Commit 827b818e authored by Jonathan Blandford's avatar Jonathan Blandford
Browse files

much more work on the progressive loader.

somewhere, some how, I broke something, )-: so all you get is a black
image.  Hopefully, we can load the real image later.
parent 00c5e838
......@@ -44,7 +44,6 @@
#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
......@@ -74,30 +73,60 @@ struct _GifContext
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)
......@@ -109,7 +138,7 @@ ReadColorMap (FILE *file,
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;
}
......@@ -127,13 +156,13 @@ ReadColorMap (FILE *file,
}
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]);
......@@ -145,7 +174,7 @@ DoExtension (FILE *file, GifContext *context, int label)
else
context->gif89.transparent = -1;
}
while (GetDataBlock (file, (unsigned char *) buf) != 0)
while (GetDataBlock (context, (unsigned char *) buf) != 0)
;
return FALSE;
break;
......@@ -154,7 +183,7 @@ DoExtension (FILE *file, GifContext *context, int label)
break;
}
while (GetDataBlock (file, (unsigned char *) buf) != 0)
while (GetDataBlock (context, (unsigned char *) buf) != 0)
;
return FALSE;
......@@ -163,19 +192,19 @@ DoExtension (FILE *file, GifContext *context, int label)
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;
}
......@@ -184,7 +213,7 @@ GetDataBlock (FILE *file,
}
static int
GetCode (FILE *file,
GetCode (GifContext *context,
int code_size,
int flag)
{
......@@ -211,7 +240,7 @@ GetCode (FILE *file,
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;
......@@ -229,76 +258,69 @@ GetCode (FILE *file,
}
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)
......@@ -308,54 +330,44 @@ LWZReadByte (FILE *file,
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;
......@@ -365,12 +377,12 @@ ReadImage (FILE *file,
/*
** 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;
}
......@@ -382,24 +394,24 @@ ReadImage (FILE *file,
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:
......@@ -413,7 +425,7 @@ ReadImage (FILE *file,
break;
}
if (ypos >= height) {
if (ypos >= context->frame_height) {
pass++;
switch (pass) {
case 1:
......@@ -433,42 +445,38 @@ ReadImage (FILE *file,
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);
......@@ -476,13 +484,13 @@ image_load (FILE *file)
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]);
......@@ -495,81 +503,116 @@ image_load (FILE *file)
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;
}