ref: 28f4567ba615c4036c079021392825757ef2a008
dir: /sys/src/games/gba/ppu.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include "dat.h"
#include "fns.h"
int hblank, ppuy;
u8int bldy, blda, bldb;
u32int hblclock;
int ppux0;
u32int pixcol[480];
u8int pixpri[480];
u8int pixwin[240];
uchar pic[240*160*3*2];
int objalpha;
typedef struct bg bg;
struct bg {
uchar n;
s32int rpx0, rpy0, rpx1, rpy1, rpx, rpy;
u16int tx, ty;
u8int tnx, tny;
u8int mosaic, mctr, lasti;
u32int curc;
u8int curpri;
};
static bg bgst[4] = {{.n = 0}, {.n = 1}, {.n = 2}, {.n = 3}};
Var ppuvars[] = {
VAR(hblank), VAR(ppuy), VAR(hblclock),
VAR(bldy), VAR(blda), VAR(bldb), VAR(objalpha),
VAR(bgst[2].rpx0), VAR(bgst[2].rpy0), VAR(bgst[3].rpx0), VAR(bgst[3].rpy0),
{nil, 0, 0},
};
typedef struct sprite sprite;
struct sprite {
uchar w, wb, h;
s16int x;
uchar ysh;
uchar *base;
u16int *pal;
u16int inc;
u32int t0;
u16int t1;
uchar depth;
s32int rx, ry;
s16int dx, dy;
u8int mctr, mcol;
};
static sprite sprt[128], *sp = sprt;
enum {
SPRROT = 1<<8,
SPRDIS = 1<<9,
SPRDOUB = 1<<9,
SPRMOSA = 1<<12,
SPR8 = 1<<13,
SPRWIDE = 1<<14,
SPRTALL = 1<<15,
SPRHFLIP = 1<<28,
SPRVFLIP = 1<<29,
SPRSIZE0 = 1<<30,
SPRSIZE1 = 1<<31,
NOWIN = 0,
OBJWIN = 1,
WIN2 = 2,
WIN1 = 4,
OBJALPHA = 1<<16,
SRCOBJ = 4<<17,
SRCBACK = 5<<17,
VACANT = 0x10,
BACKDROP = 8,
};
#define SRCBG(n) ((n)<<17)
void
sprinit(void)
{
u16int *p, *pp;
u16int cnt, t1;
u32int t0;
int budg;
uchar ws, h, hb, d, dy, s;
static uchar wss[16] = {3, 4, 5, 6, 4, 5, 5, 6, 3, 3, 4, 5};
static uchar hss[16] = {3, 4, 5, 6, 3, 3, 4, 5, 4, 5, 5, 6};
sp = sprt;
cnt = reg[DISPCNT];
budg = (cnt & HBLFREE) != 0 ? 954 : 1210;
for(p = oam; p < oam + 512; p += 4){
t0 = p[0];
if((t0 & (SPRROT|SPRDIS)) == SPRDIS)
continue;
t0 |= p[1] << 16;
s = t0 >> 30 & 3 | t0 >> 12 & 12;
hb = h = 1 << hss[s];
dy = ppuy - (u8int) t0;
if((t0 & (SPRROT|SPRDOUB)) == (SPRROT|SPRDOUB))
hb <<= 1;
if(dy >= hb || (u8int)t0 + hb > 256 && ppuy + 256 - (u8int)t0 >= hb)
continue;
if((t0 & SPRMOSA) != 0){
dy = dy - dy % ((reg[MOSAIC] >> 12 & 15) + 1);
sp->mctr = 0;
}
sp->x = (s32int)(t0 << 7) >> 23;
sp->t0 = t0;
ws = wss[s];
sp->wb = sp->w = 1<<ws;
sp->h = h;
sp->t1 = t1 = p[2];
sp->base = vram + 0x10000 + ((t1 & 0x3ff) << 5);
d = (t0 & SPR8) != 0;
sp->ysh = (cnt & OBJNOMAT) != 0 ? 2 + d + ws : 10;
