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page: avoid drawing background if image has no alpha channel

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cinap_lenrek 2011-10-18 03:41:57 +02:00
parent 18bfca7978
commit b318debfc2
1 changed files with 37 additions and 23 deletions
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60
sys/src/cmd/page.c
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@ -856,8 +856,6 @@ gendrawdiff(Image *dst, Rectangle bot, Rectangle top,
Point origin;
Point delta;
USED(op);
if(Dx(bot)*Dy(bot) == 0)
return;
@ -906,18 +904,23 @@ gendrawdiff(Image *dst, Rectangle bot, Rectangle top,
}
}
void
zoomdraw(Image *d, Rectangle r, Rectangle top, Image *s, Point sp, int f)
int
alphachan(ulong chan)
{
int w, x, y;
for(; chan; chan >>= 8)
if(TYPE(chan) == CAlpha)
return 1;
return 0;
}
void
zoomdraw(Image *d, Rectangle r, Rectangle top, Image *b, Image *s, Point sp, int f)
{
Rectangle dr;
Image *t;
Point a;
int w;
if(f <= 1){
gendrawdiff(d, r, top, paper, sp, nil, ZP, SoverD);
gendrawdiff(d, r, top, s, sp, nil, ZP, SoverD);
return;
}
a = ZP;
if(r.min.x < d->r.min.x){
sp.x += (d->r.min.x - r.min.x)/f;
@ -933,23 +936,34 @@ zoomdraw(Image *d, Rectangle r, Rectangle top, Image *s, Point sp, int f)
w = s->r.max.x - sp.x;
if(w > Dx(r))
w = Dx(r);
t = allocimage(display, Rect(r.min.x, r.min.y, r.min.x+w, r.max.y), s->chan, 0, 0);
if(t == nil)
dr = r;
dr.max.x = dr.min.x+w;
if(!alphachan(s->chan))
b = nil;
if(f <= 1){
if(b) gendrawdiff(d, dr, top, b, sp, nil, ZP, SoverD);
gendrawdiff(d, dr, top, s, sp, nil, ZP, SoverD);
return;
for(y=r.min.y; y<r.max.y; y++){
draw(t, Rect(r.min.x, y, r.min.x+w, y+1), s, nil, sp);
}
if((t = allocimage(display, dr, s->chan, 0, 0)) == nil)
return;
for(; dr.min.y < r.max.y; dr.min.y++){
dr.max.y = dr.min.y+1;
draw(t, dr, s, nil, sp);
if(++a.y == f){
a.y = 0;
sp.y++;
}
}
x=r.min.x;
for(sp=r.min; x<r.max.x; sp.x++){
gendrawdiff(d, Rect(x, r.min.y, x+1, r.max.y), top, paper, sp, nil, ZP, SoverD);
gendrawdiff(d, Rect(x, r.min.y, x+1, r.max.y), top, t, sp, nil, ZP, SoverD);
for(x++; ++a.x<f && x<r.max.x; x++)
gendrawdiff(d, Rect(x, r.min.y, x+1, r.max.y), top, d,
Pt(x-1, r.min.y), nil, ZP, SoverD);
dr = r;
for(sp=dr.min; dr.min.x < r.max.x; sp.x++){
dr.max.x = dr.min.x+1;
if(b) gendrawdiff(d, dr, top, b, sp, nil, ZP, SoverD);
gendrawdiff(d, dr, top, t, sp, nil, ZP, SoverD);
for(dr.min.x++; ++a.x < f && dr.min.x < r.max.x; dr.min.x++){
dr.max.x = dr.min.x+1;
gendrawdiff(d, dr, top, d, Pt(dr.min.x-1, dr.min.y), nil, ZP, SoverD);
}
a.x = 0;
}
freeimage(t);
@ -977,7 +991,7 @@ drawpage(Page *p)
if(i = p->image){
r = rectaddpt(Rpt(ZP, pagesize(p)), addpt(pos, screen->r.min));
zoomdraw(screen, r, ZR, i, i->r.min, zoom);
zoomdraw(screen, r, ZR, paper, i, i->r.min, zoom);
} else {
r = Rpt(ZP, stringsize(font, p->label));
r = rectaddpt(r, addpt(subpt(divpt(subpt(screen->r.max, screen->r.min), 2),
@ -1002,7 +1016,7 @@ translate(Page *p, Point d)
nr = rectaddpt(r, d);
rectclip(&r, screen->r);
draw(screen, rectaddpt(r, d), screen, nil, r.min);
zoomdraw(screen, nr, rectaddpt(r, d), i, i->r.min, zoom);
zoomdraw(screen, nr, rectaddpt(r, d), paper, i, i->r.min, zoom);
drawframe(nr);
}