[project @ 2003-06-06 09:19:54 by philpem]

Improved GIF loader

svn path=/import/netsurf/; revision=175
This commit is contained in:
Philip Pemberton 2003-06-06 09:19:54 +00:00
parent 2b07d36f5c
commit 1982b1b51d

View File

@ -10,7 +10,7 @@
* Add better error handling
* - especially where bad GIFs are concerned.
*
* $Id: gif.c,v 1.4 2003/06/06 08:06:55 philpem Exp $
* $Id: gif.c,v 1.5 2003/06/06 09:19:54 philpem Exp $
*/
#include <assert.h>
@ -25,27 +25,14 @@
#include "netsurf/utils/log.h"
#include "netsurf/utils/utils.h"
/* maps colours to 256 mode colour numbers */
static os_colour_number colour_table[4096];
static int
// Constants for GIF interlacing
const int
InterlacedOffset[] = { 0, 4, 2, 1 }, /* The way Interlaced image should. */
InterlacedJumps[] = { 8, 8, 4, 2 }; /* be read - offsets and jumps... */
void nsgif_init(void)
{
// Generate a colour lookup table
// TODO: Use the PNG colour table instead of the GIF table...
unsigned int red, green, blue;
for (red = 0; red != 0xf; red++)
for (green = 0; green != 0xf; green++)
for (blue = 0; blue != 0xf; blue++)
colour_table[red << 8 | green << 4 | blue] =
colourtrans_return_colour_number_for_mode(
blue << 28 | blue << 24 |
green << 20 | green << 16 |
red << 12 | red << 8, 21, 0);
}
// Called when Netsurf wants us to prepare to decode a GIF
@ -110,7 +97,7 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
char *row, **row_pointers;
int i, j, bit_depth, color_type, log2bpp, interlace;
unsigned int rowbytes, sprite_size;
unsigned long width, height;
unsigned long width, height, left, top;
os_palette *palette;
os_sprite_palette *sprite_palette;
osspriteop_area *sprite_area;
@ -181,6 +168,10 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
// TODO: ^^^ better error checking
c->data.gif.sprite_area = sprite_area;
height = c->data.gif.giffile->Image.Height;
width = c->data.gif.giffile->Image.Width;
left = c->data.gif.giffile->Image.Left;
top = c->data.gif.giffile->Image.Top;
if (c->data.gif.giffile->Image.Interlace)
{
@ -189,11 +180,11 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
for (count = i = 0; i < 4; i++)
{
LOG(("Interlaced GIF file"));
for (j=InterlacedOffset[i]; j < height; j += InterlacedJumps[i])
for (j=(top+InterlacedOffset[i]); j < (top+c->data.gif.giffile->Image.Height); j += InterlacedJumps[i])
{
LOG(("gif line %d", count));
count++;
assert (DGifGetLine(c->data.gif.giffile, c->data.gif.sprite_image + j * ((c->width + 3) & ~3u), width) != GIF_ERROR);
assert (DGifGetLine(c->data.gif.giffile, c->data.gif.sprite_image + (j * ((c->width + 3) & ~3u)) + left, width) != GIF_ERROR);
// TODO: ^^^ better error checking
}
}
@ -201,10 +192,10 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
else
{
LOG(("running DGifGetLine"));
for (i=0; i<height; i++)
for (i=top; i<(height+top); i++)
{
// assert(DGifGetLine(c->data.gif.giffile, c->data.gif.sprite_image + i * ((c->width + 3) & ~3u), width) != GIF_ERROR);
if (DGifGetLine(c->data.gif.giffile, c->data.gif.sprite_image + i * ((c->width + 3) & ~3u), width) == GIF_ERROR)
if (DGifGetLine(c->data.gif.giffile, c->data.gif.sprite_image + (i * ((c->width + 3) & ~3u))+left, width) == GIF_ERROR)
{
LOG(("error: gif line %d - error %d", i, GifLastError()));
LOG(("exp height = %d, width = %d", height, width));