1 files changed, 84 insertions, 0 deletions
diff --git a/examples/life.c b/examples/life.c
new file mode 100644
index 0000000..212ece9
--- /dev/null
+++ b/examples/life.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+
+#define W 60
+#define H 40
+
+typedef unsigned char Board[W*H/8];
+static Board board;
+
+static _Bool
+get(Board *b, unsigned x, unsigned y) {
+   x %= W; y %= H;
+   unsigned idx = x + y * W;
+   return (*b)[idx/8] & (1 << (idx % 8));
+}
+
+static void
+set(Board *b, unsigned x, unsigned y, _Bool set) {
+   x %= W; y %= H;
+   unsigned idx = x + y * W;
+   (*b)[idx/8] &= ~(1 << (idx % 8));
+   if (set)
+      (*b)[idx/8] |= (1 << (idx % 8));
+}
+
+static void
+next(Board *b) {
+   Board temp;
+   memcpy(temp, &**b, sizeof temp);
+   for (int y = 0; y < H; ++y)
+      for (int x = 0; x < W; ++x) {
+         #define C(ox, oy) get(&temp, x + ox, y + oy)
+         int n = C(-1,-1) + C(0,-1) + C(1,-1)
+               + C(-1, 0)      +      C(1, 0)
+               + C(-1, 1) + C(0, 1) + C(1, 1);
+
+         set(b, x, y, 0);
+         if (get(&temp, x, y))
+            set(b, x, y, n == 3);
+         else if (n == 2)
+            set(b, x, y, 1);
+         else if (n == 3)
+            set(b, x, y, 1);
+      }
+}
+
+static
+void draw(Board *b) {
+   printf("\x1B[H\n");
+   printf("\n");
+   for (int y = 0; y < H; ++y) {
+      printf(" ");
+      for (int x = 0; x < W; ++x) {
+         if (get(b, x, y)) {
+            printf("W");
+         } else {
+            printf(" ");
+         }
+      }
+      printf(" \n");
+   }
+}
+
+
+static void
+init(Board *b) {
+   int time(void *);
+   unsigned rnd = time(0);
+   for (int y = 0; y < H; ++y) {
+      for (int x = 0; x < W; ++x) {
+         set(b, x, y, (_Bool)((rnd >> 31) & 1));
+         rnd = (rnd * 134775813) + 1;
+      }
+   }
+}
+
+void usleep(unsigned);
+int main () {
+   init(&board);
+   for (;;) {
+      draw(&board);
+      usleep(100);
+      next(&board);
+   }
+}