sys/src/games/nes/nes.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <draw.h>
   4 #include <thread.h>
   5 #include <mouse.h>
   6 #include <keyboard.h>
   7 #include "dat.h"
   8 #include "fns.h"
   9
  10 extern uchar ppuram[16384];
  11 int nprg, nchr, map, chrram;
  12 uchar *prg, *chr;
  13 int scale;
  14 Rectangle picr;
  15 Image *tmp, *bg;
  16 int clock, ppuclock, apuclock, dmcclock, dmcfreq, sampclock, msgclock, saveclock;
  17 Mousectl *mc;
  18 int keys, keys2, paused, savereq, loadreq, oflag, savefd = -1;
  19 int mirr;
  20 QLock pauselock;
  21
  22 void
  23 message(char *fmt, ...)
  24 {
  25         va_list va;
  26         static char buf[512];
  27
  28         va_start(va, fmt);
  29         vsnprint(buf, sizeof buf, fmt, va);
  30         string(screen, Pt(10, 10), display->black, ZP, display->defaultfont, buf);
  31         msgclock = FREQ;
  32         va_end(va);
  33 }
  34
  35 void
  36 flushram(void)
  37 {
  38         if(savefd >= 0)
  39                 pwrite(savefd, mem + 0x6000, 0x2000, 0);
  40         saveclock = 0;
  41 }
  42
  43 void
  44 loadrom(char *file, int sflag)
  45 {
  46         int fd;
  47         int nes20;
  48         char *s;
  49         static uchar header[16];
  50         static u32int flags;
  51         static char buf[512];
  52
  53         fd = open(file, OREAD);
  54         if(fd < 0)
  55                 sysfatal("open: %r");
  56         if(readn(fd, header, sizeof(header)) < sizeof(header))
  57                 sysfatal("read: %r");
  58         if(memcmp(header, "NES\x1a", 4) != 0)
  59                 sysfatal("not a ROM");
  60         if(header[15] != 0)
  61                 memset(header + 7, 0, 9);
  62         flags = header[6] | header[7] << 8;
  63         nes20 = (flags & FLNES20M) == FLNES20V;
  64         if(flags & (FLVS | FLPC10))
  65                 sysfatal("ROM not supported");
  66         nprg = header[HPRG];
  67         if(nes20)
  68                 nprg |= (header[HROMH] & 0xf) << 8;
  69         if(nprg == 0)
  70                 sysfatal("invalid ROM");
  71         nchr = header[HCHR];
  72         if(nes20)
  73                 nchr |= (header[HROMH] & 0xf0) << 4;
  74         map = (flags >> FLMAPPERL) & 0x0f | (((flags >> FLMAPPERH) & 0x0f) << 4);
  75         if(nes20)
  76                 map |= (header[8] & 0x0f) << 8;
  77         if(map >= 256 || mapper[map] == nil)
  78                 sysfatal("unimplemented mapper %d", map);
  79
  80         memset(mem, 0, sizeof(mem));
  81         if((flags & FLTRAINER) != 0 && readn(fd, mem + 0x7000, 512) < 512)
  82                         sysfatal("read: %r");
  83         prg = malloc(nprg * PRGSZ);
  84         if(prg == nil)
  85                 sysfatal("malloc: %r");
  86         if(readn(fd, prg, nprg * PRGSZ) < nprg * PRGSZ)
  87                 sysfatal("read: %r");
  88         chrram = nchr == 0;
  89         if(nchr != 0){
  90                 chr = malloc(nchr * CHRSZ);
  91                 if(chr == nil)
  92                         sysfatal("malloc: %r");
  93                 if(readn(fd, chr, nchr * CHRSZ) < nchr * CHRSZ)
  94                         sysfatal("read: %r");
  95         }else{
  96                 nchr = 1;
  97                 chr = malloc(nchr * CHRSZ);
  98                 if(chr == nil)
  99                         sysfatal("malloc: %r");
 100         }
 101         if((flags & FLFOUR) != 0)
 102                 mirr = MFOUR;
 103         else if((flags & FLMIRROR) != 0)
 104                 mirr = MVERT;
 105         else
 106                 mirr = MHORZ;
 107         if(sflag){
 108                 strncpy(buf, file, sizeof buf - 5);
 109                 s = buf + strlen(buf) - 4;
 110                 if(s < buf || strcmp(s, ".nes") != 0)
 111                         s += 4;
 112                 strcpy(s, ".sav");
 113                 savefd = create(buf, ORDWR | OEXCL, 0666);
 114                 if(savefd < 0)
 115                         savefd = open(buf, ORDWR);
 116                 if(savefd < 0)
 117                         message("open: %r");
 118                 else