if((t0 & SPRROT) != 0){
if((t0 & SPRDOUB) != 0)
sp->wb <<= 1;
budg -= 10 + sp->w*2;
pp = oam + 3 + (t0 >> 21 & 0x1f0);
sp->dx = pp[0];
sp->dy = pp[8];
sp->rx = (dy - hb/2) * (s16int) pp[4] + (sp->w << 7) - sp->dx * sp->wb/2;
sp->ry = (dy - hb/2) * (s16int)pp[12] + (sp->h << 7) - sp->dy * sp->wb/2;
if(sp->x < 0){
sp->rx -= sp->x * sp->dx;
sp->ry -= sp->x * sp->dy;
}
}else{
budg -= sp->w;
if((t0 & SPRVFLIP) != 0)
dy = h - 1 - dy;
sp->base += (dy & 7) << 2 + d;
sp->base += dy >> 3 << sp->ysh;
if((t0 & SPRHFLIP) != 0)
sp->base += sp->w - 7 << 2 + d;
sp->inc = (1 << 5 + d) - (1 << 2 + d);
if(sp->x < 0)
if((t0 & SPRHFLIP) != 0){
sp->base -= ((-sp->x & 7) >> 1 - d) + (-sp->x >> 3 << 5 + d);
if((t0 & SPR8) == 0 && (sp->x & 1) != 0)
sp->base--;
}else
sp->base += ((-sp->x & 7) >> 1 - d) + (-sp->x >> 3 << 5 + d);
}
if((t0 & SPR8) != 0)
sp->pal = pram + 0x100;
else
sp->pal = pram + 0x100 + (t1 >> 8 & 0xf0);
if(budg < 0)
break;
sp++;
}
}
void
spr(int x1)
{
int x0, i, dx, sx0, sx1;
u8int pri, v, d, *b;
u16int x, y;
u32int c, t0;
sprite *s;
x0 = ppux0;
for(s = sprt; s < sp; s++){
if(s->x >= x1 || s->x + s->wb <= x0)
continue;
t0 = s->t0;
pri = s->t1 >> 10 & 3;
sx0 = s->x >= x0 ? s->x : x0;
sx1 = s->x + s->wb;
if(x1 < sx1)
sx1 = x1;
dx = sx0 - s->x;
for(i = sx0; i < sx1; i++, dx++){
if((t0 & SPRROT) != 0){
d = (t0 & SPR8) != 0;
x = s->rx >> 8;
y = s->ry >> 8;
s->rx += s->dx;
s->ry += s->dy;
if(x < s->w && y < s->h){
b = s->base;
b += (y & 7) << 2 + d;
b += y >> 3 << s->ysh;
b += (x & 7) >> 1 - d;
b += x >> 3 << 5 + d;
v = *b;
if(!d)
if((x & 1) != 0)
v >>= 4;
else
v &= 0xf;
}else
v = 0;
}else if((t0 & SPRHFLIP) != 0){
if((t0 & SPR8) != 0)
v = *--s->base;
else if((dx & 1) != 0)
v = *s->base & 0x0f;
else
v = *--s->base >> 4;
if((dx & 7) == 7)
s->base -= s->inc;
}else{
v = *s->base;
if((t0 & SPR8) != 0)
s->base++;
else if((dx & 1) != 0){
v >>= 4;
s->base++;
}else
v &= 0xf;
if((dx & 7) == 7)
s->base += s->inc;
}
if((t0 & SPRMOSA) != 0)
if(s->mctr == 0){
s->mctr = reg[MOSAIC] >> 8 & 15;
s->mcol = v;
}else{
--s->mctr;
v = s->mcol;
}
if(v != 0){
c = s->pal[v] | SRCOBJ;
switch(t0 >> 10 & 3){
case 1:
c |= OBJALPHA;
objalpha++;
case 0:
if(pri < pixpri[i]){
pixcol[i] = c;
pixpri[i] = pri;
}
break;
case 2:
if((reg[DISPCNT] & 1<<15) != 0)
