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[project @ 2003-06-07 13:07:48 by philpem]

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Added transparency support for GIFs

svn path=/import/netsurf/; revision=176
This commit is contained in:
Philip Pemberton 2003-06-07 13:07:48 +00:00
parent 1982b1b51d
commit 15a6d278a7
1 changed files with 53 additions and 30 deletions
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83
riscos/gif.c
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@ -10,7 +10,7 @@
* Add better error handling * Add better error handling
* - especially where bad GIFs are concerned. * - especially where bad GIFs are concerned.
* *
* $Id: gif.c,v 1.5 2003/06/06 09:19:54 philpem Exp $ * $Id: gif.c,v 1.6 2003/06/07 13:07:48 philpem Exp $
*/ */
#include <assert.h> #include <assert.h>
@ -47,8 +47,6 @@ void nsgif_create(struct content *c)
// yet) // yet)
c->data.gif.length = 0; c->data.gif.length = 0;
c->data.gif.buffer_pos = 0; c->data.gif.buffer_pos = 0;
LOG(("gif object created"));
} }
// Called when Netsurf has got some more data for us // Called when Netsurf has got some more data for us
@ -85,25 +83,24 @@ int nsgif_input_callback(GifFileType *giffile, GifByteType *data, int length)
} }
// Well, we've got enough data. Give libungif as much as it wants. // Well, we've got enough data. Give libungif as much as it wants.
memcpy(data, &c->data.gif.data[c->data.gif.buffer_pos], length); memcpy(data, &c->data.gif.data[c->data.gif.buffer_pos], (unsigned int) length);
c->data.gif.buffer_pos += length; c->data.gif.buffer_pos += length;
return length; return length;
} }
// Called when Netsurf wants us to convert the image // Called when Netsurf wants us to convert the image
int nsgif_convert(struct content *c, unsigned int width, unsigned int height) int nsgif_convert(struct content *c, unsigned int iwidth, unsigned int iheight)
{ {
char *row, **row_pointers; unsigned long i, j;
int i, j, bit_depth, color_type, log2bpp, interlace; unsigned int sprite_size;
unsigned int rowbytes, sprite_size;
unsigned long width, height, left, top; unsigned long width, height, left, top;
os_palette *palette;
os_sprite_palette *sprite_palette; os_sprite_palette *sprite_palette;
osspriteop_area *sprite_area; osspriteop_area *sprite_area;
osspriteop_header *sprite; osspriteop_header *sprite;
// The next three lines are for vars. used by the gif decoding engine // The next three lines are for vars. used by the gif decoding engine
int recordtype, cur_row, extcode, count, got_image_data; int recordtype, extcode, count, got_image_data;
int trancol;
GifByteType *extension; GifByteType *extension;
GifColorType *colormap; GifColorType *colormap;
@ -123,14 +120,14 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
width = c->data.gif.giffile->SWidth; width = c->data.gif.giffile->SWidth;
height = c->data.gif.giffile->SHeight; height = c->data.gif.giffile->SHeight;
LOG(("gif image width = %d, height = %d", width, height)); LOG(("gif image width = %lu, height = %lu", width, height));
sprite_size = sizeof(*sprite_area) + sizeof(*sprite); sprite_size = sizeof(*sprite_area) + sizeof(*sprite);
// GIFs can't be more than 256 colours (8 bits). // GIFs can't be more than 256 colours (8 bits).
sprite_size += 8 * 256 + height * ((width + 3) & ~3u); sprite_size += (8 * 256) + (height * ((width + 3) & ~3u) * 2);
sprite_area = xcalloc(sprite_size + 1000, 1); sprite_area = xcalloc((sprite_size) + 1000, 1);
sprite_area->size = sprite_size; sprite_area->size = sprite_size;
sprite_area->sprite_count = 1; sprite_area->sprite_count = 1;
sprite_area->first = sizeof(*sprite_area); sprite_area->first = sizeof(*sprite_area);
@ -143,7 +140,9 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
sprite->width = ((width + 3) & ~3u) / 4 - 1; sprite->width = ((width + 3) & ~3u) / 4 - 1;
sprite->left_bit = 0; sprite->left_bit = 0;
sprite->right_bit = (8 * (((width - 1) % 4) + 1)) -1; sprite->right_bit = (8 * (((width - 1) % 4) + 1)) -1;
sprite->mask = sprite->image = sizeof(*sprite) + 8 * 256; sprite->image = sizeof(*sprite) + 8 * 256;
sprite->mask = sizeof(*sprite) + (8 * 256) + (height * ((width + 3) & ~3u));
LOG(("image = %d, mask = %d", sprite->image, sprite->mask));
sprite->mode = (os_mode) 21; sprite->mode = (os_mode) 21;
sprite_palette = (os_sprite_palette *) (sprite + 1); sprite_palette = (os_sprite_palette *) (sprite + 1);
c->data.gif.sprite_image = ((char *) sprite) + sprite->image; c->data.gif.sprite_image = ((char *) sprite) + sprite->image;
