMAT_BC6H_TYPELESS = 94, + DXGI_FORMAT_BC6H_UF16 = 95, + DXGI_FORMAT_BC6H_SF16 = 96, + DXGI_FORMAT_BC7_TYPELESS = 97, + DXGI_FORMAT_BC7_UNORM = 98, + DXGI_FORMAT_BC7_UNORM_SRGB = 99, + DXGI_FORMAT_AYUV = 100, + DXGI_FORMAT_Y410 = 101, + DXGI_FORMAT_Y416 = 102, + DXGI_FORMAT_NV12 = 103, + DXGI_FORMAT_P010 = 104, + DXGI_FORMAT_P016 = 105, + DXGI_FORMAT_420_OPAQUE = 106, + DXGI_FORMAT_YUY2 = 107, + DXGI_FORMAT_Y210 = 108, + DXGI_FORMAT_Y216 = 109, + DXGI_FORMAT_NV11 = 110, + DXGI_FORMAT_AI44 = 111, + DXGI_FORMAT_IA44 = 112, + DXGI_FORMAT_P8 = 113, + DXGI_FORMAT_A8P8 = 114, + DXGI_FORMAT_B4G4R4A4_UNORM = 115, + DXGI_FORMAT_P208 = 130, + DXGI_FORMAT_V208 = 131, + DXGI_FORMAT_V408 = 132, + DXGI_FORMAT_FORCE_UINT = 0xffffffff +} DXGI_FORMAT; + +enum D3D10_RESOURCE_DIMENSION +{ + D3D10_RESOURCE_DIMENSION_UNKNOWN = 0, + D3D10_RESOURCE_DIMENSION_BUFFER = 1, + D3D10_RESOURCE_DIMENSION_TEXTURE1D = 2, + D3D10_RESOURCE_DIMENSION_TEXTURE2D = 3, + D3D10_RESOURCE_DIMENSION_TEXTURE3D = 4 +}; + +struct DDS_HEADER_DXT10 +{ + DXGI_FORMAT dxgiFormat; + D3D10_RESOURCE_DIMENSION resourceDimension; + uint32_t miscFlag; + uint32_t arraySize; + uint32_t miscFlags2; +}; + diff --git a/lodepng.cpp b/lodepng.cpp new file mode 100644 index 0000000..742766f --- /dev/null +++ b/lodepng.cpp @@ -0,0 +1,6232 @@ +/* +LodePNG version 20161127 + +Copyright (c) 2005-2016 Lode Vandevenne + +This software is provided 'as-is', without any express or implied +warranty. In no event will the authors be held liable for any damages +arising from the use of this software. + +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it +freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + + 3. This notice may not be removed or altered from any source + distribution. +*/ + +/* +The manual and changelog are in the header file "lodepng.h" +Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C. +*/ + +#include "lodepng.h" + +#include +#include +#include + +#if defined(_MSC_VER) && (_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/ +#pragma warning( disable : 4244 ) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/ +#pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/ +#endif /*_MSC_VER */ + +const char* LODEPNG_VERSION_STRING = "20161127"; + +/* +This source file is built up in the following large parts. The code sections +with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way. +-Tools for C and common code for PNG and Zlib +-C Code for Zlib (huffman, deflate, ...) +-C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...) +-The C++ wrapper around all of the above +*/ + +/*The malloc, realloc and free functions defined here with "lodepng_" in front +of the name, so that you can easily change them to others related to your +platform if needed. Everything else in the code calls these. Pass +-DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out +#define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and +define them in your own project's source files without needing to change +lodepng source code. Don't forget to remove "static" if you copypaste them +from here.*/ + +#ifdef LODEPNG_COMPILE_ALLOCATORS +static void* lodepng_malloc(size_t size) +{ + return malloc(size); +} + +static void* lodepng_realloc(void* ptr, size_t new_size) +{ + return realloc(ptr, new_size); +} + +static void lodepng_free(void* ptr) +{ + free(ptr); +} +#else /*LODEPNG_COMPILE_ALLOCATORS*/ +void* lodepng_malloc(size_t size); +void* lodepng_realloc(void* ptr, size_t new_size); +void lodepng_free(void* ptr); +#endif /*LODEPNG_COMPILE_ALLOCATORS*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // Tools for C, and common code for PNG and Zlib. // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ + +/* +Often in case of an error a value is assigned to a variable and then it breaks +out of a loop (to go to the cleanup phase of a function). This macro does that. +It makes the error handling code shorter and more readable. + +Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83); +*/ +#define CERROR_BREAK(errorvar, code)\ +{\ + errorvar = code;\ + break;\ +} + +/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/ +#define ERROR_BREAK(code) CERROR_BREAK(error, code) + +/*Set error var to the error code, and return it.*/ +#define CERROR_RETURN_ERROR(errorvar, code)\ +{\ + errorvar = code;\ + return code;\ +} + +/*Try the code, if it returns error, also return the error.*/ +#define CERROR_TRY_RETURN(call)\ +{\ + unsigned error = call;\ + if(error) return error;\ +} + +/*Set error var to the error code, and return from the void function.*/ +#define CERROR_RETURN(errorvar, code)\ +{\ + errorvar = code;\ + return;\ +} + +/* +About uivector, ucvector and string: +-All of them wrap dynamic arrays or text strings in a similar way. +-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version. +-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated. +-They're not used in the interface, only internally in this file as static functions. +-As with many other structs in this file, the init and cleanup functions serve as ctor and dtor. +*/ + +#ifdef LODEPNG_COMPILE_ZLIB +/*dynamic vector of unsigned ints*/ +typedef struct uivector +{ + unsigned* data; + size_t size; /*size in number of unsigned longs*/ + size_t allocsize; /*allocated size in bytes*/ +} uivector; + +static void uivector_cleanup(void* p) +{ + ((uivector*)p)->size = ((uivector*)p)->allocsize = 0; + lodepng_free(((uivector*)p)->data); + ((uivector*)p)->data = NULL; +} + +/*returns 1 if success, 0 if failure ==> nothing done*/ +static unsigned uivector_reserve(uivector* p, size_t allocsize) +{ + if (allocsize > p->allocsize) + { + size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2); + void* data = lodepng_realloc(p->data, newsize); + if (data) + { + p->allocsize = newsize; + p->data = (unsigned*)data; + } + else return 0; /*error: not enough memory*/ + } + return 1; +} + +/*returns 1 if success, 0 if failure ==> nothing done*/ +static unsigned uivector_resize(uivector* p, size_t size) +{ + if (!uivector_reserve(p, size * sizeof(unsigned))) return 0; + p->size = size; + return 1; /*success*/ +} + +/*resize and give all new elements the value*/ +static unsigned uivector_resizev(uivector* p, size_t size, unsigned value) +{ + size_t oldsize = p->size, i; + if (!uivector_resize(p, size)) return 0; + for (i = oldsize; i < size; ++i) p->data[i] = value; + return 1; +} + +static void uivector_init(uivector* p) +{ + p->data = NULL; + p->size = p->allocsize = 0; +} + +#ifdef LODEPNG_COMPILE_ENCODER +/*returns 1 if success, 0 if failure ==> nothing done*/ +static unsigned uivector_push_back(uivector* p, unsigned c) +{ + if (!uivector_resize(p, p->size + 1)) return 0; + p->data[p->size - 1] = c; + return 1; +} +#endif /*LODEPNG_COMPILE_ENCODER*/ +#endif /*LODEPNG_COMPILE_ZLIB*/ + +/* /////////////////////////////////////////////////////////////////////////// */ + +/*dynamic vector of unsigned chars*/ +typedef struct ucvector +{ + unsigned char* data; + size_t size; /*used size*/ + size_t allocsize; /*allocated size*/ +} ucvector; + +/*returns 1 if success, 0 if failure ==> nothing done*/ +static unsigned ucvector_reserve(ucvector* p, size_t allocsize) +{ + if (allocsize > p->allocsize) + { + size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2); + void* data = lodepng_realloc(p->data, newsize); + if (data) + { + p->allocsize = newsize; + p->data = (unsigned char*)data; + } + else return 0; /*error: not enough memory*/ + } + return 1; +} + +/*returns 1 if success, 0 if failure ==> nothing done*/ +static unsigned ucvector_resize(ucvector* p, size_t size) +{ + if (!ucvector_reserve(p, size * sizeof(unsigned char))) return 0; + p->size = size; + return 1; /*success*/ +} + +#ifdef LODEPNG_COMPILE_PNG + +static void ucvector_cleanup(void* p) +{ + ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0; + lodepng_free(((ucvector*)p)->data); + ((ucvector*)p)->data = NULL; +} + +static void ucvector_init(ucvector* p) +{ + p->data = NULL; + p->size = p->allocsize = 0; +} +#endif /*LODEPNG_COMPILE_PNG*/ + +#ifdef LODEPNG_COMPILE_ZLIB +/*you can both convert from vector to buffer&size and vica versa. If you use +init_buffer to take over a buffer and size, it is not needed to use cleanup*/ +static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size) +{ + p->data = buffer; + p->allocsize = p->size = size; +} +#endif /*LODEPNG_COMPILE_ZLIB*/ + +#if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER) +/*returns 1 if success, 0 if failure ==> nothing done*/ +static unsigned ucvector_push_back(ucvector* p, unsigned char c) +{ + if (!ucvector_resize(p, p->size + 1)) return 0; + p->data[p->size - 1] = c; + return 1; +} +#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ + + +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_PNG +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS +/*returns 1 if success, 0 if failure ==> nothing done*/ +static unsigned string_resize(char** out, size_t size) +{ + char* data = (char*)lodepng_realloc(*out, size + 1); + if (data) + { + data[size] = 0; /*null termination char*/ + *out = data; + } + return data != 0; +} + +/*init a {char*, size_t} pair for use as string*/ +static void string_init(char** out) +{ + *out = NULL; + string_resize(out, 0); +} + +/*free the above pair again*/ +static void string_cleanup(char** out) +{ + lodepng_free(*out); + *out = NULL; +} + +static void string_set(char** out, const char* in) +{ + size_t insize = strlen(in), i; + if (string_resize(out, insize)) + { + for (i = 0; i != insize; ++i) + { + (*out)[i] = in[i]; + } + } +} +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +#endif /*LODEPNG_COMPILE_PNG*/ + +/* ////////////////////////////////////////////////////////////////////////// */ + +unsigned lodepng_read32bitInt(const unsigned char* buffer) +{ + return (unsigned)((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]); +} + +#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER) +/*buffer must have at least 4 allocated bytes available*/ +static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) +{ + buffer[0] = (unsigned char)((value >> 24) & 0xff); + buffer[1] = (unsigned char)((value >> 16) & 0xff); + buffer[2] = (unsigned char)((value >> 8) & 0xff); + buffer[3] = (unsigned char)((value) & 0xff); +} +#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ + +#ifdef LODEPNG_COMPILE_ENCODER +static void lodepng_add32bitInt(ucvector* buffer, unsigned value) +{ + ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/ + lodepng_set32bitInt(&buffer->data[buffer->size - 4], value); +} +#endif /*LODEPNG_COMPILE_ENCODER*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / File IO / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_DISK + +/* returns negative value on error. This should be pure C compatible, so no fstat. */ +static long lodepng_filesize(const char* filename) +{ + FILE* file; + long size; + file = fopen(filename, "rb"); + if (!file) return -1; + + if (fseek(file, 0, SEEK_END) != 0) + { + fclose(file); + return -1; + } + + size = ftell(file); + /* It may give LONG_MAX as directory size, this is invalid for us. */ + if (size == LONG_MAX) size = -1; + + fclose(file); + return size; +} + +/* load file into buffer that already has the correct allocated size. Returns error code.*/ +static unsigned lodepng_buffer_file(unsigned char* out, size_t size, const char* filename) +{ + FILE* file; + size_t readsize; + file = fopen(filename, "rb"); + if (!file) return 78; + + readsize = fread(out, 1, size, file); + fclose(file); + + if (readsize != size) return 78; + return 0; +} + +unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) +{ + long size = lodepng_filesize(filename); + if (size < 0) return 78; + *outsize = (size_t)size; + + *out = (unsigned char*)lodepng_malloc((size_t)size); + if (!(*out) && size > 0) return 83; /*the above malloc failed*/ + + return lodepng_buffer_file(*out, (size_t)size, filename); +} + +/*write given buffer to the file, overwriting the file, it doesn't append to it.*/ +unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename) +{ + FILE* file; + file = fopen(filename, "wb"); + if (!file) return 79; + fwrite((char*)buffer, 1, buffersize, file); + fclose(file); + return 0; +} + +#endif /*LODEPNG_COMPILE_DISK*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // End of common code and tools. Begin of Zlib related code. // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_ZLIB +#ifdef LODEPNG_COMPILE_ENCODER +/*TODO: this ignores potential out of memory errors*/ +#define addBitToStream(/*size_t**/ bitpointer, /*ucvector**/ bitstream, /*unsigned char*/ bit)\ +{\ + /*add a new byte at the end*/\ + if(((*bitpointer) & 7) == 0) ucvector_push_back(bitstream, (unsigned char)0);\ + /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/\ + (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));\ + ++(*bitpointer);\ +} + +static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits) +{ + size_t i; + for (i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1)); +} + +static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits) +{ + size_t i; + for (i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1)); +} +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#ifdef LODEPNG_COMPILE_DECODER + +#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1) + +static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream) +{ + unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream)); + ++(*bitpointer); + return result; +} + +static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) +{ + unsigned result = 0, i; + for (i = 0; i != nbits; ++i) + { + result += ((unsigned)READBIT(*bitpointer, bitstream)) << i; + ++(*bitpointer); + } + return result; +} +#endif /*LODEPNG_COMPILE_DECODER*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Deflate - Huffman / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#define FIRST_LENGTH_CODE_INDEX 257 +#define LAST_LENGTH_CODE_INDEX 285 +/*256 literals, the end code, some length codes, and 2 unused codes*/ +#define NUM_DEFLATE_CODE_SYMBOLS 288 +/*the distance codes have their own symbols, 30 used, 2 unused*/ +#define NUM_DISTANCE_SYMBOLS 32 +/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/ +#define NUM_CODE_LENGTH_CODES 19 + +/*the base lengths represented by codes 257-285*/ +static const unsigned LENGTHBASE[29] += { 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, + 67, 83, 99, 115, 131, 163, 195, 227, 258 }; + +/*the extra bits used by codes 257-285 (added to base length)*/ +static const unsigned LENGTHEXTRA[29] += { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, + 4, 4, 4, 4, 5, 5, 5, 5, 0 }; + +/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/ +static const unsigned DISTANCEBASE[30] += { 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513, + 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577 }; + +/*the extra bits of backwards distances (added to base)*/ +static const unsigned DISTANCEEXTRA[30] += { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, + 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13 }; + +/*the order in which "code length alphabet code lengths" are stored, out of this +the huffman tree of the dynamic huffman tree lengths is generated*/ +static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES] += { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; + +/* ////////////////////////////////////////////////////////////////////////// */ + +/* +Huffman tree struct, containing multiple representations of the tree +*/ +typedef struct HuffmanTree +{ + unsigned* tree2d; + unsigned* tree1d; + unsigned* lengths; /*the lengths of the codes of the 1d-tree*/ + unsigned maxbitlen; /*maximum number of bits a single code can get*/ + unsigned numcodes; /*number of symbols in the alphabet = number of codes*/ +} HuffmanTree; + +/*function used for debug purposes to draw the tree in ascii art with C++*/ +/* +static void HuffmanTree_draw(HuffmanTree* tree) +{ + std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl; + for(size_t i = 0; i != tree->tree1d.size; ++i) + { + if(tree->lengths.data[i]) + std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl; + } + std::cout << std::endl; +}*/ + +static void HuffmanTree_init(HuffmanTree* tree) +{ + tree->tree2d = 0; + tree->tree1d = 0; + tree->lengths = 0; +} + +static void HuffmanTree_cleanup(HuffmanTree* tree) +{ + lodepng_free(tree->tree2d); + lodepng_free(tree->tree1d); + lodepng_free(tree->lengths); +} + +/*the tree representation used by the decoder. return value is error*/ +static unsigned HuffmanTree_make2DTree(HuffmanTree* tree) +{ + unsigned nodefilled = 0; /*up to which node it is filled*/ + unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/ + unsigned n, i; + + tree->tree2d = (unsigned*)lodepng_malloc(tree->numcodes * 2 * sizeof(unsigned)); + if (!tree->tree2d) return 83; /*alloc fail*/ + + /* + convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means + uninited, a value >= numcodes is an address to another bit, a value < numcodes + is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as + many columns as codes - 1. + A good huffman tree has N * 2 - 1 nodes, of which N - 1 are internal nodes. + Here, the internal nodes are stored (what their 0 and 1 option point to). + There is only memory for such good tree currently, if there are more nodes + (due to too long length codes), error 55 will happen + */ + for (n = 0; n < tree->numcodes * 2; ++n) + { + tree->tree2d[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/ + } + + for (n = 0; n < tree->numcodes; ++n) /*the codes*/ + { + for (i = 0; i != tree->lengths[n]; ++i) /*the bits for this code*/ + { + unsigned char bit = (unsigned char)((tree->tree1d[n] >> (tree->lengths[n] - i - 1)) & 1); + /*oversubscribed, see comment in lodepng_error_text*/ + if (treepos > 2147483647 || treepos + 2 > tree->numcodes) return 55; + if (tree->tree2d[2 * treepos + bit] == 32767) /*not yet filled in*/ + { + if (i + 1 == tree->lengths[n]) /*last bit*/ + { + tree->tree2d[2 * treepos + bit] = n; /*put the current code in it*/ + treepos = 0; + } + else + { + /*put address of the next step in here, first that address has to be found of course + (it's just nodefilled + 1)...*/ + ++nodefilled; + /*addresses encoded with numcodes added to it*/ + tree->tree2d[2 * treepos + bit] = nodefilled + tree->numcodes; + treepos = nodefilled; + } + } + else treepos = tree->tree2d[2 * treepos + bit] - tree->numcodes; + } + } + + for (n = 0; n < tree->numcodes * 2; ++n) + { + if (tree->tree2d[n] == 32767) tree->tree2d[n] = 0; /*remove possible remaining 32767's*/ + } + + return 0; +} + +/* +Second step for the ...makeFromLengths and ...makeFromFrequencies functions. +numcodes, lengths and maxbitlen must already be filled in correctly. return +value is error. +*/ +static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) +{ + uivector blcount; + uivector nextcode; + unsigned error = 0; + unsigned bits, n; + + uivector_init(&blcount); + uivector_init(&nextcode); + + tree->tree1d = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned)); + if (!tree->tree1d) error = 83; /*alloc fail*/ + + if (!uivector_resizev(&blcount, tree->maxbitlen + 1, 0) + || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0)) + error = 83; /*alloc fail*/ + + if (!error) + { + /*step 1: count number of instances of each code length*/ + for (bits = 0; bits != tree->numcodes; ++bits) ++blcount.data[tree->lengths[bits]]; + /*step 2: generate the nextcode values*/ + for (bits = 1; bits <= tree->maxbitlen; ++bits) + { + nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1; + } + /*step 3: generate all the codes*/ + for (n = 0; n != tree->numcodes; ++n) + { + if (tree->lengths[n] != 0) tree->tree1d[n] = nextcode.data[tree->lengths[n]]++; + } + } + + uivector_cleanup(&blcount); + uivector_cleanup(&nextcode); + + if (!error) return HuffmanTree_make2DTree(tree); + else return error; +} + +/* +given the code lengths (as stored in the PNG file), generate the tree as defined +by Deflate. maxbitlen is the maximum bits that a code in the tree can have. +return value is error. +*/ +static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen, + size_t numcodes, unsigned maxbitlen) +{ + unsigned i; + tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned)); + if (!tree->lengths) return 83; /*alloc fail*/ + for (i = 0; i != numcodes; ++i) tree->lengths[i] = bitlen[i]; + tree->numcodes = (unsigned)numcodes; /*number of symbols*/ + tree->maxbitlen = maxbitlen; + return HuffmanTree_makeFromLengths2(tree); +} + +#ifdef LODEPNG_COMPILE_ENCODER + +/*BPM: Boundary Package Merge, see "A Fast and Space-Economical Algorithm for Length-Limited Coding", +Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/ + +/*chain node for boundary package merge*/ +typedef struct BPMNode +{ + int weight; /*the sum of all weights in this chain*/ + unsigned index; /*index of this leaf node (called "count" in the paper)*/ + struct BPMNode* tail; /*the next nodes in this chain (null if last)*/ + int in_use; +} BPMNode; + +/*lists of chains*/ +typedef struct BPMLists +{ + /*memory pool*/ + unsigned memsize; + BPMNode* memory; + unsigned numfree; + unsigned nextfree; + BPMNode** freelist; + /*two heads of lookahead chains per list*/ + unsigned listsize; + BPMNode** chains0; + BPMNode** chains1; +} BPMLists; + +/*creates a new chain node with the given parameters, from the memory in the lists */ +static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMNode* tail) +{ + unsigned i; + BPMNode* result; + + /*memory full, so garbage collect*/ + if (lists->nextfree >= lists->numfree) + { + /*mark only those that are in use*/ + for (i = 0; i != lists->memsize; ++i) lists->memory[i].in_use = 0; + for (i = 0; i != lists->listsize; ++i) + { + BPMNode* node; + for (node = lists->chains0[i]; node != 0; node = node->tail) node->in_use = 1; + for (node = lists->chains1[i]; node != 0; node = node->tail) node->in_use = 1; + } + /*collect those that are free*/ + lists->numfree = 0; + for (i = 0; i != lists->memsize; ++i) + { + if (!lists->memory[i].in_use) lists->freelist[lists->numfree++] = &lists->memory[i]; + } + lists->nextfree = 0; + } + + result = lists->freelist[lists->nextfree++]; + result->weight = weight; + result->index = index; + result->tail = tail; + return result; +} + +/*sort the leaves with stable mergesort*/ +static void bpmnode_sort(BPMNode* leaves, size_t num) +{ + BPMNode* mem = (BPMNode*)lodepng_malloc(sizeof(*leaves) * num); + size_t width, counter = 0; + for (width = 1; width < num; width *= 2) + { + BPMNode* a = (counter & 1) ? mem : leaves; + BPMNode* b = (counter & 1) ? leaves : mem; + size_t p; + for (p = 0; p < num; p += 2 * width) + { + size_t q = (p + width > num) ? num : (p + width); + size_t r = (p + 2 * width > num) ? num : (p + 2 * width); + size_t i = p, j = q, k; + for (k = p; k < r; k++) + { + if (i < q && (j >= r || a[i].weight <= a[j].weight)) b[k] = a[i++]; + else b[k] = a[j++]; + } + } + counter++; + } + if (counter & 1) memcpy(leaves, mem, sizeof(*leaves) * num); + lodepng_free(mem); +} + +/*Boundary Package Merge step, numpresent is the amount of leaves, and c is the current chain.*/ +static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int c, int num) +{ + unsigned lastindex = lists->chains1[c]->index; + + if (c == 0) + { + if (lastindex >= numpresent) return; + lists->chains0[c] = lists->chains1[c]; + lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, 0); + } + else + { + /*sum of the weights of the head nodes of the previous lookahead chains.*/ + int sum = lists->chains0[c - 1]->weight + lists->chains1[c - 1]->weight; + lists->chains0[c] = lists->chains1[c]; + if (lastindex < numpresent && sum > leaves[lastindex].weight) + { + lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, lists->chains1[c]->tail); + return; + } + lists->chains1[c] = bpmnode_create(lists, sum, lastindex, lists->chains1[c - 1]); + /*in the end we are only interested in the chain of the last list, so no + need to recurse if we're at the last one (this gives measurable speedup)*/ + if (num + 1 < (int)(2 * numpresent - 2)) + { + boundaryPM(lists, leaves, numpresent, c - 1, num); + boundaryPM(lists, leaves, numpresent, c - 1, num); + } + } +} + +unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, + size_t numcodes, unsigned maxbitlen) +{ + unsigned error = 0; + unsigned i; + size_t numpresent = 0; /*number of symbols with non-zero frequency*/ + BPMNode* leaves; /*the symbols, only those with > 0 frequency*/ + + if (numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/ + if ((1u << maxbitlen) < numcodes) return 80; /*error: represent all symbols*/ + + leaves = (BPMNode*)lodepng_malloc(numcodes * sizeof(*leaves)); + if (!leaves) return 83; /*alloc fail*/ + + for (i = 0; i != numcodes; ++i) + { + if (frequencies[i] > 0) + { + leaves[numpresent].weight = (int)frequencies[i]; + leaves[numpresent].index = i; + ++numpresent; + } + } + + for (i = 0; i != numcodes; ++i) lengths[i] = 0; + + /*ensure at least two present symbols. There should be at least one symbol + according to RFC 1951 section 3.2.7. Some decoders incorrectly require two. To + make these work as well ensure there are at least two symbols. The + Package-Merge code below also doesn't work correctly if there's only one + symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/ + if (numpresent == 0) + { + lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/ + } + else if (numpresent == 1) + { + lengths[leaves[0].index] = 1; + lengths[leaves[0].index == 0 ? 1 : 0] = 1; + } + else + { + BPMLists lists; + BPMNode* node; + + bpmnode_sort(leaves, numpresent); + + lists.listsize = maxbitlen; + lists.memsize = 2 * maxbitlen * (maxbitlen + 1); + lists.nextfree = 0; + lists.numfree = lists.memsize; + lists.memory = (BPMNode*)lodepng_malloc(lists.memsize * sizeof(*lists.memory)); + lists.freelist = (BPMNode**)lodepng_malloc(lists.memsize * sizeof(BPMNode*)); + lists.chains0 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*)); + lists.chains1 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*)); + if (!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1) error = 83; /*alloc fail*/ + + if (!error) + { + for (i = 0; i != lists.memsize; ++i) lists.freelist[i] = &lists.memory[i]; + + bpmnode_create(&lists, leaves[0].weight, 1, 0); + bpmnode_create(&lists, leaves[1].weight, 2, 0); + + for (i = 0; i != lists.listsize; ++i) + { + lists.chains0[i] = &lists.memory[0]; + lists.chains1[i] = &lists.memory[1]; + } + + /*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/ + for (i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, (int)maxbitlen - 1, (int)i); + + for (node = lists.chains1[maxbitlen - 1]; node; node = node->tail) + { + for (i = 0; i != node->index; ++i) ++lengths[leaves[i].index]; + } + } + + lodepng_free(lists.memory); + lodepng_free(lists.freelist); + lodepng_free(lists.chains0); + lodepng_free(lists.chains1); + } + + lodepng_free(leaves); + return error; +} + +/*Create the Huffman tree given the symbol frequencies*/ +static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies, + size_t mincodes, size_t numcodes, unsigned maxbitlen) +{ + unsigned error = 0; + while (!frequencies[numcodes - 1] && numcodes > mincodes) --numcodes; /*trim zeroes*/ + tree->maxbitlen = maxbitlen; + tree->numcodes = (unsigned)numcodes; /*number of symbols*/ + tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned)); + if (!tree->lengths) return 83; /*alloc fail*/ + /*initialize all lengths to 0*/ + memset(tree->lengths, 0, numcodes * sizeof(unsigned)); + + error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen); + if (!error) error = HuffmanTree_makeFromLengths2(tree); + return error; +} + +static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index) +{ + return tree->tree1d[index]; +} + +static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index) +{ + return tree->lengths[index]; +} +#endif /*LODEPNG_COMPILE_ENCODER*/ + +/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/ +static unsigned generateFixedLitLenTree(HuffmanTree* tree) +{ + unsigned i, error = 0; + unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned)); + if (!bitlen) return 83; /*alloc fail*/ + + /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/ + for (i = 0; i <= 143; ++i) bitlen[i] = 8; + for (i = 144; i <= 255; ++i) bitlen[i] = 9; + for (i = 256; i <= 279; ++i) bitlen[i] = 7; + for (i = 280; i <= 287; ++i) bitlen[i] = 8; + + error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15); + + lodepng_free(bitlen); + return error; +} + +/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/ +static unsigned generateFixedDistanceTree(HuffmanTree* tree) +{ + unsigned i, error = 0; + unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned)); + if (!bitlen) return 83; /*alloc fail*/ + + /*there are 32 distance codes, but 30-31 are unused*/ + for (i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen[i] = 5; + error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15); + + lodepng_free(bitlen); + return error; +} + +#ifdef LODEPNG_COMPILE_DECODER + +/* +returns the code, or (unsigned)(-1) if error happened +inbitlength is the length of the complete buffer, in bits (so its byte length times 8) +*/ +static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp, + const HuffmanTree* codetree, size_t inbitlength) +{ + unsigned treepos = 0, ct; + for (;;) + { + if (*bp >= inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/ + /* + decode the symbol from the tree. The "readBitFromStream" code is inlined in + the expression below because this is the biggest bottleneck while decoding + */ + ct = codetree->tree2d[(treepos << 1) + READBIT(*bp, in)]; + ++(*bp); + if (ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/ + else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/ + + if (treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/ + } +} +#endif /*LODEPNG_COMPILE_DECODER*/ + +#ifdef LODEPNG_COMPILE_DECODER + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Inflator (Decompressor) / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/ +static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d) +{ + /*TODO: check for out of memory errors*/ + generateFixedLitLenTree(tree_ll); + generateFixedDistanceTree(tree_d); +} + +/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/ +static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d, + const unsigned char* in, size_t* bp, size_t inlength) +{ + /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/ + unsigned error = 0; + unsigned n, HLIT, HDIST, HCLEN, i; + size_t inbitlength = inlength * 8; + + /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/ + unsigned* bitlen_ll = 0; /*lit,len code lengths*/ + unsigned* bitlen_d = 0; /*dist code lengths*/ + /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/ + unsigned* bitlen_cl = 0; + HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/ + + if ((*bp) + 14 > (inlength << 3)) return 49; /*error: the bit pointer is or will go past the memory*/ + + /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/ + HLIT = readBitsFromStream(bp, in, 5) + 257; + /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/ + HDIST = readBitsFromStream(bp, in, 5) + 1; + /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/ + HCLEN = readBitsFromStream(bp, in, 4) + 4; + + if ((*bp) + HCLEN * 3 > (inlength << 3)) return 50; /*error: the bit pointer is or will go past the memory*/ + + HuffmanTree_init(&tree_cl); + + while (!error) + { + /*read the code length codes out of 3 * (amount of code length codes) bits*/ + + bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned)); + if (!bitlen_cl) ERROR_BREAK(83 /*alloc fail*/); + + for (i = 0; i != NUM_CODE_LENGTH_CODES; ++i) + { + if (i < HCLEN) bitlen_cl[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3); + else bitlen_cl[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/ + } + + error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7); + if (error) break; + + /*now we can use this tree to read the lengths for the tree that this function will return*/ + bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned)); + bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned)); + if (!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/); + for (i = 0; i != NUM_DEFLATE_CODE_SYMBOLS; ++i) bitlen_ll[i] = 0; + for (i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen_d[i] = 0; + + /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/ + i = 0; + while (i < HLIT + HDIST) + { + unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength); + if (code <= 15) /*a length code*/ + { + if (i < HLIT) bitlen_ll[i] = code; + else bitlen_d[i - HLIT] = code; + ++i; + } + else if (code == 16) /*repeat previous*/ + { + unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/ + unsigned value; /*set value to the previous code*/ + + if (i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/ + + if ((*bp + 2) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ + replength += readBitsFromStream(bp, in, 2); + + if (i < HLIT + 1) value = bitlen_ll[i - 1]; + else value = bitlen_d[i - HLIT - 1]; + /*repeat this value in the next lengths*/ + for (n = 0; n < replength; ++n) + { + if (i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/ + if (i < HLIT) bitlen_ll[i] = value; + else bitlen_d[i - HLIT] = value; + ++i; + } + } + else if (code == 17) /*repeat "0" 3-10 times*/ + { + unsigned replength = 3; /*read in the bits that indicate repeat length*/ + if ((*bp + 3) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ + replength += readBitsFromStream(bp, in, 3); + + /*repeat this value in the next lengths*/ + for (n = 0; n < replength; ++n) + { + if (i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/ + + if (i < HLIT) bitlen_ll[i] = 0; + else bitlen_d[i - HLIT] = 0; + ++i; + } + } + else if (code == 18) /*repeat "0" 11-138 times*/ + { + unsigned replength = 11; /*read in the bits that indicate repeat length*/ + if ((*bp + 7) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ + replength += readBitsFromStream(bp, in, 7); + + /*repeat this value in the next lengths*/ + for (n = 0; n < replength; ++n) + { + if (i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/ + + if (i < HLIT) bitlen_ll[i] = 0; + else bitlen_d[i - HLIT] = 0; + ++i; + } + } + else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ + { + if (code == (unsigned)(-1)) + { + /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol + (10=no endcode, 11=wrong jump outside of tree)*/ + error = (*bp) > inbitlength ? 