Imported Upstream version 0.13.2+dsfg1

libobs/graphics/libnsgif/libnsgif.h

@@ -0,0 +1,142 @@
+/*
+ * Copyright 2004 Richard Wilson <richard.wilson@netsurf-browser.org>
+ * Copyright 2008 Sean Fox <dyntryx@gmail.com>
+ *
+ * This file is part of NetSurf's libnsgif, http://www.netsurf-browser.org/
+ * Licenced under the MIT License,
+ *                http://www.opensource.org/licenses/mit-license.php
+ */
+
+/** \file
+ * Progressive animated GIF file decoding (interface).
+ */
+
+#ifndef _LIBNSGIF_H_
+#define _LIBNSGIF_H_
+
+#include <stdbool.h>
+#include <inttypes.h>
+
+#if defined(__cplusplus)
+extern "C"
+{
+#endif
+/*    Error return values
+*/
+typedef enum {
+    GIF_WORKING = 1,
+    GIF_OK = 0,
+    GIF_INSUFFICIENT_FRAME_DATA = -1,
+    GIF_FRAME_DATA_ERROR = -2,
+    GIF_INSUFFICIENT_DATA = -3,
+    GIF_DATA_ERROR = -4,
+    GIF_INSUFFICIENT_MEMORY = -5,
+    GIF_FRAME_NO_DISPLAY = -6,
+    GIF_END_OF_FRAME = -7
+} gif_result;
+
+/*    Maximum LZW bits available
+*/
+#define GIF_MAX_LZW 12
+
+/*    The GIF frame data
+*/
+typedef struct gif_frame {
+    bool display;                /**< whether the frame should be displayed/animated */
+    unsigned int frame_delay;        /**< delay (in 100th second intervals) before animating the frame */
+    /**    Internal members are listed below
+    */
+    unsigned int frame_pointer;        /**< offset (in bytes) to the GIF frame data */
+    bool virgin;                /**< whether the frame has previously been used */
+    bool opaque;                /**< whether the frame is totally opaque */
+    bool redraw_required;            /**< whether a forcable screen redraw is required */
+    unsigned char disposal_method;        /**< how the previous frame should be disposed; affects plotting */
+    bool transparency;             /**< whether we acknoledge transparency */
+    unsigned char transparency_index;    /**< the index designating a transparent pixel */
+    unsigned int redraw_x;            /**< x co-ordinate of redraw rectangle */
+    unsigned int redraw_y;            /**< y co-ordinate of redraw rectangle */
+    unsigned int redraw_width;        /**< width of redraw rectangle */
+    unsigned int redraw_height;        /**< height of redraw rectangle */
+} gif_frame;
+
+/*    API for Bitmap callbacks
+*/
+typedef void* (*gif_bitmap_cb_create)(int width, int height);
+typedef void (*gif_bitmap_cb_destroy)(void *bitmap);
+typedef unsigned char* (*gif_bitmap_cb_get_buffer)(void *bitmap);
+typedef void (*gif_bitmap_cb_set_opaque)(void *bitmap, bool opaque);
+typedef bool (*gif_bitmap_cb_test_opaque)(void *bitmap);
+typedef void (*gif_bitmap_cb_modified)(void *bitmap);
+
+/*    The Bitmap callbacks function table
+*/
+typedef struct gif_bitmap_callback_vt {
+    gif_bitmap_cb_create bitmap_create;        /**< Create a bitmap. */
+    gif_bitmap_cb_destroy bitmap_destroy;        /**< Free a bitmap. */
+    gif_bitmap_cb_get_buffer bitmap_get_buffer;    /**< Return a pointer to the pixel data in a bitmap. */
+    /**    Members below are optional
+    */
+    gif_bitmap_cb_set_opaque bitmap_set_opaque;    /**< Sets whether a bitmap should be plotted opaque. */
+    gif_bitmap_cb_test_opaque bitmap_test_opaque;    /**< Tests whether a bitmap has an opaque alpha channel. */
+    gif_bitmap_cb_modified bitmap_modified;    /**< The bitmap image has changed, so flush any persistant cache. */
+} gif_bitmap_callback_vt;
+
+/*    The GIF animation data
+*/
+typedef struct gif_animation {
+    gif_bitmap_callback_vt bitmap_callbacks;    /**< callbacks for bitmap functions */
+    unsigned char *gif_data;            /**< pointer to GIF data */
+    unsigned int width;                /**< width of GIF (may increase during decoding) */
+    unsigned int height;                /**< heigth of GIF (may increase during decoding) */
+    unsigned int frame_count;            /**< number of frames decoded */
+    unsigned int frame_count_partial;        /**< number of frames partially decoded */
+    gif_frame *frames;                /**< decoded frames */
+    int decoded_frame;                /**< current frame decoded to bitmap */
+    void *frame_image;                /**< currently decoded image; stored as bitmap from bitmap_create callback */
+    int loop_count;                    /**< number of times to loop animation */
+    gif_result current_error;            /**< current error type, or 0 for none*/
+    /**    Internal members are listed below
+    */
+    unsigned int buffer_position;            /**< current index into GIF data */
+    unsigned int buffer_size;            /**< total number of bytes of GIF data available */
+    unsigned int frame_holders;            /**< current number of frame holders */
+    unsigned int background_index;            /**< index in the colour table for the background colour */
+    unsigned int aspect_ratio;            /**< image aspect ratio (ignored) */
+    unsigned int colour_table_size;        /**< size of colour table (in entries) */
+    bool global_colours;                /**< whether the GIF has a global colour table */
+    unsigned int *global_colour_table;        /**< global colour table */
+    unsigned int *local_colour_table;        /**< local colour table */
+
+
+    /*    General LZW values. They are NO LONGER shared for all GIFs being decoded BECAUSE
+          THAT IS A TERRIBLE IDEA TO SAVE 10Kb or so per GIF.
+    */
+    unsigned char buf[4];
+    unsigned char *direct;
+
+    int table[2][(1 << GIF_MAX_LZW)];
+    unsigned char stack[(1 << GIF_MAX_LZW) * 2];
+    unsigned char *stack_pointer;
+    int code_size, set_code_size;
+    int max_code, max_code_size;
+    int clear_code, end_code;
+    int curbit, lastbit, last_byte;
+    int firstcode, oldcode;
+    bool zero_data_block;
+    bool get_done;
+
+    /*    Whether to clear the decoded image rather than plot
+    */
+    bool clear_image;
+} gif_animation;
+
+void gif_create(gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks);
+gif_result gif_initialise(gif_animation *gif, size_t size, unsigned char *data);
+gif_result gif_decode_frame(gif_animation *gif, unsigned int frame);
+void gif_finalise(gif_animation *gif);
+
+#if defined(__cplusplus)
+};
+#endif
+
+#endif