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remove deprecated old-precision jpg path from stb_image.h

tweak license reference wording
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Sean Barrett
Sean Barrett committed Mar 3, 2017
1 parent 51a5368 commit 47685c5f84900b7a70fb7e3a7b6b58b585c852b0
Showing with 110 additions and 173 deletions.
  1. +1 −1 stb_c_lexer.h
  2. +1 −1 stb_connected_components.h
  3. +1 −1 stb_divide.h
  4. +1 −1 stb_dxt.h
  5. +1 −1 stb_easy_font.h
  6. +52 −160 stb_image.h
  7. +53 −8 stb_image_write.h
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@@ -36,7 +36,7 @@
//
// LICENSE
//
-// See end of file for licensing information.
+// See end of file for license information.
#ifndef STB_C_LEXER_DEFINITIONS
// to change the default parsing rules, copy the following lines
@@ -52,7 +52,7 @@
//
// LICENSE
//
-// See end of file for licensing information.
+// See end of file for license information.
//
// ALGORITHM
//
View
@@ -78,7 +78,7 @@
//
// LICENSE
//
-// See end of file for licensing information.
+// See end of file for license information.
#ifndef INCLUDE_STB_DIVIDE_H
View
@@ -19,7 +19,7 @@
//
// LICENSE
//
-// See end of file for licensing information.
+// See end of file for license information.
#ifndef STB_INCLUDE_STB_DXT_H
#define STB_INCLUDE_STB_DXT_H
View
@@ -67,7 +67,7 @@
//
// LICENSE
//
-// See end of file for licensing information.
+// See end of file for license information.
//
// VERSION HISTORY
//
View
@@ -21,7 +21,7 @@
avoid problematic images and only need the trivial interface
JPEG baseline & progressive (12 bpc/arithmetic not supported, same as stock IJG lib)
- PNG 1/2/4/8-bit-per-channel (16 bpc not supported)
+ PNG 1/2/4/8/16-bit-per-channel
TGA (not sure what subset, if a subset)
BMP non-1bpp, non-RLE
@@ -42,110 +42,13 @@
Full documentation under "DOCUMENTATION" below.
- Revision 2.00 release notes:
-
- - Progressive JPEG is now supported.
-
- - PPM and PGM binary formats are now supported, thanks to Ken Miller.
-
- - x86 platforms now make use of SSE2 SIMD instructions for
- JPEG decoding, and ARM platforms can use NEON SIMD if requested.
- This work was done by Fabian "ryg" Giesen. SSE2 is used by
- default, but NEON must be enabled explicitly; see docs.
-
- With other JPEG optimizations included in this version, we see
- 2x speedup on a JPEG on an x86 machine, and a 1.5x speedup
- on a JPEG on an ARM machine, relative to previous versions of this
- library. The same results will not obtain for all JPGs and for all
- x86/ARM machines. (Note that progressive JPEGs are significantly
- slower to decode than regular JPEGs.) This doesn't mean that this
- is the fastest JPEG decoder in the land; rather, it brings it
- closer to parity with standard libraries. If you want the fastest
- decode, look elsewhere. (See "Philosophy" section of docs below.)
-
- See final bullet items below for more info on SIMD.
-
- - Added STBI_MALLOC, STBI_REALLOC, and STBI_FREE macros for replacing
- the memory allocator. Unlike other STBI libraries, these macros don't
- support a context parameter, so if you need to pass a context in to
- the allocator, you'll have to store it in a global or a thread-local
- variable.
-
- - Split existing STBI_NO_HDR flag into two flags, STBI_NO_HDR and
- STBI_NO_LINEAR.
- STBI_NO_HDR: suppress implementation of .hdr reader format
- STBI_NO_LINEAR: suppress high-dynamic-range light-linear float API
-
- - You can suppress implementation of any of the decoders to reduce
- your code footprint by #defining one or more of the following
- symbols before creating the implementation.
-
- STBI_NO_JPEG
- STBI_NO_PNG
- STBI_NO_BMP
- STBI_NO_PSD
- STBI_NO_TGA
- STBI_NO_GIF
- STBI_NO_HDR
- STBI_NO_PIC
- STBI_NO_PNM (.ppm and .pgm)
-
- - You can request *only* certain decoders and suppress all other ones
- (this will be more forward-compatible, as addition of new decoders
- doesn't require you to disable them explicitly):
-
- STBI_ONLY_JPEG
- STBI_ONLY_PNG
- STBI_ONLY_BMP
- STBI_ONLY_PSD
- STBI_ONLY_TGA
- STBI_ONLY_GIF
- STBI_ONLY_HDR
- STBI_ONLY_PIC
- STBI_ONLY_PNM (.ppm and .pgm)
-
- Note that you can define multiples of these, and you will get all
- of them ("only x" and "only y" is interpreted to mean "only x&y").
