ref: 71ac88392f2033256b29f22bd8afdd7374100e5a
dir: /sys/src/games/nes/nes.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <mouse.h>
#include <keyboard.h>
#include "dat.h"
#include "fns.h"
extern uchar ppuram[16384];
int nprg, nchr, map, chrram;
uchar *prg, *chr;
int scale;
Rectangle picr;
Image *tmp, *bg;
int clock, ppuclock, apuclock, dmcclock, dmcfreq, sampclock, msgclock, saveclock;
Mousectl *mc;
int keys, keys2, paused, savereq, loadreq, oflag, savefd = -1;
int mirr;
QLock pauselock;
void
message(char *fmt, ...)
{
va_list va;
static char buf[512];
va_start(va, fmt);
vsnprint(buf, sizeof buf, fmt, va);
string(screen, Pt(10, 10), display->black, ZP, display->defaultfont, buf);
msgclock = FREQ;
va_end(va);
}
void
flushram(void)
{
if(savefd >= 0)
pwrite(savefd, mem + 0x6000, 0x2000, 0);
saveclock = 0;
}
void
loadrom(char *file, int sflag)
{
int fd;
int nes20;
char *s;
static uchar header[16];
static u32int flags;
static char buf[512];
fd = open(file, OREAD);
if(fd < 0)
sysfatal("open: %r");
if(readn(fd, header, sizeof(header)) < sizeof(header))
sysfatal("read: %r");
if(memcmp(header, "NES\x1a", 4) != 0)
sysfatal("not a ROM");
if(header[15] != 0)
memset(header + 7, 0, 9);
flags = header[6] | header[7] << 8;
nes20 = (flags & FLNES20M) == FLNES20V;
if(flags & (FLVS | FLPC10))
sysfatal("ROM not supported");
nprg = header[HPRG];
if(nes20)
nprg |= (header[HROMH] & 0xf) << 8;
if(nprg == 0)
sysfatal("invalid ROM");
nchr = header[HCHR];
if(nes20)
nchr |= (header[HROMH] & 0xf0) << 4;
map = (flags >> FLMAPPERL) & 0x0f | (((flags >> FLMAPPERH) & 0x0f) << 4);
if(nes20)
map |= (header[8] & 0x0f) << 8;
if(map >= 256 || mapper[map] == nil)
sysfatal("unimplemented mapper %d", map);
memset(mem, 0, sizeof(mem));
if((flags & FLTRAINER) != 0 && readn(fd, mem + 0x7000, 512) < 512)
sysfatal("read: %r");
prg = malloc(nprg * PRGSZ);
if(prg == nil)
sysfatal("malloc: %r");
if(readn(fd, prg, nprg * PRGSZ) < nprg * PRGSZ)
sysfatal("read: %r");
chrram = nchr == 0;
if(nchr != 0){
chr = malloc(nchr * CHRSZ);
if(chr == nil)
sysfatal("malloc: %r");
if(readn(fd, chr, nchr * CHRSZ) < nchr * CHRSZ)
sysfatal("read: %r");
}else{
nchr = 1;
chr = malloc(nchr * CHRSZ);
if(chr == nil)
sysfatal("malloc: %r");
}
if((flags & FLFOUR) != 0)
mirr = MFOUR;
else if((flags & FLMIRROR) != 0)
mirr = MVERT;
else
mirr = MHORZ;
if(sflag){
strncpy(buf, file, sizeof buf - 5);
s = buf + strlen(buf) - 4;
if(s < buf || strcmp(s, ".nes") != 0)
s += 4;
strcpy(s, ".sav");
savefd = create(buf, ORDWR | OEXCL, 0666);
if(savefd < 0)
savefd = open(buf, ORDWR);
if(savefd < 0)
message("open: %r");
else
readn(savefd, mem + 0x6000, 0x2000);
atexit(flushram);
}
mapper[map](INIT, 0);
}
extern int trace;
void
joyproc(void *)
{
char *s, *down[9];
static char buf[64];
int n, k, j;
j = 1;
for(;;){
n = read(0, buf, sizeof(buf) - 1);
if(n <= 0)
sysfatal("read: %r");
buf[n] = 0;
n = getfields(buf, down, nelem(down), 1, " ");
k = 0;
for(n--; n >= 0; n--){
s = down[n];
if(strcmp(s, "joy1") == 0)
j = 1;
else if(strcmp(s, "joy2") == 0)
j = 2;
else if(strcmp(s, "a") == 0)
k |= 1<<0;
else if(strcmp(s, "b") == 0)
