commands/simple/life.c

   1 /* life - Conway's game of life         Author: Jim King */
   2
   3 /* clife.c - curses life simulator.  Translated from Pascal to C implementing
   4  *           curses Oct 1988 by pulsar@lsrhs, not jek5036@ritvax.isc.rit.edu
   5  *           life needs about 18kb stack space on MINIX.
   6  *
   7  * Flags:       -d  draw your own screen using arrows and space bar
   8  *              -p  print statistics on the bottom line during the game
   9  */
  10
  11 #include <sys/types.h>
  12 #include <signal.h>
  13 #include <time.h>
  14 #include <curses.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17 #include <stdio.h>
  18
  19 #if __minix_vmd         /* Use a more random rand(). */
  20 #define srand(seed)     srandom(seed)
  21 #define rand()          random()
  22 #endif
  23
  24 /* A value of -1 will make it go forever */
  25 /* A value of 0 will make it exit immediately */
  26 #define REPSTOP         -1      /* number of repetitions before stop */
  27
  28 int present[23][80];            /* screen 1 cycle ago */
  29 int past[23][80];               /* screen this cycle */
  30 int total;                      /* total # of changes */
  31 int icnt;                       /* counter to check for repetition */
  32 int maxrow = 22;                /* some defines to represent the screen */
  33 int maxcol = 79;
  34 int minrow = 0;
  35 int mincol = 0;
  36 int pri = 0;                    /* flag for printing stats on bottom line */
  37 int draw = 0;                   /* flag for drawing your own screen */
  38 int i, j, k;                    /* loop counters */
  39 int cycle;                      /* current cycle # */
  40 int changes;                    /* # of changes this cycle (live + die) */
  41 int die;                        /* number of deaths this cycle */
  42 int live;                       /* number of births this cycle */
  43
  44 WINDOW *mns;                    /* Main Screen */
  45 WINDOW *info;                   /* Bottom line */
  46
  47 _PROTOTYPE(void cleanup, (int s));
  48 _PROTOTYPE(void initialize, (void));
  49 _PROTOTYPE(void makscr, (void));
  50 _PROTOTYPE(void update, (void));
  51 _PROTOTYPE(void print, (void));
  52 _PROTOTYPE(int main, (int ac, char *av[]));
  53
  54 /* Cleanup - cleanup then exit */
  55 void cleanup(s)
  56 int s;
  57 {
  58   move(23, 0);                  /* go to bottom of screen */
  59   refresh();                    /* update cursor */
  60
  61   endwin();                     /* shutdown curses */
  62   exit(1);                      /* exit */
  63 }
  64
  65 /* Initialize - init windows, variables, and signals */
  66
  67 void initialize()
  68 {
  69   srand(getpid());              /* init random seed */
  70   initscr();                    /* init curses */
  71   noecho();
  72   curs_set(0);
  73   signal(SIGINT, cleanup);      /* catch ^C */
  74   mns = newwin(maxrow, maxcol, 0, 0);   /* new window */
  75   scrollok(mns, FALSE);
  76   info = newwin(1, 80, 23, 0);
  77   scrollok(info, FALSE);
  78   wclear(mns);
  79   wclear(info);
  80   wmove(info, 0, 0);
  81   wrefresh(info);
  82   if (!draw) {                  /* if no draw, make random pattern */
  83         for (j = 0; j < maxrow; j++) {
  84                 for (k = 0; k < maxcol; k++) {
  85                         present[j][k] = rand() % 2;
  86                         if (present[j][k] == 1) changes++, live++;
  87                 }
  88         }
  89   }
  90 }
  91
  92 /* Makscr - make your own screen using arrow keys and space bar */
  93 void makscr()
  94 {
  95   int curx, cury;               /* current point on screen */
  96   char c;                       /* input char */
  97
  98   wclear(info);
  99   wmove(info, 0, 0);
 100   wprintw(info, "Use arrow keys to move, space to place / erase, ^D to start", NULL);
 101   wrefresh(info);
 102   curx = cury = 1;
 103   wmove(mns, cury - 1, curx - 1);
 104   wrefresh(mns);
 105   noecho();
 106   for (;;) {
 107         c = wgetch(mns);
 108         if (c == '\004')
 109                 break;
 110         else if (c == ' ') {
 111                 if (present[cury][curx]) {
 112                         --present[cury][curx];
 113                         changes++;
 114                         die++;
