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Diffstat (limited to 'libnsgif.c')
-rw-r--r--libnsgif.c101
1 files changed, 61 insertions, 40 deletions
diff --git a/libnsgif.c b/libnsgif.c
index 1580e5e..925da90 100644
--- a/libnsgif.c
+++ b/libnsgif.c
@@ -110,19 +110,19 @@
/* Internal GIF routines
*/
-static gif_result gif_initialise_sprite(struct gif_animation *gif, unsigned int width, unsigned int height, gif_bitmap_callback_vt *bitmap_callbacks);
-static gif_result gif_initialise_frame(struct gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks);
-static gif_result gif_initialise_frame_extensions(struct gif_animation *gif, const int frame);
-static gif_result gif_skip_frame_extensions(struct gif_animation *gif);
+static gif_result gif_initialise_sprite(gif_animation *gif, unsigned int width, unsigned int height);
+static gif_result gif_initialise_frame(gif_animation *gif);
+static gif_result gif_initialise_frame_extensions(gif_animation *gif, const int frame);
+static gif_result gif_skip_frame_extensions(gif_animation *gif);
static unsigned int gif_interlaced_line(int height, int y);
/* Internal LZW routines
*/
-static void gif_init_LZW(struct gif_animation *gif);
-static bool gif_next_LZW(struct gif_animation *gif);
-static int gif_next_code(struct gif_animation *gif, int code_size);
+static void gif_init_LZW(gif_animation *gif);
+static bool gif_next_LZW(gif_animation *gif);
+static int gif_next_code(gif_animation *gif, int code_size);
/* General LZW values. They are shared for all GIFs being decoded, and
thus we can't handle progressive decoding efficiently without having
@@ -147,6 +147,20 @@ static bool get_done;
*/
static bool clear_image = false;
+/** Initialises necessary gif_animation members.
+*/
+void gif_create(gif_animation *gif) {
+ gif->gif_data = NULL;
+ gif->frame_image = NULL;
+ gif->frames = NULL;
+ gif->local_colour_table = NULL;
+ gif->global_colour_table = NULL;
+ gif->buffer_position = 0;
+ gif->frame_count = 0;
+ gif->frame_count_partial = 0;
+ gif->decoded_frame = GIF_INVALID_FRAME;
+}
+
/** Initialises any workspace held by the animation and attempts to decode
any information that hasn't already been decoded.
If an error occurs, all previously decoded frames are retained.
@@ -160,15 +174,20 @@ static bool clear_image = false;
GIF_OK for successful decoding
GIF_WORKING for successful decoding if more frames are expected
*/
-gif_result gif_initialise(struct gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks) {
+gif_result gif_initialise(gif_animation *gif, size_t size, unsigned char *data) {
unsigned char *gif_data;
unsigned int index;
gif_result return_value;
- /* The GIF format is thoroughly documented; a full description
- * can be found at http://www.w3.org/Graphics/GIF/spec-gif89a.txt
- */
+ /* The GIF format is thoroughly documented; a full description
+ * can be found at http://www.w3.org/Graphics/GIF/spec-gif89a.txt
+ */
+ /* Initialize values
+ */
+ gif->buffer_size = size;
+ gif->gif_data = data;
+
/* Check for sufficient data to be a GIF (6-byte header + 7-byte logical screen descriptor)
*/
if (gif->buffer_size < 13) return GIF_INSUFFICIENT_DATA;
@@ -227,7 +246,7 @@ gif_result gif_initialise(struct gif_animation *gif, gif_bitmap_callback_vt *bit
gif->height = gif_data[2] | (gif_data[3] << 8);
gif->global_colours = (gif_data[4] & GIF_COLOUR_TABLE_MASK);
gif->colour_table_size = (2 << (gif_data[4] & GIF_COLOUR_TABLE_SIZE_MASK));
- gif->background_colour = gif_data[5];
+ gif->background_index = gif_data[5];
gif->aspect_ratio = gif_data[6];
gif->loop_count = 1;
gif_data += 7;
@@ -255,7 +274,7 @@ gif_result gif_initialise(struct gif_animation *gif, gif_bitmap_callback_vt *bit
gif->global_colour_table = (unsigned int *)calloc(GIF_MAX_COLOURS, sizeof(int));
gif->local_colour_table = (unsigned int *)calloc(GIF_MAX_COLOURS, sizeof(int));
if ((gif->global_colour_table == NULL) || (gif->local_colour_table == NULL)) {
- gif_finalise(gif, bitmap_callbacks);
+ gif_finalise(gif);
return GIF_INSUFFICIENT_MEMORY;
}
@@ -277,15 +296,15 @@ gif_result gif_initialise(struct gif_animation *gif, gif_bitmap_callback_vt *bit
/* Initialise enough workspace for 4 frames initially
*/
if ((gif->frames = (gif_frame *)malloc(sizeof(gif_frame))) == NULL) {
