ref: 86bfd0331d842c7210a3a4758b71231b18193b5b
dir: /sys/src/games/gb/gb.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <mouse.h>
#include <cursor.h>
#include <keyboard.h>
#include "dat.h"
#include "fns.h"
uchar *cart, *ram;
int mbc, rombanks, rambanks, clock, ppuclock, divclock, timerclock, audioclock, msgclock, timerfreq, timer, keys, savefd, savereq, loadreq, scale, paused;
Rectangle picr;
Image *bg, *tmp;
Mousectl *mc;
QLock pauselock;
void
message(char *fmt, ...)
{
va_list va;
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 = CPUFREQ;
va_end(va);
}
void
loadrom(char *file)
{
int fd, i;
vlong len;
u8int ck;
char buf[512];
char title[17];
Point p;
char *s;
extern int battery, ramen;
fd = open(file, OREAD);
if(fd < 0)
sysfatal("open: %r");
len = seek(fd, 0, 2);
if(len < 0)
sysfatal("seek: %r");
if(len == 0 || len > 16*1048576)
sysfatal("are you sure this is a ROM?");
cart = malloc(len);
if(cart == nil)
sysfatal("malloc: %r");
seek(fd, 0, 0);
if(readn(fd, cart, len) < len)
sysfatal("read: %r");
close(fd);
ck = 0;
for(i = 0x134; i <= 0x14C; i++)
ck -= cart[i] + 1;
if(ck != cart[0x14D])
sysfatal("checksum mismatch: %.2x != %.2x", ck, cart[0x14D]);
memcpy(mem, cart, 32768);
memset(title, 0, sizeof(title));
memcpy(title, cart+0x134, 16);
battery = 0;
switch(cart[0x147]){
case 0x09:
battery = 1;
case 0x08:
ramen = 1;
case 0x00:
mbc = 0;
break;
case 0x03:
battery = 1;
case 0x01: case 0x02:
mbc = 1;
break;
case 0x06:
battery = 1;
case 0x05:
mbc = 2;
break;
case 0x0F: case 0x10: case 0x13:
battery = 1;
case 0x11: case 0x12:
mbc = 3;
break;
case 0x1B: case 0x1E:
battery = 1;
case 0x19: case 0x1A: case 0x1C: case 0x1D:
mbc = 5;
break;
default:
sysfatal("%s: unknown cartridge type %.2x", file, cart[0x147]);
}
switch(cart[0x148]){
case 0: case 1: case 2:
case 3: case 4: case 5:
case 6: case 7:
rombanks = 2 << (uint)cart[0x148];
break;
case 52:
rombanks = 72;
break;
case 53:
rombanks = 80;
break;
case 54:
rombanks = 96;
break;
default:
sysfatal("header field 0x148 (%.2x) invalid", cart[0x148]);
}
switch(cart[0x149]){
case 0:
if(mbc != 2){
rambanks = 0;
break;
}
/*fallthrough*/
case 1: case 2:
rambanks = 1;
break;
case 3:
rambanks = 4;
break;
default:
sysfatal("header field 0x149 (%.2x) invalid", cart[0x149]);
}
if(rambanks > 0){
ram = mallocz(rambanks * 8192, 1);
if(ram == nil)
sysfatal("malloc: %r");
}
if(len < rombanks * 0x4000)
sysfatal("cartridge image is too small, %.4x < %.4x", (int)len, rombanks * 0x4000);
initdraw(nil, nil, title);
originwindow(screen, Pt(0, 0), screen->r.min);
p = divpt(addpt(screen->r.min, screen->r.max), 2);
picr = (Rectangle){subpt(p, Pt(scale * 80, scale * 72)), addpt(p, Pt(scale * 80, scale * 72))};
bg = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, 0xCCCCCCFF);
tmp = allocimage(display, Rect(0, 0, scale * 160, scale * 144), XRGB32, 0, 0);
draw(screen, screen->r, bg, nil, ZP);
if(ram && battery){
strncpy(buf, file, sizeof buf - 4);
s = buf + strlen(buf) - 3;
if(s < buf || strcmp(s, ".gb") != 0)
s += 3;
strcpy(s, ".gbs");
savefd = create(buf, ORDWR|OEXCL, 0666);