pixwin[i] |= OBJWIN;
break;
}
}
}
}
}
void
bgpixel(bg *b, int i, u32int c, int pri)
{
u8int *p;
u32int *q;
int j;
if(b != nil){
c |= SRCBG(b->n);
if(b->mosaic){
for(j = (u8int)(b->lasti+1); j <= i; j++){
if(b->mctr == 0){
if(j == i){
b->curc = c;
b->curpri = pri;
}else
b->curpri = VACANT;
b->mctr = reg[MOSAIC] & 15;
}else
b->mctr--;
if(b->curpri != VACANT && (pixwin[j] & 1<<b->n) == 0)
bgpixel(nil, j, b->curc, b->curpri);
}
b->lasti = i;
return;
}
}
p = pixpri + i;
q = pixcol + i;
if(pri < p[0]){
p[240] = p[0];
p[0] = pri;
q[240] = q[0];
q[0] = c;
}else if(pri < p[240]){
p[240] = pri;
q[240] = c;
}
}
void
bginit(bg *b, int scal, int)
{
u16int x, y;
u16int *rr;
int msz;
b->mosaic = (reg[BG0CNT + b->n] & BGMOSAIC) != 0;
if(b->mosaic){
b->mctr = 0;
b->lasti = -1;
}
if(scal){
rr = reg + (b->n - 2 << 3);
if(ppuy == 0){
b->rpx0 = (s32int)(rr[BG2XL] | rr[BG2XH] << 16) << 4 >> 4;
b->rpy0 = (s32int)(rr[BG2YL] | rr[BG2YH] << 16) << 4 >> 4;
}
if(!b->mosaic || ppuy % ((reg[MOSAIC] >> 4 & 15) + 1) == 0){
b->rpx1 = b->rpx0;
b->rpy1 = b->rpy0;
}
b->rpx = b->rpx1;
b->rpy = b->rpy1;
b->rpx0 += (s16int)rr[BG2PB];
b->rpy0 += (s16int)rr[BG2PD];
}else{
rr = reg + (b->n << 1);
x = rr[BG0HOFS] & 0x1ff;
y = ppuy;
if(b->mosaic){
msz = (reg[MOSAIC] >> 4 & 15) + 1;
y = y - y % msz;
}
y += (rr[BG0VOFS] & 0x1ff);
b->tx = x >> 3;
b->ty = y >> 3;
b->tnx = x & 7;
b->tny = y & 7;
}
}
void
bgsinit(void)
{
switch(reg[DISPCNT] & 7){
case 0:
bginit(&bgst[0], 0, 0);
bginit(&bgst[1], 0, 0);
bginit(&bgst[2], 0, 0);
bginit(&bgst[3], 0, 0);
break;
case 1:
bginit(&bgst[0], 0, 0);
bginit(&bgst[1], 0, 0);
bginit(&bgst[2], 1, 0);
break;
case 2:
bginit(&bgst[2], 1, 0);
bginit(&bgst[3], 1, 0);
break;
case 3:
case 4:
case 5:
bginit(&bgst[2], 1, 1);
break;
}
}
void
bitbg(bg *b, int x1)
{
u8int *base, *p, pri, d;
u16int cnt, *rr, sx, sy;
int i, v;
cnt = reg[DISPCNT];
if((cnt & 1<<8 + b->n) == 0)
return;
rr = reg + (b->n - 2 << 3);
if((cnt & 7) != 5){
sx = 240 << 8;
sy = 160 << 8;
d = (cnt & 7) == 3;
}else{
sx = 160 << 8;
sy = 128 << 8;
d = 1;
}
base = vram;
if((cnt & FRAME) != 0 && (cnt & 7) != 3)
base += 0xa000;
pri = reg[BG0CNT + b->n] & 3;
for(i = ppux0; i < x1; i++){
if(((pixwin[i] & 1<<b->n) == 0 || b->mosaic) && (u32int)b->rpx < sx && (u32int)b->rpy < sy){
if(d){
