78 lines
3.0 KiB
C
78 lines
3.0 KiB
C
/*
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* This file is part of NetSurf, http://netsurf-browser.org/
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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@users.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_IMAGE_GIFREAD_H_
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#define _NETSURF_IMAGE_GIFREAD_H_
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#include <stdbool.h>
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#include "netsurf/image/bitmap.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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/* Maximum colour table size
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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 data
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*/
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typedef struct gif_frame {
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unsigned int frame_pointer; /**< offset (in bytes) to the GIF frame data */
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unsigned int frame_delay; /**< delay (in cs) before animating the frame */
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bool virgin; /**< whether the frame has previously been used */
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bool opaque; /**< whether the frame is totally opaque */
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bool redraw_required; /**< whether a forcable screen redraw is required */
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unsigned int redraw_x; /**< x co-ordinate of redraw rectangle */
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unsigned int redraw_y; /**< y co-ordinate of redraw rectangle */
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unsigned int redraw_width; /**< width of redraw rectangle */
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unsigned int redraw_height; /**< height of redraw rectangle */
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} gif_frame;
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/* The GIF animation data
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*/
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typedef struct gif_animation {
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unsigned char *gif_data; /**< pointer to GIF data */
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unsigned int buffer_position; /**< current index into GIF data */
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unsigned int buffer_size; /**< total number of bytes of GIF data available */
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unsigned int frame_holders; /**< current number of frame holders */
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int decoded_frame; /**< current frame decoded to bitmap */
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int loop_count; /**< number of times to loop animation */
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gif_frame *frames; /**< decoded frames */
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unsigned int width; /**< width of GIF (may increase during decoding) */
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unsigned int height; /**< heigth of GIF (may increase during decoding) */
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unsigned int frame_count; /**< number of frames decoded */
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unsigned int frame_count_partial; /**< number of frames partially decoded */
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unsigned int background_colour; /**< image background colour */
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unsigned int aspect_ratio; /**< image aspect ratio (ignored) */
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unsigned int colour_table_size; /**< size of colour table (in entries) */
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bool global_colours; /**< whether the GIF has a global colour table */
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unsigned int *global_colour_table; /**< global colour table */
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unsigned int *local_colour_table; /**< local colour table */
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int dirty_frame; /**< the current dirty frame, or -1 for none */
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struct bitmap *frame_image; /**< currently decoded image */
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int current_error; /**< current error type, or 0 for none*/
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} gif_animation;
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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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