#define INTERLACE 0x40
#define LOCALCOLORMAP 0x80
#define BitSet(byte, bit) (((byte) & (bit)) == (bit))
-#define ReadOK(file,buffer,len) (fread(buffer, len, 1, file) != 0)
#define LM_to_uint(a,b) (((b)<<8)|(a))
#define GRAYSCALE 1
int gray_scale;
GdkPixbuf *pixbuf;
Gif89 gif89;
+ gint stage;
+
+ /* stuff per frame. As we only support the first one, not so
+ * relevant. But still needed */
+ int frame_len;
+ int frame_height;
+ int frame_interlace;
+
+ /* Static read only */
+ FILE *file;
+
+ /* progressive read, only. */
+ ModulePreparedNotifyFunc func;
+ gpointer user_data;
+ guchar *buf;
+ guint ptr;
+ guint size;
+
+ /* our lwz context */
+ int lwz_fresh;
+ int lwz_code_size;
+ int lwz_set_code_size;
+ int lwz_max_code;
+ int lwz_max_code_size;
+ int lwz_firstcode;
+ int lwz_oldcode;
+ int lwz_clear_code;
+ int lwz_end_code;
+ int lwz_table[2][(1 << MAX_LWZ_BITS)];
+ int lwz_stack[(1 << (MAX_LWZ_BITS)) * 2];
+ int *lwz_sp;
+
};
-static int ReadColorMap (FILE *, int, CMap, int *);
-static int DoExtension (FILE *file, GifContext *context, int label);
-static int GetDataBlock (FILE *, unsigned char *);
-static int GetCode (FILE *, int, int);
-static int LWZReadByte (FILE *, int, int);
+static int ReadColorMap (GifContext *, int, CMap, int *);
+static int DoExtension (GifContext *, int label);
+static int GetDataBlock (GifContext *, unsigned char *);
+static int GetCode (GifContext *, int, int);
+static int LWZReadByte (GifContext *, int, int);
-static void ReadImage (FILE *file,
- GifContext *context,
- int len,
- int height,
- CMap cmap,
- int ncols,
- int format,
- int interlace,
- int number,
- guint leftpos,
- guint toppos);
+static void ReadImage (GifContext *context);
static int
-ReadColorMap (FILE *file,
+ReadOK (GifContext *context, guchar *buffer, size_t len)
+{
+ if (context->file)
+ return fread(buffer, len, 1, context->file) != 0;
+ return 0;
+}
+
+static int
+ReadColorMap (GifContext *context,
int number,
CMap buffer,
int *format)
flag = TRUE;
for (i = 0; i < number; ++i) {
- if (!ReadOK (file, rgb, sizeof (rgb))) {
+ if (!ReadOK (context, rgb, sizeof (rgb))) {
/*g_message (_("GIF: bad colormap\n"));*/
return TRUE;
}
}
static int
-DoExtension (FILE *file, GifContext *context, int label)
+DoExtension (GifContext *context, int label)
{
static guchar buf[256];
switch (label) {
case 0xf9: /* Graphic Control Extension */
- (void) GetDataBlock (file, (unsigned char *) buf);
+ (void) GetDataBlock (context, (unsigned char *) buf);
context->gif89.disposal = (buf[0] >> 2) & 0x7;
context->gif89.input_flag = (buf[0] >> 1) & 0x1;
context->gif89.delay_time = LM_to_uint (buf[1], buf[2]);
else
context->gif89.transparent = -1;
}
- while (GetDataBlock (file, (unsigned char *) buf) != 0)
+ while (GetDataBlock (context, (unsigned char *) buf) != 0)
;
return FALSE;
break;
break;
}
- while (GetDataBlock (file, (unsigned char *) buf) != 0)
+ while (GetDataBlock (context, (unsigned char *) buf) != 0)
;
return FALSE;
static int ZeroDataBlock = FALSE;
static int
-GetDataBlock (FILE *file,
+GetDataBlock (GifContext *context,
unsigned char *buf)
{
unsigned char count;
- if (!ReadOK (file, &count, 1)) {
+ if (!ReadOK (context, &count, 1)) {
/*g_message (_("GIF: error in getting DataBlock size\n"));*/