 119                         readn(savefd, mem + 0x6000, 0x2000);
 120                 atexit(flushram);
 121         }
 122         mapper[map](INIT, 0);
 123 }
 124
 125 extern int trace;
 126
 127 void
 128 joyproc(void *)
 129 {
 130         char *s, *down[9];
 131         static char buf[64];
 132         int n, k, j;
 133
 134         j = 1;
 135         for(;;){
 136                 n = read(0, buf, sizeof(buf) - 1);
 137                 if(n <= 0)
 138                         sysfatal("read: %r");
 139                 buf[n] = 0;
 140                 n = getfields(buf, down, nelem(down), 1, " ");
 141                 k = 0;
 142                 for(n--; n >= 0; n--){
 143                         s = down[n];
 144                         if(strcmp(s, "joy1") == 0)
 145                                 j = 1;
 146                         else if(strcmp(s, "joy2") == 0)
 147                                 j = 2;
 148                         else if(strcmp(s, "a") == 0)
 149                                 k |= 1<<0;
 150                         else if(strcmp(s, "b") == 0)
 151                                 k |= 1<<1;
 152                         else if(strcmp(s, "control") == 0)
 153                                 k |= 1<<2;
 154                         else if(strcmp(s, "start") == 0)
 155                                 k |= 1<<3;
 156                         else if(strcmp(s, "up") == 0)
 157                                 k |= 1<<4;
 158                         else if(strcmp(s, "down") == 0)
 159                                 k |= 1<<5;
 160                         else if(strcmp(s, "left") == 0)
 161                                 k |= 1<<6;
 162                         else if(strcmp(s, "right") == 0)
 163                                 k |= 1<<7;
 164                 }
 165                 if(j == 2)
 166                         keys2 = k;
 167                 else
 168                         keys = k;
 169         }
 170 }
 171
 172 void
 173 keyproc(void *)
 174 {
 175         int fd, n, k;
 176         static char buf[256];
 177         char *s;
 178         Rune r;
 179
 180         fd = open("/dev/kbd", OREAD);
 181         if(fd < 0)
 182                 sysfatal("open: %r");
 183         for(;;){
 184                 if(buf[0] != 0){
 185                         n = strlen(buf)+1;
 186                         memmove(buf, buf+n, sizeof(buf)-n);
 187                 }
 188                 if(buf[0] == 0){
 189                         n = read(fd, buf, sizeof(buf)-1);
 190                         if(n <= 0)
 191                                 sysfatal("read /dev/kbd: %r");
 192                         buf[n-1] = 0;
 193                         buf[n] = 0;
 194                 }
 195                 if(buf[0] == 'c'){
 196                         if(utfrune(buf, Kdel)){
 197                                 close(fd);
 198                                 threadexitsall(nil);
 199                         }
 200                         if(utfrune(buf, KF|5))
 201                                 savereq = 1;
 202                         if(utfrune(buf, KF|6))
 203                                 loadreq = 1;
 204                         if(utfrune(buf, 't'))
 205                                 trace ^= 1;
 206                 }
 207                 if(buf[0] != 'k' && buf[0] != 'K')
 208                         continue;
 209                 s = buf + 1;
 210                 k = 0;
 211                 while(*s != 0){
 212                         s += chartorune(&r, s);
 213                         switch(r){
 214                         case Kdel: close(fd); threadexitsall(nil);
 215                         case 'x': k |= 1<<0; break;
 216                         case 'z': k |= 1<<1; break;
 217                         case Kshift: k |= 1<<2; break;
 218                         case 10: k |= 1<<3; break;
 219                         case Kup: k |= 1<<4; break;
 220                         case Kdown: k |= 1<<5; break;
 221                         case Kleft: k |= 1<<6; break;
 222                         case Kright: k |= 1<<7; break;
