298 lines
13 KiB
C++
298 lines
13 KiB
C++
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// SPDX-FileCopyrightText: stb http://nothings.org/stb
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// SPDX-License-Identifier: MIT
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/* stb_image_write - v1.16 - public domain - http://nothings.org/stb
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writes out PNG/BMP/TGA/JPEG/HDR images to C stdio - Sean Barrett 2010-2015
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no warranty implied; use at your own risk
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Before #including,
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#define STB_IMAGE_WRITE_IMPLEMENTATION
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in the file that you want to have the implementation.
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Will probably not work correctly with strict-aliasing optimizations.
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ABOUT:
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This header file is a library for writing images to C stdio or a callback.
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The PNG output is not optimal; it is 20-50% larger than the file
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written by a decent optimizing implementation; though providing a custom
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zlib compress function (see STBIW_ZLIB_COMPRESS) can mitigate that.
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This library is designed for source code compactness and simplicity,
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not optimal image file size or run-time performance.
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BUILDING:
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You can #define STBIW_ASSERT(x) before the #include to avoid using assert.h.
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You can #define STBIW_MALLOC(), STBIW_REALLOC(), and STBIW_FREE() to replace
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malloc,realloc,free.
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You can #define STBIW_MEMMOVE() to replace memmove()
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You can #define STBIW_ZLIB_COMPRESS to use a custom zlib-style compress function
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for PNG compression (instead of the builtin one), it must have the following signature:
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unsigned char * my_compress(unsigned char *data, int data_len, int *out_len, int quality);
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The returned data will be freed with STBIW_FREE() (free() by default),
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so it must be heap allocated with STBIW_MALLOC() (malloc() by default),
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UNICODE:
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If compiling for Windows and you wish to use Unicode filenames, compile
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with
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#define STBIW_WINDOWS_UTF8
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and pass utf8-encoded filenames. Call stbiw_convert_wchar_to_utf8 to convert
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Windows wchar_t filenames to utf8.
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USAGE:
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There are five functions, one for each image file format:
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int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
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int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
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int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
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int stbi_write_jpg(char const *filename, int w, int h, int comp, const void *data, int quality);
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int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
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void stbi_flip_vertically_on_write(int flag); // flag is non-zero to flip data vertically
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There are also five equivalent functions that use an arbitrary write function. You are
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expected to open/close your file-equivalent before and after calling these:
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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);
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int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
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int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality);
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where the callback is:
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void stbi_write_func(void *context, void *data, int size);
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You can configure it with these global variables:
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int stbi_write_tga_with_rle; // defaults to true; set to 0 to disable RLE
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int stbi_write_png_compression_level; // defaults to 8; set to higher for more compression
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int stbi_write_force_png_filter; // defaults to -1; set to 0..5 to force a filter mode
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You can define STBI_WRITE_NO_STDIO to disable the file variant of these
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functions, so the library will not use stdio.h at all. However, this will
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also disable HDR writing, because it requires stdio for formatted output.
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Each function returns 0 on failure and non-0 on success.
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The functions create an image file defined by the parameters. The image
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is a rectangle of pixels stored from left-to-right, top-to-bottom.
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Each pixel contains 'comp' channels of data stored interleaved with 8-bits
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per channel, in the following order: 1=Y, 2=YA, 3=RGB, 4=RGBA. (Y is
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monochrome color.) The rectangle is 'w' pixels wide and 'h' pixels tall.
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The *data pointer points to the first byte of the top-left-most pixel.
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For PNG, "stride_in_bytes" is the distance in bytes from the first byte of
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a row of pixels to the first byte of the next row of pixels.
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PNG creates output files with the same number of components as the input.
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The BMP format expands Y to RGB in the file format and does not
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output alpha.
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PNG supports writing rectangles of data even when the bytes storing rows of
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data are not consecutive in memory (e.g. sub-rectangles of a larger image),
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by supplying the stride between the beginning of adjacent rows. The other
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formats do not. (Thus you cannot write a native-format BMP through the BMP
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writer, both because it is in BGR order and because it may have padding
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at the end of the line.)
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PNG allows you to set the deflate compression level by setting the global
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variable 'stbi_write_png_compression_level' (it defaults to 8).
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HDR expects linear float data. Since the format is always 32-bit rgb(e)
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data, alpha (if provided) is discarded, and for monochrome data it is
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replicated across all three channels.
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TGA supports RLE or non-RLE compressed data. To use non-RLE-compressed
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data, set the global variable 'stbi_write_tga_with_rle' to 0.
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JPEG does ignore alpha channels in input data; quality is between 1 and 100.
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Higher quality looks better but results in a bigger image.
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JPEG baseline (no JPEG progressive).
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CREDITS:
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Sean Barrett - PNG/BMP/TGA
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Baldur Karlsson - HDR
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Jean-Sebastien Guay - TGA monochrome
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Tim Kelsey - misc enhancements
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Alan Hickman - TGA RLE
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Emmanuel Julien - initial file IO callback implementation
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Jon Olick - original jo_jpeg.cpp code
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Daniel Gibson - integrate JPEG, allow external zlib
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Aarni Koskela - allow choosing PNG filter
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bugfixes:
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github:Chribba
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Guillaume Chereau
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github:jry2
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github:romigrou
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Sergio Gonzalez
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Jonas Karlsson
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Filip Wasil
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Thatcher Ulrich
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github:poppolopoppo
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Patrick Boettcher
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github:xeekworx
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Cap Petschulat
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Simon Rodriguez
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Ivan Tikhonov
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github:ignotion
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Adam Schackart
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Andrew Kensler
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LICENSE
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See end of file for license information.
