zakarya/puzzles
1
0
Fork 0
mirror of git://git.tartarus.org/simon/puzzles.git synced 2025-04-20 23:51:29 -07:00
Code Issues Packages Projects Releases Wiki Activity

Reference my just-published article about aperiodic tilings.

Browse Source 
In commit 8d6647548f7d005 I added the Hats grid type to Loopy, and
mentioned in the commit message that I was very pleased with the
algorithm I came up with.

In fact, I was so pleased with it that I've decided it deserves a
proper public writeup. So I've spent the Easter weekend producing one:

  https://www.chiark.greenend.org.uk/~sgtatham/quasiblog/aperiodic-tilings/

In this commit I adjust the header comments in both penrose.c and
hat.c to refer to the article (replacing a previous comment in
penrose.c to a much less polished page containing a copy of my
jotting-grade personal notes that I sent James Harvey once). Also,
added some code to hatgen.c to output Python hat descriptions in a
similar style to hat-test, which I used to generate a couple of the
more difficult diagrams in the new article, and didn't want to lose.
This commit is contained in:
Simon Tatham
2023-04-10 14:56:34 +01:00
parent 71cf891fdc
commit 6fb890e0ea
3 changed files with 59 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
auxiliary/hatgen.c
View File

@ -1330,6 +1330,26 @@ static void draw_hats_svg(const Hat *hats, size_t n,
printf("</svg>\n");
}
static void draw_hats_python(const Hat *hats, size_t n)
{
size_t i, j;
printf("def hats(hat):\n");
for (i = 0; i < n; i++) {
const Hat *hat = &hats[i];
Point vertices[HAT_NVERT];
size_t nv = hat_vertices(*hat, vertices);
printf(" hat('%c', %d, None, [",
"HTPF"[hat->parent->type], hat->index);
for (j = 0; j < nv; j++) {
Point v = vertices[j];
printf("%s(%d,%d)", j ? ", " : "", (v.x * 2 + v.y) / 3, v.y);
}
printf("])\n");
}
}
typedef enum KiteStep { KS_LEFT, KS_RIGHT, KS_F_LEFT, KS_F_RIGHT } KiteStep;
static inline Point kite_step(Point k, KiteStep step)
@ -1459,6 +1479,31 @@ int main(int argc, char **argv)
return 0;
}
if (argv[1][0] == 'P' && argv[1][1] && strchr("HTPF", argv[1][1])) {
int niter = atoi(argv[1] + 2);
MetatileType type = (argv[1][1] == 'H' ? MT_H :
argv[1][1] == 'T' ? MT_T :
argv[1][1] == 'P' ? MT_P : MT_F);
MetatileSet *tiles = metatile_initial_set(type);
while (niter-- > 0) {
MetatileSet *t2 = metatile_set_expand(tiles);
metatile_free_set(tiles);
tiles = t2;
}
{
size_t nh;
Hat *h = metatile_set_to_hats(tiles, &nh, NULL);
draw_hats_python(h, nh);
sfree(h);
}
metatile_free_set(tiles);
return 0;
}
if (!strcmp(argv[1], "--tables")) {
size_t i, j, k;