 223                         case Kesc:
 224                                 if(paused)
 225                                         qunlock(&pauselock);
 226                                 else
 227                                         qlock(&pauselock);
 228                                 paused = !paused;
 229                                 break;
 230                         }
 231                 }
 232                 keys = k;
 233         }
 234 }
 235
 236 void
 237 threadmain(int argc, char **argv)
 238 {
 239         int t, h, sflag;
 240         Point p;
 241
 242         scale = 1;
 243         h = 240;
 244         sflag = 0;
 245         ARGBEGIN {
 246         case 'a':
 247                 initaudio();
 248                 break;
 249         case '2':
 250                 scale = 2;
 251                 break;
 252         case '3':
 253                 scale = 3;
 254                 break;
 255         case 'o':
 256                 oflag = 1;
 257                 h -= 16;
 258                 break;
 259         case 's':
 260                 sflag = 1;
 261                 break;
 262         default:
 263                 goto usage;
 264         } ARGEND;
 265
 266         if(argc != 1){
 267         usage:
 268                 fprint(2, "usage: %s [-23aos] rom\n", argv0);
 269                 threadexitsall("usage");
 270         }
 271         loadrom(argv[0], sflag);
 272         if(initdraw(nil, nil, nil) < 0)
 273                 sysfatal("initdraw: %r");
 274         mc = initmouse(nil, screen);
 275         if(mc == nil)
 276                 sysfatal("initmouse: %r");
 277         proccreate(joyproc, nil, 8192);
 278         proccreate(keyproc, nil, 8192);
 279         originwindow(screen, Pt(0, 0), screen->r.min);
 280         p = divpt(addpt(screen->r.min, screen->r.max), 2);
 281         picr = (Rectangle){subpt(p, Pt(scale * 128, scale * h/2)), addpt(p, Pt(scale * 128, scale * h/2))};
 282         tmp = allocimage(display, Rect(0, 0, scale * 256, scale * h), XRGB32, 0, 0);
 283         bg = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, 0xCCCCCCFF);
 284         draw(screen, screen->r, bg, nil, ZP);
 285
 286         pc = memread(0xFFFC) | memread(0xFFFD) << 8;
 287         rP = FLAGI;
 288         dmcfreq = 12 * 428;
 289         for(;;){
 290                 if(savereq){
 291                         savestate("nes.save");
 292                         savereq = 0;
 293                 }
 294                 if(loadreq){
 295                         loadstate("nes.save");
 296                         loadreq = 0;
 297                 }
 298                 if(paused){
 299                         qlock(&pauselock);
 300                         qunlock(&pauselock);
 301                 }
 302                 t = step() * 12;
 303                 clock += t;
 304                 ppuclock += t;
 305                 apuclock += t;
 306                 sampclock += t;
 307                 dmcclock += t;
 308                 while(ppuclock >= 4){
 309                         ppustep();
 310                         ppuclock -= 4;
 311                 }
 312                 if(apuclock >= APUDIV){
 313                         apustep();
 314                         apuclock -= APUDIV;
 315                 }
 316                 if(sampclock >= SAMPDIV){
 317                         audiosample();
 318                         sampclock -= SAMPDIV;
 319                 }
 320                 if(dmcclock >= dmcfreq){
 321                         dmcstep();
 322                         dmcclock -= dmcfreq;
 323                 }
 324                 if(msgclock > 0){
 325                         msgclock -= t;
 326                         if(msgclock <= 0){
 327                                 draw(screen, screen->r, bg, nil, ZP);
 328                                 msgclock = 0;
 329                         }
 330                 }
 331                 if(saveclock > 0){
 332                         saveclock -= t;
 333                         if(saveclock <= 0)
 334                                 flushram();
 335                 }
 336         }
 337 }