10 : 11; + } + else error = 16; /*unexisting code, this can never happen*/ + break; + } + } + if (error) break; + + if (bitlen_ll[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/ + + /*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/ + error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 15); + if (error) break; + error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15); + + break; /*end of error-while*/ + } + + lodepng_free(bitlen_cl); + lodepng_free(bitlen_ll); + lodepng_free(bitlen_d); + HuffmanTree_cleanup(&tree_cl); + + return error; +} + +/*inflate a block with dynamic of fixed Huffman tree*/ +static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp, + size_t* pos, size_t inlength, unsigned btype) +{ + unsigned error = 0; + HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/ + HuffmanTree tree_d; /*the huffman tree for distance codes*/ + size_t inbitlength = inlength * 8; + + HuffmanTree_init(&tree_ll); + HuffmanTree_init(&tree_d); + + if (btype == 1) getTreeInflateFixed(&tree_ll, &tree_d); + else if (btype == 2) error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength); + + while (!error) /*decode all symbols until end reached, breaks at end code*/ + { + /*code_ll is literal, length or end code*/ + unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength); + if (code_ll <= 255) /*literal symbol*/ + { + /*ucvector_push_back would do the same, but for some reason the two lines below run 10% faster*/ + if (!ucvector_resize(out, (*pos) + 1)) ERROR_BREAK(83 /*alloc fail*/); + out->data[*pos] = (unsigned char)code_ll; + ++(*pos); + } + else if (code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ + { + unsigned code_d, distance; + unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/ + size_t start, forward, backward, length; + + /*part 1: get length base*/ + length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX]; + + /*part 2: get extra bits and add the value of that to length*/ + numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX]; + if ((*bp + numextrabits_l) > inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/ + length += readBitsFromStream(bp, in, numextrabits_l); + + /*part 3: get distance code*/ + code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength); + if (code_d > 29) + { + if (code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ + { + /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol + (10=no endcode, 11=wrong jump outside of tree)*/ + error = (*bp) > inlength * 8 ? 10 : 11; + } + else error = 18; /*error: invalid distance code (30-31 are never used)*/ + break; + } + distance = DISTANCEBASE[code_d]; + + /*part 4: get extra bits from distance*/ + numextrabits_d = DISTANCEEXTRA[code_d]; + if ((*bp + numextrabits_d) > inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/ + distance += readBitsFromStream(bp, in, numextrabits_d); + + /*part 5: fill in all the out[n] values based on the length and dist*/ + start = (*pos); + if (distance > start) ERROR_BREAK(52); /*too long backward distance*/ + backward = start - distance; + + if (!ucvector_resize(out, (*pos) + length)) ERROR_BREAK(83 /*alloc fail*/); + if (distance < length) { + for (forward = 0; forward < length; ++forward) + { + out->data[(*pos)++] = out->data[backward++]; + } + } + else { + memcpy(out->data + *pos, out->data + backward, length); + *pos += length; + } + } + else if (code_ll == 256) + { + break; /*end code, break the loop*/ + } + else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ + { + /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol + (10=no endcode, 11=wrong jump outside of tree)*/ + error = ((*bp) > inlength * 8) ? 10 : 11; + break; + } + } + + HuffmanTree_cleanup(&tree_ll); + HuffmanTree_cleanup(&tree_d); + + return error; +} + +static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength) +{ + size_t p; + unsigned LEN, NLEN, n, error = 0; + + /*go to first boundary of byte*/ + while (((*bp) & 0x7) != 0) ++(*bp); + p = (*bp) / 8; /*byte position*/ + + /*read LEN (2 bytes) and NLEN (2 bytes)*/ + if (p + 4 >= inlength) return 52; /*error, bit pointer will jump past memory*/ + LEN = in[p] + 256u * in[p + 1]; p += 2; + NLEN = in[p] + 256u * in[p + 1]; p += 2; + + /*check if 16-bit NLEN is really the one's complement of LEN*/ + if (LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/ + + if (!ucvector_resize(out, (*pos) + LEN)) return 83; /*alloc fail*/ + + /*read the literal data: LEN bytes are now stored in the out buffer*/ + if (p + LEN > inlength) return 23; /*error: reading outside of in buffer*/ + for (n = 0; n < LEN; ++n) out->data[(*pos)++] = in[p++]; + + (*bp) = p * 8; + + return error; +} + +static unsigned lodepng_inflatev(ucvector* out, + const unsigned char* in, size_t insize, + const LodePNGDecompressSettings* settings) +{ + /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/ + size_t bp = 0; + unsigned BFINAL = 0; + size_t pos = 0; /*byte position in the out buffer*/ + unsigned error = 0; + + (void)settings; + + while (!BFINAL) + { + unsigned BTYPE; + if (bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/ + BFINAL = readBitFromStream(&bp, in); + BTYPE = 1u * readBitFromStream(&bp, in); + BTYPE += 2u * readBitFromStream(&bp, in); + + if (BTYPE == 3) return 20; /*error: invalid BTYPE*/ + else if (BTYPE == 0) error = inflateNoCompression(out, in, &bp, &pos, insize); /*no compression*/ + else error = inflateHuffmanBlock(out, in, &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/ + + if (error) return error; + } + + return error; +} + +unsigned lodepng_inflate(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGDecompressSettings* settings) +{ + unsigned error; + ucvector v; + ucvector_init_buffer(&v, *out, *outsize); + error = lodepng_inflatev(&v, in, insize, settings); + *out = v.data; + *outsize = v.size; + return error; +} + +static unsigned inflate(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGDecompressSettings* settings) +{ + if (settings->custom_inflate) + { + return settings->custom_inflate(out, outsize, in, insize, settings); + } + else + { + return lodepng_inflate(out, outsize, in, insize, settings); + } +} + +#endif /*LODEPNG_COMPILE_DECODER*/ + +#ifdef LODEPNG_COMPILE_ENCODER + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Deflator (Compressor) / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258; + +/*bitlen is the size in bits of the code*/ +static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen) +{ + addBitsToStreamReversed(bp, compressed, code, bitlen); +} + +/*search the index in the array, that has the largest value smaller than or equal to the given value, +given array must be sorted (if no value is smaller, it returns the size of the given array)*/ +static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value) +{ + /*binary search (only small gain over linear). TODO: use CPU log2 instruction for getting symbols instead*/ + size_t left = 1; + size_t right = array_size - 1; + + while (left <= right) { + size_t mid = (left + right) >> 1; + if (array[mid] >= value) right = mid - 1; + else left = mid + 1; + } + if (left >= array_size || array[left] > value) left--; + return left; +} + +static void addLengthDistance(uivector* values, size_t length, size_t distance) +{ + /*values in encoded vector are those used by deflate: + 0-255: literal bytes + 256: end + 257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits) + 286-287: invalid*/ + + unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length); + unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]); + unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance); + unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]); + + uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX); + uivector_push_back(values, extra_length); + uivector_push_back(values, dist_code); + uivector_push_back(values, extra_distance); +} + +/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3 +bytes as input because 3 is the minimum match length for deflate*/ +static const unsigned HASH_NUM_VALUES = 65536; +static const unsigned HASH_BIT_MASK = 65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/ + +typedef struct Hash +{ + int* head; /*hash value to head circular pos - can be outdated if went around window*/ + /*circular pos to prev circular pos*/ + unsigned short* chain; + int* val; /*circular pos to hash value*/ + + /*TODO: do this not only for zeros but for any repeated byte. However for PNG + it's always going to be the zeros that dominate, so not important for PNG*/ + int* headz; /*similar to head, but for chainz*/ + unsigned short* chainz; /*those with same amount of zeros*/ + unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/ +} Hash; + +static unsigned hash_init(Hash* hash, unsigned windowsize) +{ + unsigned i; + hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES); + hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize); + hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); + + hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); + hash->headz = (int*)lodepng_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1)); + hash->chainz = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); + + if (!hash->head || !hash->chain || !hash->val || !hash->headz || !hash->chainz || !hash->zeros) + { + return 83; /*alloc fail*/ + } + + /*initialize hash table*/ + for (i = 0; i != HASH_NUM_VALUES; ++i) hash->head[i] = -1; + for (i = 0; i != windowsize; ++i) hash->val[i] = -1; + for (i = 0; i != windowsize; ++i) hash->chain[i] = i; /*same value as index indicates uninitialized*/ + + for (i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; ++i) hash->headz[i] = -1; + for (i = 0; i != windowsize; ++i) hash->chainz[i] = i; /*same value as index indicates uninitialized*/ + + return 0; +} + +static void hash_cleanup(Hash* hash) +{ + lodepng_free(hash->head); + lodepng_free(hash->val); + lodepng_free(hash->chain); + + lodepng_free(hash->zeros); + lodepng_free(hash->headz); + lodepng_free(hash->chainz); +} + + + +static unsigned getHash(const unsigned char* data, size_t size, size_t pos) +{ + unsigned result = 0; + if (pos + 2 < size) + { + /*A simple shift and xor hash is used. Since the data of PNGs is dominated + by zeroes due to the filters, a better hash does not have a significant + effect on speed in traversing the chain, and causes more time spend on + calculating the hash.*/ + result ^= (unsigned)(data[pos + 0] << 0u); + result ^= (unsigned)(data[pos + 1] << 4u); + result ^= (unsigned)(data[pos + 2] << 8u); + } + else { + size_t amount, i; + if (pos >= size) return 0; + amount = size - pos; + for (i = 0; i != amount; ++i) result ^= (unsigned)(data[pos + i] << (i * 8u)); + } + return result & HASH_BIT_MASK; +} + +static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) +{ + const unsigned char* start = data + pos; + const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH; + if (end > data + size) end = data + size; + data = start; + while (data != end && *data == 0) ++data; + /*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/ + return (unsigned)(data - start); +} + +/*wpos = pos & (windowsize - 1)*/ +static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros) +{ + hash->val[wpos] = (int)hashval; + if (hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval]; + hash->head[hashval] = wpos; + + hash->zeros[wpos] = numzeros; + if (hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros]; + hash->headz[numzeros] = wpos; +} + +/* +LZ77-encode the data. Return value is error code. The input are raw bytes, the output +is in the form of unsigned integers with codes representing for example literal bytes, or +length/distance pairs. +It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a +sliding window (of windowsize) is used, and all past bytes in that window can be used as +the "dictionary". A brute force search through all possible distances would be slow, and +this hash technique is one out of several ways to speed this up. +*/ +static unsigned encodeLZ77(uivector* out, Hash* hash, + const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize, + unsigned minmatch, unsigned nicematch, unsigned lazymatching) +{ + size_t pos; + unsigned i, error = 0; + /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/ + unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8; + unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64; + + unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/ + unsigned numzeros = 0; + + unsigned offset; /*the offset represents the distance in LZ77 terminology*/ + unsigned length; + unsigned lazy = 0; + unsigned lazylength = 0, lazyoffset = 0; + unsigned hashval; + unsigned current_offset, current_length; + unsigned prev_offset; + const unsigned char *lastptr, *foreptr, *backptr; + unsigned hashpos; + + if (windowsize == 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/ + if ((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/ + + if (nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH; + + for (pos = inpos; pos < insize; ++pos) + { + size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/ + unsigned chainlength = 0; + + hashval = getHash(in, insize, pos); + + if (usezeros && hashval == 0) + { + if (numzeros == 0) numzeros = countZeros(in, insize, pos); + else if (pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; + } + else + { + numzeros = 0; + } + + updateHashChain(hash, wpos, hashval, numzeros); + + /*the length and offset found for the current position*/ + length = 0; + offset = 0; + + hashpos = hash->chain[wpos]; + + lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH]; + + /*search for the longest string*/ + prev_offset = 0; + for (;;) + { + if (chainlength++ >= maxchainlength) break; + current_offset = hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize; + + if (current_offset < prev_offset) break; /*stop when went completely around the circular buffer*/ + prev_offset = current_offset; + if (current_offset > 0) + { + /*test the next characters*/ + foreptr = &in[pos]; + backptr = &in[pos - current_offset]; + + /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/ + if (numzeros >= 3) + { + unsigned skip = hash->zeros[hashpos]; + if (skip > numzeros) skip = numzeros; + backptr += skip; + foreptr += skip; + } + + while (foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/ + { + ++backptr; + ++foreptr; + } + current_length = (unsigned)(foreptr - &in[pos]); + + if (current_length > length) + { + length = current_length; /*the longest length*/ + offset = current_offset; /*the offset that is related to this longest length*/ + /*jump out once a length of max length is found (speed gain). This also jumps + out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/ + if (current_length >= nicematch) break; + } + } + + if (hashpos == hash->chain[hashpos]) break; + + if (numzeros >= 3 && length > numzeros) + { + hashpos = hash->chainz[hashpos]; + if (hash->zeros[hashpos] != numzeros) break; + } + else + { + hashpos = hash->chain[hashpos]; + /*outdated hash value, happens if particular value was not encountered in whole last window*/ + if (hash->val[hashpos] != (int)hashval) break; + } + } + + if (lazymatching) + { + if (!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH) + { + lazy = 1; + lazylength = length; + lazyoffset = offset; + continue; /*try the next byte*/ + } + if (lazy) + { + lazy = 0; + if (pos == 0) ERROR_BREAK(81); + if (length > lazylength + 1) + { + /*push the previous character as literal*/ + if (!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/); + } + else + { + length = lazylength; + offset = lazyoffset; + hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/ + hash->headz[numzeros] = -1; /*idem*/ + --pos; + } + } + } + if (length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/); + + /*encode it as length/distance pair or literal value*/ + if (length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ + { + if (!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); + } + else if (length < minmatch || (length == 3 && offset > 4096)) + { + /*compensate for the fact that longer offsets have more extra bits, a + length of only 3 may be not worth it then*/ + if (!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); + } + else + { + addLengthDistance(out, length, offset); + for (i = 1; i < length; ++i) + { + ++pos; + wpos = pos & (windowsize - 1); + hashval = getHash(in, insize, pos); + if (usezeros && hashval == 0) + { + if (numzeros == 0) numzeros = countZeros(in, insize, pos); + else if (pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; + } + else + { + numzeros = 0; + } + updateHashChain(hash, wpos, hashval, numzeros); + } + } + } /*end of the loop through each character of input*/ + + return error; +} + +/* /////////////////////////////////////////////////////////////////////////// */ + +static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) +{ + /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte, + 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/ + + size_t i, j, numdeflateblocks = (datasize + 65534) / 65535; + unsigned datapos = 0; + for (i = 0; i != numdeflateblocks; ++i) + { + unsigned BFINAL, BTYPE, LEN, NLEN; + unsigned char firstbyte; + + BFINAL = (i == numdeflateblocks - 1); + BTYPE = 0; + + firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1)); + ucvector_push_back(out, firstbyte); + + LEN = 65535; + if (datasize - datapos < 65535) LEN = (unsigned)datasize - datapos; + NLEN = 65535 - LEN; + + ucvector_push_back(out, (unsigned char)(LEN & 255)); + ucvector_push_back(out, (unsigned char)(LEN >> 8)); + ucvector_push_back(out, (unsigned char)(NLEN & 255)); + ucvector_push_back(out, (unsigned char)(NLEN >> 8)); + + /*Decompressed data*/ + for (j = 0; j < 65535 && datapos < datasize; ++j) + { + ucvector_push_back(out, data[datapos++]); + } + } + + return 0; +} + +/* +write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees. +tree_ll: the tree for lit and len codes. +tree_d: the tree for distance codes. +*/ +static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded, + const HuffmanTree* tree_ll, const HuffmanTree* tree_d) +{ + size_t i = 0; + for (i = 0; i != lz77_encoded->size; ++i) + { + unsigned val = lz77_encoded->data[i]; + addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val)); + if (val > 256) /*for a length code, 3 more things have to be added*/ + { + unsigned length_index = val - FIRST_LENGTH_CODE_INDEX; + unsigned n_length_extra_bits = LENGTHEXTRA[length_index]; + unsigned length_extra_bits = lz77_encoded->data[++i]; + + unsigned distance_code = lz77_encoded->data[++i]; + + unsigned distance_index = distance_code; + unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index]; + unsigned distance_extra_bits = lz77_encoded->data[++i]; + + addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits); + addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code), + HuffmanTree_getLength(tree_d, distance_code)); + addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits); + } + } +} + +/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/ +static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, + const unsigned char* data, size_t datapos, size_t dataend, + const LodePNGCompressSettings* settings, unsigned final) +{ + unsigned error = 0; + + /* + A block is compressed as follows: The PNG data is lz77 encoded, resulting in + literal bytes and length/distance pairs. This is then huffman compressed with + two huffman trees. One huffman tree is used for the lit and len values ("ll"), + another huffman tree is used for the dist values ("d"). These two trees are + stored using their code lengths, and to compress even more these code lengths + are also run-length encoded and huffman compressed. This gives a huffman tree + of code lengths "cl". The code lenghts used to describe this third tree are + the code length code lengths ("clcl"). + */ + + /*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/ + uivector lz77_encoded; + HuffmanTree tree_ll; /*tree for lit,len values*/ + HuffmanTree tree_d; /*tree for distance codes*/ + HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/ + uivector frequencies_ll; /*frequency of lit,len codes*/ + uivector frequencies_d; /*frequency of dist codes*/ + uivector frequencies_cl; /*frequency of code length codes*/ + uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/ + uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/ + /*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl + (these are written as is in the file, it would be crazy to compress these using yet another huffman + tree that needs to be represented by yet another set of code lengths)*/ + uivector bitlen_cl; + size_t datasize = dataend - datapos; + + /* + Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies: + bitlen_lld is to tree_cl what data is to tree_ll and tree_d. + bitlen_lld_e is to bitlen_lld what lz77_encoded is to data. + bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded. + */ + + unsigned BFINAL = final; + size_t numcodes_ll, numcodes_d, i; + unsigned HLIT, HDIST, HCLEN; + + uivector_init(&lz77_encoded); + HuffmanTree_init(&tree_ll); + HuffmanTree_init(&tree_d); + HuffmanTree_init(&tree_cl); + uivector_init(&frequencies_ll); + uivector_init(&frequencies_d); + uivector_init(&frequencies_cl); + uivector_init(&bitlen_lld); + uivector_init(&bitlen_lld_e); + uivector_init(&bitlen_cl); + + /*This while loop never loops due to a break at the end, it is here to + allow breaking out of it to the cleanup phase on error conditions.*/ + while (!error) + { + if (settings->use_lz77) + { + error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, + settings->minmatch, settings->nicematch, settings->lazymatching); + if (error) break; + } + else + { + if (!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/); + for (i = datapos; i < dataend; ++i) lz77_encoded.data[i - datapos] = data[i]; /*no LZ77, but still will be Huffman compressed*/ + } + + if (!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/); + if (!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*alloc fail*/); + + /*Count the frequencies of lit, len and dist codes*/ + for (i = 0; i != lz77_encoded.size; ++i) + { + unsigned symbol = lz77_encoded.data[i]; + ++frequencies_ll.data[symbol]; + if (symbol > 256) + { + unsigned dist = lz77_encoded.data[i + 2]; + ++frequencies_d.data[dist]; + i += 3; + } + } + frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/ + + /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/ + error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, 257, frequencies_ll.size, 15); + if (error) break; + /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/ + error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, frequencies_d.size, 15); + if (error) break; + + numcodes_ll = tree_ll.numcodes; if (numcodes_ll > 286) numcodes_ll = 286; + numcodes_d = tree_d.numcodes; if (numcodes_d > 30) numcodes_d = 30; + /*store the code lengths of both generated trees in bitlen_lld*/ + for (i = 0; i != numcodes_ll; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i)); + for (i = 0; i != numcodes_d; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i)); + + /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times), + 17 (3-10 zeroes), 18 (11-138 zeroes)*/ + for (i = 0; i != (unsigned)bitlen_lld.size; ++i) + { + unsigned j = 0; /*amount of repititions*/ + while (i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) ++j; + + if (bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/ + { + ++j; /*include the first zero*/ + if (j <= 10) /*repeat code 17 supports max 10 zeroes*/ + { + uivector_push_back(&bitlen_lld_e, 17); + uivector_push_back(&bitlen_lld_e, j - 3); + } + else /*repeat code 18 supports max 138 zeroes*/ + { + if (j > 138) j = 138; + uivector_push_back(&bitlen_lld_e, 18); + uivector_push_back(&bitlen_lld_e, j - 11); + } + i += (j - 1); + } + else if (j >= 3) /*repeat code for value other than zero*/ + { + size_t k; + unsigned num = j / 6, rest = j % 6; + uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); + for (k = 0; k < num; ++k) + { + uivector_push_back(&bitlen_lld_e, 16); + uivector_push_back(&bitlen_lld_e, 6 - 3); + } + if (rest >= 3) + { + uivector_push_back(&bitlen_lld_e, 16); + uivector_push_back(&bitlen_lld_e, rest - 3); + } + else j -= rest; + i += j; + } + else /*too short to benefit from repeat code*/ + { + uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); + } + } + + /*generate tree_cl, the huffmantree of huffmantrees*/ + + if (!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(83 /*alloc fail*/); + for (i = 0; i != bitlen_lld_e.size; ++i) + { + ++frequencies_cl.data[bitlen_lld_e.data[i]]; + /*after a repeat code come the bits that specify the number of repetitions, + those don't need to be in the frequencies_cl calculation*/ + if (bitlen_lld_e.data[i] >= 16) ++i; + } + + error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, + frequencies_cl.size, frequencies_cl.size, 7); + if (error) break; + + if (!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/); + for (i = 0; i != tree_cl.numcodes; ++i) + { + /*lenghts of code length tree is in the order as specified by deflate*/ + bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]); + } + while (bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4) + { + /*remove zeros at the end, but minimum size must be 4*/ + if (!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(83 /*alloc fail*/); + } + if (error) break; + + /* + Write everything into the output + + After the BFINAL and BTYPE, the dynamic block consists out of the following: + - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN + - (HCLEN+4)*3 bits code lengths of code length alphabet + - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length + alphabet, + possible repetition codes 16, 17, 18) + - HDIST + 1 code lengths of distance alphabet (encoded using the code length + alphabet, + possible repetition codes 16, 17, 18) + - compressed data + - 256 (end code) + */ + + /*Write block type*/ + addBitToStream(bp, out, BFINAL); + addBitToStream(bp, out, 0); /*first bit of BTYPE "dynamic"*/ + addBitToStream(bp, out, 1); /*second bit of BTYPE "dynamic"*/ + + /*write the HLIT, HDIST and HCLEN values*/ + HLIT = (unsigned)(numcodes_ll - 257); + HDIST = (unsigned)(numcodes_d - 1); + HCLEN = (unsigned)bitlen_cl.size - 4; + /*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/ + while (!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) --HCLEN; + addBitsToStream(bp, out, HLIT, 5); + addBitsToStream(bp, out, HDIST, 5); + addBitsToStream(bp, out, HCLEN, 4); + + /*write the code lenghts of the code length alphabet*/ + for (i = 0; i != HCLEN + 4; ++i) addBitsToStream(bp, out, bitlen_cl.data[i], 3); + + /*write the lenghts of the lit/len AND the dist alphabet*/ + for (i = 0; i != bitlen_lld_e.size; ++i) + { + addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]), + HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i])); + /*extra bits of repeat codes*/ + if (bitlen_lld_e.data[i] == 16) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 2); + else if (bitlen_lld_e.data[i] == 17) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 3); + else if (bitlen_lld_e.data[i] == 18) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 7); + } + + /*write the compressed data symbols*/ + writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); + /*error: the length of the end code 256 must be larger than 0*/ + if (HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64); + + /*write the end code*/ + addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); + + break; /*end of error-while*/ + } + + /*cleanup*/ + uivector_cleanup(&lz77_encoded); + HuffmanTree_cleanup(&tree_ll); + HuffmanTree_cleanup(&tree_d); + HuffmanTree_cleanup(&tree_cl); + uivector_cleanup(&frequencies_ll); + uivector_cleanup(&frequencies_d); + uivector_cleanup(&frequencies_cl); + uivector_cleanup(&bitlen_lld_e); + uivector_cleanup(&bitlen_lld); + uivector_cleanup(&bitlen_cl); + + return error; +} + +static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash, + const unsigned char* data, + size_t datapos, size_t dataend, + const LodePNGCompressSettings* settings, unsigned final) +{ + HuffmanTree tree_ll; /*tree for literal values and length codes*/ + HuffmanTree tree_d; /*tree for distance codes*/ + + unsigned BFINAL = final; + unsigned error = 0; + size_t i; + + HuffmanTree_init(&tree_ll); + HuffmanTree_init(&tree_d); + + generateFixedLitLenTree(&tree_ll); + generateFixedDistanceTree(&tree_d); + + addBitToStream(bp, out, BFINAL); + addBitToStream(bp, out, 1); /*first bit of BTYPE*/ + addBitToStream(bp, out, 0); /*second bit of BTYPE*/ + + if (settings->use_lz77) /*LZ77 encoded*/ + { + uivector lz77_encoded; + uivector_init(&lz77_encoded); + error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, + settings->minmatch, settings->nicematch, settings->lazymatching); + if (!error) writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); + uivector_cleanup(&lz77_encoded); + } + else /*no LZ77, but still will be Huffman compressed*/ + { + for (i = datapos; i < dataend; ++i) + { + addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i])); + } + } + /*add END code*/ + if (!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); + + /*cleanup*/ + HuffmanTree_cleanup(&tree_ll); + HuffmanTree_cleanup(&tree_d); + + return error; +} + +static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize, + const LodePNGCompressSettings* settings) +{ + unsigned error = 0; + size_t i, blocksize, numdeflateblocks; + size_t bp = 0; /*the bit pointer*/ + Hash hash; + + if (settings->btype > 2) return 61; + else if (settings->btype == 0) return deflateNoCompression(out, in, insize); + else if (settings->btype == 1) blocksize = insize; + else /*if(settings->btype == 2)*/ + { + /*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/ + blocksize = insize / 8 + 8; + if (blocksize < 65536) blocksize = 65536; + if (blocksize > 262144) blocksize = 262144; + } + + numdeflateblocks = (insize + blocksize - 1) / blocksize; + if (numdeflateblocks == 0) numdeflateblocks = 1; + + error = hash_init(&hash, settings->windowsize); + if (error) return error; + + for (i = 0; i != numdeflateblocks && !error; ++i) + { + unsigned final = (i == numdeflateblocks - 1); + size_t start = i * blocksize; + size_t end = start + blocksize; + if (end > insize) end = insize; + + if (settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final); + else if (settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final); + } + + hash_cleanup(&hash); + + return error; +} + +unsigned lodepng_deflate(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGCompressSettings* settings) +{ + unsigned error; + ucvector v; + ucvector_init_buffer(&v, *out, *outsize); + error = lodepng_deflatev(&v, in, insize, settings); + *out = v.data; + *outsize = v.size; + return error; +} + +static unsigned deflate(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGCompressSettings* settings) +{ + if (settings->custom_deflate) + { + return settings->custom_deflate(out, outsize, in, insize, settings); + } + else + { + return lodepng_deflate(out, outsize, in, insize, settings); + } +} + +#endif /*LODEPNG_COMPILE_DECODER*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Adler32 */ +/* ////////////////////////////////////////////////////////////////////////// */ + +static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) +{ + unsigned s1 = adler & 0xffff; + unsigned s2 = (adler >> 16) & 0xffff; + + while (len > 0) + { + /*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/ + unsigned amount = len > 5550 ? 5550 : len; + len -= amount; + while (amount > 0) + { + s1 += (*data++); + s2 += s1; + --amount; + } + s1 %= 65521; + s2 %= 65521; + } + + return (s2 << 16) | s1; +} + +/*Return the adler32 of the bytes data[0..len-1]*/ +static unsigned adler32(const unsigned char* data, unsigned len) +{ + return update_adler32(1L, data, len); +} + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Zlib / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_DECODER + +unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGDecompressSettings* settings) +{ + unsigned error = 0; + unsigned CM, CINFO, FDICT; + + if (insize < 2) return 53; /*error, size of zlib data too small*/ + /*read information from zlib header*/ + if ((in[0] * 256 + in[1]) % 31 != 0) + { + /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/ + return 24; + } + + CM = in[0] & 15; + CINFO = (in[0] >> 4) & 15; + /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/ + FDICT = (in[1] >> 5) & 1; + /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/ + + if (CM != 8 || CINFO > 7) + { + /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/ + return 25; + } + if (FDICT != 0) + { + /*error: the specification of PNG says about the zlib stream: + "The additional flags shall not specify a preset dictionary."