/*
* Palette images with <= 8 bits/sample are handled
* with a table to avoid lots of shifts and masks. The table
* is setup so that put*cmaptile (below) can retrieve 8/bitspersample
* pixel values simply by indexing into the table with one
* number.
*/
static int
makecmap(TIFFRGBAImage* img)
{
int bitspersample = img->bitspersample;
int nsamples = 8 / bitspersample;
uint16* r = img->redcmap;
uint16* g = img->greencmap;
uint16* b = img->bluecmap;
uint32 *p;
int i;
img->PALmap = (uint32**) _TIFFmalloc(
256*sizeof (uint32 *)+(256*nsamples*sizeof(uint32)));
if (img->PALmap == NULL) {
TIFFError(TIFFFileName(img->tif), "No space for Palette mapping table");
return (0);
}
p = (uint32*)(img->PALmap + 256);
for (i = 0; i < 256; i++) {
TIFFRGBValue c;
img->PALmap[i] = p;
#define CMAP(x) c = x; *p++ = PACK(r[c]&0xff, g[c]&0xff, b[c]&0xff);
switch (bitspersample) {
case 1:
CMAP(i>>7);
CMAP((i>>6)&1);
CMAP((i>>5)&1);
CMAP((i>>4)&1);
CMAP((i>>3)&1);
CMAP((i>>2)&1);
CMAP((i>>1)&1);
CMAP(i&1);
break;
case 2:
CMAP(i>>6);
CMAP((i>>4)&3);
CMAP((i>>2)&3);
CMAP(i&3);
break;
case 4:
CMAP(i>>4);
CMAP(i&0xf);
break;
case 8:
CMAP(i);
break;
}
#undef CMAP
}
return (1);
}
/*
* Palette images with <= 8 bits/sample are handled
* with a table to avoid lots of shifts and masks. The table
* is setup so that put*cmaptile (below) can retrieve 8/bitspersample_
* pixel values simply by indexing into the table with one
* number.
*/
boolean TIFFRasterImpl::makecmap(
const u_short* rmap, const u_short* gmap, const u_short* bmap
) {
register int i;
int nsamples = 8 / bitspersample_;
register u_long *p;
PALmap_ = (u_long **)malloc(
256*sizeof (u_long *)+(256*nsamples*sizeof(u_long))
);
if (PALmap_ == nil) {
TIFFError(TIFFFileName(tif_), "No space for Palette mapping table");
return (false);
}
p = (u_long *)(PALmap_ + 256);
for (i = 0; i < 256; i++) {
PALmap_[i] = p;
#define CMAP(x) \
c = x; *p++ = PACK(rmap[c]&0xff, gmap[c]&0xff, bmap[c]&0xff);
switch (bitspersample_) {
register RGBvalue c;
case 1:
CMAP(i>>7);
CMAP((i>>6)&1);
CMAP((i>>5)&1);
CMAP((i>>4)&1);
CMAP((i>>3)&1);
CMAP((i>>2)&1);
CMAP((i>>1)&1);
CMAP(i&1);
break;
case 2:
CMAP(i>>6);
CMAP((i>>4)&3);
CMAP((i>>2)&3);
CMAP(i&3);
break;
case 4:
CMAP(i>>4);
CMAP(i&0xf);
break;
case 8:
CMAP(i);
break;
}
#undef CMAP
}
return (true);
}