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games/snes: flush screen in parallel to audio (fixes buffer underruns on x200s) 

the x200s is too slow on a single core to keep up without
audio buffer underruns, so the idea is to flush screen
in parallel to witing audio samples in a separate process.

with the proc, we also can keep updating the screen on resize
when paused.
front
cinap_lenrek 2014-11-18 16:07:34 +01:00
parent 844612fcb8
commit 763231588c
1 changed files with 68 additions and 44 deletions
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112
sys/src/games/snes/snes.c
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@ -13,6 +13,7 @@ int nprg, nsram, hirom, battery;
int ppuclock, spcclock, dspclock, stimerclock, saveclock, msgclock, paused, perfclock, cpupause;
Mousectl *mc;
Channel *flushc;
QLock pauselock;
u32int keys;
int savefd, scale, profile, mouse, loadreq, savereq;
@ -184,6 +185,68 @@ screeninit(void)
draw(screen, screen->r, bg, nil, ZP);
}
void
screenproc(void *)
{
extern uchar pic[256*240*2*3];
Mouse m;
Point p;
enum { AMOUSE, ARESIZE, AFLUSH, AEND };
Alt a[AEND+1] = {
{ mc->c, &m, CHANRCV },
{ mc->resizec, nil, CHANRCV },
{ flushc, nil, CHANRCV },
{ nil, nil, CHANEND }
};
for(;;){
switch(alt(a)){
case AMOUSE:
if(mouse && ptinrect(m.xy, picr)){
p = subpt(m.xy, picr.min);
p.x /= scale;
p.y /= scale;
keys = keys & 0xff3f0000 | p.x | p.y << 8;
if((m.buttons & 1) != 0)
keys |= 1<<22;
if((m.buttons & 4) != 0)
keys |= 1<<23;
if((m.buttons & 2) != 0)
lastkeys = keys;
}
break;
case ARESIZE:
if(getwindow(display, Refnone) < 0)
sysfatal("resize failed: %r");
screeninit();
/* wet floor */
case AFLUSH:
if(scale == 1){
loadimage(tmp, tmp->r, pic, 256*239*2);
draw(screen, picr, tmp, nil, ZP);
} else {
Rectangle r;
uchar *s;
int w;
s = pic;
r = picr;
w = 256*2*scale;
while(r.min.y < picr.max.y){
loadimage(tmp, tmp->r, s, w);
s += w;
r.max.y = r.min.y+scale;
draw(screen, r, tmp, nil, ZP);
r.min.y = r.max.y;
}
}
flushimage(display, 1);
break;
}
}
}
void
timing(void)
{
@ -242,14 +305,16 @@ usage:
threadexitsall("usage");
}
loadrom(argv[0]);
if(initdraw(nil, nil, nil) < 0)
if(initdraw(nil, nil, argv0) < 0)
sysfatal("initdraw: %r");
flushc = chancreate(sizeof(ulong), 1);
mc = initmouse(nil, screen);
if(mc == nil)
sysfatal("initmouse: %r");
screeninit();
loadbat(argv[0]);
proccreate(keyproc, 0, 8192);
proccreate(screenproc, 0, 8192);
loadbat(argv[0]);
cpureset();
memreset();
spcreset();
@ -314,48 +379,7 @@ usage:
void
flush(void)
{
extern uchar pic[256*240*2*3];
Mouse m;
Point p;
if(nbrecvul(mc->resizec) > 0){
if(getwindow(display, Refnone) < 0)
sysfatal("resize failed: %r");
screeninit();
}
while(nbrecv(mc->c, &m) > 0)
if(mouse && ptinrect(m.xy, picr)){
p = subpt(m.xy, picr.min);
p.x /= scale;
p.y /= scale;
keys = keys & 0xff3f0000 | p.x | p.y << 8;
if((m.buttons & 1) != 0)
keys |= 1<<22;
if((m.buttons & 4) != 0)
keys |= 1<<23;
if((m.buttons & 2) != 0)
lastkeys = keys;
}
if(scale == 1){
loadimage(tmp, tmp->r, pic, 256*239*2);
draw(screen, picr, tmp, nil, ZP);
} else {
Rectangle r;
uchar *s;
int w;
s = pic;
r = picr;
w = 256*2*scale;
while(r.min.y < picr.max.y){
loadimage(tmp, tmp->r, s, w);
s += w;
r.max.y = r.min.y+scale;
draw(screen, r, tmp, nil, ZP);
r.min.y = r.max.y;
}
}
flushimage(display, 1);
sendul(flushc, 1); /* flush screen */
audioout();
}