ref: afccf58e8e174dec825412bc200c3c9af31bef3b
dir: /sys/src/games/2600/tia.c/
#include <u.h>
#include <libc.h>
#include "../eui.h"
#include "dat.h"
#include "fns.h"
int ppux=1, ppuy;
int col, pri;
u8int p0x, p1x, m0x, m1x, blx;
u16int coll;
u8int disp;
int p0difc;
int bwmod = 1<<3;
enum {
SRCPF,
SRCP0,
SRCP1,
SRCM0,
SRCM1,
SRCBL,
};
static void
pixeldraw(u8int v)
{
u32int c;
union { u32int l; u8int c[4]; } u;
u32int *p;
static u32int col[] = {
0x000000, 0x404040, 0x6C6C6C, 0x909090, 0xB0B0B0, 0xC8C8C8, 0xDCDCDC, 0xECECEC,
0x444400, 0x646410, 0x848424, 0xA0A034, 0xB8B840, 0xD0D050, 0xE8E85C, 0xFCFC68,
0x702800, 0x844414, 0x985C28, 0xAC783C, 0xBC8C4C, 0xCCA05C, 0xDCB468, 0xECC878,
0x841800, 0x983418, 0xAC5030, 0xC06848, 0xD0805C, 0xE09470, 0xECA880, 0xFCBC94,
0x880000, 0x9C2020, 0xB03C3C, 0xC05858, 0xD07070, 0xE08888, 0xECA0A0, 0xFCB4B4,
0x78005C, 0x8C2074, 0xA03C88, 0xB0589C, 0xC070B0, 0xD084C0, 0xDC9CD0, 0xECB0E0,
0x480078, 0x602090, 0x783CA4, 0x8C58B8, 0xA070CC, 0xB484DC, 0xC49CEC, 0xD4B0FC,
0x140084, 0x302098, 0x4C3CAC, 0x6858C0, 0x7C70D0, 0x9488E0, 0xA8A0EC, 0xBCB4FC,
0x000088, 0x1C209C, 0x3840B0, 0x505CC0, 0x6874D0, 0x7C8CE0, 0x90A4EC, 0xA4B8FC,
0x00187C, 0x1C3890, 0x3854A8, 0x5070BC, 0x6888CC, 0x7C9CDC, 0x90B4EC, 0xA4C8FC,
0x002C5C, 0x1C4C78, 0x386890, 0x5084AC, 0x689CC0, 0x7CB4D4, 0x90CCE8, 0xA4E0FC,
0x003C2C, 0x1C5C48, 0x387C64, 0x509C80, 0x68B494, 0x7CD0AC, 0x90E4C0, 0xA4FCD4,
0x003C00, 0x205C20, 0x407C40, 0x5C9C5C, 0x74B474, 0x8CD08C, 0xA4E4A4, 0xB8FCB8,
0x143800, 0x345C1C, 0x507C38, 0x6C9850, 0x84B468, 0x9CCC7C, 0xB4E490, 0xC8FCA4,
0x2C3000, 0x4C501C, 0x687034, 0x848C4C, 0x9CA864, 0xB4C078, 0xCCD488, 0xE0EC9C,
0x442800, 0x644818, 0x846830, 0xA08444, 0xB89C58, 0xD0B46C, 0xE8CC7C, 0xFCE08C,
};
c = col[v >> 1];
u.c[0] = c;
u.c[1] = c >> 8;
u.c[2] = c >> 16;
u.c[3] = 0xff;
p = (u32int *)pic + ppuy * PICW * scale + ppux * 2 * scale;
switch(scale){
case 16: *p++ = u.l; *p++ = u.l;
case 15: *p++ = u.l; *p++ = u.l;
case 14: *p++ = u.l; *p++ = u.l;
case 13: *p++ = u.l; *p++ = u.l;
case 12: *p++ = u.l; *p++ = u.l;
case 11: *p++ = u.l; *p++ = u.l;
case 10: *p++ = u.l; *p++ = u.l;
case 9: *p++ = u.l; *p++ = u.l;
case 8: *p++ = u.l; *p++ = u.l;
case 7: *p++ = u.l; *p++ = u.l;
case 6: *p++ = u.l; *p++ = u.l;
case 5: *p++ = u.l; *p++ = u.l;
case 4: *p++ = u.l; *p++ = u.l;
case 3: *p++ = u.l; *p++ = u.l;
case 2: *p++ = u.l; *p++ = u.l;
default: *p++ = u.l; *p = u.l;
}
}
static void
pixel(u8int v, int p, int s)
