vmware-svga/lib/util/png.h
2009-04-13 07:05:42 +00:00

94 lines
2.5 KiB
C

/**********************************************************
* Copyright 2008-2009 VMware, Inc. All rights reserved.
*
* 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.
*
**********************************************************/
/*
* png.h --
*
* An extremely simple library for reading in-memory PNG images.
*
* This library has no validation at all, so it must be used only
* with images from trusted sources.
*/
#ifndef __PNG_H__
#define __PNG_H__
#include "types.h"
/*
* PNG fields are in Big Endian byte order. Define a new data type
* for Big Endian numbers, and an inline function to do 32-bit byte
* swapping.
*/
typedef uint32 be32;
static inline uint32
bswap32(uint32 x)
{
__asm__ ("bswap %0" : "+r" (x));
return x;
}
/*
* PNG data types
*/
typedef struct {
be32 length;
uint32 type;
uint8 data[0];
} PNGChunk;
typedef struct {
PNGChunk hdr;
be32 width;
be32 height;
uint8 bitDepth;
uint8 colorType;
uint8 compression;
uint8 filter;
uint8 interlace;
} PNGChunkIHDR;
#define PNG_CHUNK(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24))
#define PNG_IHDR PNG_CHUNK('I','H','D','R')
#define PNG_IDAT PNG_CHUNK('I','D','A','T')
#define PNG_IEND PNG_CHUNK('I','E','N','D')
/*
* Public functions
*/
PNGChunkIHDR *PNG_Header(void *pngData);
PNGChunk *PNG_NextChunk(PNGChunk *lastChunk);
void PNG_DecompressBGRX(PNGChunkIHDR *ihdr, uint32 *framebuffer, uint32 pitch);
#endif /* __PNG_H_ */