if(savefd < 0)
savefd = open(buf, ORDWR);
if(savefd < 0)
message("open: %r");
else
readn(savefd, ram, rambanks * 8192);
atexit(flushram);
}
}
void
keyproc(void *)
{
int fd;
char buf[256], *s;
Rune r;
fd = open("/dev/kbd", OREAD);
if(fd < 0)
sysfatal("open: %r");
for(;;){
if(read(fd, buf, 256) <= 0)
sysfatal("read /dev/kbd: %r");
if(buf[0] == 'c'){
if(utfrune(buf, Kdel))
threadexitsall(nil);
if(utfrune(buf, KF|5))
savereq = 1;
if(utfrune(buf, KF|6))
loadreq = 1;
}
if(buf[0] != 'k' && buf[0] != 'K')
continue;
s = buf + 1;
keys = 0;
while(*s != 0){
s += chartorune(&r, s);
switch(r){
case Kesc:
if(paused)
qunlock(&pauselock);
else
qlock(&pauselock);
paused = !paused;
break;
case Kdel:
threadexitsall(nil);
case Kdown:
keys |= 1<<3;
break;
case Kup:
keys |= 1<<2;
break;
case Kleft:
keys |= 1<<1;
break;
case Kright:
keys |= 1<<0;
break;
case 'x':
keys |= 1<<4;
break;
case 'z':
keys |= 1<<5;
break;
case Kshift:
keys |= 1<<6;
break;
case 10:
keys |= 1<<7;
break;
}
}
}
}
void
threadmain(int argc, char** argv)
{
int t;
scale = 1;
ARGBEGIN{
case 'a':
initaudio();
break;
case '2':
scale = 2;
break;
case '3':
scale = 3;
break;
default:
sysfatal("unknown flag -%c", ARGC());
}ARGEND;
if(argc == 0)
sysfatal("argument missing");
pc = 0x100;
sp = 0xFFFE;
R[rA] = 0x01;
R[rC] = 0x13;
R[rE] = 0xD8;
R[rL] = 0x4D;
R[rH] = 0x01;
Fl = 0xB0;
loadrom(argv[0]);
mc = initmouse(nil, screen);
if(mc == nil)
sysfatal("init mouse: %r");
proccreate(keyproc, nil, 8192);
for(;;){
if(savereq){
savestate("gb.save");
savereq = 0;
}
if(loadreq){
loadstate("gb.save");
loadreq = 0;
}
if(paused){
qlock(&pauselock);
qunlock(&pauselock);
}
t = step();
clock += t;
ppuclock += t;
divclock += t;
audioclock += t;
timerclock += t;
if(ppuclock >= 456){
ppustep();
ppuclock -= 456;
}
if(divclock >= 256){
mem[DIV]++;
divclock = 0;
}
if(audioclock >= CPUFREQ / SAMPLE){
audiosample();
audioclock -= CPUFREQ / SAMPLE;
}
if(timer && timerclock >= timerfreq){
mem[TIMA]++;
if(mem[TIMA] == 0){
mem[TIMA] = mem[TMA];
interrupt(INTTIMER);
}
timerclock = 0;
}
if(msgclock > 0){
msgclock -= t;
if(msgclock <= 0){
draw(screen, screen->r, bg, nil, ZP);
msgclock = 0;
}
}
}
}
void
flush(void)
{
extern uchar pic[160*144*4*3*3];
Mouse m;
Point p;
static vlong old;
vlong new, diff;
while(nbrecv(mc->c, &m) > 0)
;
if(nbrecvul(mc->resizec) > 0){
if(getwindow(display, Refnone) < 0)
sysfatal("resize failed: %r");
p = divpt(addpt(screen->r.min, screen->r.max), 2);
picr = (Rectangle){subpt(p, Pt(scale * 80, scale * 72)), addpt(p, Pt(scale * 80, scale * 72))};
if(bg->chan != screen->chan){
freeimage(bg);
bg = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, 0xCCCCCCFF);
}
draw(screen, screen->r, bg, nil, ZP);
}
if(screen->chan != tmp->chan){
loadimage(tmp, tmp->r, pic, 160*144*4*scale*scale);
draw(screen, picr, tmp, nil, ZP);
}else
loadimage(screen, picr, pic, 160*144*4*scale*scale);
flushimage(display, 1);
memset(pic, sizeof pic, 0);
if(audioout() < 0){
new = nsec();
if(old != 0){
diff = BILLION/60 - (new - old);
if(diff >= MILLION)
sleep(diff/MILLION);
}
old = nsec();
}
}