p = base + 2 * (b->rpx >> 8) + 480 * (b->rpy >> 8);
v = p[0] | p[1] << 8;
}else{
v = base[(b->rpx >> 8) + 240 * (b->rpy >> 8)];
if(v != 0)
v = pram[v];
else
v = -1;
}
if(v >= 0)
bgpixel(b, i, v, pri);
}
b->rpx += (s16int) rr[BG2PA];
b->rpy += (s16int) rr[BG2PC];
}
}
void
txtbg(bg *b, int x1)
{
u8int y, v, d, *cp;
u16int bgcnt, ta0, ta, tx, ty, t, *pal;
u32int ca;
int i, x, mx;
if((reg[DISPCNT] & 1<<8 + b->n) == 0)
return;
bgcnt = reg[BG0CNT + b->n];
d = bgcnt >> 7 & 1;
tx = b->tx;
ty = b->ty;
ta0 = (bgcnt << 3 & 0xf800) + ((ty & 0x1f) << 6);
switch(bgcnt >> 14){
case 2: ta0 += ty << 6 & 0x800; break;
case 3: ta0 += ty << 7 & 0x1000; break;
}
x = ppux0;
i = b->tnx;
for(; x < x1; tx++, i = 0){
ta = ta0 + ((tx & 0x1f) << 1);
if((bgcnt & 1<<14) != 0)
ta += tx << 6 & 0x800;
t = vram[ta] | vram[ta+1] << 8;
if(d)
pal = pram;
else
pal = pram + (t >> 8 & 0xf0);
ca = (bgcnt << 12 & 0xc000) + ((t & 0x3ff) << 5+d);
if(ca >= 0x10000)
continue;
y = b->tny;
if((t & 1<<11) != 0)
y ^= 7;
ca += y << 2+d;
cp = vram + ca;
for(; i < 8; i++, x++){
if(x >= x1)
goto out;
if((pixwin[x] & 1<<b->n) != 0 && !b->mosaic)
continue;
mx = i;
if((t & 1<<10) != 0)
mx ^= 7;
v = cp[mx >> 1-d];
if(!d)
if((mx & 1) != 0)
v >>= 4;
else
v &= 0xf;
if(v != 0)
bgpixel(b, x, pal[v], bgcnt & 3);
}
}
out:
b->tx = tx;
b->tnx = i;
}
void
rotbg(bg *b, int x1)
{
uchar *p, v;
u16int bgcnt, *rr, ta;
int i, row, sz, x, y;
rr = reg + (b->n - 2 << 3);
if((reg[DISPCNT] & 1<<8 + b->n) == 0)
return;
bgcnt = reg[BG0CNT + b->n];
row = (bgcnt >> 14) + 4;
sz = 1 << 3 + row;
for(i = ppux0; i < x1; i++){
x = b->rpx >> 8;
y = b->rpy >> 8;
b->rpx += (s16int) rr[BG2PA];
b->rpy += (s16int) rr[BG2PC];
if((pixwin[i] & 1<<b->n) != 0 && !b->mosaic)
continue;
if((bgcnt & DISPWRAP) != 0){
x &= sz - 1;
y &= sz - 1;
}else if((uint)x >= sz || (uint)y >= sz)
continue;
ta = (bgcnt << 3 & 0xf800) + ((y >> 3) << row) + (x >> 3);
p = vram + (bgcnt << 12 & 0xc000) + (vram[ta] << 6);
p += (x & 7) + ((y & 7) << 3);
if((v = *p) != 0)
bgpixel(b, i, pram[v], bgcnt & 3);
}
}
void
windows(int x1)
{
static u8int wintab[8] = {2, 3, 1, 1, 0, 0, 0, 0};
int i, sx0, sx1;
u16int v, h;
u16int cnt;
cnt = reg[DISPCNT];
if((cnt >> 13) != 0){
if((cnt & 1<<13) != 0){
v = reg[WIN0V];
h = reg[WIN0H];
if(ppuy < (u8int)v && ppuy >= v >> 8){
sx1 = (u8int)h;