{
if(p > pri){
col = v;
pri = p;
}
disp |= 1<<s;
}
static void
playfield(void)
{
int x, p;
u8int c;
x = ppux / 4;
if(x >= 20)
if((reg[CTRLPF] & 1) != 0)
x = 39 - x;
else
x = x - 20;
if(x < 4){
if((reg[PF0] & 0x10<<x) == 0)
return;
}else if(x < 12){
if((reg[PF1] & 0x800>>x) == 0)
return;
}else
if((reg[PF2] & 1<<x-12) == 0)
return;
if((reg[CTRLPF] & 6) == 2)
if(ppux < 80){
c = reg[COLUP0];
p = 3;
}else{
c = reg[COLUP1];
p = 2;
}
else{
c = reg[COLUPF];
p = (reg[CTRLPF] & 4) + 1;
}
pixel(c, p, SRCPF);
}
static void
player(int n)
{
u8int c;
int x;
c = reg[GRP0 + n];
x = ppux - (n ? p1x : p0x);
if(x < 0)
return;
switch(reg[NUSIZ0 + n] & 7){
default: if(x >= 8) return; break;
case 1: if(x >= 8 && (x < 16 || x >= 24)) return; break;
case 2: if(x >= 8 && (x < 32 || x >= 40)) return; break;
case 3: if(x >= 40 || ((x & 15) >= 8)) return; break;
case 4: if(x >= 8 && (x < 64 || x >= 72)) return; break;
case 5: if(x >= 16) return; x >>= 1; break;
case 6: if(x >= 72 || ((x & 31) >= 8)) return; break;
case 7: if(x >= 32) return; x >>= 2; break;
}
x &= 7;
if((reg[REFP0 + n] & 8) == 0)
x ^= 7;
if((c & 1<<x) == 0)
return;
c = reg[COLUP0 + n];
pixel(c, 3 - n, SRCP0 + n);
}
static void
missile(int n)
{
int x;
x = ppux - (n ? m1x : m0x);
if((reg[RESMP0 + n] & 2) != 0){
if(n)
m1x = p1x;
else
m0x = p0x;
return;
}
if(x < 0 || x >= 1<<(reg[NUSIZ0] >> 4 & 3) || (reg[ENAM0 + n] & 2) == 0)
return;
pixel(reg[COLUP0 + n], 3 - n, SRCM0 + n);
}
static void
ball(void)
{
int x;
x = ppux - blx;
if(x < 0 || x >= 1<<(reg[CTRLPF] >> 4 & 3) || (reg[ENABL] & 2) == 0)
return;
pixel(reg[COLUPF], (reg[CTRLPF] & 4) + 1, SRCBL);
}
void
tiastep(void)
{
static u16int colltab[64] = {
0x0000, 0x0000, 0x0000, 0x0020, 0x0000, 0x0080, 0x8000, 0x80a0,
0x0000, 0x0200, 0x0001, 0x0221, 0x0002, 0x0282, 0x8003, 0x82a3,
0x0000, 0x0800, 0x0008, 0x0828, 0x0004, 0x0884, 0x800c, 0x88ac,
0x4000, 0x4a00, 0x4009, 0x4a29, 0x4006, 0x4a86, 0xc00f, 0xcaaf,
0x0000, 0x2000, 0x0010, 0x2030, 0x0040, 0x20c0, 0x8050, 0xa0f0,
0x0100, 0x2300, 0x0111, 0x2331, 0x0142, 0x23c2, 0x8153, 0xa3f3,
0x0400, 0x2c00, 0x0418, 0x2c38, 0x0444, 0x2cc4, 0x845c, 0xacfc,
0x4500, 0x6f00, 0x4519, 0x6f39, 0x4546, 0x6fc6, 0xc55f, 0xefff,
};
if(ppuy < PICH && ppux < 160){
col = reg[COLUBK];
pri = 0;
disp = 0;
playfield();
player(0);
player(1);
missile(0);
missile(1);
ball();
coll |= colltab[disp];
pixeldraw(col);
}
if(ppux == 160)
nrdy = 0;
if(++ppux == 228){
ppuy++;
ppux = 0;
}
}