*/ + return 26; + } + + error = inflate(out, outsize, in + 2, insize - 2, settings); + if (error) return error; + + if (!settings->ignore_adler32) + { + unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]); + unsigned checksum = adler32(*out, (unsigned)(*outsize)); + if (checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/ + } + + return 0; /*no error*/ +} + +static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGDecompressSettings* settings) +{ + if (settings->custom_zlib) + { + return settings->custom_zlib(out, outsize, in, insize, settings); + } + else + { + return lodepng_zlib_decompress(out, outsize, in, insize, settings); + } +} + +#endif /*LODEPNG_COMPILE_DECODER*/ + +#ifdef LODEPNG_COMPILE_ENCODER + +unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGCompressSettings* settings) +{ + /*initially, *out must be NULL and outsize 0, if you just give some random *out + that's pointing to a non allocated buffer, this'll crash*/ + ucvector outv; + size_t i; + unsigned error; + unsigned char* deflatedata = 0; + size_t deflatesize = 0; + + /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/ + unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/ + unsigned FLEVEL = 0; + unsigned FDICT = 0; + unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64; + unsigned FCHECK = 31 - CMFFLG % 31; + CMFFLG += FCHECK; + + /*ucvector-controlled version of the output buffer, for dynamic array*/ + ucvector_init_buffer(&outv, *out, *outsize); + + ucvector_push_back(&outv, (unsigned char)(CMFFLG >> 8)); + ucvector_push_back(&outv, (unsigned char)(CMFFLG & 255)); + + error = deflate(&deflatedata, &deflatesize, in, insize, settings); + + if (!error) + { + unsigned ADLER32 = adler32(in, (unsigned)insize); + for (i = 0; i != deflatesize; ++i) ucvector_push_back(&outv, deflatedata[i]); + lodepng_free(deflatedata); + lodepng_add32bitInt(&outv, ADLER32); + } + + *out = outv.data; + *outsize = outv.size; + + return error; +} + +/* compress using the default or custom zlib function */ +static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGCompressSettings* settings) +{ + if (settings->custom_zlib) + { + return settings->custom_zlib(out, outsize, in, insize, settings); + } + else + { + return lodepng_zlib_compress(out, outsize, in, insize, settings); + } +} + +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#else /*no LODEPNG_COMPILE_ZLIB*/ + +#ifdef LODEPNG_COMPILE_DECODER +static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGDecompressSettings* settings) +{ + if (!settings->custom_zlib) return 87; /*no custom zlib function provided */ + return settings->custom_zlib(out, outsize, in, insize, settings); +} +#endif /*LODEPNG_COMPILE_DECODER*/ +#ifdef LODEPNG_COMPILE_ENCODER +static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGCompressSettings* settings) +{ + if (!settings->custom_zlib) return 87; /*no custom zlib function provided */ + return settings->custom_zlib(out, outsize, in, insize, settings); +} +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#endif /*LODEPNG_COMPILE_ZLIB*/ + +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_ENCODER + +/*this is a good tradeoff between speed and compression ratio*/ +#define DEFAULT_WINDOWSIZE 2048 + +void lodepng_compress_settings_init(LodePNGCompressSettings* settings) +{ + /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/ + settings->btype = 2; + settings->use_lz77 = 1; + settings->windowsize = DEFAULT_WINDOWSIZE; + settings->minmatch = 3; + settings->nicematch = 128; + settings->lazymatching = 1; + + settings->custom_zlib = 0; + settings->custom_deflate = 0; + settings->custom_context = 0; +} + +const LodePNGCompressSettings lodepng_default_compress_settings = { 2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0 }; + + +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#ifdef LODEPNG_COMPILE_DECODER + +void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) +{ + settings->ignore_adler32 = 0; + + settings->custom_zlib = 0; + settings->custom_inflate = 0; + settings->custom_context = 0; +} + +const LodePNGDecompressSettings lodepng_default_decompress_settings = { 0, 0, 0, 0 }; + +#endif /*LODEPNG_COMPILE_DECODER*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // End of Zlib related code. Begin of PNG related code. // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_PNG + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / CRC32 / */ +/* ////////////////////////////////////////////////////////////////////////// */ + + +#ifndef LODEPNG_NO_COMPILE_CRC +/* CRC polynomial: 0xedb88320 */ +static unsigned lodepng_crc32_table[256] = { + 0u, 1996959894u, 3993919788u, 2567524794u, 124634137u, 1886057615u, 3915621685u, 2657392035u, + 249268274u, 2044508324u, 3772115230u, 2547177864u, 162941995u, 2125561021u, 3887607047u, 2428444049u, + 498536548u, 1789927666u, 4089016648u, 2227061214u, 450548861u, 1843258603u, 4107580753u, 2211677639u, + 325883990u, 1684777152u, 4251122042u, 2321926636u, 335633487u, 1661365465u, 4195302755u, 2366115317u, + 997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u, + 901097722u, 1119000684u, 3686517206u, 2898065728u, 853044451u, 1172266101u, 3705015759u, 2882616665u, + 651767980u, 1373503546u, 3369554304u, 3218104598u, 565507253u, 1454621731u, 3485111705u, 3099436303u, + 671266974u, 1594198024u, 3322730930u, 2970347812u, 795835527u, 1483230225u, 3244367275u, 3060149565u, + 1994146192u, 31158534u, 2563907772u, 4023717930u, 1907459465u, 112637215u, 2680153253u, 3904427059u, + 2013776290u, 251722036u, 2517215374u, 3775830040u, 2137656763u, 141376813u, 2439277719u, 3865271297u, + 1802195444u, 476864866u, 2238001368u, 4066508878u, 1812370925u, 453092731u, 2181625025u, 4111451223u, + 1706088902u, 314042704u, 2344532202u, 4240017532u, 1658658271u, 366619977u, 2362670323u, 4224994405u, + 1303535960u, 984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u, + 1131014506u, 879679996u, 2909243462u, 3663771856u, 1141124467u, 855842277u, 2852801631u, 3708648649u, + 1342533948u, 654459306u, 3188396048u, 3373015174u, 1466479909u, 544179635u, 3110523913u, 3462522015u, + 1591671054u, 702138776u, 2966460450u, 3352799412u, 1504918807u, 783551873u, 3082640443u, 3233442989u, + 3988292384u, 2596254646u, 62317068u, 1957810842u, 3939845945u, 2647816111u, 81470997u, 1943803523u, + 3814918930u, 2489596804u, 225274430u, 2053790376u, 3826175755u, 2466906013u, 167816743u, 2097651377u, + 4027552580u, 2265490386u, 503444072u, 1762050814u, 4150417245u, 2154129355u, 426522225u, 1852507879u, + 4275313526u, 2312317920u, 282753626u, 1742555852u, 4189708143u, 2394877945u, 397917763u, 1622183637u, + 3604390888u, 2714866558u, 953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u, + 3624741850u, 2936675148u, 906185462u, 1090812512u, 3747672003u, 2825379669u, 829329135u, 1181335161u, + 3412177804u, 3160834842u, 628085408u, 1382605366u, 3423369109u, 3138078467u, 570562233u, 1426400815u, + 3317316542u, 2998733608u, 733239954u, 1555261956u, 3268935591u, 3050360625u, 752459403u, 1541320221u, + 2607071920u, 3965973030u, 1969922972u, 40735498u, 2617837225u, 3943577151u, 1913087877u, 83908371u, + 2512341634u, 3803740692u, 2075208622u, 213261112u, 2463272603u, 3855990285u, 2094854071u, 198958881u, + 2262029012u, 4057260610u, 1759359992u, 534414190u, 2176718541u, 4139329115u, 1873836001u, 414664567u, + 2282248934u, 4279200368u, 1711684554u, 285281116u, 2405801727u, 4167216745u, 1634467795u, 376229701u, + 2685067896u, 3608007406u, 1308918612u, 956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u, + 2932959818u, 3654703836u, 1088359270u, 936918000u, 2847714899u, 3736837829u, 1202900863u, 817233897u, + 3183342108u, 3401237130u, 1404277552u, 615818150u, 3134207493u, 3453421203u, 1423857449u, 601450431u, + 3009837614u, 3294710456u, 1567103746u, 711928724u, 3020668471u, 3272380065u, 1510334235u, 755167117u +}; + +/*Return the CRC of the bytes buf[0..len-1].*/ +unsigned lodepng_crc32(const unsigned char* data, size_t length) +{ + unsigned r = 0xffffffffu; + size_t i; + for (i = 0; i < length; ++i) + { + r = lodepng_crc32_table[(r ^ data[i]) & 0xff] ^ (r >> 8); + } + return r ^ 0xffffffffu; +} +#else /* !LODEPNG_NO_COMPILE_CRC */ +unsigned lodepng_crc32(const unsigned char* data, size_t length); +#endif /* !LODEPNG_NO_COMPILE_CRC */ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Reading and writing single bits and bytes from/to stream for LodePNG / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream) +{ + unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1); + ++(*bitpointer); + return result; +} + +static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) +{ + unsigned result = 0; + size_t i; + for (i = 0; i < nbits; ++i) + { + result <<= 1; + result |= (unsigned)readBitFromReversedStream(bitpointer, bitstream); + } + return result; +} + +#ifdef LODEPNG_COMPILE_DECODER +static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) +{ + /*the current bit in bitstream must be 0 for this to work*/ + if (bit) + { + /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/ + bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7))); + } + ++(*bitpointer); +} +#endif /*LODEPNG_COMPILE_DECODER*/ + +static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) +{ + /*the current bit in bitstream may be 0 or 1 for this to work*/ + if (bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7)))); + else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7))); + ++(*bitpointer); +} + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / PNG chunks / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +unsigned lodepng_chunk_length(const unsigned char* chunk) +{ + return lodepng_read32bitInt(&chunk[0]); +} + +void lodepng_chunk_type(char type[5], const unsigned char* chunk) +{ + unsigned i; + for (i = 0; i != 4; ++i) type[i] = (char)chunk[4 + i]; + type[4] = 0; /*null termination char*/ +} + +unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type) +{ + if (strlen(type) != 4) return 0; + return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]); +} + +unsigned char lodepng_chunk_ancillary(const unsigned char* chunk) +{ + return((chunk[4] & 32) != 0); +} + +unsigned char lodepng_chunk_private(const unsigned char* chunk) +{ + return((chunk[6] & 32) != 0); +} + +unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) +{ + return((chunk[7] & 32) != 0); +} + +unsigned char* lodepng_chunk_data(unsigned char* chunk) +{ + return &chunk[8]; +} + +const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) +{ + return &chunk[8]; +} + +unsigned lodepng_chunk_check_crc(const unsigned char* chunk) +{ + unsigned length = lodepng_chunk_length(chunk); + unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]); + /*the CRC is taken of the data and the 4 chunk type letters, not the length*/ + unsigned checksum = lodepng_crc32(&chunk[4], length + 4); + if (CRC != checksum) return 1; + else return 0; +} + +void lodepng_chunk_generate_crc(unsigned char* chunk) +{ + unsigned length = lodepng_chunk_length(chunk); + unsigned CRC = lodepng_crc32(&chunk[4], length + 4); + lodepng_set32bitInt(chunk + 8 + length, CRC); +} + +unsigned char* lodepng_chunk_next(unsigned char* chunk) +{ + unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; + return &chunk[total_chunk_length]; +} + +const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk) +{ + unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; + return &chunk[total_chunk_length]; +} + +unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk) +{ + unsigned i; + unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; + unsigned char *chunk_start, *new_buffer; + size_t new_length = (*outlength) + total_chunk_length; + if (new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/ + + new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); + if (!new_buffer) return 83; /*alloc fail*/ + (*out) = new_buffer; + (*outlength) = new_length; + chunk_start = &(*out)[new_length - total_chunk_length]; + + for (i = 0; i != total_chunk_length; ++i) chunk_start[i] = chunk[i]; + + return 0; +} + +unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, + const char* type, const unsigned char* data) +{ + unsigned i; + unsigned char *chunk, *new_buffer; + size_t new_length = (*outlength) + length + 12; + if (new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/ + new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); + if (!new_buffer) return 83; /*alloc fail*/ + (*out) = new_buffer; + (*outlength) = new_length; + chunk = &(*out)[(*outlength) - length - 12]; + + /*1: length*/ + lodepng_set32bitInt(chunk, (unsigned)length); + + /*2: chunk name (4 letters)*/ + chunk[4] = (unsigned char)type[0]; + chunk[5] = (unsigned char)type[1]; + chunk[6] = (unsigned char)type[2]; + chunk[7] = (unsigned char)type[3]; + + /*3: the data*/ + for (i = 0; i != length; ++i) chunk[8 + i] = data[i]; + + /*4: CRC (of the chunkname characters and the data)*/ + lodepng_chunk_generate_crc(chunk); + + return 0; +} + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Color types and such / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +/*return type is a LodePNG error code*/ +static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/ +{ + switch (colortype) + { + case 0: if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/ + case 2: if (!(bd == 8 || bd == 16)) return 37; break; /*RGB*/ + case 3: if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8)) return 37; break; /*palette*/ + case 4: if (!(bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/ + case 6: if (!(bd == 8 || bd == 16)) return 37; break; /*RGBA*/ + default: return 31; + } + return 0; /*allowed color type / bits combination*/ +} + +static unsigned getNumColorChannels(LodePNGColorType colortype) +{ + switch (colortype) + { + case 0: return 1; /*grey*/ + case 2: return 3; /*RGB*/ + case 3: return 1; /*palette*/ + case 4: return 2; /*grey + alpha*/ + case 6: return 4; /*RGBA*/ + } + return 0; /*unexisting color type*/ +} + +static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) +{ + /*bits per pixel is amount of channels * bits per channel*/ + return getNumColorChannels(colortype) * bitdepth; +} + +/* ////////////////////////////////////////////////////////////////////////// */ + +void lodepng_color_mode_init(LodePNGColorMode* info) +{ + info->key_defined = 0; + info->key_r = info->key_g = info->key_b = 0; + info->colortype = LCT_RGBA; + info->bitdepth = 8; + info->palette = 0; + info->palettesize = 0; +} + +void lodepng_color_mode_cleanup(LodePNGColorMode* info) +{ + lodepng_palette_clear(info); +} + +unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) +{ + size_t i; + lodepng_color_mode_cleanup(dest); + *dest = *source; + if (source->palette) + { + dest->palette = (unsigned char*)lodepng_malloc(1024); + if (!dest->palette && source->palettesize) return 83; /*alloc fail*/ + for (i = 0; i != source->palettesize * 4; ++i) dest->palette[i] = source->palette[i]; + } + return 0; +} + +static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) +{ + size_t i; + if (a->colortype != b->colortype) return 0; + if (a->bitdepth != b->bitdepth) return 0; + if (a->key_defined != b->key_defined) return 0; + if (a->key_defined) + { + if (a->key_r != b->key_r) return 0; + if (a->key_g != b->key_g) return 0; + if (a->key_b != b->key_b) return 0; + } + /*if one of the palette sizes is 0, then we consider it to be the same as the + other: it means that e.g. the palette was not given by the user and should be + considered the same as the palette inside the PNG.*/ + if (1/*a->palettesize != 0 && b->palettesize != 0*/) { + if (a->palettesize != b->palettesize) return 0; + for (i = 0; i != a->palettesize * 4; ++i) + { + if (a->palette[i] != b->palette[i]) return 0; + } + } + return 1; +} + +void lodepng_palette_clear(LodePNGColorMode* info) +{ + if (info->palette) lodepng_free(info->palette); + info->palette = 0; + info->palettesize = 0; +} + +unsigned lodepng_palette_add(LodePNGColorMode* info, + unsigned char r, unsigned char g, unsigned char b, unsigned char a) +{ + unsigned char* data; + /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with + the max of 256 colors, it'll have the exact alloc size*/ + if (!info->palette) /*allocate palette if empty*/ + { + /*room for 256 colors with 4 bytes each*/ + data = (unsigned char*)lodepng_realloc(info->palette, 1024); + if (!data) return 83; /*alloc fail*/ + else info->palette = data; + } + info->palette[4 * info->palettesize + 0] = r; + info->palette[4 * info->palettesize + 1] = g; + info->palette[4 * info->palettesize + 2] = b; + info->palette[4 * info->palettesize + 3] = a; + ++info->palettesize; + return 0; +} + +unsigned lodepng_get_bpp(const LodePNGColorMode* info) +{ + /*calculate bits per pixel out of colortype and bitdepth*/ + return lodepng_get_bpp_lct(info->colortype, info->bitdepth); +} + +unsigned lodepng_get_channels(const LodePNGColorMode* info) +{ + return getNumColorChannels(info->colortype); +} + +unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) +{ + return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA; +} + +unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) +{ + return (info->colortype & 4) != 0; /*4 or 6*/ +} + +unsigned lodepng_is_palette_type(const LodePNGColorMode* info) +{ + return info->colortype == LCT_PALETTE; +} + +unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) +{ + size_t i; + for (i = 0; i != info->palettesize; ++i) + { + if (info->palette[i * 4 + 3] < 255) return 1; + } + return 0; +} + +unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) +{ + return info->key_defined + || lodepng_is_alpha_type(info) + || lodepng_has_palette_alpha(info); +} + +size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) +{ + /*will not overflow for any color type if roughly w * h < 268435455*/ + size_t bpp = lodepng_get_bpp(color); + size_t n = w * h; + return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8; +} + +size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) +{ + /*will not overflow for any color type if roughly w * h < 268435455*/ + size_t bpp = lodepng_get_bpp_lct(colortype, bitdepth); + size_t n = w * h; + return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8; +} + + +#ifdef LODEPNG_COMPILE_PNG +#ifdef LODEPNG_COMPILE_DECODER +/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer*/ +static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, const LodePNGColorMode* color) +{ + /*will not overflow for any color type if roughly w * h < 268435455*/ + size_t bpp = lodepng_get_bpp(color); + size_t line = ((w / 8) * bpp) + ((w & 7) * bpp + 7) / 8; + return h * line; +} +#endif /*LODEPNG_COMPILE_DECODER*/ +#endif /*LODEPNG_COMPILE_PNG*/ + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + +static void LodePNGUnknownChunks_init(LodePNGInfo* info) +{ + unsigned i; + for (i = 0; i != 3; ++i) info->unknown_chunks_data[i] = 0; + for (i = 0; i != 3; ++i) info->unknown_chunks_size[i] = 0; +} + +static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info) +{ + unsigned i; + for (i = 0; i != 3; ++i) lodepng_free(info->unknown_chunks_data[i]); +} + +static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) +{ + unsigned i; + + LodePNGUnknownChunks_cleanup(dest); + + for (i = 0; i != 3; ++i) + { + size_t j; + dest->unknown_chunks_size[i] = src->unknown_chunks_size[i]; + dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]); + if (!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/ + for (j = 0; j < src->unknown_chunks_size[i]; ++j) + { + dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j]; + } + } + + return 0; +} + +/******************************************************************************/ + +static void LodePNGText_init(LodePNGInfo* info) +{ + info->text_num = 0; + info->text_keys = NULL; + info->text_strings = NULL; +} + +static void LodePNGText_cleanup(LodePNGInfo* info) +{ + size_t i; + for (i = 0; i != info->text_num; ++i) + { + string_cleanup(&info->text_keys[i]); + string_cleanup(&info->text_strings[i]); + } + lodepng_free(info->text_keys); + lodepng_free(info->text_strings); +} + +static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source) +{ + size_t i = 0; + dest->text_keys = 0; + dest->text_strings = 0; + dest->text_num = 0; + for (i = 0; i != source->text_num; ++i) + { + CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i])); + } + return 0; +} + +void lodepng_clear_text(LodePNGInfo* info) +{ + LodePNGText_cleanup(info); +} + +unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str) +{ + char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1))); + char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1))); + if (!new_keys || !new_strings) + { + lodepng_free(new_keys); + lodepng_free(new_strings); + return 83; /*alloc fail*/ + } + + ++info->text_num; + info->text_keys = new_keys; + info->text_strings = new_strings; + + string_init(&info->text_keys[info->text_num - 1]); + string_set(&info->text_keys[info->text_num - 1], key); + + string_init(&info->text_strings[info->text_num - 1]); + string_set(&info->text_strings[info->text_num - 1], str); + + return 0; +} + +/******************************************************************************/ + +static void LodePNGIText_init(LodePNGInfo* info) +{ + info->itext_num = 0; + info->itext_keys = NULL; + info->itext_langtags = NULL; + info->itext_transkeys = NULL; + info->itext_strings = NULL; +} + +static void LodePNGIText_cleanup(LodePNGInfo* info) +{ + size_t i; + for (i = 0; i != info->itext_num; ++i) + { + string_cleanup(&info->itext_keys[i]); + string_cleanup(&info->itext_langtags[i]); + string_cleanup(&info->itext_transkeys[i]); + string_cleanup(&info->itext_strings[i]); + } + lodepng_free(info->itext_keys); + lodepng_free(info->itext_langtags); + lodepng_free(info->itext_transkeys); + lodepng_free(info->itext_strings); +} + +static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source) +{ + size_t i = 0; + dest->itext_keys = 0; + dest->itext_langtags = 0; + dest->itext_transkeys = 0; + dest->itext_strings = 0; + dest->itext_num = 0; + for (i = 0; i != source->itext_num; ++i) + { + CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i], + source->itext_transkeys[i], source->itext_strings[i])); + } + return 0; +} + +void lodepng_clear_itext(LodePNGInfo* info) +{ + LodePNGIText_cleanup(info); +} + +unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, + const char* transkey, const char* str) +{ + char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1))); + char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1))); + char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1))); + char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1))); + if (!new_keys || !new_langtags || !new_transkeys || !new_strings) + { + lodepng_free(new_keys); + lodepng_free(new_langtags); + lodepng_free(new_transkeys); + lodepng_free(new_strings); + return 83; /*alloc fail*/ + } + + ++info->itext_num; + info->itext_keys = new_keys; + info->itext_langtags = new_langtags; + info->itext_transkeys = new_transkeys; + info->itext_strings = new_strings; + + string_init(&info->itext_keys[info->itext_num - 1]); + string_set(&info->itext_keys[info->itext_num - 1], key); + + string_init(&info->itext_langtags[info->itext_num - 1]); + string_set(&info->itext_langtags[info->itext_num - 1], langtag); + + string_init(&info->itext_transkeys[info->itext_num - 1]); + string_set(&info->itext_transkeys[info->itext_num - 1], transkey); + + string_init(&info->itext_strings[info->itext_num - 1]); + string_set(&info->itext_strings[info->itext_num - 1], str); + + return 0; +} +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +void lodepng_info_init(LodePNGInfo* info) +{ + lodepng_color_mode_init(&info->color); + info->interlace_method = 0; + info->compression_method = 0; + info->filter_method = 0; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + info->background_defined = 0; + info->background_r = info->background_g = info->background_b = 0; + + LodePNGText_init(info); + LodePNGIText_init(info); + + info->time_defined = 0; + info->phys_defined = 0; + + LodePNGUnknownChunks_init(info); +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +} + +void lodepng_info_cleanup(LodePNGInfo* info) +{ + lodepng_color_mode_cleanup(&info->color); +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + LodePNGText_cleanup(info); + LodePNGIText_cleanup(info); + + LodePNGUnknownChunks_cleanup(info); +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +} + +unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) +{ + lodepng_info_cleanup(dest); + *dest = *source; + lodepng_color_mode_init(&dest->color); + CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color)); + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + CERROR_TRY_RETURN(LodePNGText_copy(dest, source)); + CERROR_TRY_RETURN(LodePNGIText_copy(dest, source)); + + LodePNGUnknownChunks_init(dest); + CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source)); +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + return 0; +} + +void lodepng_info_swap(LodePNGInfo* a, LodePNGInfo* b) +{ + LodePNGInfo temp = *a; + *a = *b; + *b = temp; +} + +/* ////////////////////////////////////////////////////////////////////////// */ + +/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/ +static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) +{ + unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/ + /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/ + unsigned p = index & m; + in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/ + in = in << (bits * (m - p)); + if (p == 0) out[index * bits / 8] = in; + else out[index * bits / 8] |= in; +} + +typedef struct ColorTree ColorTree; + +/* +One node of a color tree +This is the data structure used to count the number of unique colors and to get a palette +index for a color. It's like an octree, but because the alpha channel is used too, each +node has 16 instead of 8 children. +*/ +struct ColorTree +{ + ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/ + int index; /*the payload. Only has a meaningful value if this is in the last level*/ +}; + +static void color_tree_init(ColorTree* tree) +{ + int i; + for (i = 0; i != 16; ++i) tree->children[i] = 0; + tree->index = -1; +} + +static void color_tree_cleanup(ColorTree* tree) +{ + int i; + for (i = 0; i != 16; ++i) + { + if (tree->children[i]) + { + color_tree_cleanup(tree->children[i]); + lodepng_free(tree->children[i]); + } + } +} + +/*returns -1 if color not present, its index otherwise*/ +static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) +{ + int bit = 0; + for (bit = 0; bit < 8; ++bit) + { + int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); + if (!tree->children[i]) return -1; + else tree = tree->children[i]; + } + return tree ? tree->index : -1; +} + +#ifdef LODEPNG_COMPILE_ENCODER +static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) +{ + return color_tree_get(tree, r, g, b, a) >= 0; +} +#endif /*LODEPNG_COMPILE_ENCODER*/ + +/*color is not allowed to already exist. +Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/ +static void color_tree_add(ColorTree* tree, + unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index) +{ + int bit; + for (bit = 0; bit < 8; ++bit) + { + int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); + if (!tree->children[i]) + { + tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree)); + color_tree_init(tree->children[i]); + } + tree = tree->children[i]; + } + tree->index = (int)index; +} + +/*put a pixel, given its RGBA color, into image of any color type*/ +static unsigned rgba8ToPixel(unsigned char* out, size_t i, + const LodePNGColorMode* mode, ColorTree* tree /*for palette*/, + unsigned char r, unsigned char g, unsigned char b, unsigned char a) +{ + if (mode->colortype == LCT_GREY) + { + unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/; + if (mode->bitdepth == 8) out[i] = grey; + else if (mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey; + else + { + /*take the most significant bits of grey*/ + grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1); + addColorBits(out, i, mode->bitdepth, grey); + } + } + else if (mode->colortype == LCT_RGB) + { + if (mode->bitdepth == 8) + { + out[i * 3 + 0] = r; + out[i * 3 + 1] = g; + out[i * 3 + 2] = b; + } + else + { + out[i * 6 + 0] = out[i * 6 + 1] = r; + out[i * 6 + 2] = out[i * 6 + 3] = g; + out[i * 6 + 4] = out[i * 6 + 5] = b; + } + } + else if (mode->colortype == LCT_PALETTE) + { + int index = color_tree_get(tree, r, g, b, a); + if (index < 0) return 82; /*color not in palette*/ + if (mode->bitdepth == 8) out[i] = index; + else addColorBits(out, i, mode->bitdepth, (unsigned)index); + } + else if (mode->colortype == LCT_GREY_ALPHA) + { + unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/; + if (mode->bitdepth == 8) + { + out[i * 2 + 0] = grey; + out[i * 2 + 1] = a; + } + else if (mode->bitdepth == 16) + { + out[i * 4 + 0] = out[i * 4 + 1] = grey; + out[i * 4 + 2] = out[i * 4 + 3] = a; + } + } + else if (mode->colortype == LCT_RGBA) + { + if (mode->bitdepth == 8) + { + out[i * 4 + 0] = r; + out[i * 4 + 1] = g; + out[i * 4 + 2] = b; + out[i * 4 + 3] = a; + } + else + { + out[i * 8 + 0] = out[i * 8 + 1] = r; + out[i * 8 + 2] = out[i * 8 + 3] = g; + out[i * 8 + 4] = out[i * 8 + 5] = b; + out[i * 8 + 6] = out[i * 8 + 7] = a; + } + } + + return 0; /*no error*/ +} + +/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/ +static void rgba16ToPixel(unsigned char* out, size_t i, + const LodePNGColorMode* mode, + unsigned short r, unsigned short g, unsigned short b, unsigned short a) +{ + if (mode->colortype == LCT_GREY) + { + unsigned short grey = r; /*((unsigned)r + g + b) / 3*/; + out[i * 2 + 0] = (grey >> 8) & 255; + out[i * 2 + 1] = grey & 255; + } + else if (mode->colortype == LCT_RGB) + { + out[i * 6 + 0] = (r >> 8) & 255; + out[i * 6 + 1] = r & 255; + out[i * 6 + 2] = (g >> 8) & 255; + out[i * 6 + 3] = g & 255; + out[i * 6 + 4] = (b >> 8) & 255; + out[i * 6 + 5] = b & 255; + } + else if (mode->colortype == LCT_GREY_ALPHA) + { + unsigned short grey = r; /*((unsigned)r + g + b) / 3*/; + out[i * 4 + 0] = (grey >> 8) & 255; + out[i * 4 + 1] = grey & 255; + out[i * 4 + 2] = (a >> 8) & 255; + out[i * 4 + 3] = a & 255; + } + else if (mode->colortype == LCT_RGBA) + { + out[i * 8 + 0] = (r >> 8) & 255; + out[i * 8 + 1] = r & 255; + out[i * 8 + 2] = (g >> 8) & 255; + out[i * 8 + 3] = g & 255; + out[i * 8 + 4] = (b >> 8) & 255; + out[i * 8 + 5] = b & 255; + out[i * 8 + 6] = (a >> 8) & 255; + out[i * 8 + 7] = a & 255; + } +} + +/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/ +static void getPixelColorRGBA8(unsigned char* r, unsigned char* g, + unsigned char* b, unsigned char* a, + const unsigned char* in, size_t i, + const LodePNGColorMode* mode) +{ + if (mode->colortype == LCT_GREY) + { + if (mode->bitdepth == 8) + { + *r = *g = *b = in[i]; + if (mode->key_defined && *r == mode->key_r) *a = 0; + else *a = 255; + } + else if (mode->bitdepth == 16) + { + *r = *g = *b = in[i * 2 + 0]; + if (mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; + else *a = 255; + } + else + { + unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ + size_t j = i * mode->bitdepth; + unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); + *r = *g = *b = (value * 255) / highest; + if (mode->key_defined && value == mode->key_r) *a = 0; + else *a = 255; + } + } + else if (mode->colortype == LCT_RGB) + { + if (mode->bitdepth == 8) + { + *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2]; + if (mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0; + else *a = 255; + } + else + { + *r = in[i * 6 + 0]; + *g = in[i * 6 + 2]; + *b = in[i * 6 + 4]; + if (mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r + && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g + && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; + else *a = 255; + } + } + else if (mode->colortype == LCT_PALETTE) + { + unsigned index; + if (mode->bitdepth == 8) index = in[i]; + else + { + size_t j = i * mode->bitdepth; + index = readBitsFromReversedStream(&j, in, mode->bitdepth); + } + + if (index >= mode->palettesize) + { + /*This is an error according to the PNG spec, but common PNG decoders make it black instead. + Done here too, slightly faster due to no error handling needed.*/ + *r = *g = *b = 0; + *a = 255; + } + else + { + *r = mode->palette[index * 4 + 0]; + *g = mode->palette[index * 4 + 1]; + *b = mode->palette[index * 4 + 2]; + *a = mode->palette[index * 4 + 3]; + } + } + else if (mode->colortype == LCT_GREY_ALPHA) + { + if (mode->bitdepth == 8) + { + *r = *g = *b = in[i * 2 + 0]; + *a = in[i * 2 + 1]; + } + else + { + *r = *g = *b = in[i * 4 + 0]; + *a = in[i * 4 + 2]; + } + } + else if (mode->colortype == LCT_RGBA) + { + if (mode->bitdepth == 8) + { + *r = in[i * 4 + 0]; + *g = in[i * 4 + 1]; + *b = in[i * 4 + 2]; + *a = in[i * 4 + 3]; + } + else + { + *r = in[i * 8 + 0]; + *g = in[i * 8 + 2]; + *b = in[i * 8 + 4]; + *a = in[i * 8 + 6]; + } + } +} + +/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color +mode test cases, optimized to convert the colors much faster, when converting +to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with +enough memory, if has_alpha is true the output is RGBA. mode has the color mode +of the input buffer.