return -1;
}
ZeroDataBlock = count == 0;
- if ((count != 0) && (!ReadOK (file, buf, count))) {
+ if ((count != 0) && (!ReadOK (context, buf, count))) {
/*g_message (_("GIF: error in reading DataBlock\n"));*/
return -1;
}
}
static int
-GetCode (FILE *file,
+GetCode (GifContext *context,
int code_size,
int flag)
{
buf[0] = buf[last_byte - 2];
buf[1] = buf[last_byte - 1];
- if ((count = GetDataBlock (file, &buf[2])) == 0)
+ if ((count = GetDataBlock (context, &buf[2])) == 0)
done = TRUE;
last_byte = 2 + count;
}
static int
-LWZReadByte (FILE *file,
+LWZReadByte (GifContext *context,
int flag,
int input_code_size)
{
- static int fresh = FALSE;
int code, incode;
- static int code_size, set_code_size;
- static int max_code, max_code_size;
- static int firstcode, oldcode;
- static int clear_code, end_code;
- static int table[2][(1 << MAX_LWZ_BITS)];
- static int stack[(1 << (MAX_LWZ_BITS)) * 2], *sp;
register int i;
if (flag) {
- set_code_size = input_code_size;
- code_size = set_code_size + 1;
- clear_code = 1 << set_code_size;
- end_code = clear_code + 1;
- max_code_size = 2 * clear_code;
- max_code = clear_code + 2;
+ context->lwz_set_code_size = input_code_size;
+ context->lwz_code_size = context->lwz_set_code_size + 1;
+ context->lwz_clear_code = 1 << context->lwz_set_code_size;
+ context->lwz_end_code = context->lwz_clear_code + 1;
+ context->lwz_max_code_size = 2 * context->lwz_clear_code;
+ context->lwz_max_code = context->lwz_clear_code + 2;
- GetCode (file, 0, TRUE);
+ GetCode (context, 0, TRUE);
- fresh = TRUE;
+ context->lwz_fresh = TRUE;
- for (i = 0; i < clear_code; ++i) {
- table[0][i] = 0;
- table[1][i] = i;
+ for (i = 0; i < context->lwz_clear_code; ++i) {
+ context->lwz_table[0][i] = 0;
+ context->lwz_table[1][i] = i;
}
for (; i < (1 << MAX_LWZ_BITS); ++i)
- table[0][i] = table[1][0] = 0;
+ context->lwz_table[0][i] = context->lwz_table[1][0] = 0;
- sp = stack;
+ context->lwz_sp = context->lwz_stack;
return 0;
- } else if (fresh) {
- fresh = FALSE;
+ } else if (context->lwz_fresh) {
+ context->lwz_fresh = FALSE;
do {
- firstcode = oldcode = GetCode (file, code_size, FALSE);
- } while (firstcode == clear_code);
- return firstcode;
+ context->lwz_firstcode = context->lwz_oldcode = GetCode (context, context->lwz_code_size, FALSE);
+ } while (context->lwz_firstcode == context->lwz_clear_code);
+ return context->lwz_firstcode;
}
- if (sp > stack)
- return *--sp;
+ if (context->lwz_sp > context->lwz_stack)
+ return *--(context->lwz_sp);
- while ((code = GetCode (file, code_size, FALSE)) >= 0) {
- if (code == clear_code) {
- for (i = 0; i < clear_code; ++i) {
- table[0][i] = 0;
- table[1][i] = i;
+ while ((code = GetCode (context, context->lwz_code_size, FALSE)) >= 0) {
+ if (code == context->lwz_clear_code) {
+ for (i = 0; i < context->lwz_clear_code; ++i) {
+ context->lwz_table[0][i] = 0;
+ context->lwz_table[1][i] = i;
}
for (; i < (1 << MAX_LWZ_BITS); ++i)
- table[0][i] = table[1][i] = 0;
- code_size = set_code_size + 1;
- max_code_size = 2 * clear_code;
- max_code = clear_code + 2;
- sp = stack;
- firstcode = oldcode =
- GetCode (file, code_size, FALSE);
- return firstcode;
- } else if (code == end_code) {
+ context->lwz_table[0][i] = context->lwz_table[1][i] = 0;
