netsurf/riscos/gifread.h

99 lines
2.1 KiB
C

/*
* This file is part of NetSurf, http://netsurf.sourceforge.net/
* Licensed under the GNU General Public License,
* http://www.opensource.org/licenses/gpl-license
* Copyright 2004 Richard Wilson <not_ginger_matt@sourceforge.net>
*/
/** \file
* Progressive animated GIF file decoding (interface).
*/
#ifndef _NETSURF_RISCOS_GIFREAD_H_
#define _NETSURF_RISCOS_GIFREAD_H_
#include "oslib/osspriteop.h"
/* Error return values
*/
#define GIF_INSUFFICIENT_FRAME_DATA -1
#define GIF_FRAME_DATA_ERROR -2
#define GIF_INSUFFICIENT_DATA -3
#define GIF_DATA_ERROR -4
#define GIF_INSUFFICIENT_MEMORY -5
/* Colour map size constant. Because we don't want to allocate
memory each time we decode a frame we get enough so all frames
will fit in there.
*/
#define GIF_MAX_COLOURS 256
/* Maximum LZW bits available
*/
#define GIF_MAX_LZW 12
/* The GIF frame dats
*/
typedef struct gif_frame {
/* Frame data
*/
unsigned int frame_pointer;
unsigned int frame_delay;
/* Redraw characteristics
*/
unsigned int redraw_required;
unsigned int redraw_x;
unsigned int redraw_y;
unsigned int redraw_width;
unsigned int redraw_height;
} gif_frame;
/* A simple hold-all for our GIF data
*/
typedef struct gif_animation {
/* Encoded GIF data
*/
unsigned char *gif_data;
unsigned int buffer_position;
unsigned int buffer_size;
/* Progressive decoding data
*/
unsigned int global_colours;
unsigned int frame_holders;
unsigned int colour_table_size;
/* Animation data
*/
unsigned int decoded_frame;
int loop_count;
gif_frame *frames;
/* Decoded GIF data
*/
unsigned int width;
unsigned int height;
unsigned int frame_count;
unsigned int frame_count_partial;
unsigned int background_colour;
unsigned int aspect_ratio;
unsigned int *global_colour_table;
unsigned int *local_colour_table;
/* Decoded frame data
*/
unsigned int dirty_frame; // Frame needs erasing before next
osspriteop_header *frame_image;
} gif_animation;
/* Function declarations
*/
int gif_initialise(struct gif_animation *gif);
int gif_decode_frame(struct gif_animation *gif, unsigned int frame);
void gif_finalise(struct gif_animation *gif);
#endif