*/ +static void getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels, + unsigned has_alpha, const unsigned char* in, + const LodePNGColorMode* mode) +{ + unsigned num_channels = has_alpha ? 4 : 3; + size_t i; + if (mode->colortype == LCT_GREY) + { + if (mode->bitdepth == 8) + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = buffer[1] = buffer[2] = in[i]; + if (has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255; + } + } + else if (mode->bitdepth == 16) + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = buffer[1] = buffer[2] = in[i * 2]; + if (has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255; + } + } + else + { + unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ + size_t j = 0; + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); + buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest; + if (has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255; + } + } + } + else if (mode->colortype == LCT_RGB) + { + if (mode->bitdepth == 8) + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = in[i * 3 + 0]; + buffer[1] = in[i * 3 + 1]; + buffer[2] = in[i * 3 + 2]; + if (has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r + && buffer[1] == mode->key_g && buffer[2] == mode->key_b ? 0 : 255; + } + } + else + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = in[i * 6 + 0]; + buffer[1] = in[i * 6 + 2]; + buffer[2] = in[i * 6 + 4]; + if (has_alpha) buffer[3] = mode->key_defined + && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r + && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g + && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255; + } + } + } + else if (mode->colortype == LCT_PALETTE) + { + unsigned index; + size_t j = 0; + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + if (mode->bitdepth == 8) index = in[i]; + else index = readBitsFromReversedStream(&j, in, mode->bitdepth); + + if (index >= mode->palettesize) + { + /*This is an error according to the PNG spec, but most PNG decoders make it black instead. + Done here too, slightly faster due to no error handling needed.*/ + buffer[0] = buffer[1] = buffer[2] = 0; + if (has_alpha) buffer[3] = 255; + } + else + { + buffer[0] = mode->palette[index * 4 + 0]; + buffer[1] = mode->palette[index * 4 + 1]; + buffer[2] = mode->palette[index * 4 + 2]; + if (has_alpha) buffer[3] = mode->palette[index * 4 + 3]; + } + } + } + else if (mode->colortype == LCT_GREY_ALPHA) + { + if (mode->bitdepth == 8) + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0]; + if (has_alpha) buffer[3] = in[i * 2 + 1]; + } + } + else + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0]; + if (has_alpha) buffer[3] = in[i * 4 + 2]; + } + } + } + else if (mode->colortype == LCT_RGBA) + { + if (mode->bitdepth == 8) + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = in[i * 4 + 0]; + buffer[1] = in[i * 4 + 1]; + buffer[2] = in[i * 4 + 2]; + if (has_alpha) buffer[3] = in[i * 4 + 3]; + } + } + else + { + for (i = 0; i != numpixels; ++i, buffer += num_channels) + { + buffer[0] = in[i * 8 + 0]; + buffer[1] = in[i * 8 + 2]; + buffer[2] = in[i * 8 + 4]; + if (has_alpha) buffer[3] = in[i * 8 + 6]; + } + } + } +} + +/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with +given color type, but the given color type must be 16-bit itself.*/ +static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a, + const unsigned char* in, size_t i, const LodePNGColorMode* mode) +{ + if (mode->colortype == LCT_GREY) + { + *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1]; + if (mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; + else *a = 65535; + } + else if (mode->colortype == LCT_RGB) + { + *r = 256u * in[i * 6 + 0] + in[i * 6 + 1]; + *g = 256u * in[i * 6 + 2] + in[i * 6 + 3]; + *b = 256u * in[i * 6 + 4] + in[i * 6 + 5]; + if (mode->key_defined + && 256u * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r + && 256u * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g + && 256u * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; + else *a = 65535; + } + else if (mode->colortype == LCT_GREY_ALPHA) + { + *r = *g = *b = 256u * in[i * 4 + 0] + in[i * 4 + 1]; + *a = 256u * in[i * 4 + 2] + in[i * 4 + 3]; + } + else if (mode->colortype == LCT_RGBA) + { + *r = 256u * in[i * 8 + 0] + in[i * 8 + 1]; + *g = 256u * in[i * 8 + 2] + in[i * 8 + 3]; + *b = 256u * in[i * 8 + 4] + in[i * 8 + 5]; + *a = 256u * in[i * 8 + 6] + in[i * 8 + 7]; + } +} + +unsigned lodepng_convert(unsigned char* out, const unsigned char* in, + const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, + unsigned w, unsigned h) +{ + size_t i; + ColorTree tree; + size_t numpixels = w * h; + + if (lodepng_color_mode_equal(mode_out, mode_in)) + { + size_t numbytes = lodepng_get_raw_size(w, h, mode_in); + for (i = 0; i != numbytes; ++i) out[i] = in[i]; + return 0; + } + + if (mode_out->colortype == LCT_PALETTE) + { + size_t palettesize = mode_out->palettesize; + const unsigned char* palette = mode_out->palette; + size_t palsize = 1u << mode_out->bitdepth; + /*if the user specified output palette but did not give the values, assume + they want the values of the input color type (assuming that one is palette). + Note that we never create a new palette ourselves.*/ + if (palettesize == 0) + { + palettesize = mode_in->palettesize; + palette = mode_in->palette; + } + if (palettesize < palsize) palsize = palettesize; + color_tree_init(&tree); + for (i = 0; i != palsize; ++i) + { + const unsigned char* p = &palette[i * 4]; + color_tree_add(&tree, p[0], p[1], p[2], p[3], i); + } + } + + if (mode_in->bitdepth == 16 && mode_out->bitdepth == 16) + { + for (i = 0; i != numpixels; ++i) + { + unsigned short r = 0, g = 0, b = 0, a = 0; + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); + rgba16ToPixel(out, i, mode_out, r, g, b, a); + } + } + else if (mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) + { + getPixelColorsRGBA8(out, numpixels, 1, in, mode_in); + } + else if (mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) + { + getPixelColorsRGBA8(out, numpixels, 0, in, mode_in); + } + else + { + unsigned char r = 0, g = 0, b = 0, a = 0; + for (i = 0; i != numpixels; ++i) + { + getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); + CERROR_TRY_RETURN(rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a)); + } + } + + if (mode_out->colortype == LCT_PALETTE) + { + color_tree_cleanup(&tree); + } + + return 0; /*no error*/ +} + +#ifdef LODEPNG_COMPILE_ENCODER + +void lodepng_color_profile_init(LodePNGColorProfile* profile) +{ + profile->colored = 0; + profile->key = 0; + profile->key_r = profile->key_g = profile->key_b = 0; + profile->alpha = 0; + profile->numcolors = 0; + profile->bits = 1; +} + +/*function used for debug purposes with C++*/ +/*void printColorProfile(LodePNGColorProfile* p) +{ + std::cout << "colored: " << (int)p->colored << ", "; + std::cout << "key: " << (int)p->key << ", "; + std::cout << "key_r: " << (int)p->key_r << ", "; + std::cout << "key_g: " << (int)p->key_g << ", "; + std::cout << "key_b: " << (int)p->key_b << ", "; + std::cout << "alpha: " << (int)p->alpha << ", "; + std::cout << "numcolors: " << (int)p->numcolors << ", "; + std::cout << "bits: " << (int)p->bits << std::endl; +}*/ + +/*Returns how many bits needed to represent given value (max 8 bit)*/ +static unsigned getValueRequiredBits(unsigned char value) +{ + if (value == 0 || value == 255) return 1; + /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/ + if (value % 17 == 0) return value % 85 == 0 ? 2 : 4; + return 8; +} + +/*profile must already have been inited with mode. +It's ok to set some parameters of profile to done already.*/ +unsigned lodepng_get_color_profile(LodePNGColorProfile* profile, + const unsigned char* in, unsigned w, unsigned h, + const LodePNGColorMode* mode) +{ + unsigned error = 0; + size_t i; + ColorTree tree; + size_t numpixels = w * h; + + unsigned colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0; + unsigned alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1; + unsigned numcolors_done = 0; + unsigned bpp = lodepng_get_bpp(mode); + unsigned bits_done = bpp == 1 ? 1 : 0; + unsigned maxnumcolors = 257; + unsigned sixteen = 0; + if (bpp <= 8) maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256)); + + color_tree_init(&tree); + + /*Check if the 16-bit input is truly 16-bit*/ + if (mode->bitdepth == 16) + { + unsigned short r, g, b, a; + for (i = 0; i != numpixels; ++i) + { + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); + if ((r & 255) != ((r >> 8) & 255) || (g & 255) != ((g >> 8) & 255) || + (b & 255) != ((b >> 8) & 255) || (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/ + { + sixteen = 1; + break; + } + } + } + + if (sixteen) + { + unsigned short r = 0, g = 0, b = 0, a = 0; + profile->bits = 16; + bits_done = numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/ + + for (i = 0; i != numpixels; ++i) + { + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); + + if (!colored_done && (r != g || r != b)) + { + profile->colored = 1; + colored_done = 1; + } + + if (!alpha_done) + { + unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b); + if (a != 65535 && (a != 0 || (profile->key && !matchkey))) + { + profile->alpha = 1; + profile->key = 0; + alpha_done = 1; + } + else if (a == 0 && !profile->alpha && !profile->key) + { + profile->key = 1; + profile->key_r = r; + profile->key_g = g; + profile->key_b = b; + } + else if (a == 65535 && profile->key && matchkey) + { + /* Color key cannot be used if an opaque pixel also has that RGB color. */ + profile->alpha = 1; + profile->key = 0; + alpha_done = 1; + } + } + if (alpha_done && numcolors_done && colored_done && bits_done) break; + } + + if (profile->key && !profile->alpha) + { + for (i = 0; i != numpixels; ++i) + { + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); + if (a != 0 && r == profile->key_r && g == profile->key_g && b == profile->key_b) + { + /* Color key cannot be used if an opaque pixel also has that RGB color. */ + profile->alpha = 1; + profile->key = 0; + alpha_done = 1; + } + } + } + } + else /* < 16-bit */ + { + unsigned char r = 0, g = 0, b = 0, a = 0; + for (i = 0; i != numpixels; ++i) + { + getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode); + + if (!bits_done && profile->bits < 8) + { + /*only r is checked, < 8 bits is only relevant for greyscale*/ + unsigned bits = getValueRequiredBits(r); + if (bits > profile->bits) profile->bits = bits; + } + bits_done = (profile->bits >= bpp); + + if (!colored_done && (r != g || r != b)) + { + profile->colored = 1; + colored_done = 1; + if (profile->bits < 8) profile->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/ + } + + if (!alpha_done) + { + unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b); + if (a != 255 && (a != 0 || (profile->key && !matchkey))) + { + profile->alpha = 1; + profile->key = 0; + alpha_done = 1; + if (profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + } + else if (a == 0 && !profile->alpha && !profile->key) + { + profile->key = 1; + profile->key_r = r; + profile->key_g = g; + profile->key_b = b; + } + else if (a == 255 && profile->key && matchkey) + { + /* Color key cannot be used if an opaque pixel also has that RGB color. */ + profile->alpha = 1; + profile->key = 0; + alpha_done = 1; + if (profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + } + } + + if (!numcolors_done) + { + if (!color_tree_has(&tree, r, g, b, a)) + { + color_tree_add(&tree, r, g, b, a, profile->numcolors); + if (profile->numcolors < 256) + { + unsigned char* p = profile->palette; + unsigned n = profile->numcolors; + p[n * 4 + 0] = r; + p[n * 4 + 1] = g; + p[n * 4 + 2] = b; + p[n * 4 + 3] = a; + } + ++profile->numcolors; + numcolors_done = profile->numcolors >= maxnumcolors; + } + } + + if (alpha_done && numcolors_done && colored_done && bits_done) break; + } + + if (profile->key && !profile->alpha) + { + for (i = 0; i != numpixels; ++i) + { + getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode); + if (a != 0 && r == profile->key_r && g == profile->key_g && b == profile->key_b) + { + /* Color key cannot be used if an opaque pixel also has that RGB color. */ + profile->alpha = 1; + profile->key = 0; + alpha_done = 1; + if (profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + } + } + } + + /*make the profile's key always 16-bit for consistency - repeat each byte twice*/ + profile->key_r += (profile->key_r << 8); + profile->key_g += (profile->key_g << 8); + profile->key_b += (profile->key_b << 8); + } + + color_tree_cleanup(&tree); + return error; +} + +/*Automatically chooses color type that gives smallest amount of bits in the +output image, e.g. grey if there are only greyscale pixels, palette if there +are less than 256 colors, ... +Updates values of mode with a potentially smaller color model. mode_out should +contain the user chosen color model, but will be overwritten with the new chosen one.*/ +unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, + const unsigned char* image, unsigned w, unsigned h, + const LodePNGColorMode* mode_in) +{ + LodePNGColorProfile prof; + unsigned error = 0; + unsigned i, n, palettebits, palette_ok; + + lodepng_color_profile_init(&prof); + error = lodepng_get_color_profile(&prof, image, w, h, mode_in); + if (error) return error; + mode_out->key_defined = 0; + + if (prof.key && w * h <= 16) + { + prof.alpha = 1; /*too few pixels to justify tRNS chunk overhead*/ + prof.key = 0; + if (prof.bits < 8) prof.bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + } + n = prof.numcolors; + palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8)); + palette_ok = n <= 256 && prof.bits <= 8; + if (w * h < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/ + if (!prof.colored && prof.bits <= palettebits) palette_ok = 0; /*grey is less overhead*/ + + if (palette_ok) + { + unsigned char* p = prof.palette; + lodepng_palette_clear(mode_out); /*remove potential earlier palette*/ + for (i = 0; i != prof.numcolors; ++i) + { + error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]); + if (error) break; + } + + mode_out->colortype = LCT_PALETTE; + mode_out->bitdepth = palettebits; + + if (mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize + && mode_in->bitdepth == mode_out->bitdepth) + { + /*If input should have same palette colors, keep original to preserve its order and prevent conversion*/ + lodepng_color_mode_cleanup(mode_out); + lodepng_color_mode_copy(mode_out, mode_in); + } + } + else /*8-bit or 16-bit per channel*/ + { + mode_out->bitdepth = prof.bits; + mode_out->colortype = prof.alpha ? (prof.colored ? LCT_RGBA : LCT_GREY_ALPHA) + : (prof.colored ? LCT_RGB : LCT_GREY); + + if (prof.key) + { + unsigned mask = (1u << mode_out->bitdepth) - 1u; /*profile always uses 16-bit, mask converts it*/ + mode_out->key_r = prof.key_r & mask; + mode_out->key_g = prof.key_g & mask; + mode_out->key_b = prof.key_b & mask; + mode_out->key_defined = 1; + } + } + + return error; +} + +#endif /* #ifdef LODEPNG_COMPILE_ENCODER */ + +/* +Paeth predicter, used by PNG filter type 4 +The parameters are of type short, but should come from unsigned chars, the shorts +are only needed to make the paeth calculation correct. +*/ +static unsigned char paethPredictor(short a, short b, short c) +{ + short pa = abs(b - c); + short pb = abs(a - c); + short pc = abs(a + b - c - c); + + if (pc < pa && pc < pb) return (unsigned char)c; + else if (pb < pa) return (unsigned char)b; + else return (unsigned char)a; +} + +/*shared values used by multiple Adam7 related functions*/ + +static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/ +static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/ +static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/ +static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/ + +/* +Outputs various dimensions and positions in the image related to the Adam7 reduced images. +passw: output containing the width of the 7 passes +passh: output containing the height of the 7 passes +filter_passstart: output containing the index of the start and end of each + reduced image with filter bytes +padded_passstart output containing the index of the start and end of each + reduced image when without filter bytes but with padded scanlines +passstart: output containing the index of the start and end of each reduced + image without padding between scanlines, but still padding between the images +w, h: width and height of non-interlaced image +bpp: bits per pixel +"padded" is only relevant if bpp is less than 8 and a scanline or image does not + end at a full byte +*/ +static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8], + size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) +{ + /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/ + unsigned i; + + /*calculate width and height in pixels of each pass*/ + for (i = 0; i != 7; ++i) + { + passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i]; + passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i]; + if (passw[i] == 0) passh[i] = 0; + if (passh[i] == 0) passw[i] = 0; + } + + filter_passstart[0] = padded_passstart[0] = passstart[0] = 0; + for (i = 0; i != 7; ++i) + { + /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/ + filter_passstart[i + 1] = filter_passstart[i] + + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0); + /*bits padded if needed to fill full byte at end of each scanline*/ + padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8); + /*only padded at end of reduced image*/ + passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8; + } +} + +#ifdef LODEPNG_COMPILE_DECODER + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / PNG Decoder / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +/*read the information from the header and store it in the LodePNGInfo. return value is error*/ +unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state, + const unsigned char* in, size_t insize) +{ + LodePNGInfo* info = &state->info_png; + if (insize == 0 || in == 0) + { + CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/ + } + if (insize < 33) + { + CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/ + } + + /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/ + lodepng_info_cleanup(info); + lodepng_info_init(info); + + if (in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 + || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) + { + CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/ + } + if (lodepng_chunk_length(in + 8) != 13) + { + CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/ + } + if (!lodepng_chunk_type_equals(in + 8, "IHDR")) + { + CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/ + } + + /*read the values given in the header*/ + *w = lodepng_read32bitInt(&in[16]); + *h = lodepng_read32bitInt(&in[20]); + info->color.bitdepth = in[24]; + info->color.colortype = (LodePNGColorType)in[25]; + info->compression_method = in[26]; + info->filter_method = in[27]; + info->interlace_method = in[28]; + + if (*w == 0 || *h == 0) + { + CERROR_RETURN_ERROR(state->error, 93); + } + + if (!state->decoder.ignore_crc) + { + unsigned CRC = lodepng_read32bitInt(&in[29]); + unsigned checksum = lodepng_crc32(&in[12], 17); + if (CRC != checksum) + { + CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/ + } + } + + /*error: only compression method 0 is allowed in the specification*/ + if (info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32); + /*error: only filter method 0 is allowed in the specification*/ + if (info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33); + /*error: only interlace methods 0 and 1 exist in the specification*/ + if (info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34); + + state->error = checkColorValidity(info->color.colortype, info->color.bitdepth); + return state->error; +} + +static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon, + size_t bytewidth, unsigned char filterType, size_t length) +{ + /* + For PNG filter method 0 + unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, + the filter works byte per byte (bytewidth = 1) + precon is the previous unfiltered scanline, recon the result, scanline the current one + the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead + recon and scanline MAY be the same memory address! precon must be disjoint. + */ + + size_t i; + switch (filterType) + { + case 0: + for (i = 0; i != length; ++i) recon[i] = scanline[i]; + break; + case 1: + for (i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; + for (i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth]; + break; + case 2: + if (precon) + { + for (i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i]; + } + else + { + for (i = 0; i != length; ++i) recon[i] = scanline[i]; + } + break; + case 3: + if (precon) + { + for (i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + (precon[i] >> 1); + for (i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1); + } + else + { + for (i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; + for (i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1); + } + break; + case 4: + if (precon) + { + for (i = 0; i != bytewidth; ++i) + { + recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/ + } + for (i = bytewidth; i < length; ++i) + { + recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth])); + } + } + else + { + for (i = 0; i != bytewidth; ++i) + { + recon[i] = scanline[i]; + } + for (i = bytewidth; i < length; ++i) + { + /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/ + recon[i] = (scanline[i] + recon[i - bytewidth]); + } + } + break; + default: return 36; /*error: unexisting filter type given*/ + } + return 0; +} + +static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) +{ + /* + For PNG filter method 0 + this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times) + out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline + w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel + in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes) + */ + + unsigned y; + unsigned char* prevline = 0; + + /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ + size_t bytewidth = (bpp + 7) / 8; + size_t linebytes = (w * bpp + 7) / 8; + + for (y = 0; y < h; ++y) + { + size_t outindex = linebytes * y; + size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ + unsigned char filterType = in[inindex]; + + CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes)); + + prevline = &out[outindex]; + } + + return 0; +} + +/* +in: Adam7 interlaced image, with no padding bits between scanlines, but between + reduced images so that each reduced image starts at a byte. +out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h +bpp: bits per pixel +out has the following size in bits: w * h * bpp. +in is possibly bigger due to padding bits between reduced images. +out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation +(because that's likely a little bit faster) +NOTE: comments about padding bits are only relevant if bpp < 8 +*/ +static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) +{ + unsigned passw[7], passh[7]; + size_t filter_passstart[8], padded_passstart[8], passstart[8]; + unsigned i; + + Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); + + if (bpp >= 8) + { + for (i = 0; i != 7; ++i) + { + unsigned x, y, b; + size_t bytewidth = bpp / 8; + for (y = 0; y < passh[i]; ++y) + for (x = 0; x < passw[i]; ++x) + { + size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth; + size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; + for (b = 0; b < bytewidth; ++b) + { + out[pixeloutstart + b] = in[pixelinstart + b]; + } + } + } + } + else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ + { + for (i = 0; i != 7; ++i) + { + unsigned x, y, b; + unsigned ilinebits = bpp * passw[i]; + unsigned olinebits = bpp * w; + size_t obp, ibp; /*bit pointers (for out and in buffer)*/ + for (y = 0; y < passh[i]; ++y) + for (x = 0; x < passw[i]; ++x) + { + ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp); + obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; + for (b = 0; b < bpp; ++b) + { + unsigned char bit = readBitFromReversedStream(&ibp, in); + /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/ + setBitOfReversedStream0(&obp, out, bit); + } + } + } + } +} + +static void removePaddingBits(unsigned char* out, const unsigned char* in, + size_t olinebits, size_t ilinebits, unsigned h) +{ + /* + After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need + to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers + for the Adam7 code, the color convert code and the output to the user. + in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must + have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits + also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7 + only useful if (ilinebits - olinebits) is a value in the range 1..7 + */ + unsigned y; + size_t diff = ilinebits - olinebits; + size_t ibp = 0, obp = 0; /*input and output bit pointers*/ + for (y = 0; y < h; ++y) + { + size_t x; + for (x = 0; x < olinebits; ++x) + { + unsigned char bit = readBitFromReversedStream(&ibp, in); + setBitOfReversedStream(&obp, out, bit); + } + ibp += diff; + } +} + +/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from +the IDAT chunks (with filter index bytes and possible padding bits) +return value is error*/ +static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, + unsigned w, unsigned h, const LodePNGInfo* info_png) +{ + /* + This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype. + Steps: + *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8) + *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace + NOTE: the in buffer will be overwritten with intermediate data! + */ + unsigned bpp = lodepng_get_bpp(&info_png->color); + if (bpp == 0) return 31; /*error: invalid colortype*/ + + if (info_png->interlace_method == 0) + { + if (bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) + { + CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp)); + removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h); + } + /*we can immediately filter into the out buffer, no other steps needed*/ + else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp)); + } + else /*interlace_method is 1 (Adam7)*/ + { + unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; + unsigned i; + + Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); + + for (i = 0; i != 7; ++i) + { + CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp)); + /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline, + move bytes instead of bits or move not at all*/ + if (bpp < 8) + { + /*remove padding bits in scanlines; after this there still may be padding + bits between the different reduced images: each reduced image still starts nicely at a byte*/ + removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp, + ((passw[i] * bpp + 7) / 8) * 8, passh[i]); + } + } + + Adam7_deinterlace(out, in, w, h, bpp); + } + + return 0; +} + +static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) +{ + unsigned pos = 0, i; + if (color->palette) lodepng_free(color->palette); + color->palettesize = chunkLength / 3; + color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize); + if (!color->palette && color->palettesize) + { + color->palettesize = 0; + return 83; /*alloc fail*/ + } + if (color->palettesize > 256) return 38; /*error: palette too big*/ + + for (i = 0; i != color->palettesize; ++i) + { + color->palette[4 * i + 0] = data[pos++]; /*R*/ + color->palette[4 * i + 1] = data[pos++]; /*G*/ + color->palette[4 * i + 2] = data[pos++]; /*B*/ + color->palette[4 * i + 3] = 255; /*alpha*/ + } + + return 0; /* OK */ +} + +static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) +{ + unsigned i; + if (color->colortype == LCT_PALETTE) + { + /*error: more alpha values given than there are palette entries*/ + if (chunkLength > color->palettesize) return 38; + + for (i = 0; i != chunkLength; ++i) color->palette[4 * i + 3] = data[i]; + } + else if (color->colortype == LCT_GREY) + { + /*error: this chunk must be 2 bytes for greyscale image*/ + if (chunkLength != 2) return 30; + + color->key_defined = 1; + color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1]; + } + else if (color->colortype == LCT_RGB) + { + /*error: this chunk must be 6 bytes for RGB image*/ + if (chunkLength != 6) return 41; + + color->key_defined = 1; + color->key_r = 256u * data[0] + data[1]; + color->key_g = 256u * data[2] + data[3]; + color->key_b = 256u * data[4] + data[5]; + } + else return 42; /*error: tRNS chunk not allowed for other color models*/ + + return 0; /* OK */ +} + + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS +/*background color chunk (bKGD)*/ +static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) +{ + if (info->color.colortype == LCT_PALETTE) + { + /*error: this chunk must be 1 byte for indexed color image*/ + if (chunkLength != 1) return 43; + + info->background_defined = 1; + info->background_r = info->background_g = info->background_b = data[0]; + } + else if (info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) + { + /*error: this chunk must be 2 bytes for greyscale image*/ + if (chunkLength != 2) return 44; + + info->background_defined = 1; + info->background_r = info->background_g = info->background_b = 256u * data[0] + data[1]; + } + else if (info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) + { + /*error: this chunk must be 6 bytes for greyscale image*/ + if (chunkLength != 6) return 45; + + info->background_defined = 1; + info->background_r = 256u * data[0] + data[1]; + info->background_g = 256u * data[2] + data[3]; + info->background_b = 256u * data[4] + data[5]; + } + + return 0; /* OK */ +} + +/*text chunk (tEXt)*/ +static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) +{ + unsigned error = 0; + char *key = 0, *str = 0; + unsigned i; + + while (!error) /*not really a while loop, only used to break on error*/ + { + unsigned length, string2_begin; + + length = 0; + while (length < chunkLength && data[length] != 0) ++length; + /*even though it's not allowed by the standard, no error is thrown if + there's no null termination char, if the text is empty*/ + if (length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ + + key = (char*)lodepng_malloc(length + 1); + if (!key) CERROR_BREAK(error, 83); /*alloc fail*/ + + key[length] = 0; + for (i = 0; i != length; ++i) key[i] = (char)data[i]; + + string2_begin = length + 1; /*skip keyword null terminator*/ + + length = chunkLength < string2_begin ? 0 : chunkLength - string2_begin; + str = (char*)lodepng_malloc(length + 1); + if (!str) CERROR_BREAK(error, 83); /*alloc fail*/ + + str[length] = 0; + for (i = 0; i != length; ++i) str[i] = (char)data[string2_begin + i]; + + error = lodepng_add_text(info, key, str); + + break; + } + + lodepng_free(key); + lodepng_free(str); + + return error; +} + +/*compressed text chunk (zTXt)*/ +static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, + const unsigned char* data, size_t chunkLength) +{ + unsigned error = 0; + unsigned i; + + unsigned length, string2_begin; + char *key = 0; + ucvector decoded; + + ucvector_init(&decoded); + + while (!error) /*not really a while loop, only used to break on error*/ + { + for (length = 0; length < chunkLength && data[length] != 0; ++length); + if (length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ + if (length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ + + key = (char*)lodepng_malloc(length + 1); + if (!key) CERROR_BREAK(error, 83); /*alloc fail*/ + + key[length] = 0; + for (i = 0; i != length; ++i) key[i] = (char)data[i]; + + if (data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ + + string2_begin = length + 2; + if (string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ + + length = chunkLength - string2_begin; + /*will fail if zlib error, e.g. if length is too small*/ + error = zlib_decompress(&decoded.data, &decoded.size, + (unsigned char*)(&data[string2_begin]), + length, zlibsettings); + if (error) break; + ucvector_push_back(&decoded, 0); + + error = lodepng_add_text(info, key, (char*)decoded.data); + + break; + } + + lodepng_free(key); + ucvector_cleanup(&decoded); + + return error; +} + +/*international text chunk (iTXt)*/ +static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, + const unsigned char* data, size_t chunkLength) +{ + unsigned error = 0; + unsigned i; + + unsigned length, begin, compressed; + char *key = 0, *langtag = 0, *transkey = 0; + ucvector decoded; + ucvector_init(&decoded); + + while (!error) /*not really a while loop, only used to break on error*/ + { + /*Quick check if the chunk length isn't too small. Even without check + it'd still fail with other error checks below if it's too short. This just gives a different error code.