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libmemdraw: fix drawing to color mapped with alpha chan (m8a8)

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This commit is contained in:
cinap_lenrek 2013-06-16 00:39:31 +02:00
parent 4cbfe26da4
commit 56073b7381
1 changed files with 17 additions and 5 deletions
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22
sys/src/libmemdraw/draw.c
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@ -1541,8 +1541,8 @@ readcmap(Param *p, uchar *buf, int y)
static void
writecmap(Param *p, uchar *w, Buffer src)
{
uchar *cmap, *red, *grn, *blu;
int i, dx, delta;
uchar *cmap, *red, *grn, *blu, *alpha;
int i, dx, delta, a, m;
cmap = p->img->cmap->rgb2cmap;
@ -1552,8 +1552,20 @@ writecmap(Param *p, uchar *w, Buffer src)
blu = src.blu;
dx = p->dx;
for(i=0; i<dx; i++, red+=delta, grn+=delta, blu+=delta)
*w++ = cmap[(*red>>4)*256+(*grn>>4)*16+(*blu>>4)];
if(p->img->flags&Falpha){
alpha = src.alpha;
m = p->img->shift[CMap]/8;
a = p->img->shift[CAlpha]/8;
for(i=0; i<dx; i++, red+=delta, grn+=delta, blu+=delta, w+=2){
w[a] = *alpha;
if(alpha != &ones)
alpha+=delta;
w[m] = cmap[(*red>>4)*256+(*grn>>4)*16+(*blu>>4)];
}
} else {
for(i=0; i<dx; i++, red+=delta, grn+=delta, blu+=delta)
*w++ = cmap[(*red>>4)*256+(*grn>>4)*16+(*blu>>4)];
}
}
#define DBG if(0)
@ -1752,7 +1764,7 @@ writefn(Memimage *img)
{
if(img->depth < 8)
return writenbit;
if(img->chan == CMAP8)
if(img->nbits[CMap] == 8)
return writecmap;
return writebyte;
}