diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2014-12-30 12:44:42 +0100 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2014-12-30 12:44:42 +0100 |
| commit | 9f880e595c9b6a3bb606339f87ea9c6c2e368671 (patch) | |
| tree | 7ffb4106c663f250877dbc8c8a58c38939a94c9c | |
| parent | 5935eeb6de5597072b083fadbcc3f9e94d1e36c1 (diff) | |
libmemdraw: never point Buffer.alpha to nil (thanks mischief)
the boolcopy optimization doesnt doesnt use Buffer.alpha, tho
the debug function dumpbuf() still can dereference it. to keep
it simple, always have Buffer.alpha point to the channel or
&ones when not used.
| -rw-r--r-- | sys/src/libmemdraw/draw.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/sys/src/libmemdraw/draw.c b/sys/src/libmemdraw/draw.c index 906949ac7..6ed2a242b 100644 --- a/sys/src/libmemdraw/draw.c +++ b/sys/src/libmemdraw/draw.c @@ -405,7 +405,7 @@ struct Buffer { uchar *red; uchar *grn; uchar *blu; - uchar *alpha; + uchar *alpha; /* is &ones when unused, never nil */ uchar *grey; ulong *rgba; int delta; /* number of bytes to add to pointer to get next pixel to the right */ @@ -1677,7 +1677,7 @@ DBG print("%x\n", w[-1]); b.grey = buf+copyalpha; b.red = b.grn = b.blu = buf+copyalpha; b.delta = copyalpha+1; -DBG print("alpha %x grey %x\n", b.alpha ? *b.alpha : 0xFF, *b.grey); +DBG print("alpha %x grey %x\n", *b.alpha, *b.grey); }else{ b.blu = buf+copyalpha; b.grn = buf+copyalpha+1; @@ -1695,7 +1695,7 @@ writebyte(Param *p, uchar *w, Buffer src) { Memimage *img; int i, isalpha, isgrey, nb, delta, dx, adelta; - uchar ff, *red, *grn, *blu, *grey, *alpha; + uchar *red, *grn, *blu, *grey, *alpha; ulong u, mask; img = p->img; @@ -1714,11 +1714,8 @@ writebyte(Param *p, uchar *w, Buffer src) isgrey = img->flags&Fgrey; adelta = src.delta; - if(isalpha && (alpha == nil || alpha == &ones)){ - ff = 0xFF; - alpha = &ff; + if(isalpha && alpha == &ones) adelta = 0; - } if((img->flags&Fbytes) != 0){ int ogry, ored, ogrn, oblu, oalp; @@ -1829,7 +1826,8 @@ readptr(Param *p, uchar *s, int y) USED(s); q = p->bytermin + y*p->bwidth; b.red = q; /* ptr to data */ - b.grn = b.blu = b.grey = b.alpha = nil; + b.grn = b.blu = b.grey = nil; + b.alpha = &ones; b.rgba = (ulong*)q; b.delta = p->img->depth/8; return b; @@ -1947,7 +1945,8 @@ genconv(Param *p, uchar *buf, int y) } b.red = buf; - b.blu = b.grn = b.grey = b.alpha = nil; + b.blu = b.grn = b.grey = nil; + b.alpha = &ones; b.rgba = (ulong*)buf; b.delta = 0; |