*/ + if (chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/ + + /*read the key*/ + for (length = 0; length < chunkLength && data[length] != 0; ++length); + if (length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/ + if (length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ + + key = (char*)lodepng_malloc(length + 1); + if (!key) CERROR_BREAK(error, 83); /*alloc fail*/ + + key[length] = 0; + for (i = 0; i != length; ++i) key[i] = (char)data[i]; + + /*read the compression method*/ + compressed = data[length + 1]; + if (data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ + + /*even though it's not allowed by the standard, no error is thrown if + there's no null termination char, if the text is empty for the next 3 texts*/ + + /*read the langtag*/ + begin = length + 3; + length = 0; + for (i = begin; i < chunkLength && data[i] != 0; ++i) ++length; + + langtag = (char*)lodepng_malloc(length + 1); + if (!langtag) CERROR_BREAK(error, 83); /*alloc fail*/ + + langtag[length] = 0; + for (i = 0; i != length; ++i) langtag[i] = (char)data[begin + i]; + + /*read the transkey*/ + begin += length + 1; + length = 0; + for (i = begin; i < chunkLength && data[i] != 0; ++i) ++length; + + transkey = (char*)lodepng_malloc(length + 1); + if (!transkey) CERROR_BREAK(error, 83); /*alloc fail*/ + + transkey[length] = 0; + for (i = 0; i != length; ++i) transkey[i] = (char)data[begin + i]; + + /*read the actual text*/ + begin += length + 1; + + length = chunkLength < begin ? 0 : chunkLength - begin; + + if (compressed) + { + /*will fail if zlib error, e.g. if length is too small*/ + error = zlib_decompress(&decoded.data, &decoded.size, + (unsigned char*)(&data[begin]), + length, zlibsettings); + if (error) break; + if (decoded.allocsize < decoded.size) decoded.allocsize = decoded.size; + ucvector_push_back(&decoded, 0); + } + else + { + if (!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/); + + decoded.data[length] = 0; + for (i = 0; i != length; ++i) decoded.data[i] = data[begin + i]; + } + + error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data); + + break; + } + + lodepng_free(key); + lodepng_free(langtag); + lodepng_free(transkey); + ucvector_cleanup(&decoded); + + return error; +} + +static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) +{ + if (chunkLength != 7) return 73; /*invalid tIME chunk size*/ + + info->time_defined = 1; + info->time.year = 256u * data[0] + data[1]; + info->time.month = data[2]; + info->time.day = data[3]; + info->time.hour = data[4]; + info->time.minute = data[5]; + info->time.second = data[6]; + + return 0; /* OK */ +} + +static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) +{ + if (chunkLength != 9) return 74; /*invalid pHYs chunk size*/ + + info->phys_defined = 1; + info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3]; + info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7]; + info->phys_unit = data[8]; + + return 0; /* OK */ +} +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/ +static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, + LodePNGState* state, + const unsigned char* in, size_t insize) +{ + unsigned char IEND = 0; + const unsigned char* chunk; + size_t i; + ucvector idat; /*the data from idat chunks*/ + ucvector scanlines; + size_t predict; + size_t numpixels; + size_t outsize = 0; + + /*for unknown chunk order*/ + unsigned unknown = 0; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/ +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + + /*provide some proper output values if error will happen*/ + *out = 0; + + state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/ + if (state->error) return; + + numpixels = *w * *h; + + /*multiplication overflow*/ + if (*h != 0 && numpixels / *h != *w) CERROR_RETURN(state->error, 92); + /*multiplication overflow possible further below. Allows up to 2^31-1 pixel + bytes with 16-bit RGBA, the rest is room for filter bytes.*/ + if (numpixels > 268435455) CERROR_RETURN(state->error, 92); + + ucvector_init(&idat); + chunk = &in[33]; /*first byte of the first chunk after the header*/ + + /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. + IDAT data is put at the start of the in buffer*/ + while (!IEND && !state->error) + { + unsigned chunkLength; + const unsigned char* data; /*the data in the chunk*/ + + /*error: size of the in buffer too small to contain next chunk*/ + if ((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(state->error, 30); + + /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/ + chunkLength = lodepng_chunk_length(chunk); + /*error: chunk length larger than the max PNG chunk size*/ + if (chunkLength > 2147483647) CERROR_BREAK(state->error, 63); + + if ((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) + { + CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/ + } + + data = lodepng_chunk_data_const(chunk); + + /*IDAT chunk, containing compressed image data*/ + if (lodepng_chunk_type_equals(chunk, "IDAT")) + { + size_t oldsize = idat.size; + if (!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(state->error, 83 /*alloc fail*/); + for (i = 0; i != chunkLength; ++i) idat.data[oldsize + i] = data[i]; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + critical_pos = 3; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + } + /*IEND chunk*/ + else if (lodepng_chunk_type_equals(chunk, "IEND")) + { + IEND = 1; + } + /*palette chunk (PLTE)*/ + else if (lodepng_chunk_type_equals(chunk, "PLTE")) + { + state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength); + if (state->error) break; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + critical_pos = 2; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + } + /*palette transparency chunk (tRNS)*/ + else if (lodepng_chunk_type_equals(chunk, "tRNS")) + { + state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength); + if (state->error) break; + } +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /*background color chunk (bKGD)*/ + else if (lodepng_chunk_type_equals(chunk, "bKGD")) + { + state->error = readChunk_bKGD(&state->info_png, data, chunkLength); + if (state->error) break; + } + /*text chunk (tEXt)*/ + else if (lodepng_chunk_type_equals(chunk, "tEXt")) + { + if (state->decoder.read_text_chunks) + { + state->error = readChunk_tEXt(&state->info_png, data, chunkLength); + if (state->error) break; + } + } + /*compressed text chunk (zTXt)*/ + else if (lodepng_chunk_type_equals(chunk, "zTXt")) + { + if (state->decoder.read_text_chunks) + { + state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); + if (state->error) break; + } + } + /*international text chunk (iTXt)*/ + else if (lodepng_chunk_type_equals(chunk, "iTXt")) + { + if (state->decoder.read_text_chunks) + { + state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); + if (state->error) break; + } + } + else if (lodepng_chunk_type_equals(chunk, "tIME")) + { + state->error = readChunk_tIME(&state->info_png, data, chunkLength); + if (state->error) break; + } + else if (lodepng_chunk_type_equals(chunk, "pHYs")) + { + state->error = readChunk_pHYs(&state->info_png, data, chunkLength); + if (state->error) break; + } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + else /*it's not an implemented chunk type, so ignore it: skip over the data*/ + { + /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/ + if (!lodepng_chunk_ancillary(chunk)) CERROR_BREAK(state->error, 69); + + unknown = 1; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + if (state->decoder.remember_unknown_chunks) + { + state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1], + &state->info_png.unknown_chunks_size[critical_pos - 1], chunk); + if (state->error) break; + } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + } + + if (!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ + { + if (lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/ + } + + if (!IEND) chunk = lodepng_chunk_next_const(chunk); + } + + ucvector_init(&scanlines); + /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation. + If the decompressed size does not match the prediction, the image must be corrupt.*/ + if (state->info_png.interlace_method == 0) + { + /*The extra *h is added because this are the filter bytes every scanline starts with*/ + predict = lodepng_get_raw_size_idat(*w, *h, &state->info_png.color) + *h; + } + else + { + /*Adam-7 interlaced: predicted size is the sum of the 7 sub-images sizes*/ + const LodePNGColorMode* color = &state->info_png.color; + predict = 0; + predict += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, color) + ((*h + 7) >> 3); + if (*w > 4) predict += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, color) + ((*h + 7) >> 3); + predict += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, color) + ((*h + 3) >> 3); + if (*w > 2) predict += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, color) + ((*h + 3) >> 2); + predict += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, color) + ((*h + 1) >> 2); + if (*w > 1) predict += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, color) + ((*h + 1) >> 1); + predict += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, color) + ((*h + 0) >> 1); + } + if (!state->error && !ucvector_reserve(&scanlines, predict)) state->error = 83; /*alloc fail*/ + if (!state->error) + { + state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data, + idat.size, &state->decoder.zlibsettings); + if (!state->error && scanlines.size != predict) state->error = 91; /*decompressed size doesn't match prediction*/ + } + ucvector_cleanup(&idat); + + if (!state->error) + { + outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color); + *out = (unsigned char*)lodepng_malloc(outsize); + if (!*out) state->error = 83; /*alloc fail*/ + } + if (!state->error) + { + for (i = 0; i < outsize; i++) (*out)[i] = 0; + state->error = postProcessScanlines(*out, scanlines.data, *w, *h, &state->info_png); + } + ucvector_cleanup(&scanlines); +} + +unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, + LodePNGState* state, + const unsigned char* in, size_t insize) +{ + *out = 0; + decodeGeneric(out, w, h, state, in, insize); + if (state->error) return state->error; + if (!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) + { + /*same color type, no copying or converting of data needed*/ + /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype + the raw image has to the end user*/ + if (!state->decoder.color_convert) + { + state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color); + if (state->error) return state->error; + } + } + else + { + /*color conversion needed; sort of copy of the data*/ + unsigned char* data = *out; + size_t outsize; + + /*TODO: check if this works according to the statement in the documentation: "The converter can convert + from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/ + if (!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA) + && !(state->info_raw.bitdepth == 8)) + { + return 56; /*unsupported color mode conversion*/ + } + + outsize = lodepng_get_raw_size(*w, *h, &state->info_raw); + *out = (unsigned char*)lodepng_malloc(outsize); + if (!(*out)) + { + state->error = 83; /*alloc fail*/ + } + else state->error = lodepng_convert(*out, data, &state->info_raw, + &state->info_png.color, *w, *h); + lodepng_free(data); + } + return state->error; +} + +unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, + size_t insize, LodePNGColorType colortype, unsigned bitdepth) +{ + unsigned error; + LodePNGState state; + lodepng_state_init(&state); + state.info_raw.colortype = colortype; + state.info_raw.bitdepth = bitdepth; + error = lodepng_decode(out, w, h, &state, in, insize); + lodepng_state_cleanup(&state); + return error; +} + +unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) +{ + return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8); +} + +unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) +{ + return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8); +} + +#ifdef LODEPNG_COMPILE_DISK +unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename, + LodePNGColorType colortype, unsigned bitdepth) +{ + unsigned char* buffer = 0; + size_t buffersize; + unsigned error; + error = lodepng_load_file(&buffer, &buffersize, filename); + if (!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth); + lodepng_free(buffer); + return error; +} + +unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) +{ + return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8); +} + +unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) +{ + return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8); +} +#endif /*LODEPNG_COMPILE_DISK*/ + +void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) +{ + settings->color_convert = 1; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + settings->read_text_chunks = 1; + settings->remember_unknown_chunks = 0; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + settings->ignore_crc = 0; + lodepng_decompress_settings_init(&settings->zlibsettings); +} + +#endif /*LODEPNG_COMPILE_DECODER*/ + +#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) + +void lodepng_state_init(LodePNGState* state) +{ +#ifdef LODEPNG_COMPILE_DECODER + lodepng_decoder_settings_init(&state->decoder); +#endif /*LODEPNG_COMPILE_DECODER*/ +#ifdef LODEPNG_COMPILE_ENCODER + lodepng_encoder_settings_init(&state->encoder); +#endif /*LODEPNG_COMPILE_ENCODER*/ + lodepng_color_mode_init(&state->info_raw); + lodepng_info_init(&state->info_png); + state->error = 1; +} + +void lodepng_state_cleanup(LodePNGState* state) +{ + lodepng_color_mode_cleanup(&state->info_raw); + lodepng_info_cleanup(&state->info_png); +} + +void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) +{ + lodepng_state_cleanup(dest); + *dest = *source; + lodepng_color_mode_init(&dest->info_raw); + lodepng_info_init(&dest->info_png); + dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if (dest->error) return; + dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if (dest->error) return; +} + +#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */ + +#ifdef LODEPNG_COMPILE_ENCODER + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / PNG Encoder / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +/*chunkName must be string of 4 characters*/ +static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length) +{ + CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data)); + out->allocsize = out->size; /*fix the allocsize again*/ + return 0; +} + +static void writeSignature(ucvector* out) +{ + /*8 bytes PNG signature, aka the magic bytes*/ + ucvector_push_back(out, 137); + ucvector_push_back(out, 80); + ucvector_push_back(out, 78); + ucvector_push_back(out, 71); + ucvector_push_back(out, 13); + ucvector_push_back(out, 10); + ucvector_push_back(out, 26); + ucvector_push_back(out, 10); +} + +static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method) +{ + unsigned error = 0; + ucvector header; + ucvector_init(&header); + + lodepng_add32bitInt(&header, w); /*width*/ + lodepng_add32bitInt(&header, h); /*height*/ + ucvector_push_back(&header, (unsigned char)bitdepth); /*bit depth*/ + ucvector_push_back(&header, (unsigned char)colortype); /*color type*/ + ucvector_push_back(&header, 0); /*compression method*/ + ucvector_push_back(&header, 0); /*filter method*/ + ucvector_push_back(&header, interlace_method); /*interlace method*/ + + error = addChunk(out, "IHDR", header.data, header.size); + ucvector_cleanup(&header); + + return error; +} + +static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info) +{ + unsigned error = 0; + size_t i; + ucvector PLTE; + ucvector_init(&PLTE); + for (i = 0; i != info->palettesize * 4; ++i) + { + /*add all channels except alpha channel*/ + if (i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); + } + error = addChunk(out, "PLTE", PLTE.data, PLTE.size); + ucvector_cleanup(&PLTE); + + return error; +} + +static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info) +{ + unsigned error = 0; + size_t i; + ucvector tRNS; + ucvector_init(&tRNS); + if (info->colortype == LCT_PALETTE) + { + size_t amount = info->palettesize; + /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/ + for (i = info->palettesize; i != 0; --i) + { + if (info->palette[4 * (i - 1) + 3] == 255) --amount; + else break; + } + /*add only alpha channel*/ + for (i = 0; i != amount; ++i) ucvector_push_back(&tRNS, info->palette[4 * i + 3]); + } + else if (info->colortype == LCT_GREY) + { + if (info->key_defined) + { + ucvector_push_back(&tRNS, (unsigned char)(info->key_r >> 8)); + ucvector_push_back(&tRNS, (unsigned char)(info->key_r & 255)); + } + } + else if (info->colortype == LCT_RGB) + { + if (info->key_defined) + { + ucvector_push_back(&tRNS, (unsigned char)(info->key_r >> 8)); + ucvector_push_back(&tRNS, (unsigned char)(info->key_r & 255)); + ucvector_push_back(&tRNS, (unsigned char)(info->key_g >> 8)); + ucvector_push_back(&tRNS, (unsigned char)(info->key_g & 255)); + ucvector_push_back(&tRNS, (unsigned char)(info->key_b >> 8)); + ucvector_push_back(&tRNS, (unsigned char)(info->key_b & 255)); + } + } + + error = addChunk(out, "tRNS", tRNS.data, tRNS.size); + ucvector_cleanup(&tRNS); + + return error; +} + +static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize, + LodePNGCompressSettings* zlibsettings) +{ + ucvector zlibdata; + unsigned error = 0; + + /*compress with the Zlib compressor*/ + ucvector_init(&zlibdata); + error = zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings); + if (!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size); + ucvector_cleanup(&zlibdata); + + return error; +} + +static unsigned addChunk_IEND(ucvector* out) +{ + unsigned error = 0; + error = addChunk(out, "IEND", 0, 0); + return error; +} + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + +static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) +{ + unsigned error = 0; + size_t i; + ucvector text; + ucvector_init(&text); + for (i = 0; keyword[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)keyword[i]); + if (i < 1 || i > 79) return 89; /*error: invalid keyword size*/ + ucvector_push_back(&text, 0); /*0 termination char*/ + for (i = 0; textstring[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)textstring[i]); + error = addChunk(out, "tEXt", text.data, text.size); + ucvector_cleanup(&text); + + return error; +} + +static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring, + LodePNGCompressSettings* zlibsettings) +{ + unsigned error = 0; + ucvector data, compressed; + size_t i, textsize = strlen(textstring); + + ucvector_init(&data); + ucvector_init(&compressed); + for (i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]); + if (i < 1 || i > 79) return 89; /*error: invalid keyword size*/ + ucvector_push_back(&data, 0); /*0 termination char*/ + ucvector_push_back(&data, 0); /*compression method: 0*/ + + error = zlib_compress(&compressed.data, &compressed.size, + (unsigned char*)textstring, textsize, zlibsettings); + if (!error) + { + for (i = 0; i != compressed.size; ++i) ucvector_push_back(&data, compressed.data[i]); + error = addChunk(out, "zTXt", data.data, data.size); + } + + ucvector_cleanup(&compressed); + ucvector_cleanup(&data); + return error; +} + +static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag, + const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings) +{ + unsigned error = 0; + ucvector data; + size_t i, textsize = strlen(textstring); + + ucvector_init(&data); + + for (i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]); + if (i < 1 || i > 79) return 89; /*error: invalid keyword size*/ + ucvector_push_back(&data, 0); /*null termination char*/ + ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/ + ucvector_push_back(&data, 0); /*compression method*/ + for (i = 0; langtag[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)langtag[i]); + ucvector_push_back(&data, 0); /*null termination char*/ + for (i = 0; transkey[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)transkey[i]); + ucvector_push_back(&data, 0); /*null termination char*/ + + if (compressed) + { + ucvector compressed_data; + ucvector_init(&compressed_data); + error = zlib_compress(&compressed_data.data, &compressed_data.size, + (unsigned char*)textstring, textsize, zlibsettings); + if (!error) + { + for (i = 0; i != compressed_data.size; ++i) ucvector_push_back(&data, compressed_data.data[i]); + } + ucvector_cleanup(&compressed_data); + } + else /*not compressed*/ + { + for (i = 0; textstring[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)textstring[i]); + } + + if (!error) error = addChunk(out, "iTXt", data.data, data.size); + ucvector_cleanup(&data); + return error; +} + +static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info) +{ + unsigned error = 0; + ucvector bKGD; + ucvector_init(&bKGD); + if (info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) + { + ucvector_push_back(&bKGD, (unsigned char)(info->background_r >> 8)); + ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); + } + else if (info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) + { + ucvector_push_back(&bKGD, (unsigned char)(info->background_r >> 8)); + ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); + ucvector_push_back(&bKGD, (unsigned char)(info->background_g >> 8)); + ucvector_push_back(&bKGD, (unsigned char)(info->background_g & 255)); + ucvector_push_back(&bKGD, (unsigned char)(info->background_b >> 8)); + ucvector_push_back(&bKGD, (unsigned char)(info->background_b & 255)); + } + else if (info->color.colortype == LCT_PALETTE) + { + ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); /*palette index*/ + } + + error = addChunk(out, "bKGD", bKGD.data, bKGD.size); + ucvector_cleanup(&bKGD); + + return error; +} + +static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time) +{ + unsigned error = 0; + unsigned char* data = (unsigned char*)lodepng_malloc(7); + if (!data) return 83; /*alloc fail*/ + data[0] = (unsigned char)(time->year >> 8); + data[1] = (unsigned char)(time->year & 255); + data[2] = (unsigned char)time->month; + data[3] = (unsigned char)time->day; + data[4] = (unsigned char)time->hour; + data[5] = (unsigned char)time->minute; + data[6] = (unsigned char)time->second; + error = addChunk(out, "tIME", data, 7); + lodepng_free(data); + return error; +} + +static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info) +{ + unsigned error = 0; + ucvector data; + ucvector_init(&data); + + lodepng_add32bitInt(&data, info->phys_x); + lodepng_add32bitInt(&data, info->phys_y); + ucvector_push_back(&data, info->phys_unit); + + error = addChunk(out, "pHYs", data.data, data.size); + ucvector_cleanup(&data); + + return error; +} + +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline, + size_t length, size_t bytewidth, unsigned char filterType) +{ + size_t i; + switch (filterType) + { + case 0: /*None*/ + for (i = 0; i != length; ++i) out[i] = scanline[i]; + break; + case 1: /*Sub*/ + for (i = 0; i != bytewidth; ++i) out[i] = scanline[i]; + for (i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth]; + break; + case 2: /*Up*/ + if (prevline) + { + for (i = 0; i != length; ++i) out[i] = scanline[i] - prevline[i]; + } + else + { + for (i = 0; i != length; ++i) out[i] = scanline[i]; + } + break; + case 3: /*Average*/ + if (prevline) + { + for (i = 0; i != bytewidth; ++i) out[i] = scanline[i] - (prevline[i] >> 1); + for (i = bytewidth; i < length; ++i) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) >> 1); + } + else + { + for (i = 0; i != bytewidth; ++i) out[i] = scanline[i]; + for (i = bytewidth; i < length; ++i) out[i] = scanline[i] - (scanline[i - bytewidth] >> 1); + } + break; + case 4: /*Paeth*/ + if (prevline) + { + /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/ + for (i = 0; i != bytewidth; ++i) out[i] = (scanline[i] - prevline[i]); + for (i = bytewidth; i < length; ++i) + { + out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth])); + } + } + else + { + for (i = 0; i != bytewidth; ++i) out[i] = scanline[i]; + /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/ + for (i = bytewidth; i < length; ++i) out[i] = (scanline[i] - scanline[i - bytewidth]); + } + break; + default: return; /*unexisting filter type given*/ + } +} + +/* log2 approximation. A slight bit faster than std::log. */ +static float flog2(float f) +{ + float result = 0; + while (f > 32) { result += 4; f /= 16; } + while (f > 2) { ++result; f /= 2; } + return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f); +} + +static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, + const LodePNGColorMode* info, const LodePNGEncoderSettings* settings) +{ + /* + For PNG filter method 0 + out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are + the scanlines with 1 extra byte per scanline + */ + + unsigned bpp = lodepng_get_bpp(info); + /*the width of a scanline in bytes, not including the filter type*/ + size_t linebytes = (w * bpp + 7) / 8; + /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ + size_t bytewidth = (bpp + 7) / 8; + const unsigned char* prevline = 0; + unsigned x, y; + unsigned error = 0; + LodePNGFilterStrategy strategy = settings->filter_strategy; + + /* + There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard: + * If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e. + use fixed filtering, with the filter None). + * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is + not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply + all five filters and select the filter that produces the smallest sum of absolute values per row. + This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true. + + If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed, + but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum + heuristic is used. + */ + if (settings->filter_palette_zero && + (info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO; + + if (bpp == 0) return 31; /*error: invalid color type*/ + + if (strategy == LFS_ZERO) + { + for (y = 0; y != h; ++y) + { + size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ + size_t inindex = linebytes * y; + out[outindex] = 0; /*filter type byte*/ + filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0); + prevline = &in[inindex]; + } + } + else if (strategy == LFS_MINSUM) + { + /*adaptive filtering*/ + size_t sum[5]; + unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ + size_t smallest = 0; + unsigned char type, bestType = 0; + + for (type = 0; type != 5; ++type) + { + attempt[type] = (unsigned char*)lodepng_malloc(linebytes); + if (!attempt[type]) return 83; /*alloc fail*/ + } + + if (!error) + { + for (y = 0; y != h; ++y) + { + /*try the 5 filter types*/ + for (type = 0; type != 5; ++type) + { + filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); + + /*calculate the sum of the result*/ + sum[type] = 0; + if (type == 0) + { + for (x = 0; x != linebytes; ++x) sum[type] += (unsigned char)(attempt[type][x]); + } + else + { + for (x = 0; x != linebytes; ++x) + { + /*For differences, each byte should be treated as signed, values above 127 are negative + (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there. + This means filtertype 0 is almost never chosen, but that is justified.*/ + unsigned char s = attempt[type][x]; + sum[type] += s < 128 ? s : (255U - s); + } + } + + /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ + if (type == 0 || sum[type] < smallest) + { + bestType = type; + smallest = sum[type]; + } + } + + prevline = &in[y * linebytes]; + + /*now fill the out values*/ + out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ + for (x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; + } + } + + for (type = 0; type != 5; ++type) lodepng_free(attempt[type]); + } + else if (strategy == LFS_ENTROPY) + { + float sum[5]; + unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ + float smallest = 0; + unsigned type, bestType = 0; + unsigned count[256]; + + for (type = 0; type != 5; ++type) + { + attempt[type] = (unsigned char*)lodepng_malloc(linebytes); + if (!attempt[type]) return 83; /*alloc fail*/ + } + + for (y = 0; y != h; ++y) + { + /*try the 5 filter types*/ + for (type = 0; type != 5; ++type) + { + filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); + for (x = 0; x != 256; ++x) count[x] = 0; + for (x = 0; x != linebytes; ++x) ++count[attempt[type][x]]; + ++count[type]; /*the filter type itself is part of the scanline*/ + sum[type] = 0; + for (x = 0; x != 256; ++x) + { + float p = count[x] / (float)(linebytes + 1); + sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p; + } + /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ + if (type == 0 || sum[type] < smallest) + { + bestType = type; + smallest = sum[type]; + } + } + + prevline = &in[y * linebytes]; + + /*now fill the out values*/ + out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ + for (x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; + } + + for (type = 0; type != 5; ++type) lodepng_free(attempt[type]); + } + else if (strategy == LFS_PREDEFINED) + { + for (y = 0; y != h; ++y) + { + size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ + size_t inindex = linebytes * y; + unsigned char type = settings->predefined_filters[y]; + out[outindex] = type; /*filter type byte*/ + filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type); + prevline = &in[inindex]; + } + } + else if (strategy == LFS_BRUTE_FORCE) + { + /*brute force filter chooser. + deflate the scanline after every filter attempt to see which one deflates best. + This is very slow and gives only slightly smaller, sometimes even larger, result*/ + size_t size[5]; + unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ + size_t smallest = 0; + unsigned type = 0, bestType = 0; + unsigned char* dummy; + LodePNGCompressSettings zlibsettings = settings->zlibsettings; + /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose, + to simulate the true case where the tree is the same for the whole image. Sometimes it gives + better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare + cases better compression. It does make this a bit less slow, so it's worth doing this.*/ + zlibsettings.btype = 1; + /*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG + images only, so disable it*/ + zlibsettings.custom_zlib = 0; + zlibsettings.custom_deflate = 0; + for (type = 0; type != 5; ++type) + { + attempt[type] = (unsigned char*)lodepng_malloc(linebytes); + if (!attempt[type]) return 83; /*alloc fail*/ + } + for (y = 0; y != h; ++y) /*try the 5 filter types*/ + { + for (type = 0; type != 5; ++type) + { + unsigned testsize = linebytes; + /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/ + + filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); + size[type] = 0; + dummy = 0; + zlib_compress(&dummy, &size[type], attempt[type], testsize, &zlibsettings); + lodepng_free(dummy); + /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/ + if (type == 0 || size[type] < smallest) + { + bestType = type; + smallest = size[type]; + } + } + prevline = &in[y * linebytes]; + out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ + for (x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; + } + for (type = 0; type != 5; ++type) lodepng_free(attempt[type]); + } + else return 88; /* unknown filter strategy */ + + return error; +} + +static void addPaddingBits(unsigned char* out, const unsigned char* in, + size_t olinebits, size_t ilinebits, unsigned h) +{ + /*The opposite of the removePaddingBits function + olinebits must be >= ilinebits*/ + unsigned y; + size_t diff = olinebits - ilinebits; + size_t obp = 0, ibp = 0; /*bit pointers*/ + for (y = 0; y != h; ++y) + { + size_t x; + for (x = 0; x < ilinebits; ++x) + { + unsigned char bit = readBitFromReversedStream(&ibp, in); + setBitOfReversedStream(&obp, out, bit); + } + /*obp += diff; --> no, fill in some value in the padding bits too, to avoid + "Use of uninitialised value of size ###" warning from valgrind*/ + for (x = 0; x != diff; ++x) setBitOfReversedStream(&obp, out, 0); + } +} + +/* +in: non-interlaced image with size w*h +out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with + no padding bits between scanlines, but between reduced images so that each + reduced image starts at a byte. +bpp: bits per pixel +there are no padding bits, not between scanlines, not between reduced images +in has the following size in bits: w * h * bpp. +out is possibly bigger due to padding bits between reduced images +NOTE: comments about padding bits are only relevant if bpp < 8 +*/ +static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) +{ + unsigned passw[7], passh[7]; + size_t filter_passstart[8], padded_passstart[8], passstart[8]; + unsigned i; + + Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); + + if (bpp >= 8) + { + for (i = 0; i != 7; ++i) + { + unsigned x, y, b; + size_t bytewidth = bpp / 8; + for (y = 0; y < passh[i]; ++y) + for (x = 0; x < passw[i]; ++x) + { + size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; + size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth; + for (b = 0; b < bytewidth; ++b) + { + out[pixeloutstart + b] = in[pixelinstart + b]; + } + } + } + } + else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ + { + for (i = 0; i != 7; ++i) + { + unsigned x, y, b; + unsigned ilinebits = bpp * passw[i]; + unsigned olinebits = bpp * w; + size_t obp, ibp; /*bit pointers (for out and in buffer)*/ + for (y = 0; y < passh[i]; ++y) + for (x = 0; x < passw[i]; ++x) + { + ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; + obp = (8 * passstart[i]) + (y * ilinebits + x * bpp); + for (b = 0; b < bpp; ++b) + { + unsigned char bit = readBitFromReversedStream(&ibp, in); + setBitOfReversedStream(&obp, out, bit); + } + } + } + } +} + +/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image. +return value is error**/ +static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in, + unsigned w, unsigned h, + const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings) +{ + /* + This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps: + *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter + *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter + */ + unsigned bpp = lodepng_get_bpp(&info_png->color); + unsigned error = 0; + + if (info_png->interlace_method == 0) + { + *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/ + *out = (unsigned char*)lodepng_malloc(*outsize); + if (!