RetroArch/libretro-common/formats/png/rpng_internal.h

/* Copyright  (C) 2010-2015 The RetroArch team
 *
 * ---------------------------------------------------------------------------------------
 * The following license statement only applies to this file (rpng.c).
 * ---------------------------------------------------------------------------------------
 *
 * 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.
 */

#ifndef _RPNG_COMMON_H
#define _RPNG_COMMON_H

#include <retro_inline.h>
#include <formats/rpng.h>
#include <stdint.h>

#undef GOTO_END_ERROR
#define GOTO_END_ERROR() do { \
   fprintf(stderr, "[RPNG]: Error in line %d.\n", __LINE__); \
   ret = false; \
   goto end; \
} while(0)

#ifndef ARRAY_SIZE
#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
#endif

static const uint8_t png_magic[8] = {
   0x89, 'P', 'N', 'G', 0x0d, 0x0a, 0x1a, 0x0a,
};

enum png_chunk_type
{
   PNG_CHUNK_NOOP = 0,
   PNG_CHUNK_ERROR,
   PNG_CHUNK_IHDR,
   PNG_CHUNK_IDAT,
   PNG_CHUNK_PLTE,
   PNG_CHUNK_IEND
};

enum png_line_filter
{
   PNG_FILTER_NONE = 0,
   PNG_FILTER_SUB,
   PNG_FILTER_UP,
   PNG_FILTER_AVERAGE,
   PNG_FILTER_PAETH
};

enum png_ihdr_color_type
{
   PNG_IHDR_COLOR_GRAY       = 0,
   PNG_IHDR_COLOR_RGB        = 2,
   PNG_IHDR_COLOR_PLT        = 3,
   PNG_IHDR_COLOR_GRAY_ALPHA = 4,
   PNG_IHDR_COLOR_RGBA       = 6
};

struct adam7_pass
{
   unsigned x;
   unsigned y;
   unsigned stride_x;
   unsigned stride_y;
};

struct idat_buffer
{
   uint8_t *data;
   size_t size;
};

struct png_chunk
{
   uint32_t size;
   char type[4];
   uint8_t *data;
};

struct png_ihdr
{
   uint32_t width;
   uint32_t height;
   uint8_t depth;
   uint8_t color_type;
   uint8_t compression;
   uint8_t filter;
   uint8_t interlace;
};

struct rpng_process_t
{
   bool initialized;
   bool inflate_initialized;
   bool adam7_pass_initialized;
   bool pass_initialized;
   uint32_t *data;
   uint32_t *palette;
   struct png_ihdr ihdr;
   uint8_t *prev_scanline;
   uint8_t *decoded_scanline;
   uint8_t *inflate_buf;
   size_t restore_buf_size;
   size_t adam7_restore_buf_size;
   size_t data_restore_buf_size;
   size_t inflate_buf_size;
   unsigned bpp;
   unsigned pitch;
   unsigned h;
   struct
   {
      unsigned width;
      unsigned height;
      size_t   size;
      unsigned pos;
   } pass;
   void *stream;
   zlib_file_handle_t handle;
};

struct rpng
{
   struct rpng_process_t process;
   bool has_ihdr;
   bool has_idat;
   bool has_iend;
   bool has_plte;
   struct idat_buffer idat_buf;
   struct png_ihdr ihdr;
   uint8_t *buff_data;
   uint32_t palette[256];
};

/* Paeth prediction filter. */
static INLINE int paeth(int a, int b, int c)
{
   int p  = a + b - c;
   int pa = abs(p - a);
   int pb = abs(p - b);
   int pc = abs(p - c);

   if (pa <= pb && pa <= pc)
      return a;
   else if (pb <= pc)
      return b;
   return c;
}

static INLINE uint32_t dword_be(const uint8_t *buf)
{
   return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | (buf[3] << 0);
}

int rpng_load_image_argb_process_inflate_init(rpng_t *rpng,
      uint32_t **data, unsigned *width, unsigned *height);

#endif