+ context->lwz_code_size = context->lwz_set_code_size + 1;
+ context->lwz_max_code_size = 2 * context->lwz_clear_code;
+ context->lwz_max_code = context->lwz_clear_code + 2;
+ context->lwz_sp = context->lwz_stack;
+ context->lwz_firstcode = context->lwz_oldcode =
+ GetCode (context, context->lwz_code_size, FALSE);
+ return context->lwz_firstcode;
+ } else if (code == context->lwz_end_code) {
int count;
unsigned char buf[260];
if (ZeroDataBlock)
return -2;
- while ((count = GetDataBlock (file, buf)) > 0)
+ while ((count = GetDataBlock (context, buf)) > 0)
;
if (count != 0)
incode = code;
- if (code >= max_code) {
- *sp++ = firstcode;
- code = oldcode;
+ if (code >= context->lwz_max_code) {
+ *(context->lwz_sp)++ = context->lwz_firstcode;
+ code = context->lwz_oldcode;
}
- while (code >= clear_code) {
- *sp++ = table[1][code];
- if (code == table[0][code]) {
+ while (code >= context->lwz_clear_code) {
+ *(context->lwz_sp)++ = context->lwz_table[1][code];
+ if (code == context->lwz_table[0][code]) {
/*g_message (_("GIF: circular table entry BIG ERROR\n"));*/
/*gimp_quit ();*/
return -1;
}
- code = table[0][code];
+ code = context->lwz_table[0][code];
}
- *sp++ = firstcode = table[1][code];
+ *(context->lwz_sp)++ = context->lwz_firstcode = context->lwz_table[1][code];
- if ((code = max_code) < (1 << MAX_LWZ_BITS)) {
- table[0][code] = oldcode;
- table[1][code] = firstcode;
- ++max_code;
- if ((max_code >= max_code_size) &&
- (max_code_size < (1 << MAX_LWZ_BITS))) {
- max_code_size *= 2;
- ++code_size;
+ if ((code = context->lwz_max_code) < (1 << MAX_LWZ_BITS)) {
+ context->lwz_table[0][code] = context->lwz_oldcode;
+ context->lwz_table[1][code] = context->lwz_firstcode;
+ ++context->lwz_max_code;
+ if ((context->lwz_max_code >= context->lwz_max_code_size) &&
+ (context->lwz_max_code_size < (1 << MAX_LWZ_BITS))) {
+ context->lwz_max_code_size *= 2;
+ ++context->lwz_code_size;
}
}
- oldcode = incode;
+ context->lwz_oldcode = incode;
- if (sp > stack)
- return *--sp;
+ if (context->lwz_sp > context->lwz_stack)
+ return *--(context->lwz_sp);
}
return code;
}
static void
-ReadImage (FILE *file,
- GifContext *context,
- int len,
- int height,
- CMap cmap,
- int ncols,
- int format,
- int interlace,
- int number,
- guint leftpos,
- guint toppos)
+ReadImage (GifContext *context)
{
guchar *dest, *temp;
guchar c;
/*
** Initialize the Compression routines
*/
- if (!ReadOK (file, &c, 1)) {
+ if (!ReadOK (context, &c, 1)) {
/*g_message (_("GIF: EOF / read error on image data\n"));*/
return;
}
- if (LWZReadByte (file, TRUE, c) < 0) {
+ if (LWZReadByte (context, TRUE, c) < 0) {
/*g_message (_("GIF: error while reading\n"));*/
return;
}
context->height);
dest = gdk_pixbuf_get_pixels (context->pixbuf);
- while ((v = LWZReadByte (file, FALSE, c)) >= 0) {
+ while ((v = LWZReadByte ( context, FALSE, c)) >= 0) {
if (context->gif89.transparent) {
temp = dest + ypos * gdk_pixbuf_get_rowstride (context->pixbuf) + xpos * 4;
- *temp = cmap [0][(guchar) v];
- *(temp+1) = cmap [1][(guchar) v];
- *(temp+2) = cmap [2][(guchar) v];
+ *temp = context->color_map [0][(guchar) v];
+ *(temp+1) = context->color_map [1][(guchar) v];
+ *(temp+2) = context->color_map [2][(guchar) v];
