mirror of
https://github.com/netsurf-browser/netsurf
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f29ad7e266
Improved GIF animation and a decoding bug fix. svn path=/import/netsurf/; revision=845
99 lines
2.1 KiB
C
99 lines
2.1 KiB
C
/*
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* This file is part of NetSurf, http://netsurf.sourceforge.net/
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* Licensed under the GNU General Public License,
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* http://www.opensource.org/licenses/gpl-license
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* Copyright 2004 Richard Wilson <not_ginger_matt@sourceforge.net>
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*/
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/** \file
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* Progressive animated GIF file decoding (interface).
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*/
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#ifndef _NETSURF_RISCOS_GIFREAD_H_
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#define _NETSURF_RISCOS_GIFREAD_H_
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#include "oslib/osspriteop.h"
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/* Error return values
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*/
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#define GIF_INSUFFICIENT_FRAME_DATA -1
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#define GIF_FRAME_DATA_ERROR -2
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#define GIF_INSUFFICIENT_DATA -3
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#define GIF_DATA_ERROR -4
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#define GIF_INSUFFICIENT_MEMORY -5
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/* Colour map size constant. Because we don't want to allocate
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memory each time we decode a frame we get enough so all frames
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will fit in there.
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*/
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#define GIF_MAX_COLOURS 256
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/* Maximum LZW bits available
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*/
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#define GIF_MAX_LZW 12
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/* The GIF frame dats
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*/
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typedef struct gif_frame {
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/* Frame data
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*/
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unsigned int frame_pointer;
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unsigned int frame_delay;
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/* Redraw characteristics
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*/
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unsigned int redraw_required;
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unsigned int redraw_x;
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unsigned int redraw_y;
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unsigned int redraw_width;
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unsigned int redraw_height;
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} gif_frame;
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/* A simple hold-all for our GIF data
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*/
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typedef struct gif_animation {
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/* Encoded GIF data
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*/
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unsigned char *gif_data;
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unsigned int buffer_position;
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unsigned int buffer_size;
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/* Progressive decoding data
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*/
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unsigned int global_colours;
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unsigned int frame_holders;
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unsigned int colour_table_size;
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/* Animation data
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*/
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unsigned int decoded_frame;
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int loop_count;
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gif_frame *frames;
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/* Decoded GIF data
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*/
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unsigned int width;
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unsigned int height;
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unsigned int frame_count;
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unsigned int frame_count_partial;
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unsigned int background_colour;
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unsigned int aspect_ratio;
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unsigned int *global_colour_table;
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unsigned int *local_colour_table;
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/* Decoded frame data
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*/
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unsigned int dirty_frame; // Frame needs erasing before next
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osspriteop_header *frame_image;
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} gif_animation;
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/* Function declarations
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*/
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int gif_initialise(struct gif_animation *gif);
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int gif_decode_frame(struct gif_animation *gif, unsigned int frame);
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void gif_finalise(struct gif_animation *gif);
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#endif
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