ref: 6184a4ef2eba1d49f0386e9ce94f4877d3d9edb2
dir: /sys/src/games/gb/ppu.c/
#include <u.h> #include <libc.h> #include <thread.h> #include "../eui.h" #include "dat.h" #include "fns.h" u8int ppustate, ppuy; ulong hblclock, rendclock; jmp_buf mainjmp, renderjmp; static int cyc, done, ppux, ppux0; extern int prish; extern u32int white; Var ppuvars[] = {VAR(ppustate), VAR(ppuy), VAR(hblclock), VAR(rendclock), {nil, 0, 0}}; #define ryield() {if(setjmp(renderjmp) == 0) longjmp(mainjmp, 1);} #define myield() {if(setjmp(mainjmp) == 0) longjmp(renderjmp, 1);} typedef struct sprite sprite; struct sprite { u8int dy, x, t; u8int fetched, pal; u16int chr; }; enum { SPRPRI = 0x80, SPRYFL = 0x40, SPRXFL = 0x20, SPRPAL = 0x10, SPRBANK = 0x08, TILCOL0 = 0x01, TILPRI = 0x02, TILSPR = 0x04, }; sprite spr[10], *sprm; void ppurender(void) { int x, y, i, n, m, win; u16int ta, ca, chr; u8int tile, attr, pali; u32int sr[8], *picp; #define eat(nc) if(cyc <= nc){for(i = 0; i < nc; i++) if(--cyc == 0) ryield();} else cyc -= nc; ryield(); attr = 0; for(;;){ eat(6*2); m = 168 + (reg[SCX] & 7); win = 0; if((reg[LCDC] & WINEN) != 0 && ppuy >= reg[WY] && reg[WX] <= 166) if(reg[WX] == 0) m = 7; else if(reg[WX] == 166) m = 0; else{ m = reg[WX] + (reg[SCX] & 7) + 1; win = -1; } ppux = 0; ppux0 = 0; picp = (u32int*)pic + ppuy * PICW * scale; y = ppuy + reg[SCY] << 1 & 14; ta = 0x1800 | reg[LCDC] << 7 & 0x400 | ppuy + reg[SCY] << 2 & 0x3e0 | reg[SCX] >> 3; x = -(reg[SCX] & 7); restart: do{ tile = vram[ta]; if((mode & COL) != 0) attr = vram[8192 + ta]; if((reg[LCDC] & BGTILE) != 0) ca = (tile << 4) + y; else ca = 0x1000 + ((s32int)(tile << 24) >> 20) + y; if((attr & 0x40) != 0) ca ^= 14; ca |= (attr & 8) << 10; chr = vram[ca] << 8 | vram[ca+1]; pali = attr << 2 & 0x1c; if((attr & 0x20) == 0) for(i = 0; i < 8; i++){ sr[i] = pal[pali | chr >> 15 | chr >> 6 & 2] | ((chr & 0x8080) == 0) << prish; chr <<= 1; } else for(i = 0; i < 8; i++){ sr[i] = pal[pali | chr << 1 & 2 | chr >> 8 & 1] | ((chr & 0x0101) == 0) << prish; chr >>= 1; } if((attr & 0x80) != 0) for(i = 0; i < 8; i++) sr[i] |= 2 << prish; if((reg[LCDC] & BGEN) == 0 && (mode & COL) == 0 && ((mode & CGB) != 0 || win == 0)) for(i = 0; i < 8; i++) sr[i] = white; if(cyc <= 2*8){ for(i = 0; i < 2*8; i++) if(--cyc == 0) ryield(); y = ppuy + reg[SCY] << 1 & 14; ta = 0x1800 | reg[LCDC] << 7 & 0x400 | ppuy + reg[SCY] << 2 & 0x3e0 | ta & 0x1f; }else cyc -= 2*8; m -= 8; n = m < 8 ? m : 8; if((ta & 0x1f) == 0x1f) ta &= ~0x1f; else ta++; for(i = 0; i < n; i++, x++) if(x >= 0) picp[x] = sr[i]; ppux = x; }while(m > 8); if(win == -1){ win = 1; ta = 0x1800 | reg[LCDC] << 4 & 0x400 | ppuy - reg[WY] << 2 & 0x3e0; y = ppuy - reg[WY] << 1 & 14; cyc += 2; m = 175 - reg[WX]; goto restart; } done = 1; ryield(); } } void oamsearch(void) { u8int *p; sprite *q; int y0, sy; u8int t, tn; u8int *chrp; y0 = ppuy + 16; sy = (reg[LCDC] & SPR16) != 0 ? 