Fix mask calculation (thanks to Fredrik Wikstrom)

This commit is contained in:
Chris Young 2012-08-12 11:02:12 +01:00
parent 59784ba852
commit 8b31fc0e78
1 changed files with 5 additions and 5 deletions

View File

@ -478,24 +478,24 @@ PLANEPTR ami_bitmap_get_mask(struct bitmap *bitmap, int width,
uint32 *bmi = (uint32 *) bitmap->pixdata;
UBYTE maskbit = 0;
ULONG bm_width;
int y, x, w;
int y, x, bpr;
if((height != bitmap->height) || (width != bitmap->width)) return NULL;
if(bitmap_get_opaque(bitmap) == true) return NULL;
if(bitmap->native_mask) return bitmap->native_mask;
bm_width = GetBitMapAttr(n_bm, BMA_WIDTH);
bpr = RASSIZE(bm_width, 1);
bitmap->native_mask = AllocRaster(bm_width, height);
int bpr = RASSIZE(bm_width, 1);
SetMem(bitmap->native_mask, 0, bpr * height);
for(y=0; y<height; y++) {
for(x=0; x<width; x++) {
if ((*bmi & 0x000000ffU) <= (ULONG)nsoption_int(mask_alpha)) maskbit = 0;
else maskbit = 1;
bmi++;
bitmap->native_mask[(y*bpr) + (x/8)] =
(bitmap->native_mask[(y*bpr) + (x/8)] << 1) | maskbit;
bitmap->native_mask[(y*bpr) + (x/8)] |=
maskbit << (7 - (x % 8));
}
}