*(temp+3) = (guchar) ((v == context->gif89.transparent) ? 0 : 65535);
} else {
temp = dest + ypos * gdk_pixbuf_get_rowstride (context->pixbuf) + xpos * 3;
- *temp = cmap [0][(guchar) v];
- *(temp+1) = cmap [1][(guchar) v];
- *(temp+2) = cmap [2][(guchar) v];
+ *temp = context->color_map [0][(guchar) v];
+ *(temp+1) = context->color_map [1][(guchar) v];
+ *(temp+2) = context->color_map [2][(guchar) v];
}
xpos++;
- if (xpos == len) {
+ if (xpos == context->frame_len) {
xpos = 0;
- if (interlace) {
+ if (context->frame_interlace) {
switch (pass) {
case 0:
case 1:
break;
}
- if (ypos >= height) {
+ if (ypos >= context->frame_height) {
pass++;
switch (pass) {
case 1:
ypos++;
}
}
- if (ypos >= height)
+ if (ypos >= context->frame_height)
break;
}
fini:
ypos = 0;
- if (LWZReadByte (file, FALSE, c) >= 0)
+ if (LWZReadByte (context, FALSE, c) >= 0)
g_print ("GIF: too much input data, ignoring extra...\n");
}
-/* Shared library entry point */
-GdkPixbuf *
-image_load (FILE *file)
+/* called until 1 is returned.
+ * if -1 is returned, then there was an error, and we must stop loading the image
+ * if 0 is returned, we need more bytes. However, this isn't handled correctly currently,
+ * so we assume that the initial 128 bytes is enough to get us started.
+ * If 1 is returned, then we are ready to start loading the image. */
+
+static gint
+prepare_iter_loop (GifContext *context)
{
unsigned char buf[16];
unsigned char c;
- CMap localColorMap;
- int useGlobalColormap;
- int bitPixel;
- int imageCount = 0;
char version[4];
- GifContext *context;
-
- g_return_val_if_fail (file != NULL, NULL);
-
- context = g_new (GifContext, 1);
- if (!ReadOK (file, buf, 6)) {
+ if (!ReadOK (context, buf, 6)) {
/* Unable to read magic number */
- return NULL;
+ return 0;
}
if (strncmp ((char *) buf, "GIF", 3) != 0) {
/* Not a GIF file */
- return NULL;
+ return -1;
}
strncpy (version, (char *) buf + 3, 3);
if ((strcmp (version, "87a") != 0) && (strcmp (version, "89a") != 0)) {
/* bad version number, not '87a' or '89a' */
- return NULL;
+ return -1;
}
/* read the screen descriptor */
- if (!ReadOK (file, buf, 7)) {
+ if (!ReadOK (context, buf, 7)) {
/* Failed to read screen descriptor */
- return NULL;
+ return 0;
}
context->width = LM_to_uint (buf[0], buf[1]);
if (BitSet (buf[4], LOCALCOLORMAP)) {
/* Global Colormap */
- if (ReadColorMap (file, context->bit_pixel,
+ if (ReadColorMap (context, context->bit_pixel,
context->color_map,
&context->gray_scale)) {
- g_free (context);
- return NULL;
+ return -1;
}
}
- if (context->aspect_ratio != 0 && context->aspect_ratio != 49) {
- /*g_message (_("GIF: warning - non-square pixels\n"));*/
- }
-
+ context->stage = 1;
for (;;) {
- if (!ReadOK (file, &c, 1)) {
- /*g_message (_("GIF: EOF / read error on image data\n"));*/
- return context->pixbuf;
+ if (!ReadOK (context, &c, 1)) {
+ return 0;
}
-
+
if (c == ';') {
/* GIF terminator */
- return context->pixbuf;
+ /* hmm. Not 100% sure what to do about this. Should
+ * i try to return a blank image instead? */
+ return -1;
}
if (c == '!') {
- /* Extension */
- if (!ReadOK (file, &c, 1)) {
- /*g_message (_("GIF: EOF / read error on extension function code\n"));*/
- return context->pixbuf; /* will be -1 if failed on first image! */
+ /* Check the extention */
