ref: af8c91cf6d30628c17c7d7cb9733dee9e7488ab0
parent: 2bfcea9197d7b18219a7f2dea1a079ec91cf2cc5
author: aiju <devnull@localhost>
date: Sat Feb 22 12:43:15 EST 2014
games/nes: mmc3 and bugfixes
--- a/sys/src/games/nes/cpu.c
+++ b/sys/src/games/nes/cpu.c
@@ -5,7 +5,7 @@
u16int pc, curpc;
u8int rA, rX, rY, rS, rP;
-int nmi;
+u8int irq, nmi;
static u8int
fetch8(void)
@@ -247,6 +247,10 @@
if(nmi){interrupt(1, 0);
nmi = 0;
+ return 7;
+ }
+ if(irq && (rP & 4) == 0){+ interrupt(0, 0);
return 7;
}
curpc = pc;
--- a/sys/src/games/nes/dat.h
+++ b/sys/src/games/nes/dat.h
@@ -1,13 +1,14 @@
extern u16int pc, curpc;
extern u8int rA, rX, rY, rS, rP;
+extern u8int irq, nmi;
extern uchar mem[32768], ppuram[16384], oam[256];
extern u16int pput, ppuv;
extern u8int ppusx, vrambuf;
extern int mirr, ppux, ppuy, odd, vramlatch, keylatch;
-extern int map, scale;
+extern int map, scale, mmc3hack;
extern uchar *prg, *chr;
-extern int nprg, nchr, nmi, map, chrram;
+extern int nprg, nchr, map, chrram;
extern int keys, clock, ppuclock;
@@ -37,7 +38,7 @@
GRAYSCALE = 1<<0,
BG8DISP = 1<<1,
- BG8SPRITE = 1<<2,
+ SPRITE8DISP = 1<<2,
BGDISP = 1<<3,
SPRITEDISP = 1<<4,
@@ -84,4 +85,5 @@
INIT = -1,
SAVE = -2,
RSTR = -3,
+ SCAN = -4,
};
--- a/sys/src/games/nes/mem.c
+++ b/sys/src/games/nes/mem.c
@@ -8,10 +8,11 @@
uchar mem[32768];
uchar ppuram[16384];
uchar oam[256];
-uchar *prgb[2], *chrb[2];
+uchar *prgb[16], *chrb[16];
u16int pput, ppuv;
u8int ppusx, vrambuf;
int vramlatch = 1, keylatch = 0xFF;
+int prgsh, chrsh, mmc3hack;
static void
nope(int p)
@@ -32,10 +33,12 @@
prgb[1] = prg;
else
prgb[1] = prg + 0x4000;
+ prgsh = 14;
chrb[0] = chr;
- chrb[1] = chr + 0x1000;
+ chrsh = 13;
break;
case SAVE:
+ case SCAN:
break;
default:
nope(p);
@@ -52,6 +55,8 @@
switch(v){case INIT:
mode = 0x0C;
+ prgsh = 14;
+ chrsh = 12;
goto t;
case RSTR:
mode = get8();
@@ -71,6 +76,8 @@
break;
default:
nope(v);
+ case SCAN:
+ break;
}
return;
}
@@ -131,14 +138,103 @@
}
static void
-mmc7(int v, u8int p)
+mmc3(int p, u8int v)
{+ static u8int m, b[8], l, n, en;
+ int i, j, c;
+
+ if(p < 0){+ switch(p){+ case INIT:
+ prgsh = 13;
+ chrsh = 10;
+ mmc3hack = 1;
+ prgb[2] = prg + (2 * nprg - 2) * 0x2000;
+ prgb[3] = prgb[2] + 0x2000;
+ goto t;
+ case SCAN:
+ if(n == 0)
+ n = l;
+ else
+ n--;
+ if(n == 0 && en)
+ irq |= 2;
+ return;
+ case SAVE:
+ put8(m);
+ for(i = 0; i < 8; i++)
+ put8(b[i]);
+ put8(l);
+ put8(n);
+ put8(en);
+ return;
+ case RSTR:
+ m = get8();
+ for(i = 0; i < 8; i++)
+ b[i] = get8();
+ l = get8();
+ n = get8();
+ en = get8();
+ goto t;
+ }
+ }
+ switch(p & 0xE001){+ case 0x8000:
+ if(((m ^ v) & 0xc0) != 0){+ m = v;
+ goto t;
+ }
+ m = v;
+ break;
+ case 0x8001:
+ i = m & 7;
+ if(i < 6)
+ v %= 8 * nchr;
+ else
+ v %= 2 * nprg;
+ b[i] = v;
+ goto t;
+ case 0xA000:
+ if(mirr == MFOUR)
+ break;
+ if(v & 1)
+ mirr = MHORZ;
+ else
+ mirr = MVERT;
+ break;
+ case 0xC000: l = v; break;
+ case 0xC001: n = 0; break;
+ case 0xE000: en = 0; irq &= ~2; break;
+ case 0xE001: en = 1; break;
+ }
+ return;
+t:
+ if((m & 0x40) != 0){+ prgb[0] = prg + (2 * nprg - 2) * 0x2000;
+ prgb[2] = prg + b[6] * 0x2000;
+ }else{+ prgb[0] = prg + b[6] * 0x2000;
+ prgb[2] = prg + (2 * nprg - 2) * 0x2000;
+ }
+ prgb[1] = prg + b[7] * 0x2000;
+ c = (m & 0x80) >> 6;
+ for(i = 0; i < 2; i++){+ chrb[j = (i << 1) ^ c] = chr + (b[i] >> 1) * 0x800;