(*out) && (*outsize)) error = 83; /*alloc fail*/ + + if (!error) + { + /*non multiple of 8 bits per scanline, padding bits needed per scanline*/ + if (bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) + { + unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8)); + if (!padded) error = 83; /*alloc fail*/ + if (!error) + { + addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h); + error = filter(*out, padded, w, h, &info_png->color, settings); + } + lodepng_free(padded); + } + else + { + /*we can immediately filter into the out buffer, no other steps needed*/ + error = filter(*out, in, w, h, &info_png->color, settings); + } + } + } + else /*interlace_method is 1 (Adam7)*/ + { + unsigned passw[7], passh[7]; + size_t filter_passstart[8], padded_passstart[8], passstart[8]; + unsigned char* adam7; + + Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); + + *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/ + *out = (unsigned char*)lodepng_malloc(*outsize); + if (!(*out)) error = 83; /*alloc fail*/ + + adam7 = (unsigned char*)lodepng_malloc(passstart[7]); + if (!adam7 && passstart[7]) error = 83; /*alloc fail*/ + + if (!error) + { + unsigned i; + + Adam7_interlace(adam7, in, w, h, bpp); + for (i = 0; i != 7; ++i) + { + if (bpp < 8) + { + unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]); + if (!padded) ERROR_BREAK(83); /*alloc fail*/ + addPaddingBits(padded, &adam7[passstart[i]], + ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]); + error = filter(&(*out)[filter_passstart[i]], padded, + passw[i], passh[i], &info_png->color, settings); + lodepng_free(padded); + } + else + { + error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], + passw[i], passh[i], &info_png->color, settings); + } + + if (error) break; + } + } + + lodepng_free(adam7); + } + + return error; +} + +/* +palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA... +returns 0 if the palette is opaque, +returns 1 if the palette has a single color with alpha 0 ==> color key +returns 2 if the palette is semi-translucent. +*/ +static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize) +{ + size_t i; + unsigned key = 0; + unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/ + for (i = 0; i != palettesize; ++i) + { + if (!key && palette[4 * i + 3] == 0) + { + r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2]; + key = 1; + i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/ + } + else if (palette[4 * i + 3] != 255) return 2; + /*when key, no opaque RGB may have key's RGB*/ + else if (key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2; + } + return key; +} + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS +static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) +{ + unsigned char* inchunk = data; + while ((size_t)(inchunk - data) < datasize) + { + CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk)); + out->allocsize = out->size; /*fix the allocsize again*/ + inchunk = lodepng_chunk_next(inchunk); + } + return 0; +} +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +unsigned lodepng_encode(unsigned char** out, size_t* outsize, + const unsigned char* image, unsigned w, unsigned h, + LodePNGState* state) +{ + LodePNGInfo info; + ucvector outv; + unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/ + size_t datasize = 0; + + /*provide some proper output values if error will happen*/ + *out = 0; + *outsize = 0; + state->error = 0; + + lodepng_info_init(&info); + lodepng_info_copy(&info, &state->info_png); + + if ((info.color.colortype == LCT_PALETTE || state->encoder.force_palette) + && (info.color.palettesize == 0 || info.color.palettesize > 256)) + { + state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/ + return state->error; + } + + if (state->encoder.auto_convert) + { + state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw); + } + if (state->error) return state->error; + + if (state->encoder.zlibsettings.btype > 2) + { + CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/ + } + if (state->info_png.interlace_method > 1) + { + CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/ + } + + state->error = checkColorValidity(info.color.colortype, info.color.bitdepth); + if (state->error) return state->error; /*error: unexisting color type given*/ + state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth); + if (state->error) return state->error; /*error: unexisting color type given*/ + + if (!lodepng_color_mode_equal(&state->info_raw, &info.color)) + { + unsigned char* converted; + size_t size = (w * h * (size_t)lodepng_get_bpp(&info.color) + 7) / 8; + + converted = (unsigned char*)lodepng_malloc(size); + if (!converted && size) state->error = 83; /*alloc fail*/ + if (!state->error) + { + state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h); + } + if (!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder); + lodepng_free(converted); + } + else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder); + + ucvector_init(&outv); + while (!state->error) /*while only executed once, to break on error*/ + { +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + size_t i; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + /*write signature and chunks*/ + writeSignature(&outv); + /*IHDR*/ + addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method); +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /*unknown chunks between IHDR and PLTE*/ + if (info.unknown_chunks_data[0]) + { + state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]); + if (state->error) break; + } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + /*PLTE*/ + if (info.color.colortype == LCT_PALETTE) + { + addChunk_PLTE(&outv, &info.color); + } + if (state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) + { + addChunk_PLTE(&outv, &info.color); + } + /*tRNS*/ + if (info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0) + { + addChunk_tRNS(&outv, &info.color); + } + if ((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined) + { + addChunk_tRNS(&outv, &info.color); + } +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /*bKGD (must come between PLTE and the IDAt chunks*/ + if (info.background_defined) addChunk_bKGD(&outv, &info); + /*pHYs (must come before the IDAT chunks)*/ + if (info.phys_defined) addChunk_pHYs(&outv, &info); + + /*unknown chunks between PLTE and IDAT*/ + if (info.unknown_chunks_data[1]) + { + state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]); + if (state->error) break; + } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + /*IDAT (multiple IDAT chunks must be consecutive)*/ + state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings); + if (state->error) break; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /*tIME*/ + if (info.time_defined) addChunk_tIME(&outv, &info.time); + /*tEXt and/or zTXt*/ + for (i = 0; i != info.text_num; ++i) + { + if (strlen(info.text_keys[i]) > 79) + { + state->error = 66; /*text chunk too large*/ + break; + } + if (strlen(info.text_keys[i]) < 1) + { + state->error = 67; /*text chunk too small*/ + break; + } + if (state->encoder.text_compression) + { + addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings); + } + else + { + addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]); + } + } + /*LodePNG version id in text chunk*/ + if (state->encoder.add_id) + { + unsigned alread_added_id_text = 0; + for (i = 0; i != info.text_num; ++i) + { + if (!strcmp(info.text_keys[i], "LodePNG")) + { + alread_added_id_text = 1; + break; + } + } + if (alread_added_id_text == 0) + { + addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/ + } + } + /*iTXt*/ + for (i = 0; i != info.itext_num; ++i) + { + if (strlen(info.itext_keys[i]) > 79) + { + state->error = 66; /*text chunk too large*/ + break; + } + if (strlen(info.itext_keys[i]) < 1) + { + state->error = 67; /*text chunk too small*/ + break; + } + addChunk_iTXt(&outv, state->encoder.text_compression, + info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i], + &state->encoder.zlibsettings); + } + + /*unknown chunks between IDAT and IEND*/ + if (info.unknown_chunks_data[2]) + { + state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]); + if (state->error) break; + } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + addChunk_IEND(&outv); + + break; /*this isn't really a while loop; no error happened so break out now!*/ + } + + lodepng_info_cleanup(&info); + lodepng_free(data); + /*instead of cleaning the vector up, give it to the output*/ + *out = outv.data; + *outsize = outv.size; + + return state->error; +} + +unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image, + unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) +{ + unsigned error; + LodePNGState state; + lodepng_state_init(&state); + state.info_raw.colortype = colortype; + state.info_raw.bitdepth = bitdepth; + state.info_png.color.colortype = colortype; + state.info_png.color.bitdepth = bitdepth; + lodepng_encode(out, outsize, image, w, h, &state); + error = state.error; + lodepng_state_cleanup(&state); + return error; +} + +unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) +{ + return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8); +} + +unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) +{ + return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8); +} + +#ifdef LODEPNG_COMPILE_DISK +unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth) +{ + unsigned char* buffer; + size_t buffersize; + unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth); + if (!error) error = lodepng_save_file(buffer, buffersize, filename); + lodepng_free(buffer); + return error; +} + +unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) +{ + return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8); +} + +unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) +{ + return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8); +} +#endif /*LODEPNG_COMPILE_DISK*/ + +void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) +{ + lodepng_compress_settings_init(&settings->zlibsettings); + settings->filter_palette_zero = 1; + settings->filter_strategy = LFS_MINSUM; + settings->auto_convert = 1; + settings->force_palette = 0; + settings->predefined_filters = 0; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + settings->add_id = 0; + settings->text_compression = 1; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +} + +#endif /*LODEPNG_COMPILE_ENCODER*/ +#endif /*LODEPNG_COMPILE_PNG*/ + +#ifdef LODEPNG_COMPILE_ERROR_TEXT +/* +This returns the description of a numerical error code in English. This is also +the documentation of all the error codes. +*/ +const char* lodepng_error_text(unsigned code) +{ + switch (code) + { + case 0: return "no error, everything went ok"; + case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/ + case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/ + case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/ + case 13: return "problem while processing dynamic deflate block"; + case 14: return "problem while processing dynamic deflate block"; + case 15: return "problem while processing dynamic deflate block"; + case 16: return "unexisting code while processing dynamic deflate block"; + case 17: return "end of out buffer memory reached while inflating"; + case 18: return "invalid distance code while inflating"; + case 19: return "end of out buffer memory reached while inflating"; + case 20: return "invalid deflate block BTYPE encountered while decoding"; + case 21: return "NLEN is not ones complement of LEN in a deflate block"; + /*end of out buffer memory reached while inflating: + This can happen if the inflated deflate data is longer than the amount of bytes required to fill up + all the pixels of the image, given the color depth and image dimensions. Something that doesn't + happen in a normal, well encoded, PNG image.*/ + case 22: return "end of out buffer memory reached while inflating"; + case 23: return "end of in buffer memory reached while inflating"; + case 24: return "invalid FCHECK in zlib header"; + case 25: return "invalid compression method in zlib header"; + case 26: return "FDICT encountered in zlib header while it's not used for PNG"; + case 27: return "PNG file is smaller than a PNG header"; + /*Checks the magic file header, the first 8 bytes of the PNG file*/ + case 28: return "incorrect PNG signature, it's no PNG or corrupted"; + case 29: return "first chunk is not the header chunk"; + case 30: return "chunk length too large, chunk broken off at end of file"; + case 31: return "illegal PNG color type or bpp"; + case 32: return "illegal PNG compression method"; + case 33: return "illegal PNG filter method"; + case 34: return "illegal PNG interlace method"; + case 35: return "chunk length of a chunk is too large or the chunk too small"; + case 36: return "illegal PNG filter type encountered"; + case 37: return "illegal bit depth for this color type given"; + case 38: return "the palette is too big"; /*more than 256 colors*/ + case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette"; + case 40: return "tRNS chunk has wrong size for greyscale image"; + case 41: return "tRNS chunk has wrong size for RGB image"; + case 42: return "tRNS chunk appeared while it was not allowed for this color type"; + case 43: return "bKGD chunk has wrong size for palette image"; + case 44: return "bKGD chunk has wrong size for greyscale image"; + case 45: return "bKGD chunk has wrong size for RGB image"; + case 48: return "empty input buffer given to decoder. Maybe caused by non-existing file?"; + case 49: return "jumped past memory while generating dynamic huffman tree"; + case 50: return "jumped past memory while generating dynamic huffman tree"; + case 51: return "jumped past memory while inflating huffman block"; + case 52: return "jumped past memory while inflating"; + case 53: return "size of zlib data too small"; + case 54: return "repeat symbol in tree while there was no value symbol yet"; + /*jumped past tree while generating huffman tree, this could be when the + tree will have more leaves than symbols after generating it out of the + given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/ + case 55: return "jumped past tree while generating huffman tree"; + case 56: return "given output image colortype or bitdepth not supported for color conversion"; + case 57: return "invalid CRC encountered (checking CRC can be disabled)"; + case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)"; + case 59: return "requested color conversion not supported"; + case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)"; + case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)"; + /*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/ + case 62: return "conversion from color to greyscale not supported"; + case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/ + /*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/ + case 64: return "the length of the END symbol 256 in the Huffman tree is 0"; + case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes"; + case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte"; + case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors"; + case 69: return "unknown chunk type with 'critical' flag encountered by the decoder"; + case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)"; + case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)"; + case 73: return "invalid tIME chunk size"; + case 74: return "invalid pHYs chunk size"; + /*length could be wrong, or data chopped off*/ + case 75: return "no null termination char found while decoding text chunk"; + case 76: return "iTXt chunk too short to contain required bytes"; + case 77: return "integer overflow in buffer size"; + case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/ + case 79: return "failed to open file for writing"; + case 80: return "tried creating a tree of 0 symbols"; + case 81: return "lazy matching at pos 0 is impossible"; + case 82: return "color conversion to palette requested while a color isn't in palette"; + case 83: return "memory allocation failed"; + case 84: return "given image too small to contain all pixels to be encoded"; + case 86: return "impossible offset in lz77 encoding (internal bug)"; + case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined"; + case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy"; + case 89: return "text chunk keyword too short or long: must have size 1-79"; + /*the windowsize in the LodePNGCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/ + case 90: return "windowsize must be a power of two"; + case 91: return "invalid decompressed idat size"; + case 92: return "too many pixels, not supported"; + case 93: return "zero width or height is invalid"; + case 94: return "header chunk must have a size of 13 bytes"; + } + return "unknown error code"; +} +#endif /*LODEPNG_COMPILE_ERROR_TEXT*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // C++ Wrapper // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_CPP +namespace lodepng +{ + +#ifdef LODEPNG_COMPILE_DISK + unsigned load_file(std::vector& buffer, const std::string& filename) + { + long size = lodepng_filesize(filename.c_str()); + if (size < 0) return 78; + buffer.resize((size_t)size); + return size == 0 ? 0 : lodepng_buffer_file(&buffer[0], (size_t)size, filename.c_str()); + } + + /*write given buffer to the file, overwriting the file, it doesn't append to it.*/ + unsigned save_file(const std::vector& buffer, const std::string& filename) + { + return lodepng_save_file(buffer.empty() ? 0 : &buffer[0], buffer.size(), filename.c_str()); + } +#endif /* LODEPNG_COMPILE_DISK */ + +#ifdef LODEPNG_COMPILE_ZLIB +#ifdef LODEPNG_COMPILE_DECODER + unsigned decompress(std::vector& out, const unsigned char* in, size_t insize, + const LodePNGDecompressSettings& settings) + { + unsigned char* buffer = 0; + size_t buffersize = 0; + unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings); + if (buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + lodepng_free(buffer); + } + return error; + } + + unsigned decompress(std::vector& out, const std::vector& in, + const LodePNGDecompressSettings& settings) + { + return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings); + } +#endif /* LODEPNG_COMPILE_DECODER */ + +#ifdef LODEPNG_COMPILE_ENCODER + unsigned compress(std::vector& out, const unsigned char* in, size_t insize, + const LodePNGCompressSettings& settings) + { + unsigned char* buffer = 0; + size_t buffersize = 0; + unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings); + if (buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + lodepng_free(buffer); + } + return error; + } + + unsigned compress(std::vector& out, const std::vector& in, + const LodePNGCompressSettings& settings) + { + return compress(out, in.empty() ? 0 : &in[0], in.size(), settings); + } +#endif /* LODEPNG_COMPILE_ENCODER */ +#endif /* LODEPNG_COMPILE_ZLIB */ + + +#ifdef LODEPNG_COMPILE_PNG + + State::State() + { + lodepng_state_init(this); + } + + State::State(const State& other) + { + lodepng_state_init(this); + lodepng_state_copy(this, &other); + } + + State::~State() + { + lodepng_state_cleanup(this); + } + + State& State::operator=(const State& other) + { + lodepng_state_copy(this, &other); + return *this; + } + +#ifdef LODEPNG_COMPILE_DECODER + + unsigned decode(std::vector& out, unsigned& w, unsigned& h, const unsigned char* in, + size_t insize, LodePNGColorType colortype, unsigned bitdepth) + { + unsigned char* buffer; + unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth); + if (buffer && !error) + { + State state; + state.info_raw.colortype = colortype; + state.info_raw.bitdepth = bitdepth; + size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + lodepng_free(buffer); + } + return error; + } + + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + const std::vector& in, LodePNGColorType colortype, unsigned bitdepth) + { + return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth); + } + + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + State& state, + const unsigned char* in, size_t insize) + { + unsigned char* buffer = NULL; + unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize); + if (buffer && !error) + { + size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + } + lodepng_free(buffer); + return error; + } + + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + State& state, + const std::vector& in) + { + return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size()); + } + +#ifdef LODEPNG_COMPILE_DISK + unsigned decode(std::vector& out, unsigned& w, unsigned& h, const std::string& filename, + LodePNGColorType colortype, unsigned bitdepth) + { + std::vector buffer; + unsigned error = load_file(buffer, filename); + if (error) return error; + return decode(out, w, h, buffer, colortype, bitdepth); + } +#endif /* LODEPNG_COMPILE_DECODER */ +#endif /* LODEPNG_COMPILE_DISK */ + +#ifdef LODEPNG_COMPILE_ENCODER + unsigned encode(std::vector& out, const unsigned char* in, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth) + { + unsigned char* buffer; + size_t buffersize; + unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth); + if (buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + lodepng_free(buffer); + } + return error; + } + + unsigned encode(std::vector& out, + const std::vector& in, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth) + { + if (lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; + return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); + } + + unsigned encode(std::vector& out, + const unsigned char* in, unsigned w, unsigned h, + State& state) + { + unsigned char* buffer; + size_t buffersize; + unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state); + if (buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + lodepng_free(buffer); + } + return error; + } + + unsigned encode(std::vector& out, + const std::vector& in, unsigned w, unsigned h, + State& state) + { + if (lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84; + return encode(out, in.empty() ? 0 : &in[0], w, h, state); + } + +#ifdef LODEPNG_COMPILE_DISK + unsigned encode(const std::string& filename, + const unsigned char* in, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth) + { + std::vector buffer; + unsigned error = encode(buffer, in, w, h, colortype, bitdepth); + if (!error) error = save_file(buffer, filename); + return error; + } + + unsigned encode(const std::string& filename, + const std::vector& in, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth) + { + if (lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; + return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); + } +#endif /* LODEPNG_COMPILE_DISK */ +#endif /* LODEPNG_COMPILE_ENCODER */ +#endif /* LODEPNG_COMPILE_PNG */ +} /* namespace lodepng */ +#endif /*LODEPNG_COMPILE_CPP*/ diff --git a/lodepng.h b/lodepng.h new file mode 100644 index 0000000..df0f1e7 --- /dev/null +++ b/lodepng.h @@ -0,0 +1,1761 @@ +/* +LodePNG version 20161127 + +Copyright (c) 2005-2016 Lode Vandevenne + +This software is provided 'as-is', without any express or implied +warranty. In no event will the authors be held liable for any damages +arising from the use of this software. + +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it +freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + + 3. This notice may not be removed or altered from any source + distribution. +*/ + +#ifndef LODEPNG_H +#define LODEPNG_H + +#include /*for size_t*/ + +extern const char* LODEPNG_VERSION_STRING; + +/* +The following #defines are used to create code sections. They can be disabled +to disable code sections, which can give faster compile time and smaller binary. +The "NO_COMPILE" defines are designed to be used to pass as defines to the +compiler command to disable them without modifying this header, e.g. +-DLODEPNG_NO_COMPILE_ZLIB for gcc. +In addition to those below, you can also define LODEPNG_NO_COMPILE_CRC to +allow implementing a custom lodepng_crc32. +*/ +/*deflate & zlib. If disabled, you must specify alternative zlib functions in +the custom_zlib field of the compress and decompress settings*/ +#ifndef LODEPNG_NO_COMPILE_ZLIB +#define LODEPNG_COMPILE_ZLIB +#endif +/*png encoder and png decoder*/ +#ifndef LODEPNG_NO_COMPILE_PNG +#define LODEPNG_COMPILE_PNG +#endif +/*deflate&zlib decoder and png decoder*/ +#ifndef LODEPNG_NO_COMPILE_DECODER +#define LODEPNG_COMPILE_DECODER +#endif +/*deflate&zlib encoder and png encoder*/ +#ifndef LODEPNG_NO_COMPILE_ENCODER +#define LODEPNG_COMPILE_ENCODER +#endif +/*the optional built in harddisk file loading and saving functions*/ +#ifndef LODEPNG_NO_COMPILE_DISK +#define LODEPNG_COMPILE_DISK +#endif +/*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/ +#ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS +#define LODEPNG_COMPILE_ANCILLARY_CHUNKS +#endif +/*ability to convert error numerical codes to English text string*/ +#ifndef LODEPNG_NO_COMPILE_ERROR_TEXT +#define LODEPNG_COMPILE_ERROR_TEXT +#endif +/*Compile the default allocators (C's free, malloc and realloc). If you disable this, +you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your +source files with custom allocators.*/ +#ifndef LODEPNG_NO_COMPILE_ALLOCATORS +#define LODEPNG_COMPILE_ALLOCATORS +#endif +/*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/ +#ifdef __cplusplus +#ifndef LODEPNG_NO_COMPILE_CPP +#define LODEPNG_COMPILE_CPP +#endif +#endif + +#ifdef LODEPNG_COMPILE_CPP +#include +#include +#endif /*LODEPNG_COMPILE_CPP*/ + +#ifdef LODEPNG_COMPILE_PNG +/*The PNG color types (also used for raw).*/ +typedef enum LodePNGColorType +{ + LCT_GREY = 0, /*greyscale: 1,2,4,8,16 bit*/ + LCT_RGB = 2, /*RGB: 8,16 bit*/ + LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/ + LCT_GREY_ALPHA = 4, /*greyscale with alpha: 8,16 bit*/ + LCT_RGBA = 6 /*RGB with alpha: 8,16 bit*/ +} LodePNGColorType; + +#ifdef LODEPNG_COMPILE_DECODER +/* +Converts PNG data in memory to raw pixel data. +out: Output parameter. Pointer to buffer that will contain the raw pixel data. + After decoding, its size is w * h * (bytes per pixel) bytes larger than + initially. Bytes per pixel depends on colortype and bitdepth. + Must be freed after usage with free(*out). + Note: for 16-bit per channel colors, uses big endian format like PNG does. +w: Output parameter. Pointer to width of pixel data. +h: Output parameter. Pointer to height of pixel data. +in: Memory buffer with the PNG file. +insize: size of the in buffer. +colortype: the desired color type for the raw output image. See explanation on PNG color types. +bitdepth: the desired bit depth for the raw output image. See explanation on PNG color types. +Return value: LodePNG error code (0 means no error). +*/ +unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, + const unsigned char* in, size_t insize, + LodePNGColorType colortype, unsigned bitdepth); + +/*Same as lodepng_decode_memory, but always decodes to 32-bit RGBA raw image*/ +unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, + const unsigned char* in, size_t insize); + +/*Same as lodepng_decode_memory, but always decodes to 24-bit RGB raw image*/ +unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, + const unsigned char* in, size_t insize); + +#ifdef LODEPNG_COMPILE_DISK +/* +Load PNG from disk, from file with given name. +Same as the other decode functions, but instead takes a filename as input. +*/ +unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, + const char* filename, + LodePNGColorType colortype, unsigned bitdepth); + +/*Same as lodepng_decode_file, but always decodes to 32-bit RGBA raw image.*/ +unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, + const char* filename); + +/*Same as lodepng_decode_file, but always decodes to 24-bit RGB raw image.*/ +unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, + const char* filename); +#endif /*LODEPNG_COMPILE_DISK*/ +#endif /*LODEPNG_COMPILE_DECODER*/ + + +#ifdef LODEPNG_COMPILE_ENCODER +/* +Converts raw pixel data into a PNG image in memory. The colortype and bitdepth + of the output PNG image cannot be chosen, they are automatically determined + by the colortype, bitdepth and content of the input pixel data. + Note: for 16-bit per channel colors, needs big endian format like PNG does. +out: Output parameter. Pointer to buffer that will contain the PNG image data. + Must be freed after usage with free(*out). +outsize: Output parameter. Pointer to the size in bytes of the out buffer. +image: The raw pixel data to encode. The size of this buffer should be + w * h * (bytes per pixel), bytes per pixel depends on colortype and bitdepth. +w: width of the raw pixel data in pixels. +h: height of the raw pixel data in pixels. +colortype: the color type of the raw input image. See explanation on PNG color types. +bitdepth: the bit depth of the raw input image. See explanation on PNG color types. +Return value: LodePNG error code (0 means no error). +*/ +unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, + const unsigned char* image, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth); + +/*Same as lodepng_encode_memory, but always encodes from 32-bit RGBA raw image.*/ +unsigned lodepng_encode32(unsigned char** out, size_t* outsize, + const unsigned char* image, unsigned w, unsigned h); + +/*Same as lodepng_encode_memory, but always encodes from 24-bit RGB raw image.*/ +unsigned lodepng_encode24(unsigned char** out, size_t* outsize, + const unsigned char* image, unsigned w, unsigned h); + +#ifdef LODEPNG_COMPILE_DISK +/* +Converts raw pixel data into a PNG file on disk. +Same as the other encode functions, but instead takes a filename as output. +NOTE: This overwrites existing files without warning! +*/ +unsigned lodepng_encode_file(const char* filename, + const unsigned char* image, unsigned w, unsigned h, + LodePNGColorType colortype, unsigned bitdepth); + +/*Same as lodepng_encode_file, but always encodes from 32-bit RGBA raw image.*/ +unsigned lodepng_encode32_file(const char* filename, + const unsigned char* image, unsigned w, unsigned h); + +/*Same as lodepng_encode_file, but always encodes from 24-bit RGB raw image.*/ +unsigned lodepng_encode24_file(const char* filename, + const unsigned char* image, unsigned w, unsigned h); +#endif /*LODEPNG_COMPILE_DISK*/ +#endif /*LODEPNG_COMPILE_ENCODER*/ + + +#ifdef LODEPNG_COMPILE_CPP +namespace lodepng +{ +#ifdef LODEPNG_COMPILE_DECODER + /*Same as lodepng_decode_memory, but decodes to an std::vector. The colortype + is the format to output the pixels to. Default is RGBA 8-bit per channel.*/ + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + const unsigned char* in, size_t insize, + LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + const std::vector& in, + LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); +#ifdef LODEPNG_COMPILE_DISK + /* + Converts PNG file from disk to raw pixel data in memory. + Same as the other decode functions, but instead takes a filename as input. + */ + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + const std::string& filename, + LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); +#endif /* LODEPNG_COMPILE_DISK */ +#endif /* LODEPNG_COMPILE_DECODER */ + +#ifdef LODEPNG_COMPILE_ENCODER + /*Same as lodepng_encode_memory, but encodes to an std::vector. colortype + is that of the raw input data. The output PNG color type will be auto chosen.*/ + unsigned encode(std::vector& out, + const unsigned char* in, unsigned w, unsigned h, + LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); + unsigned encode(std::vector& out, + const std::vector& in, unsigned w, unsigned h, + LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); +#ifdef LODEPNG_COMPILE_DISK + /* + Converts 32-bit RGBA raw pixel data into a PNG file on disk. + Same as the other encode functions, but instead takes a filename as output. + NOTE: This overwrites existing files without warning! + */ + unsigned encode(const std::string& filename, + const unsigned char* in, unsigned w, unsigned h, + LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); + unsigned encode(const std::string& filename, + const std::vector& in, unsigned w, unsigned h, + LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); +#endif /* LODEPNG_COMPILE_DISK */ +#endif /* LODEPNG_COMPILE_ENCODER */ +} /* namespace lodepng */ +#endif /*LODEPNG_COMPILE_CPP*/ +#endif /*LODEPNG_COMPILE_PNG*/ + +#ifdef LODEPNG_COMPILE_ERROR_TEXT +/*Returns an English description of the numerical error code.