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 60