sx0 = h >> 8;
if(sx0 < ppux0)
sx0 = ppux0;
if(sx1 > x1)
sx1 = x1;
for(i = sx0; i < sx1; i++)
pixwin[i] |= WIN1;
}
}
if((cnt & 1<<14) != 0){
v = reg[WIN1V];
h = reg[WIN1H];
if(ppuy < (u8int)v && ppuy >= v >> 8){
sx1 = (u8int)h;
sx0 = h >> 8;
if(sx0 < ppux0)
sx0 = ppux0;
if(sx1 > x1)
sx1 = x1;
for(i = sx0; i < sx1; i++)
pixwin[i] |= WIN2;
}
}
for(i = ppux0; i < x1; i++){
v = wintab[pixwin[i]];
h = reg[WININ + (v & 2) / 2];
if((v & 1) != 0)
h >>= 8;
pixwin[i] = ~h;
}
}
for(i = ppux0; i < x1; i++)
if(pixpri[i] == VACANT || (pixwin[i] & 1<<4) != 0){
pixcol[i] = pram[0] | SRCBACK;
pixpri[i] = BACKDROP;
}else{
pixcol[i+240] = pram[0] | SRCBACK;
pixpri[i+240] = BACKDROP;
}
objalpha = 0;
}
u16int
mix(u16int c1, u16int c2)
{
u16int r, g, b, eva, evb;
eva = blda;
evb = bldb;
b = ((c1 & 0x7c00) * eva + (c2 & 0x7c00) * evb) >> 4;
g = ((c1 & 0x03e0) * eva + (c2 & 0x03e0) * evb) >> 4;
r = ((c1 & 0x001f) * eva + (c2 & 0x001f) * evb) >> 4;
if(b > 0x7c00) b = 0x7c00;
if(g > 0x03e0) g = 0x03e0;
if(r > 0x001f) r = 0x001f;
return b & 0x7c00 | g & 0x03e0 | r;
}
u16int
brighten(u16int c1)
{
u16int r, g, b, y;
y = bldy;
b = c1 & 0x7c00;
b = b + (0x7c00 - b) * y / 16;
g = c1 & 0x03e0;
g = g + (0x03e0 - g) * y / 16;
r = c1 & 0x001f;
r = r + (0x001f - r) * y / 16;
if(b > 0x7c00) b = 0x7c00;
if(g > 0x03e0) g = 0x03e0;
if(r > 0x001f) r = 0x001f;
return b & 0x7c00 | g & 0x03e0 | r;
}
u16int
darken(u16int c1)
{
u16int r, g, b, y;
y = 16 - bldy;
b = c1 & 0x7c00;
b = b * y / 16;
g = c1 & 0x03e0;
g = g * y / 16;
r = c1 & 0x001f;
r = r * y / 16;
return b & 0x7c00 | g & 0x03e0 | r;
}
void
colormath(int x1)
{
u16int bldcnt;
u32int *p;
int i;
bldcnt = reg[BLDCNT];
if((bldcnt & 3<<6) == 0 && objalpha == 0)
return;
p = pixcol + ppux0;
for(i = ppux0; i < x1; i++, p++){
if((*p & OBJALPHA) != 0)
goto alpha;
if((pixwin[i] & 1<<5) != 0 || (bldcnt & 1<<(*p >> 17)) == 0)
continue;
switch(bldcnt >> 6 & 3){
case 1:
alpha:
if((bldcnt & 1<<8+(p[240] >> 17)) == 0)
continue;
*p = mix(*p, p[240]);
break;
case 2:
*p = brighten(*p);
break;
case 3:
*p = darken(*p);
break;
}
}
}
void
linecopy(void)
{
u32int *p;
uchar *q;
u16int *r;
u16int v;
union { u16int w; u8int b[2]; } u;
int n;
p = pixcol;
q = pic + ppuy * 240 * 2 * scale;
r = (u16int*)q;
n = 240;
while(n--){
v = *p++;
if(scale == 1){
