ref: 5fc5c18208546c77f2c279f7f6acf6b01a2d2645
dir: /sys/src/games/md/vdp.c/
#include <u.h> #include <libc.h> #include <thread.h> #include "dat.h" #include "fns.h" u8int pic[320*224*4*4]; u16int vdpstat = 0x3400; int vdpx, vdpy, vdpyy, frame, intla; u16int hctr; static int xmax, xdisp; static int sx, snx, col, pri, lum; enum { DARK, NORM, BRIGHT }; enum { ymax = 262, yvbl = 234 }; void vdpmode(void) { if((reg[MODE4] & WIDE) != 0){ xmax = 406; xdisp = 320; }else{ xdisp = 256; xmax = 342; } intla = (reg[MODE4] & 6) == 6; } static void pixeldraw(int x, int y, int v) { u8int *p; u32int *q; union { u32int w; u8int b[4]; } u; if(scale == 1){ p = pic + (x + y * 320) * 4; p[0] = v >> 16; p[1] = v >> 8; p[2] = v; return; } u.b[0] = v >> 16; u.b[1] = v >> 8; u.b[2] = v; u.b[3] = 0; if(scale == 2){ if(intla) y = y << 1 | frame; q = (u32int*)pic + (x + y * 320) * 2; q[0] = u.w; q[1] = u.w; }else{ q = (u32int*)pic + (x + y * 320) * 3; q[0] = u.w; q[1] = u.w; q[2] = u.w; } } static u32int shade(u32int v, int l) { if(l == 1) return v; if(l == 2) return v << 1 & 0xefefef; return v >> 1 & 0xf7f7f7; } static void pixel(int v, int p) { if(p >= pri){ col = v; pri = p; } } struct pctxt { u8int ws, w, hs, h; u16int tx, ty; u8int tnx, tny; u16int t; u32int c; } pctxt[3]; int lwin, rwin; static void tile(struct pctxt *p) { u16int a; int y; switch(p - pctxt){ default: a = (reg[PANT] & 0x38) << 9; break; case 1: a = (reg[PBNT] & 7) << 12; break; case 2: a = (reg[PWNT] & 0x3e) << 9; break; } a += p->ty << p->ws; a += p->tx; p->t = vram[a]; y = p->tny; if(intla){ if((p->t & 0x1000) != 0) y = 15 - y; a = (p->t & 0x7ff) << 5 | y << 1; }else{ if((p->t & 0x1000) != 0) y = 7 - y; a = (p->t & 0x7ff) << 4 | y << 1; } p->c = vram[a] << 16 | vram[a+1]; } static void planeinit(void) { static int szs[] = {5, 6, 6, 7}; int v, a, i; struct pctxt *p; pctxt[0].hs = pctxt[1].hs = szs[reg[PLSIZ] >> 4 & 3]; pctxt[0].ws = pctxt[1].ws = szs[reg[PLSIZ] & 3]; pctxt[2].ws = (reg[MODE4] & WIDE) != 0 ? 6 : 5; pctxt[2].hs = 5; for(i = 0; i <= 2; i++){ pctxt[i].h = 1<<pctxt[i].hs; pctxt[i].w = 1<<pctxt[i].ws; } a = reg[HORSCR] << 9 & 0x7fff; switch(reg[MODE3] & 3){ case 1: a += vdpy << 1 & 0xe; break; case 2: a += vdpy << 1 & 0xff0; break; case 3: a += vdpy << 1 & 0xffe; break; } for(i = 0; i < 2; i++){ p = pctxt + i; v = -(vram[a + i] & 0x3ff); p->tnx = v & 7; p->tx = v >> 3 & pctxt[i].w - 1; if(intla){ v = vsram[i] + vdpyy; p->tny = v & 15; p->ty = v >> 4 & pctxt[i].h - 1; }else{ v = vsram[i] + vdpy; p->tny = v & 7; p->ty = v >> 3 & pctxt[i].h - 1; } tile(p); if(p->tnx != 0) if((p->t & 0x800) != 0) p->c >>= p->tnx << 2; else p->c <<= p->tnx << 2; } sx = 0; snx = 0; v = reg[WINV] << 3 & 0xf8; if((reg[WINV] & 0x80) != 0 ? vdpy < v : vdpy >= v){ lwin = 0; rwin = reg[WINH] << 4 & 0x1f0; if((reg[WINH] & 0x80) != 0){ lwin = rwin; rwin = 320; } }else{ lwin = 0; rwin = 320; } if(rwin > lwin){ p = pctxt + 2; p->tx = lwin >> 3 & pctxt[2].w - 1; p->tnx = lwin & 7; p->tny = vdpy & 7; p->ty = vdpy >> 3 & pctxt[2].h - 1; tile(p); } } static void plane(int n, int vis) { struct pctxt *p; u8int v, pr; p = pctxt + n; if((p->t & 0x800) != 0){ v = p->c & 15; p->c >>= 4; }else{ v = p->c >> 28; p->c <<= 4; } if(vis != 0){ if(v != 0){ v |= p->t >> 9 & 48; pr = 2 - (n & 1) + (p->t >> 13 & 4); pixel(v, pr); } lum |= p->t >> 15; } if(++p->tnx == 8){ p->tnx = 0; if(++p->tx == p->w) p->tx = 0; tile(pctxt + n); } } static void planes(void) { int i, w; u16int v; if((reg[MODE3] & 4) != 0 && ++snx == 16){ snx = 0; sx++; for(i = 0; i < 2; i++){ v = vsram[sx + i] + vdpy; pctxt[i].tny = v & 7; pctxt[i].ty = v >> 3 & pctxt[i].h - 1; } } w = vdpx < rwin && vdpx >= lwin; plane(0, !w); plane(1, 1); if(w) plane(2, 1); } static struct sprite { u16int y, x; u8int w, h; u16int t; u32int c[4]; } spr[21], *lsp; static void spritesinit(void) { u16int t, *p, dy, c; u32int v; int i, ns, np, nt; struct sprite *q; t = (reg[SPRTAB] << 8 & 0x7f00); p = vram + t; q = spr; ns = (reg[MODE4] & WIDE) != 0 ? 20 : 16; np = 0; nt = 0; do{ if(intla){ q->y = (p[0] & 0x3ff) - 256; q->h = (p[1] >> 8 & 3) + 1 << 4; dy = vdpyy - q->y; }else{ q->y = (p[0] & 0x3ff) - 128; q->h = (p[1] >> 8 & 3) + 1 << 3; dy = vdpy - q->y; } if(dy >= q->h) continue; q->t = p[2]; if((q->t & 0x1000) != 0) dy = q->h + ~dy; q->x = (p[3] & 0x3ff) - 128; if(q->x == 0xff80) break; q->w = (p[1] >> 10 & 3) + 1 << 3; c = ((q->t & 0x7ff) << 4+intla) + (dy << 1); for(i = 0; i < q->w >> 3 && np < xdisp; i++){ v = vram[c] << 16 | vram[(u16int)(c+1)]; c += q->h << 1; if((q->t & 0x800) != 0) q->c[(q->w >> 3) - 1 - i] = v; else q->c[i] = v; np += 8; } if((u16int)-q->x < q->w){ i = -(s16int)q->x; if((q->t & 0x800) != 0) q->c[i>>3] >>= (i & 7) << 2; else q->c[i>>3] <<= (i & 7) << 2; } if(++q == spr + ns || np >= xdisp){ vdpstat |= STATOVR; break; } }while(p = vram + (u16int)(t + ((p[1] & 0x7f) << 2)), p - vram != t && ++nt < 80); lsp = q; } static void sprites(void) { struct sprite *p; u16int dx; int v, col, set; u32int *c; set = 0; col = 0; for(p = spr; p < lsp; p++){ dx = vdpx - p->x; if(dx >= p->w) continue; c = p->c + (dx >> 3); if((p->t & 0x800) != 0){ v = *c & 15; *c >>= 4; }else{ v = *c >> 28; *c <<= 4; } if(v != 0) if(set != 0) vdpstat |= STATCOLL; else{ set = 1 | p->t & 0x8000; col = p->t >> 9 & 48 | v; } } if(set) if((reg[MODE4] & SHI) != 0) if((col & 0xfe) == 0x3e) lum = col & 1; else{ pixel(col, set >> 13 | 2); if((col & 0xf) == 0xe) lum = 1; else lum |= set >> 15; } else pixel(col, set >> 13 | 2); } void vdpstep(void) { u32int v; if(vdpx == 0){ planeinit(); spritesinit(); } if(vdpx < 320 && vdpy < 224) if(vdpx < xdisp){ col = reg[BGCOL] & 0x3f; pri = 0; lum = 0; planes(); sprites(); if((reg[MODE2] & 0x40) != 0 && (vdpx >= 8 || (reg[MODE1] & 0x20) == 0)){ v = cramc[col]; if((reg[MODE4] & SHI) != 0) v = shade(v, lum); pixeldraw(vdpx, vdpy, v); }else pixeldraw(vdpx, vdpy, 0); }else pixeldraw(vdpx, vdpy, 0xcccccc); if(++vdpx >= xmax){ z80irq = 0; vdpx = 0; if(++vdpy >= ymax){ vdpy = 0; irq &= ~INTVBL; vdpstat ^= STATFR; vdpstat &= ~(STATINT | STATVBL | STATOVR | STATCOLL); flush(); } if(intla) vdpyy = vdpy << 1 | frame; if(vdpy == 0 || vdpy >= 225) hctr = reg[HORCTR]; else if(hctr-- == 0){ if((reg[MODE1] & IE1) != 0) irq |= INTHOR; hctr = reg[HORCTR]; } if(vdpy == yvbl){ vdpstat |= STATVBL | STATINT; frame ^= 1; z80irq = 1; if((reg[MODE2] & IE0) != 0) irq |= INTVBL; } } }