*/ +const char* lodepng_error_text(unsigned code); +#endif /*LODEPNG_COMPILE_ERROR_TEXT*/ + +#ifdef LODEPNG_COMPILE_DECODER +/*Settings for zlib decompression*/ +typedef struct LodePNGDecompressSettings LodePNGDecompressSettings; +struct LodePNGDecompressSettings +{ + unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/ + + /*use custom zlib decoder instead of built in one (default: null)*/ + unsigned(*custom_zlib)(unsigned char**, size_t*, + const unsigned char*, size_t, + const LodePNGDecompressSettings*); + /*use custom deflate decoder instead of built in one (default: null) + if custom_zlib is used, custom_deflate is ignored since only the built in + zlib function will call custom_deflate*/ + unsigned(*custom_inflate)(unsigned char**, size_t*, + const unsigned char*, size_t, + const LodePNGDecompressSettings*); + + const void* custom_context; /*optional custom settings for custom functions*/ +}; + +extern const LodePNGDecompressSettings lodepng_default_decompress_settings; +void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings); +#endif /*LODEPNG_COMPILE_DECODER*/ + +#ifdef LODEPNG_COMPILE_ENCODER +/* +Settings for zlib compression. Tweaking these settings tweaks the balance +between speed and compression ratio. +*/ +typedef struct LodePNGCompressSettings LodePNGCompressSettings; +struct LodePNGCompressSettings /*deflate = compress*/ +{ + /*LZ77 related settings*/ + unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/ + unsigned use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/ + unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Default value: 2048.*/ + unsigned minmatch; /*mininum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/ + unsigned nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/ + unsigned lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/ + + /*use custom zlib encoder instead of built in one (default: null)*/ + unsigned(*custom_zlib)(unsigned char**, size_t*, + const unsigned char*, size_t, + const LodePNGCompressSettings*); + /*use custom deflate encoder instead of built in one (default: null) + if custom_zlib is used, custom_deflate is ignored since only the built in + zlib function will call custom_deflate*/ + unsigned(*custom_deflate)(unsigned char**, size_t*, + const unsigned char*, size_t, + const LodePNGCompressSettings*); + + const void* custom_context; /*optional custom settings for custom functions*/ +}; + +extern const LodePNGCompressSettings lodepng_default_compress_settings; +void lodepng_compress_settings_init(LodePNGCompressSettings* settings); +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#ifdef LODEPNG_COMPILE_PNG +/* +Color mode of an image. Contains all information required to decode the pixel +bits to RGBA colors. This information is the same as used in the PNG file +format, and is used both for PNG and raw image data in LodePNG. +*/ +typedef struct LodePNGColorMode +{ + /*header (IHDR)*/ + LodePNGColorType colortype; /*color type, see PNG standard or documentation further in this header file*/ + unsigned bitdepth; /*bits per sample, see PNG standard or documentation further in this header file*/ + + /* + palette (PLTE and tRNS) + + Dynamically allocated with the colors of the palette, including alpha. + When encoding a PNG, to store your colors in the palette of the LodePNGColorMode, first use + lodepng_palette_clear, then for each color use lodepng_palette_add. + If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette. + + When decoding, by default you can ignore this palette, since LodePNG already + fills the palette colors in the pixels of the raw RGBA output. + + The palette is only supported for color type 3. + */ + unsigned char* palette; /*palette in RGBARGBA... order. When allocated, must be either 0, or have size 1024*/ + size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/ + + /* + transparent color key (tRNS) + + This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit. + For greyscale PNGs, r, g and b will all 3 be set to the same. + + When decoding, by default you can ignore this information, since LodePNG sets + pixels with this key to transparent already in the raw RGBA output. + + The color key is only supported for color types 0 and 2. + */ + unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/ + unsigned key_r; /*red/greyscale component of color key*/ + unsigned key_g; /*green component of color key*/ + unsigned key_b; /*blue component of color key*/ +} LodePNGColorMode; + +/*init, cleanup and copy functions to use with this struct*/ +void lodepng_color_mode_init(LodePNGColorMode* info); +void lodepng_color_mode_cleanup(LodePNGColorMode* info); +/*return value is error code (0 means no error)*/ +unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source); + +void lodepng_palette_clear(LodePNGColorMode* info); +/*add 1 color to the palette*/ +unsigned lodepng_palette_add(LodePNGColorMode* info, + unsigned char r, unsigned char g, unsigned char b, unsigned char a); + +/*get the total amount of bits per pixel, based on colortype and bitdepth in the struct*/ +unsigned lodepng_get_bpp(const LodePNGColorMode* info); +/*get the amount of color channels used, based on colortype in the struct. +If a palette is used, it counts as 1 channel.*/ +unsigned lodepng_get_channels(const LodePNGColorMode* info); +/*is it a greyscale type? (only colortype 0 or 4)*/ +unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info); +/*has it got an alpha channel? (only colortype 2 or 6)*/ +unsigned lodepng_is_alpha_type(const LodePNGColorMode* info); +/*has it got a palette? (only colortype 3)*/ +unsigned lodepng_is_palette_type(const LodePNGColorMode* info); +/*only returns true if there is a palette and there is a value in the palette with alpha < 255. +Loops through the palette to check this.*/ +unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info); +/* +Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image. +Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels). +Returns false if the image can only have opaque pixels. +In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values, +or if "key_defined" is true. +*/ +unsigned lodepng_can_have_alpha(const LodePNGColorMode* info); +/*Returns the byte size of a raw image buffer with given width, height and color mode*/ +size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color); + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS +/*The information of a Time chunk in PNG.*/ +typedef struct LodePNGTime +{ + unsigned year; /*2 bytes used (0-65535)*/ + unsigned month; /*1-12*/ + unsigned day; /*1-31*/ + unsigned hour; /*0-23*/ + unsigned minute; /*0-59*/ + unsigned second; /*0-60 (to allow for leap seconds)*/ +} LodePNGTime; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +/*Information about the PNG image, except pixels, width and height.*/ +typedef struct LodePNGInfo +{ + /*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/ + unsigned compression_method;/*compression method of the original file. Always 0.*/ + unsigned filter_method; /*filter method of the original file*/ + unsigned interlace_method; /*interlace method of the original file*/ + LodePNGColorMode color; /*color type and bits, palette and transparency of the PNG file*/ + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /* + suggested background color chunk (bKGD) + This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit. + + For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding + the encoder writes the red one. For palette PNGs: When decoding, the RGB value + will be stored, not a palette index. But when encoding, specify the index of + the palette in background_r, the other two are then ignored. + + The decoder does not use this background color to edit the color of pixels. + */ + unsigned background_defined; /*is a suggested background color given?*/ + unsigned background_r; /*red component of suggested background color*/ + unsigned background_g; /*green component of suggested background color*/ + unsigned background_b; /*blue component of suggested background color*/ + + /* + non-international text chunks (tEXt and zTXt) + + The char** arrays each contain num strings. The actual messages are in + text_strings, while text_keys are keywords that give a short description what + the actual text represents, e.g. Title, Author, Description, or anything else. + + A keyword is minimum 1 character and maximum 79 characters long. It's + discouraged to use a single line length longer than 79 characters for texts. + + Don't allocate these text buffers yourself. Use the init/cleanup functions + correctly and use lodepng_add_text and lodepng_clear_text. + */ + size_t text_num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/ + char** text_keys; /*the keyword of a text chunk (e.g. "Comment")*/ + char** text_strings; /*the actual text*/ + + /* + international text chunks (iTXt) + Similar to the non-international text chunks, but with additional strings + "langtags" and "transkeys". + */ + size_t itext_num; /*the amount of international texts in this PNG*/ + char** itext_keys; /*the English keyword of the text chunk (e.g. "Comment")*/ + char** itext_langtags; /*language tag for this text's language, ISO/IEC 646 string, e.g. ISO 639 language tag*/ + char** itext_transkeys; /*keyword translated to the international language - UTF-8 string*/ + char** itext_strings; /*the actual international text - UTF-8 string*/ + + /*time chunk (tIME)*/ + unsigned time_defined; /*set to 1 to make the encoder generate a tIME chunk*/ + LodePNGTime time; + + /*phys chunk (pHYs)*/ + unsigned phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/ + unsigned phys_x; /*pixels per unit in x direction*/ + unsigned phys_y; /*pixels per unit in y direction*/ + unsigned phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/ + + /* + unknown chunks + There are 3 buffers, one for each position in the PNG where unknown chunks can appear + each buffer contains all unknown chunks for that position consecutively + The 3 buffers are the unknown chunks between certain critical chunks: + 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND + Do not allocate or traverse this data yourself. Use the chunk traversing functions declared + later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct. + */ + unsigned char* unknown_chunks_data[3]; + size_t unknown_chunks_size[3]; /*size in bytes of the unknown chunks, given for protection*/ +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +} LodePNGInfo; + +/*init, cleanup and copy functions to use with this struct*/ +void lodepng_info_init(LodePNGInfo* info); +void lodepng_info_cleanup(LodePNGInfo* info); +/*return value is error code (0 means no error)*/ +unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source); + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS +void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/ +unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/ + +void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/ +unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, + const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/ +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +/* +Converts raw buffer from one color type to another color type, based on +LodePNGColorMode structs to describe the input and output color type. +See the reference manual at the end of this header file to see which color conversions are supported. +return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported) +The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel +of the output color type (lodepng_get_bpp). +For < 8 bpp images, there should not be padding bits at the end of scanlines. +For 16-bit per channel colors, uses big endian format like PNG does. +Return value is LodePNG error code +*/ +unsigned lodepng_convert(unsigned char* out, const unsigned char* in, + const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, + unsigned w, unsigned h); + +#ifdef LODEPNG_COMPILE_DECODER +/* +Settings for the decoder. This contains settings for the PNG and the Zlib +decoder, but not the Info settings from the Info structs. +*/ +typedef struct LodePNGDecoderSettings +{ + LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/ + + unsigned ignore_crc; /*ignore CRC checksums*/ + + unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/ + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + unsigned read_text_chunks; /*if false but remember_unknown_chunks is true, they're stored in the unknown chunks*/ + /*store all bytes from unknown chunks in the LodePNGInfo (off by default, useful for a png editor)*/ + unsigned remember_unknown_chunks; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +} LodePNGDecoderSettings; + +void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings); +#endif /*LODEPNG_COMPILE_DECODER*/ + +#ifdef LODEPNG_COMPILE_ENCODER +/*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/ +typedef enum LodePNGFilterStrategy +{ + /*every filter at zero*/ + LFS_ZERO, + /*Use filter that gives minimum sum, as described in the official PNG filter heuristic.*/ + LFS_MINSUM, + /*Use the filter type that gives smallest Shannon entropy for this scanline. Depending + on the image, this is better or worse than minsum.*/ + LFS_ENTROPY, + /* + Brute-force-search PNG filters by compressing each filter for each scanline. + Experimental, very slow, and only rarely gives better compression than MINSUM. + */ + LFS_BRUTE_FORCE, + /*use predefined_filters buffer: you specify the filter type for each scanline*/ + LFS_PREDEFINED +} LodePNGFilterStrategy; + +/*Gives characteristics about the colors of the image, which helps decide which color model to use for encoding. +Used internally by default if "auto_convert" is enabled. Public because it's useful for custom algorithms.*/ +typedef struct LodePNGColorProfile +{ + unsigned colored; /*not greyscale*/ + unsigned key; /*image is not opaque and color key is possible instead of full alpha*/ + unsigned short key_r; /*key values, always as 16-bit, in 8-bit case the byte is duplicated, e.g. 65535 means 255*/ + unsigned short key_g; + unsigned short key_b; + unsigned alpha; /*image is not opaque and alpha channel or alpha palette required*/ + unsigned numcolors; /*amount of colors, up to 257. Not valid if bits == 16.*/ + unsigned char palette[1024]; /*Remembers up to the first 256 RGBA colors, in no particular order*/ + unsigned bits; /*bits per channel (not for palette). 1,2 or 4 for greyscale only. 16 if 16-bit per channel required.*/ +} LodePNGColorProfile; + +void lodepng_color_profile_init(LodePNGColorProfile* profile); + +/*Get a LodePNGColorProfile of the image.*/ +unsigned lodepng_get_color_profile(LodePNGColorProfile* profile, + const unsigned char* image, unsigned w, unsigned h, + const LodePNGColorMode* mode_in); +/*The function LodePNG uses internally to decide the PNG color with auto_convert. +Chooses an optimal color model, e.g. grey if only grey pixels, palette if < 256 colors, ...*/ +unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, + const unsigned char* image, unsigned w, unsigned h, + const LodePNGColorMode* mode_in); + +/*Settings for the encoder.*/ +typedef struct LodePNGEncoderSettings +{ + LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/ + + unsigned auto_convert; /*automatically choose output PNG color type. Default: true*/ + + /*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than + 8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to + completely follow the official PNG heuristic, filter_palette_zero must be true and + filter_strategy must be LFS_MINSUM*/ + unsigned filter_palette_zero; + /*Which filter strategy to use when not using zeroes due to filter_palette_zero. + Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: LFS_MINSUM*/ + LodePNGFilterStrategy filter_strategy; + /*used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with + the same length as the amount of scanlines in the image, and each value must <= 5. You + have to cleanup this buffer, LodePNG will never free it. Don't forget that filter_palette_zero + must be set to 0 to ensure this is also used on palette or low bitdepth images.*/ + const unsigned char* predefined_filters; + + /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette). + If colortype is 3, PLTE is _always_ created.*/ + unsigned force_palette; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /*add LodePNG identifier and version as a text chunk, for debugging*/ + unsigned add_id; + /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/ + unsigned text_compression; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +} LodePNGEncoderSettings; + +void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings); +#endif /*LODEPNG_COMPILE_ENCODER*/ + + +#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) +/*The settings, state and information for extended encoding and decoding.*/ +typedef struct LodePNGState +{ +#ifdef LODEPNG_COMPILE_DECODER + LodePNGDecoderSettings decoder; /*the decoding settings*/ +#endif /*LODEPNG_COMPILE_DECODER*/ +#ifdef LODEPNG_COMPILE_ENCODER + LodePNGEncoderSettings encoder; /*the encoding settings*/ +#endif /*LODEPNG_COMPILE_ENCODER*/ + LodePNGColorMode info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/ + LodePNGInfo info_png; /*info of the PNG image obtained after decoding*/ + unsigned error; +#ifdef LODEPNG_COMPILE_CPP + /* For the lodepng::State subclass. */ + virtual ~LodePNGState() {} +#endif +} LodePNGState; + +/*init, cleanup and copy functions to use with this struct*/ +void lodepng_state_init(LodePNGState* state); +void lodepng_state_cleanup(LodePNGState* state); +void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source); +#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */ + +#ifdef LODEPNG_COMPILE_DECODER +/* +Same as lodepng_decode_memory, but uses a LodePNGState to allow custom settings and +getting much more information about the PNG image and color mode. +*/ +unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, + LodePNGState* state, + const unsigned char* in, size_t insize); + +/* +Read the PNG header, but not the actual data. This returns only the information +that is in the header chunk of the PNG, such as width, height and color type. The +information is placed in the info_png field of the LodePNGState. +*/ +unsigned lodepng_inspect(unsigned* w, unsigned* h, + LodePNGState* state, + const unsigned char* in, size_t insize); +#endif /*LODEPNG_COMPILE_DECODER*/ + + +#ifdef LODEPNG_COMPILE_ENCODER +/*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/ +unsigned lodepng_encode(unsigned char** out, size_t* outsize, + const unsigned char* image, unsigned w, unsigned h, + LodePNGState* state); +#endif /*LODEPNG_COMPILE_ENCODER*/ + +/* +The lodepng_chunk functions are normally not needed, except to traverse the +unknown chunks stored in the LodePNGInfo struct, or add new ones to it. +It also allows traversing the chunks of an encoded PNG file yourself. + +PNG standard chunk naming conventions: +First byte: uppercase = critical, lowercase = ancillary +Second byte: uppercase = public, lowercase = private +Third byte: must be uppercase +Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy +*/ + +/* +Gets the length of the data of the chunk. Total chunk length has 12 bytes more. +There must be at least 4 bytes to read from. If the result value is too large, +it may be corrupt data. +*/ +unsigned lodepng_chunk_length(const unsigned char* chunk); + +/*puts the 4-byte type in null terminated string*/ +void lodepng_chunk_type(char type[5], const unsigned char* chunk); + +/*check if the type is the given type*/ +unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type); + +/*0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard)*/ +unsigned char lodepng_chunk_ancillary(const unsigned char* chunk); + +/*0: public, 1: private (see PNG standard)*/ +unsigned char lodepng_chunk_private(const unsigned char* chunk); + +/*0: the chunk is unsafe to copy, 1: the chunk is safe to copy (see PNG standard)*/ +unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk); + +/*get pointer to the data of the chunk, where the input points to the header of the chunk*/ +unsigned char* lodepng_chunk_data(unsigned char* chunk); +const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk); + +/*returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!)*/ +unsigned lodepng_chunk_check_crc(const unsigned char* chunk); + +/*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/ +void lodepng_chunk_generate_crc(unsigned char* chunk); + +/*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/ +unsigned char* lodepng_chunk_next(unsigned char* chunk); +const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk); + +/* +Appends chunk to the data in out. The given chunk should already have its chunk header. +The out variable and outlength are updated to reflect the new reallocated buffer. +Returns error code (0 if it went ok) +*/ +unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk); + +/* +Appends new chunk to out. The chunk to append is given by giving its length, type +and data separately. The type is a 4-letter string. +The out variable and outlength are updated to reflect the new reallocated buffer. +Returne error code (0 if it went ok) +*/ +unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, + const char* type, const unsigned char* data); + + +/*Calculate CRC32 of buffer*/ +unsigned lodepng_crc32(const unsigned char* buf, size_t len); +#endif /*LODEPNG_COMPILE_PNG*/ + + +#ifdef LODEPNG_COMPILE_ZLIB +/* +This zlib part can be used independently to zlib compress and decompress a +buffer. It cannot be used to create gzip files however, and it only supports the +part of zlib that is required for PNG, it does not support dictionaries. +*/ + +#ifdef LODEPNG_COMPILE_DECODER +/*Inflate a buffer. Inflate is the decompression step of deflate. Out buffer must be freed after use.*/ +unsigned lodepng_inflate(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGDecompressSettings* settings); + +/* +Decompresses Zlib data. Reallocates the out buffer and appends the data. The +data must be according to the zlib specification. +Either, *out must be NULL and *outsize must be 0, or, *out must be a valid +buffer and *outsize its size in bytes. out must be freed by user after usage. +*/ +unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGDecompressSettings* settings); +#endif /*LODEPNG_COMPILE_DECODER*/ + +#ifdef LODEPNG_COMPILE_ENCODER +/* +Compresses data with Zlib. Reallocates the out buffer and appends the data. +Zlib adds a small header and trailer around the deflate data. +The data is output in the format of the zlib specification. +Either, *out must be NULL and *outsize must be 0, or, *out must be a valid +buffer and *outsize its size in bytes. out must be freed by user after usage. +*/ +unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGCompressSettings* settings); + +/* +Find length-limited Huffman code for given frequencies. This function is in the +public interface only for tests, it's used internally by lodepng_deflate. +*/ +unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, + size_t numcodes, unsigned maxbitlen); + +/*Compress a buffer with deflate. See RFC 1951. Out buffer must be freed after use.*/ +unsigned lodepng_deflate(unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize, + const LodePNGCompressSettings* settings); + +#endif /*LODEPNG_COMPILE_ENCODER*/ +#endif /*LODEPNG_COMPILE_ZLIB*/ + +#ifdef LODEPNG_COMPILE_DISK +/* +Load a file from disk into buffer. The function allocates the out buffer, and +after usage you should free it. +out: output parameter, contains pointer to loaded buffer. +outsize: output parameter, size of the allocated out buffer +filename: the path to the file to load +return value: error code (0 means ok) +*/ +unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename); + +/* +Save a file from buffer to disk. Warning, if it exists, this function overwrites +the file without warning! +buffer: the buffer to write +buffersize: size of the buffer to write +filename: the path to the file to save to +return value: error code (0 means ok) +*/ +unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename); +#endif /*LODEPNG_COMPILE_DISK*/ + +#ifdef LODEPNG_COMPILE_CPP +/* The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers. */ +namespace lodepng +{ +#ifdef LODEPNG_COMPILE_PNG + class State : public LodePNGState + { + public: + State(); + State(const State& other); + virtual ~State(); + State& operator=(const State& other); + }; + +#ifdef LODEPNG_COMPILE_DECODER + /* Same as other lodepng::decode, but using a State for more settings and information. */ + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + State& state, + const unsigned char* in, size_t insize); + unsigned decode(std::vector& out, unsigned& w, unsigned& h, + State& state, + const std::vector& in); +#endif /*LODEPNG_COMPILE_DECODER*/ + +#ifdef LODEPNG_COMPILE_ENCODER + /* Same as other lodepng::encode, but using a State for more settings and information. */ + unsigned encode(std::vector& out, + const unsigned char* in, unsigned w, unsigned h, + State& state); + unsigned encode(std::vector& out, + const std::vector& in, unsigned w, unsigned h, + State& state); +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#ifdef LODEPNG_COMPILE_DISK + /* + Load a file from disk into an std::vector. + return value: error code (0 means ok) + */ + unsigned load_file(std::vector& buffer, const std::string& filename); + + /* + Save the binary data in an std::vector to a file on disk. The file is overwritten + without warning. + */ + unsigned save_file(const std::vector& buffer, const std::string& filename); +#endif /* LODEPNG_COMPILE_DISK */ +#endif /* LODEPNG_COMPILE_PNG */ + +#ifdef LODEPNG_COMPILE_ZLIB +#ifdef LODEPNG_COMPILE_DECODER + /* Zlib-decompress an unsigned char buffer */ + unsigned decompress(std::vector& out, const unsigned char* in, size_t insize, + const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings); + + /* Zlib-decompress an std::vector */ + unsigned decompress(std::vector& out, const std::vector& in, + const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings); +#endif /* LODEPNG_COMPILE_DECODER */ + +#ifdef LODEPNG_COMPILE_ENCODER + /* Zlib-compress an unsigned char buffer */ + unsigned compress(std::vector& out, const unsigned char* in, size_t insize, + const LodePNGCompressSettings& settings = lodepng_default_compress_settings); + + /* Zlib-compress an std::vector */ + unsigned compress(std::vector& out, const std::vector& in, + const LodePNGCompressSettings& settings = lodepng_default_compress_settings); +#endif /* LODEPNG_COMPILE_ENCODER */ +#endif /* LODEPNG_COMPILE_ZLIB */ +} /* namespace lodepng */ +#endif /*LODEPNG_COMPILE_CPP*/ + +/* +TODO: +[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often +[.] check compatibility with various compilers - done but needs to be redone for every newer version +[X] converting color to 16-bit per channel types +[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values) +[ ] make sure encoder generates no chunks with size > (2^31)-1 +[ ] partial decoding (stream processing) +[X] let the "isFullyOpaque" function check color keys and transparent palettes too +[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl" +[ ] don't stop decoding on errors like 69, 57, 58 (make warnings) +[ ] make warnings like: oob palette, checksum fail, data after iend, wrong/unknown crit chunk, no null terminator in text, ... +[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes +[ ] allow user to provide custom color conversion functions, e.g. for premultiplied alpha, padding bits or not, ... +[ ] allow user to give data (void*) to custom allocator +*/ + +#endif /*LODEPNG_H inclusion guard*/ + +/* +LodePNG Documentation +--------------------- + +0. table of contents +-------------------- + + 1. about + 1.1. supported features + 1.2. features not supported + 2. C and C++ version + 3. security + 4. decoding + 5. encoding + 6. color conversions + 6.1. PNG color types + 6.2. color conversions + 6.3. padding bits + 6.4. A note about 16-bits per channel and endianness + 7. error values + 8. chunks and PNG editing + 9. compiler support + 10. examples + 10.1. decoder C++ example + 10.2. decoder C example + 11. state settings reference + 12. changes + 13. contact information + + +1. about +-------- + +PNG is a file format to store raster images losslessly with good compression, +supporting different color types and alpha channel. + +LodePNG is a PNG codec according to the Portable Network Graphics (PNG) +Specification (Second Edition) - W3C Recommendation 10 November 2003. + +The specifications used are: + +*) Portable Network Graphics (PNG) Specification (Second Edition): + http://www.w3.org/TR/2003/REC-PNG-20031110 +*) RFC 1950 ZLIB Compressed Data Format version 3.3: + http://www.gzip.org/zlib/rfc-zlib.html +*) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3: + http://www.gzip.org/zlib/rfc-deflate.html + +The most recent version of LodePNG can currently be found at +http://lodev.org/lodepng/ + +LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds +extra functionality. + +LodePNG exists out of two files: +-lodepng.h: the header file for both C and C++ +-lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage + +If you want to start using LodePNG right away without reading this doc, get the +examples from the LodePNG website to see how to use it in code, or check the +smaller examples in chapter 13 here. + +LodePNG is simple but only supports the basic requirements. To achieve +simplicity, the following design choices were made: There are no dependencies +on any external library. There are functions to decode and encode a PNG with +a single function call, and extended versions of these functions taking a +LodePNGState struct allowing to specify or get more information. By default +the colors of the raw image are always RGB or RGBA, no matter what color type +the PNG file uses. To read and write files, there are simple functions to +convert the files to/from buffers in memory. + +This all makes LodePNG suitable for loading textures in games, demos and small +programs, ... It's less suitable for full fledged image editors, loading PNGs +over network (it requires all the image data to be available before decoding can +begin), life-critical systems, ... + +1.1. supported features +----------------------- + +The following features are supported by the decoder: + +*) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image, + or the same color type as the PNG +*) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image +*) Adam7 interlace and deinterlace for any color type +*) loading the image from harddisk or decoding it from a buffer from other sources than harddisk +*) support for alpha channels, including RGBA color model, translucent palettes and color keying +*) zlib decompression (inflate) +*) zlib compression (deflate) +*) CRC32 and ADLER32 checksums +*) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks. +*) the following chunks are supported (generated/interpreted) by both encoder and decoder: + IHDR: header information + PLTE: color palette + IDAT: pixel data + IEND: the final chunk + tRNS: transparency for palettized images + tEXt: textual information + zTXt: compressed textual information + iTXt: international textual information + bKGD: suggested background color + pHYs: physical dimensions + tIME: modification time + +1.2. features not supported +--------------------------- + +The following features are _not_ supported: + +*) some features needed to make a conformant PNG-Editor might be still missing. +*) partial loading/stream processing. All data must be available and is processed in one call. +*) The following public chunks are not supported but treated as unknown chunks by LodePNG + cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT + Some of these are not supported on purpose: LodePNG wants to provide the RGB values + stored in the pixels, not values modified by system dependent gamma or color models. + + +2. C and C++ version +-------------------- + +The C version uses buffers allocated with alloc that you need to free() +yourself. You need to use init and cleanup functions for each struct whenever +using a struct from the C version to avoid exploits and memory leaks. + +The C++ version has extra functions with std::vectors in the interface and the +lodepng::State class which is a LodePNGState with constructor and destructor. + +These files work without modification for both C and C++ compilers because all +the additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers +ignore it, and the C code is made to compile both with strict ISO C90 and C++. + +To use the C++ version, you need to rename the source file to lodepng.cpp +(instead of lodepng.c), and compile it with a C++ compiler. + +To use the C version, you need to rename the source file to lodepng.c (instead +of lodepng.cpp), and compile it with a C compiler. + + +3. Security +----------- + +Even if carefully designed, it's always possible that LodePNG contains possible +exploits. If you discover one, please let me know, and it will be fixed. + +When using LodePNG, care has to be taken with the C version of LodePNG, as well +as the C-style structs when working with C++. The following conventions are used +for all C-style structs: + +-if a struct has a corresponding init function, always call the init function when making a new one +-if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks +-if a struct has a corresponding copy function, use the copy function instead of "=". + The destination must also be inited already. + + +4. Decoding +----------- + +Decoding converts a PNG compressed image to a raw pixel buffer. + +Most documentation on using the decoder is at its declarations in the header +above. For C, simple decoding can be done with functions such as +lodepng_decode32, and more advanced decoding can be done with the struct +LodePNGState and lodepng_decode. For C++, all decoding can be done with the +various lodepng::decode functions, and lodepng::State can be used for advanced +features. + +When using the LodePNGState, it uses the following fields for decoding: +*) LodePNGInfo info_png: it stores extra information about the PNG (the input) in here +*) LodePNGColorMode info_raw: here you can say what color mode of the raw image (the output) you want to get +*) LodePNGDecoderSettings decoder: you can specify a few extra settings for the decoder to use + +LodePNGInfo info_png +-------------------- + +After decoding, this contains extra information of the PNG image, except the actual +pixels, width and height because these are already gotten directly from the decoder +functions. + +It contains for example the original color type of the PNG image, text comments, +suggested background color, etc... More details about the LodePNGInfo struct are +at its declaration documentation. + +LodePNGColorMode info_raw +------------------------- + +When decoding, here you can specify which color type you want +the resulting raw image to be. If this is different from the colortype of the +PNG, then the decoder will automatically convert the result. This conversion +always works, except if you want it to convert a color PNG to greyscale or to +a palette with missing colors. + +By default, 32-bit color is used for the result. + +LodePNGDecoderSettings decoder +------------------------------ + +The settings can be used to ignore the errors created by invalid CRC and Adler32 +chunks, and to disable the decoding of tEXt chunks. + +There's also a setting color_convert, true by default. If false, no conversion +is done, the resulting data will be as it was in the PNG (after decompression) +and you'll have to puzzle the colors of the pixels together yourself using the +color type information in the LodePNGInfo. + + +5. Encoding +----------- + +Encoding converts a raw pixel buffer to a PNG compressed image. + +Most documentation on using the encoder is at its declarations in the header +above. For C, simple encoding can be done with functions such as +lodepng_encode32, and more advanced decoding can be done with the struct +LodePNGState and lodepng_encode. For C++, all encoding can be done with the +various lodepng::encode functions, and lodepng::State can be used for advanced +features. + +Like the decoder, the encoder can also give errors. However it gives less errors +since the encoder input is trusted, the decoder input (a PNG image that could +be forged by anyone) is not trusted. + +When using the LodePNGState, it uses the following fields for encoding: +*) LodePNGInfo info_png: here you specify how you want the PNG (the output) to be. +*) LodePNGColorMode info_raw: here you say what color type of the raw image (the input) has +*) LodePNGEncoderSettings encoder: you can specify a few settings for the encoder to use + +LodePNGInfo info_png +-------------------- + +When encoding, you use this the opposite way as when decoding: for encoding, +you fill in the values you want the PNG to have before encoding. By default it's +not needed to specify a color type for the PNG since it's automatically chosen, +but it's possible to choose it yourself given the right settings. + +The encoder will not always exactly match the LodePNGInfo struct you give, +it tries as close as possible. Some things are ignored by the encoder. The +encoder uses, for example, the following settings from it when applicable: +colortype and bitdepth, text chunks, time chunk, the color key, the palette, the +background color, the interlace method, unknown chunks, ... + +When encoding to a PNG with colortype 3, the encoder will generate a PLTE chunk. +If the palette contains any colors for which the alpha channel is not 255 (so +there are translucent colors in the palette), it'll add a tRNS chunk. + +LodePNGColorMode info_raw +------------------------- + +You specify the color type of the raw image that you give to the input here, +including a possible transparent color key and palette you happen to be using in +your raw image data. + +By default, 32-bit color is assumed, meaning your input has to be in RGBA +format with 4 bytes (unsigned chars) per pixel. + +LodePNGEncoderSettings encoder +------------------------------ + +The following settings are supported (some are in sub-structs): +*) auto_convert: when this option is enabled, the encoder will +automatically choose the smallest possible color mode (including color key) that +can encode the colors of all pixels without information loss. +*) btype: the block type for LZ77. 