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*/
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#ifndef INCLUDE_STB_IMAGE_WRITE_H
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#define INCLUDE_STB_IMAGE_WRITE_H
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#include <stdlib.h>
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// if STB_IMAGE_WRITE_STATIC causes problems, try defining STBIWDEF to 'inline' or 'static inline'
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#ifndef STBIWDEF
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#ifdef STB_IMAGE_WRITE_STATIC
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#define STBIWDEF static
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#else
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#ifdef __cplusplus
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#define STBIWDEF extern "C"
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#else
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#define STBIWDEF extern
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#endif
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#endif
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#endif
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#ifndef STB_IMAGE_WRITE_STATIC // C++ forbids static forward declarations
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STBIWDEF int stbi_write_tga_with_rle;
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STBIWDEF int stbi_write_png_compression_level;
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STBIWDEF int stbi_write_force_png_filter;
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#endif
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#ifndef STBI_WRITE_NO_STDIO
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STBIWDEF int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
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STBIWDEF int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
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STBIWDEF int stbi_write_jpg(char const *filename, int x, int y, int comp, const void *data, int quality);
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#ifdef STBIW_WINDOWS_UTF8
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STBIWDEF int stbiw_convert_wchar_to_utf8(char *buffer, size_t bufferlen, const wchar_t* input);
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#endif
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#endif
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typedef void stbi_write_func(void *context, void *data, int size);
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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);
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STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
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STBIWDEF int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality);
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STBIWDEF unsigned char *stbi_write_png_to_mem(const unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len);
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STBIWDEF void stbi_flip_vertically_on_write(int flip_boolean);
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#endif//INCLUDE_STB_IMAGE_WRITE_H
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/* Revision history
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1.16 (2021-07-11)
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make Deflate code emit uncompressed blocks when it would otherwise expand
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support writing BMPs with alpha channel
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1.15 (2020-07-13) unknown
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1.14 (2020-02-02) updated JPEG writer to downsample chroma channels
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1.13
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1.12
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1.11 (2019-08-11)
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1.10 (2019-02-07)
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support utf8 filenames in Windows; fix warnings and platform ifdefs
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1.09 (2018-02-11)
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fix typo in zlib quality API, improve STB_I_W_STATIC in C++
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1.08 (2018-01-29)
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add stbi__flip_vertically_on_write, external zlib, zlib quality, choose PNG filter
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1.07 (2017-07-24)
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doc fix
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1.06 (2017-07-23)
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writing JPEG (using Jon Olick's code)
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1.05 ???
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1.04 (2017-03-03)
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monochrome BMP expansion
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1.03 ???
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1.02 (2016-04-02)
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avoid allocating large structures on the stack
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1.01 (2016-01-16)
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STBIW_REALLOC_SIZED: support allocators with no realloc support
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avoid race-condition in crc initialization
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minor compile issues
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1.00 (2015-09-14)
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installable file IO function
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0.99 (2015-09-13)
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warning fixes; TGA rle support
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0.98 (2015-04-08)
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added STBIW_MALLOC, STBIW_ASSERT etc
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0.97 (2015-01-18)
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fixed HDR asserts, rewrote HDR rle logic
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0.96 (2015-01-17)
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add HDR output
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fix monochrome BMP
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0.95 (2014-08-17)
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add monochrome TGA output
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0.94 (2014-05-31)
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rename private functions to avoid conflicts with stb_image.h
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0.93 (2014-05-27)
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warning fixes
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0.92 (2010-08-01)
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casts to unsigned char to fix warnings
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0.91 (2010-07-17)
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first public release
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0.90 first internal release
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*/
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/*
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------------------------------------------------------------------------------
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This software is available under 2 licenses -- choose whichever you prefer.
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------------------------------------------------------------------------------
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ALTERNATIVE A - MIT License
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Copyright (c) 2017 Sean Barrett
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Permission is hereby granted, free of charge, to any person obtaining a copy of
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this software and associated documentation files (the "Software"), to deal in
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the Software without restriction, including without limitation the rights to
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use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
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of the Software, and to permit persons to whom the Software is furnished to do
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so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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------------------------------------------------------------------------------
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ALTERNATIVE B - Public Domain (www.unlicense.org)
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This is free and unencumbered software released into the public domain.
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Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
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software, either in source code form or as a compiled binary, for any purpose,
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commercial or non-commercial, and by any means.
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In jurisdictions that recognize copyright laws, the author or authors of this
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software dedicate any and all copyright interest in the software to the public
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domain. We make this dedication for the benefit of the public at large and to
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the detriment of our heirs and successors. We intend this dedication to be an
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overt act of relinquishment in perpetuity of all present and future rights to
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this software under copyright law.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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------------------------------------------------------------------------------
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*/
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