games/md: moonwalker!

[plan9front.git] / sys / src / games / md / vdp.c

diff --git a/sys/src/games/md/vdp.c b/sys/src/games/md/vdp.c
index 7b8f1c6020c54e18f07ad1eca63e0ce05221573a..39502e1e0297a95d1bbd6a1366cc0b81025e7626 100644 (file)
--- a/sys/src/games/md/vdp.c
+++ b/sys/src/games/md/vdp.c
@@ -69,6 +69,7 @@ struct pctxt {
        u16int t;
        u32int c;
 } pctxt[3];
+int lwin, rwin;
 
 static void
 tile(struct pctxt *p)
@@ -79,7 +80,7 @@ tile(struct pctxt *p)
        switch(p - pctxt){
        default: a = (reg[PANT] & 0x38) << 9; break;
        case 1: a = (reg[PBNT] & 7) << 12; break;
-       case 2: a = (reg[PWNT] & 0x38) << 9; break;
+       case 2: a = (reg[PWNT] & 0x3e) << 9; break;
        }
        a += p->ty << p->ws;
        a += p->tx;
@@ -102,7 +103,7 @@ planeinit(void)
        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++){
+       for(i = 0; i <= 2; i++){
                pctxt[i].h = 1<<pctxt[i].hs;
                pctxt[i].w = 1<<pctxt[i].ws;
        }
@@ -120,7 +121,7 @@ planeinit(void)
                v = vsram[i] + vdpy;
                p->tny = v & 7;
                p->ty = v >> 3 & pctxt[i].h - 1;
-               tile(pctxt + i);
+               tile(p);
                if(p->tnx != 0)
                        if((p->t & 0x800) != 0)
                                p->c >>= p->tnx << 2;
@@ -129,10 +130,30 @@ planeinit(void)
        }
        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 = p->ty = 0;
+               v = vdpy - v;
+               p->tny = vdpy & 7;
+               p->ty = vdpy >> 3 & pctxt[2].h - 1;
+               tile(p);
+       }
 }
 
 static void
-plane(int n)
+plane(int n, int w)
 {
        struct pctxt *p;
        u8int v, pr;
@@ -145,7 +166,7 @@ plane(int n)
                v = p->c >> 28;
                p->c <<= 4;
        }
-       if(v != 0){
+       if(v != 0 && w != 0){
                v |= p->t >> 9 & 48;
                pr = 2 - (n & 1) + (p->t >> 13 & 4);
                pixel(v, pr);
@@ -161,7 +182,7 @@ plane(int n)
 static void
 planes(void)
 {
-       int i;
+       int i, w;
        u16int v;
 
        if((reg[MODE3] & 4) != 0 && ++snx == 16){
@@ -173,8 +194,11 @@ planes(void)
                        pctxt[i].ty = v >> 3 & pctxt[i].h - 1;
                }
        }
-       plane(0);
-       plane(1);
+       w = vdpx < rwin && vdpx >= lwin;
+       plane(0, !w);
+       plane(1, 1);
+       if(w)
+               plane(2, 1);
 }
 
 static struct sprite {
@@ -289,7 +313,7 @@ vdpstep(void)
                        vdpy = 0;
                        irq &= ~INTVBL;
                        vdpstat ^= STATFR;
-                       vdpstat &= ~(STATINT | STATFR | STATOVR | STATCOLL);
+                       vdpstat &= ~(STATINT | STATVBL | STATOVR | STATCOLL);
                        flush();
                }
                if(vdpy == 0 || vdpy >= 225)