Files
puzzles/penrose.h
Simon Tatham 62c20496bf From James Harvey (via a period of collaborative polishing), a patch
to add two kinds of Penrose tiling to the grid types supported by
Loopy.

This has involved a certain amount of infrastructure work, because of
course the whole point of Penrose tilings is that they don't have to
be the same every time: so now grid.c has grown the capacity to
describe its grids as strings, and reconstitute them from those string
descriptions. Hence a Penrose Loopy game description consists of a
string identifying a particular piece of Penrose tiling, followed by
the normal Loopy clue encoding.

All the existing grid types decline to provide a grid description
string, so their Loopy game descriptions have not changed encoding.

[originally from svn r9159]
2011-04-24 09:10:52 +00:00

60 lines
1.7 KiB
C

/* penrose.h
*
* Penrose tiling functions.
*
* Provides an interface with which to generate Penrose tilings
* by recursive subdivision of an initial tile of choice (one of the
* four sets of two pairs kite/dart, or thin/thick rhombus).
*
* You supply a callback function and a context pointer, which is
* called with each tile in turn: you choose how many times to recurse.
*/
#ifndef _PENROSE_H
#define _PENROSE_H
#ifndef PHI
#define PHI 1.6180339887
#endif
typedef struct vector vector;
double v_x(vector *vs, int i);
double v_y(vector *vs, int i);
typedef struct penrose_state penrose_state;
/* Return non-zero to clip the tree here (i.e. not recurse
* below this tile).
*
* Parameters are state, vector array, npoints, depth.
* ctx is inside state.
*/
typedef int (*tile_callback)(penrose_state *, vector *, int, int);
struct penrose_state {
int start_size; /* initial side length */
int max_depth; /* Recursion depth */
tile_callback new_tile;
void *ctx; /* for callback */
};
enum { PENROSE_P2, PENROSE_P3 };
extern int penrose(penrose_state *state, int which);
/* Returns the side-length of a penrose tile at recursion level
* gen, given a starting side length. */
extern double penrose_side_length(double start_size, int depth);
/* Returns the count of each type of tile at a given recursion depth. */
extern void penrose_count_tiles(int gen, int *nlarge, int *nsmall);
/* Calculate start size and recursion depth required to produce a
* width-by-height sized patch of penrose tiles with the given tilesize */
extern void penrose_calculate_size(int which, int tilesize, int w, int h,
double *required_radius, int *start_size, int *depth);
#endif