74 lines
1.6 KiB
C
74 lines
1.6 KiB
C
/*
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img_png.h - png format reference
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Copyright (C) 2019 Andrey Akhmichin
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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*/
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#ifndef IMG_PNG_H
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#define IMG_PNG_H
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/*
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========================================================================
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.PNG image format (Portable Network Graphics)
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========================================================================
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*/
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enum png_colortype
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{
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PNG_CT_GREY,
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PNG_CT_RGB = BIT(1),
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PNG_CT_PALLETE = (PNG_CT_RGB|BIT(0)),
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PNG_CT_ALPHA = BIT(2),
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PNG_CT_RGBA = (PNG_CT_RGB|PNG_CT_ALPHA)
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};
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enum png_filter
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{
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PNG_F_NONE,
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PNG_F_SUB,
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PNG_F_UP,
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PNG_F_AVERAGE,
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PNG_F_PAETH
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};
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#pragma pack( push, 1 )
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typedef struct png_ihdr_s
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{
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uint32_t width;
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uint32_t height;
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uint8_t bitdepth;
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uint8_t colortype;
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uint8_t compression;
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uint8_t filter;
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uint8_t interlace;
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} png_ihdr_t;
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typedef struct png_s
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{
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uint8_t sign[8];
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uint32_t ihdr_len;
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uint8_t ihdr_sign[4];
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png_ihdr_t ihdr_chunk;
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uint32_t ihdr_crc32;
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} png_t;
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typedef struct png_footer_s
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{
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uint32_t idat_crc32;
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uint32_t iend_len;
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uint8_t iend_sign[4];
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uint32_t iend_crc32;
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} png_footer_t;
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#pragma pack( pop )
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#endif // IMG_PNG_H
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