k |= 1<<1;
else if(strcmp(s, "control") == 0)
k |= 1<<2;
else if(strcmp(s, "start") == 0)
k |= 1<<3;
else if(strcmp(s, "up") == 0)
k |= 1<<4;
else if(strcmp(s, "down") == 0)
k |= 1<<5;
else if(strcmp(s, "left") == 0)
k |= 1<<6;
else if(strcmp(s, "right") == 0)
k |= 1<<7;
}
if(j == 2)
keys2 = k;
else
keys = k;
}
}
void
keyproc(void *)
{
int fd, n, k;
static char buf[256];
char *s;
Rune r;
fd = open("/dev/kbd", OREAD);
if(fd < 0)
sysfatal("open: %r");
for(;;){
if(buf[0] != 0){
n = strlen(buf)+1;
memmove(buf, buf+n, sizeof(buf)-n);
}
if(buf[0] == 0){
n = read(fd, buf, sizeof(buf)-1);
if(n <= 0)
sysfatal("read /dev/kbd: %r");
buf[n-1] = 0;
buf[n] = 0;
}
if(buf[0] == 'c'){
if(utfrune(buf, Kdel)){
close(fd);
threadexitsall(nil);
}
if(utfrune(buf, KF|5))
savereq = 1;
if(utfrune(buf, KF|6))
loadreq = 1;
if(utfrune(buf, 't'))
trace ^= 1;
}
if(buf[0] != 'k' && buf[0] != 'K')
continue;
s = buf + 1;
k = 0;
while(*s != 0){
s += chartorune(&r, s);
switch(r){
case Kdel: close(fd); threadexitsall(nil);
case 'x': k |= 1<<0; break;
case 'z': k |= 1<<1; break;
case Kshift: k |= 1<<2; break;
case 10: k |= 1<<3; break;
case Kup: k |= 1<<4; break;
case Kdown: k |= 1<<5; break;
case Kleft: k |= 1<<6; break;
case Kright: k |= 1<<7; break;
case Kesc:
if(paused)
qunlock(&pauselock);
else
qlock(&pauselock);
paused = !paused;
break;
}
}
keys = k;
}
}
void
threadmain(int argc, char **argv)
{
int t, h, sflag;
Point p;
scale = 1;
h = 240;
sflag = 0;
ARGBEGIN {
case 'a':
initaudio();
break;
case '2':
scale = 2;
break;
case '3':
scale = 3;
break;
case 'o':
oflag = 1;
h -= 16;
break;
case 's':
sflag = 1;
break;
default:
goto usage;
} ARGEND;
if(argc != 1){
usage:
fprint(2, "usage: %s [-23aos] rom\n", argv0);
threadexitsall("usage");
}
loadrom(argv[0], sflag);
if(initdraw(nil, nil, nil) < 0)
sysfatal("initdraw: %r");
mc = initmouse(nil, screen);
if(mc == nil)
sysfatal("initmouse: %r");
proccreate(joyproc, nil, 8192);
proccreate(keyproc, nil, 8192);
originwindow(screen, Pt(0, 0), screen->r.min);
p = divpt(addpt(screen->r.min, screen->r.max), 2);
picr = (Rectangle){subpt(p, Pt(scale * 128, scale * h/2)), addpt(p, Pt(scale * 128, scale * h/2))};
tmp = allocimage(display, Rect(0, 0, scale * 256, scale * h), XRGB32, 0, 0);
bg = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, 0xCCCCCCFF);
draw(screen, screen->r, bg, nil, ZP);
pc = memread(0xFFFC) | memread(0xFFFD) << 8;
rP = FLAGI;
dmcfreq = 12 * 428;
for(;;){
if(savereq){
savestate("nes.save");
savereq = 0;
}
if(loadreq){
loadstate("nes.save");
loadreq = 0;
}
if(paused){
qlock(&pauselock);
qunlock(&pauselock);
}
t = step() * 12;
clock += t;
ppuclock += t;
apuclock += t;
sampclock += t;
dmcclock += t;
while(ppuclock >= 4){
ppustep();
ppuclock -= 4;
}
if(apuclock >= APUDIV){
apustep();
apuclock -= APUDIV;
}
if(sampclock >= SAMPDIV){
audiosample();
sampclock -= SAMPDIV;
}
if(dmcclock >= dmcfreq){
dmcstep();
dmcclock -= dmcfreq;
}
if(msgclock > 0){
msgclock -= t;
if(msgclock <= 0){
draw(screen, screen->r, bg, nil, ZP);
msgclock = 0;
}
}
if(saveclock > 0){
saveclock -= t;
if(saveclock <= 0)
flushram();
}
}
}