0 = uncompressed, 1 = fixed huffman tree, + 2 = dynamic huffman tree (best compression). Should be 2 for proper + compression. +*) use_lz77: whether or not to use LZ77 for compressed block types. Should be + true for proper compression. +*) windowsize: the window size used by the LZ77 encoder (1 - 32768). Has value + 2048 by default, but can be set to 32768 for better, but slow, compression. +*) force_palette: if colortype is 2 or 6, you can make the encoder write a PLTE + chunk if force_palette is true. This can used as suggested palette to convert + to by viewers that don't support more than 256 colors (if those still exist) +*) add_id: add text chunk "Encoder: LodePNG " to the image. +*) text_compression: default 1. If 1, it'll store texts as zTXt instead of tEXt chunks. + zTXt chunks use zlib compression on the text. This gives a smaller result on + large texts but a larger result on small texts (such as a single program name). + It's all tEXt or all zTXt though, there's no separate setting per text yet. + + +6. color conversions +-------------------- + +An important thing to note about LodePNG, is that the color type of the PNG, and +the color type of the raw image, are completely independent. By default, when +you decode a PNG, you get the result as a raw image in the color type you want, +no matter whether the PNG was encoded with a palette, greyscale or RGBA color. +And if you encode an image, by default LodePNG will automatically choose the PNG +color type that gives good compression based on the values of colors and amount +of colors in the image. It can be configured to let you control it instead as +well, though. + +To be able to do this, LodePNG does conversions from one color mode to another. +It can convert from almost any color type to any other color type, except the +following conversions: RGB to greyscale is not supported, and converting to a +palette when the palette doesn't have a required color is not supported. This is +not supported on purpose: this is information loss which requires a color +reduction algorithm that is beyong the scope of a PNG encoder (yes, RGB to grey +is easy, but there are multiple ways if you want to give some channels more +weight). + +By default, when decoding, you get the raw image in 32-bit RGBA or 24-bit RGB +color, no matter what color type the PNG has. And by default when encoding, +LodePNG automatically picks the best color model for the output PNG, and expects +the input image to be 32-bit RGBA or 24-bit RGB. So, unless you want to control +the color format of the images yourself, you can skip this chapter. + +6.1. PNG color types +-------------------- + +A PNG image can have many color types, ranging from 1-bit color to 64-bit color, +as well as palettized color modes. After the zlib decompression and unfiltering +in the PNG image is done, the raw pixel data will have that color type and thus +a certain amount of bits per pixel. If you want the output raw image after +decoding to have another color type, a conversion is done by LodePNG. + +The PNG specification gives the following color types: + +0: greyscale, bit depths 1, 2, 4, 8, 16 +2: RGB, bit depths 8 and 16 +3: palette, bit depths 1, 2, 4 and 8 +4: greyscale with alpha, bit depths 8 and 16 +6: RGBA, bit depths 8 and 16 + +Bit depth is the amount of bits per pixel per color channel. So the total amount +of bits per pixel is: amount of channels * bitdepth. + +6.2. color conversions +---------------------- + +As explained in the sections about the encoder and decoder, you can specify +color types and bit depths in info_png and info_raw to change the default +behaviour. + +If, when decoding, you want the raw image to be something else than the default, +you need to set the color type and bit depth you want in the LodePNGColorMode, +or the parameters colortype and bitdepth of the simple decoding function. + +If, when encoding, you use another color type than the default in the raw input +image, you need to specify its color type and bit depth in the LodePNGColorMode +of the raw image, or use the parameters colortype and bitdepth of the simple +encoding function. + +If, when encoding, you don't want LodePNG to choose the output PNG color type +but control it yourself, you need to set auto_convert in the encoder settings +to false, and specify the color type you want in the LodePNGInfo of the +encoder (including palette: it can generate a palette if auto_convert is true, +otherwise not). + +If the input and output color type differ (whether user chosen or auto chosen), +LodePNG will do a color conversion, which follows the rules below, and may +sometimes result in an error. + +To avoid some confusion: +-the decoder converts from PNG to raw image +-the encoder converts from raw image to PNG +-the colortype and bitdepth in LodePNGColorMode info_raw, are those of the raw image +-the colortype and bitdepth in the color field of LodePNGInfo info_png, are those of the PNG +-when encoding, the color type in LodePNGInfo is ignored if auto_convert + is enabled, it is automatically generated instead +-when decoding, the color type in LodePNGInfo is set by the decoder to that of the original + PNG image, but it can be ignored since the raw image has the color type you requested instead +-if the color type of the LodePNGColorMode and PNG image aren't the same, a conversion + between the color types is done if the color types are supported. If it is not + supported, an error is returned. If the types are the same, no conversion is done. +-even though some conversions aren't supported, LodePNG supports loading PNGs from any + colortype and saving PNGs to any colortype, sometimes it just requires preparing + the raw image correctly before encoding. +-both encoder and decoder use the same color converter. + +Non supported color conversions: +-color to greyscale: no error is thrown, but the result will look ugly because +only the red channel is taken +-anything to palette when that palette does not have that color in it: in this +case an error is thrown + +Supported color conversions: +-anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA +-any grey or grey+alpha, to grey or grey+alpha +-anything to a palette, as long as the palette has the requested colors in it +-removing alpha channel +-higher to smaller bitdepth, and vice versa + +If you want no color conversion to be done (e.g. for speed or control): +-In the encoder, you can make it save a PNG with any color type by giving the +raw color mode and LodePNGInfo the same color mode, and setting auto_convert to +false. +-In the decoder, you can make it store the pixel data in the same color type +as the PNG has, by setting the color_convert setting to false. Settings in +info_raw are then ignored. + +The function lodepng_convert does the color conversion. It is available in the +interface but normally isn't needed since the encoder and decoder already call +it. + +6.3. padding bits +----------------- + +In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines +have a bit amount that isn't a multiple of 8, then padding bits are used so that each +scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output. +The raw input image you give to the encoder, and the raw output image you get from the decoder +will NOT have these padding bits, e.g. in the case of a 1-bit image with a width +of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte, +not the first bit of a new byte. + +6.4. A note about 16-bits per channel and endianness +---------------------------------------------------- + +LodePNG uses unsigned char arrays for 16-bit per channel colors too, just like +for any other color format. The 16-bit values are stored in big endian (most +significant byte first) in these arrays. This is the opposite order of the +little endian used by x86 CPU's. + +LodePNG always uses big endian because the PNG file format does so internally. +Conversions to other formats than PNG uses internally are not supported by +LodePNG on purpose, there are myriads of formats, including endianness of 16-bit +colors, the order in which you store R, G, B and A, and so on. Supporting and +converting to/from all that is outside the scope of LodePNG. + +This may mean that, depending on your use case, you may want to convert the big +endian output of LodePNG to little endian with a for loop. This is certainly not +always needed, many applications and libraries support big endian 16-bit colors +anyway, but it means you cannot simply cast the unsigned char* buffer to an +unsigned short* buffer on x86 CPUs. + + +7. error values +--------------- + +All functions in LodePNG that return an error code, return 0 if everything went +OK, or a non-zero code if there was an error. + +The meaning of the LodePNG error values can be retrieved with the function +lodepng_error_text: given the numerical error code, it returns a description +of the error in English as a string. + +Check the implementation of lodepng_error_text to see the meaning of each code. + + +8. chunks and PNG editing +------------------------- + +If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG +editor that should follow the rules about handling of unknown chunks, or if your +program is able to read other types of chunks than the ones handled by LodePNG, +then that's possible with the chunk functions of LodePNG. + +A PNG chunk has the following layout: + +4 bytes length +4 bytes type name +length bytes data +4 bytes CRC + +8.1. iterating through chunks +----------------------------- + +If you have a buffer containing the PNG image data, then the first chunk (the +IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the +signature of the PNG and are not part of a chunk. But if you start at byte 8 +then you have a chunk, and can check the following things of it. + +NOTE: none of these functions check for memory buffer boundaries. To avoid +exploits, always make sure the buffer contains all the data of the chunks. +When using lodepng_chunk_next, make sure the returned value is within the +allocated memory. + +unsigned lodepng_chunk_length(const unsigned char* chunk): + +Get the length of the chunk's data. The total chunk length is this length + 12. + +void lodepng_chunk_type(char type[5], const unsigned char* chunk): +unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type): + +Get the type of the chunk or compare if it's a certain type + +unsigned char lodepng_chunk_critical(const unsigned char* chunk): +unsigned char lodepng_chunk_private(const unsigned char* chunk): +unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk): + +Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are). +Check if the chunk is private (public chunks are part of the standard, private ones not). +Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical +chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your +program doesn't handle that type of unknown chunk. + +unsigned char* lodepng_chunk_data(unsigned char* chunk): +const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk): + +Get a pointer to the start of the data of the chunk. + +unsigned lodepng_chunk_check_crc(const unsigned char* chunk): +void lodepng_chunk_generate_crc(unsigned char* chunk): + +Check if the crc is correct or generate a correct one. + +unsigned char* lodepng_chunk_next(unsigned char* chunk): +const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk): + +Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these +functions do no boundary checking of the allocated data whatsoever, so make sure there is enough +data available in the buffer to be able to go to the next chunk. + +unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk): +unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, + const char* type, const unsigned char* data): + +These functions are used to create new chunks that are appended to the data in *out that has +length *outlength. The append function appends an existing chunk to the new data. The create +function creates a new chunk with the given parameters and appends it. Type is the 4-letter +name of the chunk. + +8.2. chunks in info_png +----------------------- + +The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3 +buffers (each with size) to contain 3 types of unknown chunks: +the ones that come before the PLTE chunk, the ones that come between the PLTE +and the IDAT chunks, and the ones that come after the IDAT chunks. +It's necessary to make the distionction between these 3 cases because the PNG +standard forces to keep the ordering of unknown chunks compared to the critical +chunks, but does not force any other ordering rules. + +info_png.unknown_chunks_data[0] is the chunks before PLTE +info_png.unknown_chunks_data[1] is the chunks after PLTE, before IDAT +info_png.unknown_chunks_data[2] is the chunks after IDAT + +The chunks in these 3 buffers can be iterated through and read by using the same +way described in the previous subchapter. + +When using the decoder to decode a PNG, you can make it store all unknown chunks +if you set the option settings.remember_unknown_chunks to 1. By default, this +option is off (0). + +The encoder will always encode unknown chunks that are stored in the info_png. +If you need it to add a particular chunk that isn't known by LodePNG, you can +use lodepng_chunk_append or lodepng_chunk_create to the chunk data in +info_png.unknown_chunks_data[x]. + +Chunks that are known by LodePNG should not be added in that way. E.g. to make +LodePNG add a bKGD chunk, set background_defined to true and add the correct +parameters there instead. + + +9. compiler support +------------------- + +No libraries other than the current standard C library are needed to compile +LodePNG. For the C++ version, only the standard C++ library is needed on top. +Add the files lodepng.c(pp) and lodepng.h to your project, include +lodepng.h where needed, and your program can read/write PNG files. + +It is compatible with C90 and up, and C++03 and up. + +If performance is important, use optimization when compiling! For both the +encoder and decoder, this makes a large difference. + +Make sure that LodePNG is compiled with the same compiler of the same version +and with the same settings as the rest of the program, or the interfaces with +std::vectors and std::strings in C++ can be incompatible. + +CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets. + +*) gcc and g++ + +LodePNG is developed in gcc so this compiler is natively supported. It gives no +warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++ +version 4.7.1 on Linux, 32-bit and 64-bit. + +*) Clang + +Fully supported and warning-free. + +*) Mingw + +The Mingw compiler (a port of gcc for Windows) should be fully supported by +LodePNG. + +*) Visual Studio and Visual C++ Express Edition + +LodePNG should be warning-free with warning level W4. Two warnings were disabled +with pragmas though: warning 4244 about implicit conversions, and warning 4996 +where it wants to use a non-standard function fopen_s instead of the standard C +fopen. + +Visual Studio may want "stdafx.h" files to be included in each source file and +give an error "unexpected end of file while looking for precompiled header". +This is not standard C++ and will not be added to the stock LodePNG. You can +disable it for lodepng.cpp only by right clicking it, Properties, C/C++, +Precompiled Headers, and set it to Not Using Precompiled Headers there. + +NOTE: Modern versions of VS should be fully supported, but old versions, e.g. +VS6, are not guaranteed to work. + +*) Compilers on Macintosh + +LodePNG has been reported to work both with gcc and LLVM for Macintosh, both for +C and C++. + +*) Other Compilers + +If you encounter problems on any compilers, feel free to let me know and I may +try to fix it if the compiler is modern and standards complient. + + +10. examples +------------ + +This decoder example shows the most basic usage of LodePNG. More complex +examples can be found on the LodePNG website. + +10.1. decoder C++ example +------------------------- + +#include "lodepng.h" +#include + +int main(int argc, char *argv[]) +{ + const char* filename = argc > 1 ? argv[1] : "test.png"; + + //load and decode + std::vector image; + unsigned width, height; + unsigned error = lodepng::decode(image, width, height, filename); + + //if there's an error, display it + if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl; + + //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ... +} + +10.2. decoder C example +----------------------- + +#include "lodepng.h" + +int main(int argc, char *argv[]) +{ + unsigned error; + unsigned char* image; + size_t width, height; + const char* filename = argc > 1 ? argv[1] : "test.png"; + + error = lodepng_decode32_file(&image, &width, &height, filename); + + if(error) printf("decoder error %u: %s\n", error, lodepng_error_text(error)); + + / * use image here * / + + free(image); + return 0; +} + +11. state settings reference +---------------------------- + +A quick reference of some settings to set on the LodePNGState + +For decoding: + +state.decoder.zlibsettings.ignore_adler32: ignore ADLER32 checksums +state.decoder.zlibsettings.custom_...: use custom inflate function +state.decoder.ignore_crc: ignore CRC checksums +state.decoder.color_convert: convert internal PNG color to chosen one +state.decoder.read_text_chunks: whether to read in text metadata chunks +state.decoder.remember_unknown_chunks: whether to read in unknown chunks +state.info_raw.colortype: desired color type for decoded image +state.info_raw.bitdepth: desired bit depth for decoded image +state.info_raw....: more color settings, see struct LodePNGColorMode +state.info_png....: no settings for decoder but ouput, see struct LodePNGInfo + +For encoding: + +state.encoder.zlibsettings.btype: disable compression by setting it to 0 +state.encoder.zlibsettings.use_lz77: use LZ77 in compression +state.encoder.zlibsettings.windowsize: tweak LZ77 windowsize +state.encoder.zlibsettings.minmatch: tweak min LZ77 length to match +state.encoder.zlibsettings.nicematch: tweak LZ77 match where to stop searching +state.encoder.zlibsettings.lazymatching: try one more LZ77 matching +state.encoder.zlibsettings.custom_...: use custom deflate function +state.encoder.auto_convert: choose optimal PNG color type, if 0 uses info_png +state.encoder.filter_palette_zero: PNG filter strategy for palette +state.encoder.filter_strategy: PNG filter strategy to encode with +state.encoder.force_palette: add palette even if not encoding to one +state.encoder.add_id: add LodePNG identifier and version as a text chunk +state.encoder.text_compression: use compressed text chunks for metadata +state.info_raw.colortype: color type of raw input image you provide +state.info_raw.bitdepth: bit depth of raw input image you provide +state.info_raw: more color settings, see struct LodePNGColorMode +state.info_png.color.colortype: desired color type if auto_convert is false +state.info_png.color.bitdepth: desired bit depth if auto_convert is false +state.info_png.color....: more color settings, see struct LodePNGColorMode +state.info_png....: more PNG related settings, see struct LodePNGInfo + + +12. changes +----------- + +The version number of LodePNG is the date of the change given in the format +yyyymmdd. + +Some changes aren't backwards compatible. Those are indicated with a (!) +symbol. + +*) 27 nov 2016: grey+alpha auto color model detection bugfix +*) 18 apr 2016: Changed qsort to custom stable sort (for platforms w/o qsort). +*) 09 apr 2016: Fixed colorkey usage detection, and better file loading (within + the limits of pure C90). +*) 08 dec 2015: Made load_file function return error if file can't be opened. +*) 24 okt 2015: Bugfix with decoding to palette output. +*) 18 apr 2015: Boundary PM instead of just package-merge for faster encoding. +*) 23 aug 2014: Reduced needless memory usage of decoder. +*) 28 jun 2014: Removed fix_png setting, always support palette OOB for + simplicity. Made ColorProfile public. +*) 09 jun 2014: Faster encoder by fixing hash bug and more zeros optimization. +*) 22 dec 2013: Power of two windowsize required for optimization. +*) 15 apr 2013: Fixed bug with LAC_ALPHA and color key. +*) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png). +*) 11 mar 2013 (!): Bugfix with custom free. Changed from "my" to "lodepng_" + prefix for the custom allocators and made it possible with a new #define to + use custom ones in your project without needing to change lodepng's code. +*) 28 jan 2013: Bugfix with color key. +*) 27 okt 2012: Tweaks in text chunk keyword length error handling. +*) 8 okt 2012 (!): Added new filter strategy (entropy) and new auto color mode. + (no palette). Better deflate tree encoding. New compression tweak settings. + Faster color conversions while decoding. Some internal cleanups. +*) 23 sep 2012: Reduced warnings in Visual Studio a little bit. +*) 1 sep 2012 (!): Removed #define's for giving custom (de)compression functions + and made it work with function pointers instead. +*) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc + and free functions and toggle #defines from compiler flags. Small fixes. +*) 6 may 2012 (!): Made plugging in custom zlib/deflate functions more flexible. +*) 22 apr 2012 (!): Made interface more consistent, renaming a lot. Removed + redundant C++ codec classes. Reduced amount of structs. Everything changed, + but it is cleaner now imho and functionality remains the same. Also fixed + several bugs and shrunk the implementation code. Made new samples. +*) 6 nov 2011 (!): By default, the encoder now automatically chooses the best + PNG color model and bit depth, based on the amount and type of colors of the + raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color. +*) 9 okt 2011: simpler hash chain implementation for the encoder. +*) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching. +*) 23 aug 2011: tweaked the zlib compression parameters after benchmarking. + A bug with the PNG filtertype heuristic was fixed, so that it chooses much + better ones (it's quite significant). A setting to do an experimental, slow, + brute force search for PNG filter types is added. +*) 17 aug 2011 (!): changed some C zlib related function names. +*) 16 aug 2011: made the code less wide (max 120 characters per line). +*) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors. +*) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled. +*) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman + to optimize long sequences of zeros. +*) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and + LodePNG_InfoColor_canHaveAlpha functions for convenience. +*) 7 nov 2010: added LodePNG_error_text function to get error code description. +*) 30 okt 2010: made decoding slightly faster +*) 26 okt 2010: (!) changed some C function and struct names (more consistent). + Reorganized the documentation and the declaration order in the header. +*) 08 aug 2010: only changed some comments and external samples. +*) 05 jul 2010: fixed bug thanks to warnings in the new gcc version. +*) 14 mar 2010: fixed bug where too much memory was allocated for char buffers. +*) 02 sep 2008: fixed bug where it could create empty tree that linux apps could + read by ignoring the problem but windows apps couldn't. +*) 06 jun 2008: added more error checks for out of memory cases. +*) 26 apr 2008: added a few more checks here and there to ensure more safety. +*) 06 mar 2008: crash with encoding of strings fixed +*) 02 feb 2008: support for international text chunks added (iTXt) +*) 23 jan 2008: small cleanups, and #defines to divide code in sections +*) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor. +*) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder. +*) 17 jan 2008: ability to encode and decode compressed zTXt chunks added + Also various fixes, such as in the deflate and the padding bits code. +*) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved + filtering code of encoder. +*) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A + C++ wrapper around this provides an interface almost identical to before. + Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code + are together in these files but it works both for C and C++ compilers. +*) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks +*) 30 aug 2007: bug fixed which makes this Borland C++ compatible +*) 09 aug 2007: some VS2005 warnings removed again +*) 21 jul 2007: deflate code placed in new namespace separate from zlib code +*) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images +*) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing + invalid std::vector element [0] fixed, and level 3 and 4 warnings removed +*) 02 jun 2007: made the encoder add a tag with version by default +*) 27 may 2007: zlib and png code separated (but still in the same file), + simple encoder/decoder functions added for more simple usage cases +*) 19 may 2007: minor fixes, some code cleaning, new error added (error 69), + moved some examples from here to lodepng_examples.cpp +*) 12 may 2007: palette decoding bug fixed +*) 24 apr 2007: changed the license from BSD to the zlib license +*) 11 mar 2007: very simple addition: ability to encode bKGD chunks. +*) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding + palettized PNG images. Plus little interface change with palette and texts. +*) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes. + Fixed a bug where the end code of a block had length 0 in the Huffman tree. +*) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented + and supported by the encoder, resulting in smaller PNGs at the output. +*) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone. +*) 24 jan 2007: gave encoder an error interface. Added color conversion from any + greyscale type to 8-bit greyscale with or without alpha. +*) 21 jan 2007: (!) Totally changed the interface. It allows more color types + to convert to and is more uniform. See the manual for how it works now. +*) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days: + encode/decode custom tEXt chunks, separate classes for zlib & deflate, and + at last made the decoder give errors for incorrect Adler32 or Crc. +*) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel. +*) 29 dec 2006: Added support for encoding images without alpha channel, and + cleaned out code as well as making certain parts faster. +*) 28 dec 2006: Added "Settings" to the encoder. +*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now. + Removed some code duplication in the decoder. Fixed little bug in an example. +*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter. + Fixed a bug of the decoder with 16-bit per color. +*) 15 okt 2006: Changed documentation structure +*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the + given image buffer, however for now it's not compressed. +*) 08 sep 2006: (!) Changed to interface with a Decoder class +*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different + way. Renamed decodePNG to decodePNGGeneric. +*) 29 jul 2006: (!) Changed the interface: image info is now returned as a + struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy. +*) 28 jul 2006: Cleaned the code and added new error checks. + Corrected terminology "deflate" into "inflate". +*) 23 jun 2006: Added SDL example in the documentation in the header, this + example allows easy debugging by displaying the PNG and its transparency. +*) 22 jun 2006: (!) Changed way to obtain error value. Added + loadFile function for convenience. Made decodePNG32 faster. +*) 21 jun 2006: (!) Changed type of info vector to unsigned. + Changed position of palette in info vector. Fixed an important bug that + happened on PNGs with an uncompressed block. +*) 16 jun 2006: Internally changed unsigned into unsigned where + needed, and performed some optimizations. +*) 07 jun 2006: (!) Renamed functions to decodePNG and placed them + in LodePNG namespace. Changed the order of the parameters. Rewrote the + documentation in the header. Renamed files to lodepng.cpp and lodepng.h +*) 22 apr 2006: Optimized and improved some code +*) 07 sep 2005: (!) Changed to std::vector interface +*) 12 aug 2005: Initial release (C++, decoder only) + + +13. contact information +----------------------- + +Feel free to contact me with suggestions, problems, comments, ... concerning +LodePNG. If you encounter a PNG image that doesn't work properly with this +decoder, feel free to send it and I'll use it to find and fix the problem. + +My email address is (puzzle the account and domain together with an @ symbol): +Domain: gmail dot com. +Account: lode dot vandevenne. + + +Copyright (c) 2005-2016 Lode Vandevenne +*/