b760b8bd |
1 | /* |
2 | * loopgen.h: interface file for loop generation functions for grid.[ch]. |
3 | */ |
4 | |
5 | #ifndef _LOOPGEN_H |
6 | #define _LOOPGEN_H |
7 | |
8 | #include "puzzles.h" |
9 | #include "grid.h" |
10 | |
11 | enum face_colour { FACE_WHITE, FACE_GREY, FACE_BLACK }; |
12 | |
13 | /* face should be of type grid_face* here. */ |
14 | #define FACE_COLOUR(face) \ |
15 | ( (face) == NULL ? FACE_BLACK : \ |
16 | board[(face) - g->faces] ) |
17 | |
18 | typedef int (*loopgen_bias_fn_t)(void *ctx, char *board, int face); |
19 | |
20 | /* 'board' should be a char array whose length is the same as |
21 | * g->num_faces: this will be filled in with FACE_WHITE or FACE_BLACK |
22 | * after loop generation. |
23 | * |
24 | * If 'bias' is non-null, it should be a user-provided function which |
25 | * rates a half-finished board (i.e. may include some FACE_GREYs) for |
26 | * desirability; this will cause the loop generator to bias in favour |
27 | * of loops with a high return value from that function. The 'face' |
28 | * parameter to the bias function indicates which face of the grid has |
29 | * been modified since the last call; it is guaranteed that only one |
30 | * will have been (so that bias functions can work incrementally |
31 | * rather than re-scanning the whole grid on every call). */ |
32 | extern void generate_loop(grid *g, char *board, random_state *rs, |
33 | loopgen_bias_fn_t bias, void *biasctx); |
34 | |
35 | #endif |