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/*
* pnglite.h - Interface for pnglite library
* Copyright (c) 2007 Daniel Karling
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not
* be misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source
* distribution.
*
* Daniel Karling
* daniel.karling@gmail.com
*/
#ifndef _PNGLITE_H_
#define _PNGLITE_H_
#include <string.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* Enumerations for pnglite.
* Negative numbers are error codes and 0 and up are okay responses.
*/
enum {
PNG_DONE = 1,
PNG_NO_ERROR = 0,
PNG_FILE_ERROR = -1,
PNG_HEADER_ERROR = -2,
PNG_IO_ERROR = -3,
PNG_EOF_ERROR = -4,
PNG_CRC_ERROR = -5,
PNG_MEMORY_ERROR = -6,
PNG_ZLIB_ERROR = -7,
PNG_UNKNOWN_FILTER = -8,
PNG_NOT_SUPPORTED = -9,
PNG_WRONG_ARGUMENTS = -10
};
/*
* The five different kinds of color storage in PNG files.
*/
enum {
PNG_GREYSCALE = 0,
PNG_TRUECOLOR = 2,
PNG_INDEXED = 3,
PNG_GREYSCALE_ALPHA = 4,
PNG_TRUECOLOR_ALPHA = 6
};
typedef struct {
void *zs; /* pointer to z_stream */
int fd;
unsigned char *image;
unsigned char *png_data;
unsigned png_datalen;
unsigned width;
unsigned height;
unsigned char depth;
unsigned char color_type;
unsigned char compression_method;
unsigned char filter_method;
unsigned char interlace_method;
unsigned char bpp;
unsigned char *readbuf;
unsigned readbuflen;
} png_t;
/*
* Function: png_open
*
* This function is used to open a png file with the internal file
* IO system.
*
* Parameters:
* png - Empty png_t struct.
* filename - Filename of the file to be opened.
*
* Returns:
* PNG_NO_ERROR on success, otherwise an error code.
*/
int png_open(png_t *png, const char *filename);
/*
* Function: png_print_info
*
* This function prints some info about the opened png file to stdout.
*
* Parameters:
* png - png struct to get info from.
*/
void png_print_info(png_t *png);
/*
* Function: png_error_string
*
* This function translates an error code to a human readable string.
*
* Parameters:
* error - Error code.
*
* Returns:
* Pointer to string.
*/
char *png_error_string(int error);
/*
* Function: png_get_data
*
* This function decodes the opened png file and stores the result in data.
* data should be big enough to hold the decoded png.
* Required size will be:
*
* > width*height*(bytes per pixel)
*
* Parameters:
* data - Where to store result.
*
* Returns:
* PNG_NO_ERROR on success, otherwise an error code.
*/
int png_get_data(png_t *png, uint8_t *data);
/*
* Function: png_close
*
* Closes an open png file pointer.
*
* Parameters:
* png - png to close.
*
* Returns:
* PNG_NO_ERROR
*/
int png_close(png_t *png);
#ifdef __cplusplus
}
#endif
#endif /* _PNGLITE_H_ */
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