-
- - If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still
- want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB
-
- - Compilation of all SIMD code can be suppressed with
- #define STBI_NO_SIMD
- It should not be necessary to disable SIMD unless you have issues
- compiling (e.g. using an x86 compiler which doesn't support SSE
- intrinsics or that doesn't support the method used to detect
- SSE2 support at run-time), and even those can be reported as
- bugs so I can refine the built-in compile-time checking to be
- smarter.
-
- - The old STBI_SIMD system which allowed installing a user-defined
- IDCT etc. has been removed. If you need this, don't upgrade. My
- assumption is that almost nobody was doing this, and those who
- were will find the built-in SIMD more satisfactory anyway.
-
- - RGB values computed for JPEG images are slightly different from
- previous versions of stb_image. (This is due to using less
- integer precision in SIMD.) The C code has been adjusted so
- that the same RGB values will be computed regardless of whether
- SIMD support is available, so your app should always produce
- consistent results. But these results are slightly different from
- previous versions. (Specifically, about 3% of available YCbCr values
- will compute different RGB results from pre-1.49 versions by +-1;
- most of the deviating values are one smaller in the G channel.)
-
- - If you must produce consistent results with previous versions of
- stb_image, #define STBI_JPEG_OLD and you will get the same results
- you used to; however, you will not get the SIMD speedups for
- the YCbCr-to-RGB conversion step (although you should still see
- significant JPEG speedup from the other changes).
-
- Please note that STBI_JPEG_OLD is a temporary feature; it will be
- removed in future versions of the library. It is only intended for
- near-term back-compatibility use.
-
-
- Latest revision history:
+LICENSE
+
+ See end of file for license information.
+
+RECENT REVISION HISTORY:
+
+ 2.14 (2017-03-03) remove deprecated STBI_JPEG_OLD
2.13 (2016-12-04) experimental 16-bit API, only for PNG so far; fixes
2.12 (2016-04-02) fix typo in 2.11 PSD fix that caused crashes
2.11 (2016-04-02) 16-bit PNGS; enable SSE2 in non-gcc x64
@@ -194,11 +97,6 @@
Philipp Wiesemann Josh Tobin github:rlyeh github:grim210@github
Blazej Dariusz Roszkowski github:sammyhw
-
-LICENSE
-
- See end of file for licensing information.
-
*/
#ifndef STBI_INCLUDE_STB_IMAGE_H
@@ -272,13 +170,13 @@ LICENSE
// and for best performance I may provide less-easy-to-use APIs that give higher
// performance, in addition to the easy to use ones. Nevertheless, it's important
// to keep in mind that from the standpoint of you, a client of this library,
-// all you care about is #1 and #3, and stb libraries do not emphasize #3 above all.
+// all you care about is #1 and #3, and stb libraries DO NOT emphasize #3 above all.
//
// Some secondary priorities arise directly from the first two, some of which
// make more explicit reasons why performance can't be emphasized.
//
// - Portable ("ease of use")
-// - Small footprint ("easy to maintain")
+// - Small source code footprint ("easy to maintain")
// - No dependencies ("ease of use")
//
// ===========================================================================
@@ -310,13 +208,6 @@ LICENSE
// (at least this is true for iOS and Android). Therefore, the NEON support is
// toggled by a build flag: define STBI_NEON to get NEON loops.
//
-// The output of the JPEG decoder is slightly different from versions where
-// SIMD support was introduced (that is, for versions before 1.49). The
-// difference is only +-1 in the 8-bit RGB channels, and only on a small
-// fraction of pixels. You can force the pre-1.49 behavior by defining
-// STBI_JPEG_OLD, but this will disable some of the SIMD decoding path
-// and hence cost some performance.
-//
// If for some reason you do not want to use any of SIMD code, or if
// you have issues compiling it, you can disable it entirely by
// defining STBI_NO_SIMD.
@@ -372,6 +263,41 @@ LICENSE
// says there's premultiplied data (currently only happens in iPhone images,
// and only if iPhone convert-to-rgb processing is on).
//
+// ===========================================================================
+//
+// ADDITIONAL CONFIGURATION
+//
+// - You can suppress implementation of any of the decoders to reduce
+// your code footprint by #defining one or more of the following
+// symbols before creating the implementation.