- gif_finalise(gif, bitmap_callbacks);
+ gif_finalise(gif);
return GIF_INSUFFICIENT_MEMORY;
}
gif->frame_holders = 1;
/* Initialise the sprite header
*/
- if ((gif->frame_image = bitmap_callbacks->bitmap_create(gif->width, gif->height)) == NULL) {
- gif_finalise(gif, bitmap_callbacks);
+ if ((gif->frame_image = gif->bitmap_callbacks.bitmap_create(gif->width, gif->height)) == NULL) {
+ gif_finalise(gif);
return GIF_INSUFFICIENT_MEMORY;
}
@@ -320,7 +339,7 @@ gif_result gif_initialise(struct gif_animation *gif, gif_bitmap_callback_vt *bit
/* Repeatedly try to initialise frames
*/
- while ((return_value = gif_initialise_frame(gif, bitmap_callbacks)) == GIF_WORKING);
+ while ((return_value = gif_initialise_frame(gif)) == GIF_WORKING);
/* If there was a memory error tell the caller
*/
@@ -346,7 +365,7 @@ gif_result gif_initialise(struct gif_animation *gif, gif_bitmap_callback_vt *bit
@return GIF_INSUFFICIENT_MEMORY for a memory error
GIF_OK for success
*/
-static gif_result gif_initialise_sprite(struct gif_animation *gif, unsigned int width, unsigned int height, gif_bitmap_callback_vt *bitmap_callbacks) {
+static gif_result gif_initialise_sprite(gif_animation *gif, unsigned int width, unsigned int height) {
unsigned int max_width;
unsigned int max_height;
struct bitmap *buffer;
@@ -363,9 +382,9 @@ static gif_result gif_initialise_sprite(struct gif_animation *gif, unsigned int
/* Allocate some more memory
*/
- if ((buffer = bitmap_callbacks->bitmap_create(max_width, max_height)) == NULL)
+ if ((buffer = gif->bitmap_callbacks.bitmap_create(max_width, max_height)) == NULL)
return GIF_INSUFFICIENT_MEMORY;
- bitmap_callbacks->bitmap_destroy(gif->frame_image);
+ gif->bitmap_callbacks.bitmap_destroy(gif->frame_image);
gif->frame_image = buffer;
gif->width = max_width;
gif->height = max_height;
@@ -387,7 +406,7 @@ static gif_result gif_initialise_sprite(struct gif_animation *gif, unsigned int
GIF_OK for successful decoding
GIF_WORKING for successful decoding if more frames are expected
*/
-static gif_result gif_initialise_frame(struct gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks) {
+static gif_result gif_initialise_frame(gif_animation *gif) {
int frame;
gif_frame *temp_buf;
@@ -517,7 +536,7 @@ static gif_result gif_initialise_frame(struct gif_animation *gif, gif_bitmap_cal
/* Boundary checking - shouldn't ever happen except with junk data
*/
- if (gif_initialise_sprite(gif, (offset_x + width), (offset_y + height), bitmap_callbacks))
+ if (gif_initialise_sprite(gif, (offset_x + width), (offset_y + height)))
return GIF_INSUFFICIENT_MEMORY;
/* Decode the flags
@@ -581,7 +600,7 @@ static gif_result gif_initialise_frame(struct gif_animation *gif, gif_bitmap_cal
@return GIF_INSUFFICIENT_FRAME_DATA for insufficient data to complete the frame
GIF_OK for successful initialisation
*/
-static gif_result gif_initialise_frame_extensions(struct gif_animation *gif, const int frame) {
+static gif_result gif_initialise_frame_extensions(gif_animation *gif, const int frame) {
unsigned char *gif_data, *gif_end;
int gif_bytes;
unsigned int block_size;
@@ -695,7 +714,7 @@ static gif_result gif_initialise_frame_extensions(struct gif_animation *gif, con
If a frame does not contain any image data, GIF_OK is returned and
gif->current_error is set to GIF_FRAME_NO_DISPLAY
*/
-gif_result gif_decode_frame(struct gif_animation *gif, unsigned int frame, gif_bitmap_callback_vt *bitmap_callbacks) {
+gif_result gif_decode_frame(gif_animation *gif, unsigned int frame) {
unsigned int index = 0;
unsigned char *gif_data, *gif_end;
int gif_bytes;
@@ -831,7 +850,7 @@ gif_result gif_decode_frame(struct gif_animation *gif, unsigned int frame, gif_b
/* Get the frame data
*/
- frame_data = (unsigned int *)bitmap_callbacks->bitmap_get_buffer(gif->frame_image);
+ frame_data = (unsigned int *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image);
if (!frame_data)
return GIF_INSUFFICIENT_MEMORY;
@@ -854,10 +873,10 @@ gif_result gif_decode_frame(struct gif_animation *gif, unsigned int frame, gif_b
* colour or this is the first frame, clear the frame data
*/
if ((frame == 0) || (gif->decoded_frame == GIF_INVALID_FRAME)) {
- memset((char*)frame_data, colour_table[gif->background_colour], gif->width * gif->height * sizeof(int));
