| 1 | /* penrose.h |
| 2 | * |
| 3 | * Penrose tiling functions. |
| 4 | * |
| 5 | * Provides an interface with which to generate Penrose tilings |
| 6 | * by recursive subdivision of an initial tile of choice (one of the |
| 7 | * four sets of two pairs kite/dart, or thin/thick rhombus). |
| 8 | * |
| 9 | * You supply a callback function and a context pointer, which is |
| 10 | * called with each tile in turn: you choose how many times to recurse. |
| 11 | */ |
| 12 | |
| 13 | #ifndef _PENROSE_H |
| 14 | #define _PENROSE_H |
| 15 | |
| 16 | #ifndef PHI |
| 17 | #define PHI 1.6180339887 |
| 18 | #endif |
| 19 | |
| 20 | typedef struct vector vector; |
| 21 | |
| 22 | double v_x(vector *vs, int i); |
| 23 | double v_y(vector *vs, int i); |
| 24 | |
| 25 | typedef struct penrose_state penrose_state; |
| 26 | |
| 27 | /* Return non-zero to clip the tree here (i.e. not recurse |
| 28 | * below this tile). |
| 29 | * |
| 30 | * Parameters are state, vector array, npoints, depth. |
| 31 | * ctx is inside state. |
| 32 | */ |
| 33 | typedef int (*tile_callback)(penrose_state *, vector *, int, int); |
| 34 | |
| 35 | struct penrose_state { |
| 36 | int start_size; /* initial side length */ |
| 37 | int max_depth; /* Recursion depth */ |
| 38 | |
| 39 | tile_callback new_tile; |
| 40 | void *ctx; /* for callback */ |
| 41 | }; |
| 42 | |
| 43 | enum { PENROSE_P2, PENROSE_P3 }; |
| 44 | |
| 45 | extern int penrose(penrose_state *state, int which, int angle); |
| 46 | |
| 47 | /* Returns the side-length of a penrose tile at recursion level |
| 48 | * gen, given a starting side length. */ |
| 49 | extern double penrose_side_length(double start_size, int depth); |
| 50 | |
| 51 | /* Returns the count of each type of tile at a given recursion depth. */ |
| 52 | extern void penrose_count_tiles(int gen, int *nlarge, int *nsmall); |
| 53 | |
| 54 | /* Calculate start size and recursion depth required to produce a |
| 55 | * width-by-height sized patch of penrose tiles with the given tilesize */ |
| 56 | extern void penrose_calculate_size(int which, int tilesize, int w, int h, |
| 57 | double *required_radius, int *start_size, int *depth); |
| 58 | |
| 59 | #endif |