 115                         mvwaddch(mns, cury, curx, ' ');
 116                 } else {
 117                         ++present[cury][curx];
 118                         changes++;
 119                         live++;
 120                         mvwaddch(mns, cury, curx, '*');
 121                 }
 122         } else if (c == '\033') {
 123                 wgetch(mns);
 124                 switch (wgetch(mns)) {
 125                     case 'A':   --cury; break;
 126                     case 'B':   ++cury; break;
 127                     case 'C':   ++curx; break;
 128                     case 'D':   --curx; break;
 129                     default:    break;
 130                 }
 131         }
 132         if (cury > maxrow) cury = minrow;
 133         if (cury < minrow) cury = maxrow;
 134         if (curx > maxcol) curx = mincol;
 135         if (curx < mincol) curx = maxcol;
 136         wmove(mns, cury, curx);
 137         wrefresh(mns);
 138   }
 139   wclear(info);
 140 }
 141
 142 /* Update rules:  2 or 3 adjacent alive --- stay alive
 143  *                3 adjacent alive -- dead to live
 144  *                all else die or stay dead
 145  */
 146 void update()
 147 {                               /* Does all mathmatical calculations */
 148   int howmany, w, x, y, z;
 149   changes = die = live = 0;
 150   for (j = 0; j < maxrow; j++) {
 151         for (k = 0; k < maxcol; k++) {
 152                 w = j - 1;
 153                 x = j + 1;
 154                 y = k - 1;
 155                 z = k + 1;
 156
 157                 howmany = (past[w][y] + past[w][k] + past[w][z] +
 158                            past[j][y] + past[j][z] + past[x][y] +
 159                            past[x][k] + past[x][z]);
 160
 161                 switch (howmany) {
 162                     case 0:
 163                     case 1:
 164                     case 4:
 165                     case 5:
 166                     case 6:
 167                     case 7:
 168                     case 8:
 169                         present[j][k] = 0;
 170                         if (past[j][k]) changes++, die++;
 171                         break;
 172                     case 3:
 173                         present[j][k] = 1;
 174                         if (!past[j][k]) changes++, live++;
 175                         break;
 176                     default:    break;
 177                 }
 178         }
 179   }
 180   if (live == die)
 181         ++icnt;
 182   else
 183         icnt = 0;
 184
 185   if (icnt == REPSTOP) cleanup(0);
 186 }
 187
 188 /* Print - updates the screen according to changes from past to present */
 189 void print()
 190 {
 191 /* Updates the screen, greatly improved using curses */
 192   if (pri) {
 193         wmove(info, 0, 0);
 194         total += changes;
 195         cycle++;
 196         wprintw(info, "Cycle %5d | %5d changes: %5d died + %5d born = %5u total changes", (char *) cycle, changes, die, live, total);
 197         wclrtoeol(info);
 198   }
 199   for (j = 1; j < maxrow; j++) {
 200         for (k = 1; k < maxcol; k++) {
 201                 if (present[j][k] != past[j][k] && present[j][k] == 1) {
 202                         wmove(mns, j, k);
 203                         wprintw(mns, "*", NULL);
 204                 } else if (present[j][k] != past[j][k] && present[j][k] == 0) {
 205                         wmove(mns, j, k);
 206                         wprintw(mns, " ", NULL);
 207                 }
 208         }
 209   }
 210   if (pri) wrefresh(info);
 211   wrefresh(mns);
 212 }
 213
 214 /* Main - main procedure */
 215 int main(ac, av)
 216 int ac;
 217 char *av[];
 218 {
 219   if (ac > 1) {
 220         for (j = 1; j < ac; j++) {
 221                 switch (av[j][1]) {
 222                     case 'd':   ++draw; break;
 223                     case 'p':   ++pri;  break;
 224                     default:
 225                         fprintf(stderr, "%s: usage: %s [-d] [-p]\n", av[0], av[0]);
 226                         exit(1);
 227                 }
 228         }
 229   }
 230
 231   initialize();
 232   if (draw) makscr();
 233
 234   for (;;) {
 235         print();
 236         for (j = 0; j < maxrow; j++) {
 237                 for (k = 0; k < maxcol; k++) past[j][k] = present[j][k];
 238         }
 239         update();
 240   }
 241 }