1 files changed, 87 insertions, 0 deletions
diff --git a/tests/life.c b/tests/life.c
new file mode 100644
index 00000000..08742f64
--- /dev/null
+++ b/tests/life.c
@@ -0,0 +1,87 @@
+// From http://rosettacode.org/wiki/Conway%27s_Game_of_Life#C
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+ 
+#define for_x for (int x = 0; x < w; x++)
+#define for_y for (int y = 0; y < h; y++)
+#define for_xy for_x for_y
+
+void show(void *u, int w, int h)
+{
+  int (*univ)[w] = u;
+  for_x printf("-"); printf("\n");
+  for_y {
+    for_x printf(univ[y][x] ? "[]" : "  ");
+    printf("\n");
+  }
+  for_x printf("-"); printf("\n");
+  fflush(stdout);
+}
+ 
+void evolve(void *u, int w, int h)
+{
+  unsigned (*univ)[w] = u;
+  unsigned new[h][w];
+ 
+  for_y for_x {
+    int n = 0;
+    for (int y1 = y - 1; y1 <= y + 1; y1++)
+      for (int x1 = x - 1; x1 <= x + 1; x1++)
+        if (univ[(y1 + h) % h][(x1 + w) % w])
+          n++;
+ 
+    if (univ[y][x]) n--;
+    new[y][x] = (n == 3 || (n == 2 && univ[y][x]));
+  }
+  for_y for_x univ[y][x] = new[y][x];
+}
+
+void nudge(void *u, int w, int h)
+{
+  unsigned (*univ)[w] = u;
+  int sum = 0;
+  for_xy sum += univ[y][x];
+  while (sum < (w*h)/8) {
+    int x = sum & (w-1);
+    int y = (sum*sum) & (h-1);
+    univ[y][x] = 1;
+    sum++;
+  }
+}
+
+void game(int w, int h, int i)
+{
+  unsigned univ[h][w];
+  //for_xy univ[y][x] = rand() < RAND_MAX / 10 ? 1 : 0;
+  int acc = 0; // nonrandom generation, for benchmarking
+  for_xy {
+    acc += (x*17) % (y*3 + 1);
+    univ[y][x] = acc & 1;
+  }
+  while (i != 0) {
+    //show(univ, w, h);
+    evolve(univ, w, h);
+    if (i > 0) {
+      i--;
+      nudge(univ, w, h); // keep it interesting for benchmark
+    } else {
+      usleep(20000);
+      show(univ, w, h);
+    }
+  }
+  show(univ, w, h);
+}
+ 
+int main(int c, char **v)
+{
+  int w = 0, h = 0, i = -1; // i = -1 means run forever, normal. otherwise, run in benchmark mode
+  if (c > 1) w = atoi(v[1]);
+  if (c > 2) h = atoi(v[2]);
+  if (c > 3) i = atoi(v[3]);
+  if (w <= 0) w = 32;
+  if (h <= 0) h = 32;
+  game(w, h, i);
+}
+