+//
+// STBI_NO_JPEG
+// STBI_NO_PNG
+// STBI_NO_BMP
+// STBI_NO_PSD
+// STBI_NO_TGA
+// STBI_NO_GIF
+// STBI_NO_HDR
+// STBI_NO_PIC
+// STBI_NO_PNM (.ppm and .pgm)
+//
+// - You can request *only* certain decoders and suppress all other ones
+// (this will be more forward-compatible, as addition of new decoders
+// doesn't require you to disable them explicitly):
+//
+// STBI_ONLY_JPEG
+// STBI_ONLY_PNG
+// STBI_ONLY_BMP
+// STBI_ONLY_PSD
+// STBI_ONLY_TGA
+// STBI_ONLY_GIF
+// STBI_ONLY_HDR
+// STBI_ONLY_PIC
+// STBI_ONLY_PNM (.ppm and .pgm)
+//
+// - If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still
+// want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB
+//
#ifndef STBI_NO_STDIO
@@ -3345,38 +3271,9 @@ static stbi_uc *stbi__resample_row_generic(stbi_uc *out, stbi_uc *in_near, stbi_
return out;
}
-#ifdef STBI_JPEG_OLD
-// this is the same YCbCr-to-RGB calculation that stb_image has used
-// historically before the algorithm changes in 1.49
-#define float2fixed(x) ((int) ((x) * 65536 + 0.5))
-static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step)
-{
- int i;
- for (i=0; i < count; ++i) {
- int y_fixed = (y[i] << 16) + 32768; // rounding
- int r,g,b;
- int cr = pcr[i] - 128;
- int cb = pcb[i] - 128;
- r = y_fixed + cr*float2fixed(1.40200f);
- g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f);
- b = y_fixed + cb*float2fixed(1.77200f);
- r >>= 16;
- g >>= 16;
- b >>= 16;
- if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; }
- if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; }
- if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; }
- out[0] = (stbi_uc)r;
- out[1] = (stbi_uc)g;
- out[2] = (stbi_uc)b;
- out[3] = 255;
- out += step;
- }
-}
-#else
// this is a reduced-precision calculation of YCbCr-to-RGB introduced
// to make sure the code produces the same results in both SIMD and scalar
-#define float2fixed(x) (((int) ((x) * 4096.0f + 0.5f)) << 8)
+#define stbi__float2fixed(x) (((int) ((x) * 4096.0f + 0.5f)) << 8)
static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step)
{
int i;
@@ -3385,9 +3282,9 @@ static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc
int r,g,b;
int cr = pcr[i] - 128;
int cb = pcb[i] - 128;
- r = y_fixed + cr* float2fixed(1.40200f);
- g = y_fixed + (cr*-float2fixed(0.71414f)) + ((cb*-float2fixed(0.34414f)) & 0xffff0000);
- b = y_fixed + cb* float2fixed(1.77200f);
+ r = y_fixed + cr* stbi__float2fixed(1.40200f);
+ g = y_fixed + (cr*-stbi__float2fixed(0.71414f)) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000);
+ b = y_fixed + cb* stbi__float2fixed(1.77200f);
r >>= 20;
g >>= 20;
b >>= 20;
@@ -3401,7 +3298,6 @@ static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc
out += step;
}
}
-#endif
#if defined(STBI_SSE2) || defined(STBI_NEON)
static void stbi__YCbCr_to_RGB_simd(stbi_uc *out, stbi_uc const *y, stbi_uc const *pcb, stbi_uc const *pcr, int count, int step)
@@ -3520,9 +3416,9 @@ static void stbi__YCbCr_to_RGB_simd(stbi_uc *out, stbi_uc const *y, stbi_uc cons
int r,g,b;
int cr = pcr[i] - 128;
int cb = pcb[i] - 128;
- r = y_fixed + cr* float2fixed(1.40200f);
- g = y_fixed + cr*-float2fixed(0.71414f) + ((cb*-float2fixed(0.34414f)) & 0xffff0000);
- b = y_fixed + cb* float2fixed(1.77200f);
+ r = y_fixed + cr* stbi__float2fixed(1.40200f);
+ g = y_fixed + cr*-stbi__float2fixed(0.71414f) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000);
+ b = y_fixed + cb* stbi__float2fixed(1.77200f);
r >>= 20;
g >>= 20;
b >>= 20;
@@ -3548,18 +3444,14 @@ static void stbi__setup_jpeg(stbi__jpeg *j)
#ifdef STBI_SSE2
if (stbi__sse2_available()) {
j->idct_block_kernel = stbi__idct_simd;
- #ifndef STBI_JPEG_OLD
j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
- #endif
j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
}
#endif
#ifdef STBI_NEON
j->idct_block_kernel = stbi__idct_simd;
- #ifndef STBI_JPEG_OLD
j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
- #endif
j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
#endif
}
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