16 : 8; sprm = spr; if((reg[LCDC] & SPREN) == 0) return; for(p = oam; p < oam + 160; p += 4){ if((u8int)(y0 - p[0]) >= sy) continue; if((mode & COL) == 0){ for(q = spr; q < sprm; q++) if(q->x > p[1]){ if(sprm != spr + 10){ memmove(q + 1, q, (sprm - q) * sizeof(sprite)); sprm++; }else memmove(q + 1, q, (sprm - 1 - q) * sizeof(sprite)); goto found; } if(q == spr + 10) continue; sprm++; found:; }else q = sprm++; q->dy = y0 - p[0]; q->x = p[1]; q->t = t = p[3]; if((t & SPRYFL) != 0) q->dy ^= sy - 1; tn = p[2]; if(sy == 16) tn = tn & ~1 | q->dy >> 3; chrp = vram + (tn << 4 | q->dy << 1 & 14); if((mode & COL) != 0){ chrp += t << 10 & 0x2000; q->pal = 0x20 | t << 2 & 0x1c; }else q->pal = 4 + (t >> 2 & 4); q->chr = chrp[0] << 8 | chrp[1]; if(p[1] < 8) if((t & SPRXFL) != 0) q->chr >>= 8 - p[1]; else q->chr <<= 8 - p[1]; q->fetched = 0; if((mode & COL) != 0 && sprm == spr + 10) break; } } void sprites(void) { sprite *q; u8int attr; u32int *picp; int x, x1; u16int chr; picp = (u32int*)pic + ppuy * PICW * scale; for(q = spr; q < sprm; q++){ if(q->x <= ppux0 || q->x >= ppux + 8) continue; x = q->x - 8; if(x < ppux0) x = ppux0; x1 = q->x; if(x1 > ppux) x1 = ppux; for(; x < x1; x++){ attr = picp[x] >> prish; chr = q->chr; if((chr & ((q->t & SPRXFL) != 0 ? 0x0101 : 0x8080)) != 0 && (attr & TILSPR) == 0 && ((mode & COL) != 0 && (reg[LCDC] & BGPRI) == 0 || (attr & TILCOL0) != 0 || (attr & TILPRI) == 0 && (q->t & SPRPRI) == 0)) if((q->t & SPRXFL) == 0) picp[x] = pal[q->pal | chr >> 15 | chr >> 6 & 2] | TILSPR << prish; else picp[x] = pal[q->pal | chr << 1 & 2 | chr >> 8 & 1] | TILSPR << prish; if((q->t & SPRXFL) != 0) q->chr >>= 1; else q->chr <<= 1; } } ppux0 = ppux; } void ppusync(void) { if(ppustate != 3) return; cyc = clock - rendclock; if(cyc != 0) myield(); sprites(); rendclock = clock; } int linelen(void) { int t; t = 174 + (reg[SCX] & 7); if((reg[LCDC] & WINEN) != 0 && ppuy >= reg[WY] && reg[WX] < 166) if(reg[WX] == 0) t += 7; else t += 6; return t*2; } static void lineexpand(void) { u32int *picp, *p, *q, l; int i; picp = (u32int*)pic + ppuy * PICW * scale; p = picp + PICW; q = picp + PICW * scale; for(i = PICW; --i >= 0; ){ l = *--p; switch(scale){ case 16: *--q = l; case 15: *--q = l; case 14: *--q = l; case 13: *--q = l; case 12: *--q = l; case 11: *--q = l; case 10: *--q = l; case 9: *--q = l; case 8: *--q = l; case 7: *--q = l; case 6: *--q = l; case 5: *--q = l; case 4: *--q = l; case 3: *--q = l; case 2: *--q = l; case 1: *--q = l; } } } void hblanktick(void *) { extern Event evhblank; int t; switch(ppustate){ case 0: hblclock = clock + evhblank.time; if(++ppuy == 144){ ppustate = 1; if((reg[STAT] & IRQM1) != 0) reg[IF] |= IRQLCDS; addevent(&evhblank, 456*2); reg[IF] |= IRQVBL; flush(); }else{ ppustate = 2; if((reg[STAT] & IRQM2) != 0) reg[IF] |= IRQLCDS; addevent(&evhblank, 80*2); } if((reg[STAT] & IRQLYC) != 0 && ppuy == reg[LYC]) reg[IF] |= IRQLCDS; break; case 1: hblclock = clock + evhblank.time; if(++ppuy == 154){ ppuy = 0; ppustate = 2; if((reg[STAT] & IRQM2) != 0) reg[IF] |= IRQLCDS; addevent(&evhblank, 80*2); }else addevent(&evhblank, 456*2); if((reg[STAT] & IRQLYC) != 0 && ppuy == reg[LYC]) reg[IF] |= IRQLCDS; break; case 2: oamsearch(); rendclock = clock + evhblank.time; ppustate = 3; addevent(&evhblank, linelen()); break; case 3: ppusync(); if(!done) print("not done?!\n"); done = 0; if(scale > 1) lineexpand(); ppustate = 0; if((reg[STAT] & IRQM0) != 0) reg[IF] |= IRQLCDS; t = hblclock + 456 * 2 - clock; addevent(&evhblank, t < 0 ? 456 * 2 : t); if(dma < 0) dma = 1; break; } } void ppuinit(void) { static char ppustack[4096]; renderjmp[JMPBUFPC] = (uintptr)ppurender; renderjmp[JMPBUFSP] = (uintptr)(ppustack + sizeof(ppustack) - 64); myield(); }