@ -182,9 +181,8 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
LOG(("Interlaced GIF file")); LOG(("Interlaced GIF file"));
for (j=(top+InterlacedOffset[i]); j < (top+c->data.gif.giffile->Image.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++; count++;
assert (DGifGetLine(c->data.gif.giffile, c->data.gif.sprite_image + (j * ((c->width + 3) & ~3u)) + left, width) != GIF_ERROR); assert (DGifGetLine(c->data.gif.giffile, c->data.gif.sprite_image + (j * ((c->width + 3) & ~3u)) + left, (int)width) != GIF_ERROR);
// TODO: ^^^ better error checking // TODO: ^^^ better error checking
} }
} }
@ -194,29 +192,38 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
LOG(("running DGifGetLine")); LOG(("running DGifGetLine"));
for (i=top; i<(height+top); 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))+left, (int) 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(("error: gif line %lu - error %d", i, GifLastError()));
LOG(("exp height = %d, width = %d", height, width)); LOG(("exp height = %lu, width = %lu", height, width));
return 1; return 1;
} }
// TODO: ^^^ better error checking // TODO: ^^^ better error checking
LOG(("gif line %d", i));
} }
} }
got_image_data = -1; got_image_data = -1;
} else recordtype = TERMINATE_RECORD_TYPE; } else recordtype = TERMINATE_RECORD_TYPE;
break; break;
case EXTENSION_RECORD_TYPE: case EXTENSION_RECORD_TYPE:
// Skip any extension blocks in the file
assert (DGifGetExtension(c->data.gif.giffile, &extcode, &extension) != GIF_ERROR); assert (DGifGetExtension(c->data.gif.giffile, &extcode, &extension) != GIF_ERROR);
// TODO: ^^^ better error checking
while (extension != NULL) if (extension == NULL)
break;
do
{ {
// Is the extension block a Graphics Rendering Info block?
if (extcode == GRAPHICS_EXT_FUNC_CODE)
{
// Yep. Grab the transparency data
if ((extension[1] & 1) == 1)
trancol = extension[4];
else
trancol = -1;
}
DGifGetExtensionNext(c->data.gif.giffile, &extension); DGifGetExtensionNext(c->data.gif.giffile, &extension);
// TODO: ^^^ better error checking } while (extension != NULL);
}
break; break;
case TERMINATE_RECORD_TYPE: case TERMINATE_RECORD_TYPE:
break; break;
@ -225,7 +232,20 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
} }
} while (recordtype != TERMINATE_RECORD_TYPE); } while (recordtype != TERMINATE_RECORD_TYPE);
LOG(("all done")); LOG(("creating image transparency mask"));
// This is one evil piece of code. Still, it works...
for (j=0; j<height; j++)
for (i=0; i<width; i++)
{
unsigned char *x = ((char *)sprite) + sprite->mask;
unsigned int pixofs = (j * ((c->width + 3) & ~3u)) + i;
if (c->data.gif.sprite_image[pixofs] == trancol)
x[pixofs] = 0x00;
else
x[pixofs] = 0xFF;
}
/* /*
And now for the obligatory quote from "The Matrix" And now for the obligatory quote from "The Matrix"
@ -253,8 +273,9 @@ int nsgif_convert(struct content *c, unsigned int width, unsigned int height)
c->height = height; c->height = height;
c->title = xcalloc(100, 1); c->title = xcalloc(100, 1);
sprintf(c->title, "GIF image (%ux%u)", c->width, c->height); sprintf(c->title, "GIF image (%lux%lu)", c->width, c->height);
// Enable this if you want to debug the GIF loader
// xosspriteop_save_sprite_file(osspriteop_USER_AREA, c->data.gif.sprite_area, // xosspriteop_save_sprite_file(osspriteop_USER_AREA, c->data.gif.sprite_area,
// "gif"); // "gif");
return 0; return 0;
@ -283,12 +304,14 @@ void nsgif_redraw(struct content *c, long x, long y,
unsigned long width, unsigned long height) unsigned long width, unsigned long height)
{ {
/* TODO: scale to width, height */ /* TODO: scale to width, height */
int size; unsigned int size;
osspriteop_trans_tab *table; osspriteop_trans_tab *table;
/* JMB - lose this, it's filling my error log up too quickly ;) /* JMB - lose this, it's filling my error log up too quickly ;)
LOG(("Redraw fired")); LOG(("Redraw fired"));
philpem - Oops. Sorry about that!
*/ */
xcolourtrans_generate_table_for_sprite(c->data.gif.sprite_area, xcolourtrans_generate_table_for_sprite(c->data.gif.sprite_area,
@ -304,7 +327,7 @@ void nsgif_redraw(struct content *c, long x, long y,
xosspriteop_put_sprite_scaled(osspriteop_PTR, xosspriteop_put_sprite_scaled(osspriteop_PTR,
c->data.gif.sprite_area, c->data.gif.sprite_area,
(osspriteop_id) (c->data.gif.sprite_area + 1), (osspriteop_id) (c->data.gif.sprite_area + 1),
x, y, 0, 0, table); x, y, 8, 0, table);
xfree(table); xfree(table);
} }