*q++ = v;
*q++ = v >> 8;
continue;
}
u.b[0] = v;
u.b[1] = v >> 8;
if(scale == 2){
*r++ = u.w;
*r++ = u.w;
}else{
*r++ = u.w;
*r++ = u.w;
*r++ = u.w;
}
}
}
void
syncppu(int x1)
{
int i;
u16int cnt;
if(hblank || ppuy >= 160)
return;
if(x1 >= 240)
x1 = 240;
else if(x1 <= ppux0)
return;
cnt = reg[DISPCNT];
if((cnt & FBLANK) != 0){
for(i = ppux0; i < x1; i++)
pixcol[i] = 0xffff;
ppux0 = x1;
return;
}
if((cnt & 1<<12) != 0)
spr(x1);
windows(x1);
switch(cnt & 7){
case 0:
txtbg(&bgst[0], x1);
txtbg(&bgst[1], x1);
txtbg(&bgst[2], x1);
txtbg(&bgst[3], x1);
break;
case 1:
txtbg(&bgst[0], x1);
txtbg(&bgst[1], x1);
rotbg(&bgst[2], x1);
break;
case 2:
rotbg(&bgst[2], x1);
rotbg(&bgst[3], x1);
break;
case 3:
case 4:
case 5:
bitbg(&bgst[2], x1);
}
colormath(x1);
ppux0 = x1;
}
void
hblanktick(void *)
{
extern Event evhblank;
u16int stat;
stat = reg[DISPSTAT];
if(hblank){
hblclock = clock + evhblank.time;
addevent(&evhblank, 240*4);
hblank = 0;
ppux0 = 0;
memset(pixpri, VACANT, sizeof(pixpri));
memset(pixwin, 0, 240);
if(++ppuy >= 228){
ppuy = 0;
flush();
}
if(ppuy < 160){
sprinit();
bgsinit();
}else if(ppuy == 160){
dmastart(DMAVBL);
if((stat & IRQVBLEN) != 0)
setif(IRQVBL);
}
if((stat & IRQVCTREN) != 0 && ppuy == stat >> 8)
setif(IRQVCTR);
}else{
syncppu(240);
if(ppuy < 160)
linecopy();
addevent(&evhblank, 68*4);
hblank = 1;
if((stat & IRQHBLEN) != 0)
setif(IRQHBL);
if(ppuy < 160)
dmastart(DMAHBL);
}
}
void
ppuwrite(u16int a, u16int v)
{
syncppu((clock - hblclock) / 4);
switch(a){
case BLDALPHA*2:
blda = v & 0x1f;
if(blda > 16)
blda = 16;
bldb = v >> 8 & 0x1f;
if(bldb > 16)
bldb = 16;
break;
case BLDY*2:
bldy = v & 0x1f;
if(bldy > 16)
bldy = 16;
break;
case BG2XL*2: bgst[2].rpx0 = bgst[2].rpx0 & 0xffff0000 | v; break;
case BG2XH*2: bgst[2].rpx0 = bgst[2].rpx0 & 0xffff | (s32int)(v << 20) >> 4; break;
case BG2YL*2: bgst[2].rpy0 = bgst[2].rpy0 & 0xffff0000 | v; break;
case BG2YH*2: bgst[2].rpy0 = bgst[2].rpy0 & 0xffff | (s32int)(v << 20) >> 4; break;
case BG3XL*2: bgst[3].rpx0 = bgst[3].rpx0 & 0xffff0000 | v; break;
case BG3XH*2: bgst[3].rpx0 = bgst[3].rpx0 & 0xffff | (s32int)(v << 20) >> 4; break;
case BG3YL*2: bgst[3].rpy0 = bgst[3].rpy0 & 0xffff0000 | v; break;
case BG3YH*2: bgst[3].rpy0 = bgst[3].rpy0 & 0xffff | (s32int)(v << 20) >> 4; break;
}
}