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stb_image_write.h
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stb_image_write.h
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/* stb_image_write - v1.02 - public domain - http://nothings.org/stb/stb_image_write.h
writes out PNG/BMP/TGA images to C stdio - Sean Barrett 2010-2015
no warranty implied; use at your own risk
Before #including,
#define STB_IMAGE_WRITE_IMPLEMENTATION
in the file that you want to have the implementation.
Will probably not work correctly with strict-aliasing optimizations.
ABOUT:
This header file is a library for writing images to C stdio. It could be
adapted to write to memory or a general streaming interface; let me know.
The PNG output is not optimal; it is 20-50% larger than the file
written by a decent optimizing implementation. This library is designed
for source code compactness and simplicity, not optimal image file size
or run-time performance.
BUILDING:
You can #define STBIW_ASSERT(x) before the #include to avoid using assert.h.
You can #define STBIW_MALLOC(), STBIW_REALLOC(), and STBIW_FREE() to replace
malloc,realloc,free.
You can define STBIW_MEMMOVE() to replace memmove()
USAGE:
There are four functions, one for each image file format:
int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
There are also four equivalent functions that use an arbitrary write function. You are
expected to open/close your file-equivalent before and after calling these:
int stbi_write_png_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data, int stride_in_bytes);
int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
where the callback is:
void stbi_write_func(void *context, void *data, int size);
You can define STBI_WRITE_NO_STDIO to disable the file variant of these
functions, so the library will not use stdio.h at all. However, this will
also disable HDR writing, because it requires stdio for formatted output.
Each function returns 0 on failure and non-0 on success.
The functions create an image file defined by the parameters. The image
is a rectangle of pixels stored from left-to-right, top-to-bottom.
Each pixel contains 'comp' channels of data stored interleaved with 8-bits
per channel, in the following order: 1=Y, 2=YA, 3=RGB, 4=RGBA. (Y is
monochrome color.) The rectangle is 'w' pixels wide and 'h' pixels tall.
The *data pointer points to the first byte of the top-left-most pixel.
For PNG, "stride_in_bytes" is the distance in bytes from the first byte of
a row of pixels to the first byte of the next row of pixels.
PNG creates output files with the same number of components as the input.
The BMP format expands Y to RGB in the file format and does not
output alpha.
PNG supports writing rectangles of data even when the bytes storing rows of
data are not consecutive in memory (e.g. sub-rectangles of a larger image),
by supplying the stride between the beginning of adjacent rows. The other
formats do not. (Thus you cannot write a native-format BMP through the BMP
writer, both because it is in BGR order and because it may have padding
at the end of the line.)
HDR expects linear float data. Since the format is always 32-bit rgb(e)
data, alpha (if provided) is discarded, and for monochrome data it is
replicated across all three channels.
TGA supports RLE or non-RLE compressed data. To use non-RLE-compressed
data, set the global variable 'stbi_write_tga_with_rle' to 0.
CREDITS:
PNG/BMP/TGA
Sean Barrett
HDR
Baldur Karlsson
TGA monochrome:
Jean-Sebastien Guay
misc enhancements:
Tim Kelsey
TGA RLE
Alan Hickman
initial file IO callback implementation
Emmanuel Julien
bugfixes:
github:Chribba
Guillaume Chereau
github:jry2
github:romigrou
Sergio Gonzalez
Jonas Karlsson
Filip Wasil
Thatcher Ulrich
LICENSE
This software is dual-licensed to the public domain and under the following
license: you are granted a perpetual, irrevocable license to copy, modify,
publish, and distribute this file as you see fit.
*/
#ifndef INCLUDE_STB_IMAGE_WRITE_H
#define INCLUDE_STB_IMAGE_WRITE_H
#ifdef __cplusplus
extern "C" {
#endif
#ifdef STB_IMAGE_WRITE_STATIC
#define STBIWDEF static
#else
#define STBIWDEF extern
extern int stbi_write_tga_with_rle;
#endif
#ifndef STBI_WRITE_NO_STDIO
STBIWDEF int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
STBIWDEF int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
#endif
typedef void stbi_write_func(void *context, void *data, int size);
STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data, int stride_in_bytes);
STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
#ifdef __cplusplus
}
#endif
#endif//INCLUDE_STB_IMAGE_WRITE_H