tsiry-sandratraina.com
A modern Music Player Daemon based on Rockbox open source high quality audio player
libadwaita
audio
rust
zig
deno
mpris
rockbox
mpd
1#ifndef PUZZLES_HAT_H
2#define PUZZLES_HAT_H
3
4struct HatPatchParams {
5 /*
6 * A patch of hat tiling is identified by giving the coordinates
7 * of the kite in one corner, using a multi-level coordinate
8 * system based on metatile expansions. Coordinates are a sequence
9 * of small non-negative integers. The valid range for each
10 * coordinate depends on the next coordinate, or on final_metatile
11 * if it's the last one in the list. The largest valid range is
12 * {0,...,12}.
13 *
14 * 'final_metatile' is one of the characters 'H', 'T', 'P' or 'F'.
15 */
16 size_t ncoords;
17 unsigned char *coords;
18 char final_metatile;
19};
20
21/*
22 * Fill in HatPatchParams with a randomly selected set of coordinates,
23 * in enough detail to generate a patch of tiling covering an area of
24 * w x h 'squares' of a kite tiling.
25 *
26 * The kites grid is considered to be oriented so that it includes
27 * horizontal lines and not vertical ones. So each of the smallest
28 * equilateral triangles in the grid has a bounding rectangle whose
29 * height is sqrt(3)/2 times its width, and either the top or the
30 * bottom of that bounding rectangle is the horizontal edge of the
31 * triangle. A 'square' of a kite tiling (for convenience of choosing
32 * grid dimensions) counts as one of those bounding rectangles.
33 *
34 * The 'coords' field of the structure will be filled in with a new
35 * dynamically allocated array. Any previous pointer in that field
36 * will be overwritten.
37 */
38void hat_tiling_randomise(struct HatPatchParams *params, int w, int h,
39 random_state *rs);
40
41/*
42 * Validate a HatPatchParams to ensure it contains no illegal
43 * coordinates. Returns NULL if it's acceptable, or an error string if
44 * not.
45 */
46const char *hat_tiling_params_invalid(const struct HatPatchParams *params);
47
48/*
49 * Generate the actual set of hat tiles from a HatPatchParams, passing
50 * each one to a callback. The callback receives the vertices of each
51 * point, as a sequence of 2*nvertices integers, with x,y coordinates
52 * interleaved.
53 *
54 * The x coordinates are measured in units of 1/4 of the side length
55 * of the smallest equilateral triangle, or equivalently, 1/2 the
56 * length of one of the long edges of a single kite. The y coordinates
57 * are measured in units of 1/6 the height of the triangle, which is
58 * also 1/2 the length of the short edge of a kite. Therefore, you can
59 * expect x to go up to 4*w and y up to 6*h.
60 */
61typedef void (*hat_tile_callback_fn)(void *ctx, size_t nvertices,
62 int *coords);
63
64void hat_tiling_generate(const struct HatPatchParams *params, int w, int h,
65 hat_tile_callback_fn cb, void *cbctx);
66
67#endif