hat-test: allow choosing a random number seed.

The default one is always the same, because the main purpose of this
tool is debugging. But one person has already wanted to use it for
actually generating a tiling patch for another use, so let's make it
easier to vary the randomness!

1 files changed, 9 insertions, 3 deletions

diff --git a/hat.c b/hat.c
index a269ae7..533855d 100644
--- a/hat.c
+++ b/hat.c
@@ -1423,7 +1423,8 @@ int main(int argc, char **argv)
     KiteEnum s[1];
     HatCoordContext ctx[1];
     HatCoords *coords[KE_NKEEP];
-    random_state *rs = random_new("12345", 5);
+    random_state *rs;
+    const char *random_seed = "12345";
     int w = 10, h = 10;
     int argpos = 0;
     size_t i;
@@ -1434,13 +1435,17 @@ int main(int argc, char **argv)
     while (--argc > 0) {
         const char *arg = *++argv;
         if (!strcmp(arg, "--help")) {
-            printf("usage: hat-test [<width>] [<height>]\n"
-                   "   or: hat-test --test\n");
+            printf("  usage: hat-test [options] [<width>] [<height>]\n"
+                   "options: --python   write a Python function call per hat\n"
+                   "         --seed=STR vary the starting random seed\n"
+                   "   also: hat-test --test\n");
             return 0;
         } else if (!strcmp(arg, "--test")) {
             return unit_tests() ? 0 : 1;
         } else if (!strcmp(arg, "--python")) {
             dctx->outfmt = OF_PYTHON;
+        } else if (!strncmp(arg, "--seed=", 7)) {
+            random_seed = arg+7;
         } else if (arg[0] == '-') {
             fprintf(stderr, "unrecognised option '%s'\n", arg);
             return 1;
@@ -1462,6 +1467,7 @@ int main(int argc, char **argv)
     for (i = 0; i < lenof(coords); i++)
         coords[i] = NULL;
 
+    rs = random_new(random_seed, strlen(random_seed));
     init_coords_random(ctx, rs);
 
     bbox->started = false;