+ chrb[j+1] = chrb[j] + 0x400;
+ }
+ for(i = 2; i < 6; i++)
+ chrb[(i + 2) ^ c] = chr + b[i] * 0x400;
+}
+
+static void
+mmc7(int p, u8int v)
+{static int b;
- if(v >= 0)
- b = p;
+ if(p >= 0)
+ b = v;
else
- switch(v){+ switch(p){case INIT:
nrom(INIT, 0);
b = 0;
@@ -150,7 +246,7 @@
b = get8();
break;
default:
- nope(v);
+ nope(p);
return;
}
prgb[0] = prg + (b & 3) * 0x8000;
@@ -160,6 +256,7 @@
void (*mapper[256])(int, u8int) = {[0] nrom,
[1] mmc1,
+ [4] mmc3,
[7] mmc7,
};
@@ -166,11 +263,16 @@
static void
incvram(void)
{+ int old;
+
+ old = ppuv;
if((mem[PPUCTRL] & VRAMINC) != 0)
ppuv += 32;
else
ppuv += 1;
ppuv &= 0x3FFF;
+ if(mmc3hack && (old & (1<<12)) == 0 && (ppuv & (1<<12)) != 0)
+ mapper[map](SCAN, 0);
}
u8int
@@ -212,10 +314,8 @@
}
}
if(p >= 0x8000){- if((p & 0x4000) != 0)
- return prgb[1][p - 0xC000];
- else
- return prgb[0][p - 0x8000];
+ p -= 0x8000;
+ return prgb[p >> prgsh][p & ((1 << prgsh) - 1)];
}
return mem[p];
}
@@ -253,6 +353,8 @@
pput = (pput & 0xFF) | (v << 8) & 0x3F00;
else{pput = (pput & 0xFF00) | v;
+ if(mmc3hack && (ppuv & (1<<12)) == 0 && (pput & (1<<12)) != 0)
+ mapper[map](SCAN, 0);
ppuv = pput;
}
vramlatch ^= 1;
@@ -295,10 +397,8 @@
case MSINGA: p &= ~0xC00; break;
case MSINGB: p |= 0xC00; break;
}
- if(p < 0x1000)
- return chrb[0] + p;
- else if(p < 0x2000)
- return chrb[1] + p - 0x1000;
+ if(p < 0x2000)
+ return chrb[p >> chrsh] + (p & ((1 << chrsh) - 1));
else
return ppuram + p;
}
--- a/sys/src/games/nes/ppu.c
+++ b/sys/src/games/nes/ppu.c
@@ -167,7 +167,7 @@
drawsprites(void)
{uchar *p;
- int big, dx, dy, i, x;
+ int big, dx, dy, i, x, cc, pri;
u8int r1, r2, c;
static int n, m, nz, s0, t0;
static struct { u8int x, a; u16int t; } s[8], *sp;@@ -212,6 +212,8 @@
mem[PPUSTATUS] |= SPRITE0HIT;
nz >>= 1;
}
+ cc = -1;
+ pri = 0;
for(i = m - 1; i >= 0; i--){dx = x - t[i].x;
if(dx < 0 || dx > 7)
@@ -218,12 +220,14 @@
continue;
c = (t[i].r1 & 1) | (t[i].r2 & 1) << 1;
if(c != 0){- if((t[i].a & (1<<5)) == 0 || !iscolor(x, ppuy))
- pixel(x, ppuy, pal(c, t[i].a & 3, 1), 0);
+ cc = pal(c, t[i].a & 3, 1);
+ pri = (t[i].a & (1<<5)) == 0;
}
t[i].r1 >>= 1;
t[i].r2 >>= 1;
}
+ if(cc != -1 && (pri || !iscolor(x, ppuy)))
+ pixel(x, ppuy, cc, 0);
}
if(ppux == 257){ for(i = 0; i < n; i++){@@ -276,18 +280,22 @@
ppustep(void)
{extern int nmi;
- int bg;
+ int mask;
if(ppuy < 240 || ppuy == 261){- bg = (mem[PPUMASK] & BGDISP) != 0;
- if(bg)
+ mask = mem[PPUMASK];
+ if((mask & BGDISP) != 0)
drawbg();
- if((mem[PPUMASK] & SPRITEDISP) != 0 && ppuy != 261)
+ if(((mask & BGDISP) == 0 && ppux <= 257 || ppux <= 10 && (mask & BG8DISP) == 0) && ppux >= 2)
+ pixel(ppux - 2, ppuy, ppuread(0x3F00), 1);
+ if((mask & SPRITEDISP) != 0 && ppuy != 261 && (ppux > 10 || (mask & SPRITE8DISP) != 0))
drawsprites();
+ if(ppux == 240 && (mask & SPRITEDISP) != 0)
+ mapper[map](SCAN, 0);
if(ppuy == 261){if(ppux == 1)
mem[PPUSTATUS] &= ~(PPUVBLANK|SPRITE0HIT);
- else if(ppux >= 280 && ppux <= 304 && bg)
+ else if(ppux >= 280 && ppux <= 304 && (mask & BGDISP) != 0)
ppuv = (pput & 0x7BE0) | (ppuv & 0x041F);
}
}else if(ppuy == 241){@@ -304,7 +312,7 @@
ppuy++;
if(ppuy > 261){ppuy = 0;
- if(odd && (mem[PPUCTRL] & (BGDISP | SPRITEDISP)) != 0)
+ if(odd && (mem[PPUMASK] & (BGDISP | SPRITEDISP)) != 0)
ppux++;
odd ^= 1;
}