+ memset((char*)frame_data, colour_table[gif->background_index], gif->width * gif->height * sizeof(int));
} else if ((frame != 0) && (gif->frames[frame - 1].disposal_method == GIF_FRAME_CLEAR)) {
clear_image = true;
- if ((return_value = gif_decode_frame(gif, (frame - 1), bitmap_callbacks)) != GIF_OK)
+ if ((return_value = gif_decode_frame(gif, (frame - 1))) != GIF_OK)
goto gif_decode_frame_exit;
clear_image = false;
/* If the previous frame's disposal method requires we restore the previous
@@ -868,13 +887,13 @@ gif_result gif_decode_frame(struct gif_animation *gif, unsigned int frame, gif_b
/* If we don't find one, clear the frame data
*/
if (last_undisposed_frame == -1) {
- memset((char*)frame_data, colour_table[gif->background_colour], gif->width * gif->height * sizeof(int));
+ memset((char*)frame_data, colour_table[gif->background_index], gif->width * gif->height * sizeof(int));
} else {
- if ((return_value = gif_decode_frame(gif, last_undisposed_frame, bitmap_callbacks)) != GIF_OK)
+ if ((return_value = gif_decode_frame(gif, last_undisposed_frame)) != GIF_OK)
goto gif_decode_frame_exit;
/* Get this frame's data
*/
- frame_data = (unsigned int *)bitmap_callbacks->bitmap_get_buffer(gif->frame_image);
+ frame_data = (unsigned int *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image);
if (!frame_data)
return GIF_INSUFFICIENT_MEMORY;
}
@@ -940,7 +959,7 @@ gif_result gif_decode_frame(struct gif_animation *gif, unsigned int frame, gif_b
if (gif->frames[frame].disposal_method == GIF_FRAME_CLEAR) {
for (y = 0; y < height; y++) {
frame_scanline = frame_data + offset_x + ((offset_y + y) * gif->width);
- memset(frame_scanline, colour_table[gif->background_colour], width * 4);
+ memset(frame_scanline, colour_table[gif->background_index], width * 4);
}
}
@@ -968,11 +987,11 @@ gif_decode_frame_exit:
/* Check if we should test for optimisation
*/
if (gif->frames[frame].virgin) {
- gif->frames[frame].opaque = bitmap_callbacks->bitmap_test_opaque(gif->frame_image);
+ gif->frames[frame].opaque = gif->bitmap_callbacks.bitmap_test_opaque(gif->frame_image);
gif->frames[frame].virgin = false;
}
- bitmap_callbacks->bitmap_set_opaque(gif->frame_image, gif->frames[frame].opaque);
- bitmap_callbacks->bitmap_modified(gif->frame_image);
+ gif->bitmap_callbacks.bitmap_set_opaque(gif->frame_image, gif->frames[frame].opaque);
+ gif->bitmap_callbacks.bitmap_modified(gif->frame_image);
/* Restore the buffer position
*/
@@ -989,7 +1008,7 @@ gif_decode_frame_exit:
@return GIF_INSUFFICIENT_FRAME_DATA for insufficient data to complete the frame
GIF_OK for successful decoding
*/
-static gif_result gif_skip_frame_extensions(struct gif_animation *gif) {
+static gif_result gif_skip_frame_extensions(gif_animation *gif) {
unsigned char *gif_data, *gif_end;
int gif_bytes;
unsigned int block_size;
@@ -1054,11 +1073,11 @@ static unsigned int gif_interlaced_line(int height, int y) {
/* Releases any workspace held by the animation
*/
-void gif_finalise(struct gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks) {
+void gif_finalise(gif_animation *gif) {
/* Release all our memory blocks
*/
if (gif->frame_image)
- bitmap_callbacks->bitmap_destroy(gif->frame_image);
+ gif->bitmap_callbacks.bitmap_destroy(gif->frame_image);
gif->frame_image = NULL;
free(gif->frames);
gif->frames = NULL;
@@ -1066,12 +1085,14 @@ void gif_finalise(struct gif_animation *gif, gif_bitmap_callback_vt *bitmap_call
gif->local_colour_table = NULL;
free(gif->global_colour_table);
gif->global_colour_table = NULL;
+ free(gif->gif_data);
+ gif->gif_data = NULL;
}
/**
* Initialise LZW decoding
*/
-void gif_init_LZW(struct gif_animation *gif) {
+void gif_init_LZW(gif_animation *gif) {
int i;
gif->current_error = 0;
@@ -1098,7 +1119,7 @@ void gif_init_LZW(struct gif_animation *gif) {
}
-static bool gif_next_LZW(struct gif_animation *gif) {
+static bool gif_next_LZW(gif_animation *gif) {
int code, incode;
int block_size;
int new_code;
@@ -1165,7 +1186,7 @@ static bool gif_next_LZW(struct gif_animation *gif) {
return true;
}
-static int gif_next_code(struct gif_animation *gif, int code_size) {
+static int gif_next_code(gif_animation *gif, int code_size) {
int i, j, end, count, ret;
unsigned char *b;
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-24 05:22:50 +0000