+ if (!ReadOK (context, &c, 1)) {
+ return 0;
}
- DoExtension (file, context, c);
+ DoExtension (context, c);
continue;
}
-
if (c != ',') {
- /* Not a valid start character */
- /*g_message (_("GIF: bogus character 0x%02x, ignoring\n"), (int) c);*/
+ /* Not a valid start character */
continue;
}
- ++imageCount;
-
- if (!ReadOK (file, buf, 9)) {
- /*g_message (_("GIF: couldn't read left/top/width/height\n"));*/
- return context->pixbuf; /* will be -1 if failed on first image! */
+ if (!ReadOK (context, buf, 9)) {
+ return 0;
}
- useGlobalColormap = !BitSet (buf[8], LOCALCOLORMAP);
-
- bitPixel = 1 << ((buf[8] & 0x07) + 1);
+ /* Okay, we got all the info we need. Lets record it */
+ context->frame_len = LM_to_uint (buf[4], buf[5]);
+ context->frame_height = LM_to_uint (buf[6], buf[7]);
+ if (context->frame_height >context->height)
+ return -1;
- if (!useGlobalColormap) {
- if (ReadColorMap (file, bitPixel, localColorMap, &context->gray_scale)) {
- /*g_message (_("GIF: error reading local colormap\n"));*/
- return context->pixbuf; /* will be -1 if failed on first image! */
+ context->frame_interlace = BitSet (buf[8], INTERLACE);
+ if (!BitSet (buf[8], LOCALCOLORMAP)) {
+ /* Does this frame have it's own colormap. */
+ /* really only relevant when looking at the first frame
+ * of an animated gif. */
+ /* if it does, we need to re-read in the colormap,
+ * the gray_scale, and the bit_pixel */
+ context->bit_pixel = 1 << ((buf[8] & 0x07) + 1);
+ if (ReadColorMap (context, context->bit_pixel, context->color_map, &context->gray_scale)) {
+ return -1;
}
- ReadImage (file, context, LM_to_uint (buf[4], buf[5]),
- LM_to_uint (buf[6], buf[7]),
- localColorMap, bitPixel,
- context->gray_scale,
- BitSet (buf[8], INTERLACE), imageCount,
- (guint) LM_to_uint (buf[0], buf[1]),
- (guint) LM_to_uint (buf[2], buf[3]));
- } else {
- ReadImage (file, context, LM_to_uint (buf[4], buf[5]),
- LM_to_uint (buf[6], buf[7]),
- context->color_map, context->bit_pixel,
- context->gray_scale,
- BitSet (buf[8], INTERLACE), imageCount,
- (guint) LM_to_uint (buf[0], buf[1]),
- (guint) LM_to_uint (buf[2], buf[3]));
}
+ return 1;
}
+ g_assert_not_reached ();
+ return -1;
+}
+
+/* Shared library entry point */
+GdkPixbuf *
+image_load (FILE *file)
+{
+ GifContext *context;
+
+ g_return_val_if_fail (file != NULL, NULL);
+ context = g_new (GifContext, 1);
+ context->lwz_fresh = FALSE;
+ context->file = file;
+ context->pixbuf = NULL;
+ context->stage = 0;
+
+ prepare_iter_loop (context);
+ ReadImage (context);
return context->pixbuf;
}
+gpointer
+image_begin_load (ModulePreparedNotifyFunc func, gpointer user_data)
+{
+ GifContext *context;
+
+ context = g_new (GifContext, 1);
+ context->func = func;
+ context->user_data = user_data;
+ context->lwz_fresh = FALSE;
+ context->file = NULL;
+ context->pixbuf = NULL;
+ context->stage = 0;
+ return (gpointer) context;
+}
+
+void
+image_stop_load (gpointer data)
+{
+ GifContext *context = (GifContext *) data;
+ if (context->pixbuf)
+ gdk_pixbuf_unref (context->pixbuf);
+ g_free (context);
+}
+
+gboolean
+image_load_increment (gpointer data, guchar *buf, guint size)
+{
+ GifContext *context = (GifContext *) data;
+
+ return FALSE;
+}
projects / gtk4.git / commitdiff