First cut at a port to the core buildsystem

svn path=/trunk/libnsgif/; revision=6983

1 files changed, 107 insertions, 0 deletions

diff --git a/include/libnsgif.h b/include/libnsgif.h
new file mode 100644
index 0000000..f60cc13
--- /dev/null
+++ b/include/libnsgif.h
@@ -0,0 +1,107 @@
+/*
+ * 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>
+
+/*	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;
+
+/*	The GIF frame data
+*/
+typedef struct gif_frame {
+  	bool display;				/**< whether the frame should be displayed/animated */
+  	unsigned int frame_delay;		/**< delay (in cs) 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 */
+} 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);
+
+#endif