* We use "-1", not "-2" here, because Euler's formula includes the
* infinite face, which we don't count. */
g->num_edges = g->num_faces + g->num_dots - 1;
+ debug(("allocating room for %d edges\n", g->num_edges));
g->edges = snewn(g->num_edges, grid_edge);
next_new_edge = g->edges;
for (i = 0; i < g->num_faces; i++) {
grid_face *f = g->faces + i;
int j;
+ assert(f->order > 2);
for (j = 0; j < f->order; j++) {
grid_edge e; /* fake edge for searching */
grid_edge *edge_found;
f->iy = ybest + 0.5;
}
+/* Generate the dual to a grid
+ * Returns a new dynamically-allocated grid whose dots are the
+ * faces of the input, and whose faces are the dots of the input.
+ * A few modifications are made: dots on input that have only two
+ * edges are deleted, and the infinite exterior face is also removed
+ * before conversion.
+ */
+static grid *grid_dual(grid *g)
+{
+ grid *new_g;
+ int i, j, k;
+ tree234* points;
+
+ new_g = grid_empty();
+ new_g->tilesize = g->tilesize;
+ new_g->faces = snewn(g->num_dots, grid_face);
+ new_g->dots = snewn(g->num_faces, grid_dot);
+ debug(("taking the dual of a grid with %d faces and %d dots\n",
+ g->num_faces,g->num_dots));
+
+ points = newtree234(grid_point_cmp_fn);
+
+ for (i=0;i<g->num_faces;i++)
+ {
+ grid_find_incentre(&(g->faces[i]));
+ }
+ for (i=0;i<g->num_dots;i++)
+ {
+ int order;
+ grid_dot *d;
+
+ d = &(g->dots[i]);
+
+ order = d->order;
+ for (j=0;j<d->order;j++)
+ {
+ if (!d->faces[j]) order--;
+ }
+ if (order>2)
+ {
+ grid_face_add_new(new_g, order);
+ for (j=0,k=0;j<d->order;j++)
+ {
+ grid_dot *new_d;
+ if (d->faces[j])
+ {
+ new_d = grid_get_dot(new_g, points,
+ d->faces[j]->ix, d->faces[j]->iy);
+ grid_face_set_dot(new_g, new_d, k++);
+ }
+ }
+ assert(k==order);
+ }
+ }
+
+ freetree234(points);
+ assert(new_g->num_faces <= g->num_dots);
+ assert(new_g->num_dots <= g->num_faces);
+
+ debug(("dual has %d faces and %d dots\n",
+ new_g->num_faces,new_g->num_dots));
+ grid_make_consistent(new_g);
+ return new_g;
+}
/* ------ Generate various types of grid ------ */
/* General method is to generate faces, by calculating their dot coordinates.
grid_make_consistent(g);
return g;
}
-
#define OCTAGONAL_TILESIZE 40
/* b/a approx sqrt(2) */
#define OCTAGONAL_A 29
static grid *(*(grid_news[]))(int, int, char*) = { GRIDGEN_LIST(FNNEW) };
static void(*(grid_sizes[]))(int, int, int*, int*, int*) = { GRIDGEN_LIST(FNSZ) };
-char *grid_new_desc(grid_type type, int width, int height, random_state *rs)
+char *grid_new_desc(grid_type type, int width, int height, int dual, random_state *rs)
{
if (type != GRID_PENROSE_P2 && type != GRID_PENROSE_P3)
return NULL;
return grid_new_desc_penrose(type, width, height, rs);
}
-char *grid_validate_desc(grid_type type, int width, int height, char *desc)
+char *grid_validate_desc(grid_type type, int width, int height, int dual, char *desc)
{
if (type != GRID_PENROSE_P2 && type != GRID_PENROSE_P3) {
if (desc != NULL)
return grid_validate_desc_penrose(type, width, height, desc);
}
-grid *grid_new(grid_type type, int width, int height, char *desc)
+grid *grid_new(grid_type type, int width, int height, int dual, char *desc)
{
- char *err = grid_validate_desc(type, width, height, desc);
+ char *err = grid_validate_desc(type, width, height, dual, desc);
if (err) assert(!"Invalid grid description.");
- return grid_news[type](width, height, desc);
+ if (!dual)
+ {
+ return grid_news[type](width, height, desc);
+ }
+ else
+ {
+ grid *temp;
+ grid *g;
+
+ temp = grid_news[type](width, height, desc);
+ g = grid_dual(temp);
+ grid_free(temp);
+ return g;
+ }
}
void grid_compute_size(grid_type type, int width, int height,