diff options
Diffstat (limited to 'grid.c')
| -rw-r--r-- | grid.c | 68 |
1 files changed, 5 insertions, 63 deletions
@@ -57,7 +57,6 @@ static grid *grid_new(void) g->edges = NULL; g->dots = NULL; g->num_faces = g->num_edges = g->num_dots = 0; - g->middle_face = NULL; g->refcount = 1; g->lowest_x = g->lowest_y = g->highest_x = g->highest_y = 0; return g; @@ -92,17 +91,9 @@ static double point_line_distance(long px, long py, * Returns the nearest edge, or NULL if no edge is reasonably * near the position. * - * This algorithm is nice and generic, and doesn't depend on any particular - * geometric layout of the grid: - * Start at any dot (pick one next to middle_face). - * Walk along a path by choosing, from all nearby dots, the one that is - * nearest the target (x,y). Hopefully end up at the dot which is closest - * to (x,y). Should work, as long as faces aren't too badly shaped. - * Then examine each edge around this dot, and pick whichever one is - * closest (perpendicular distance) to (x,y). - * Using perpendicular distance is not quite right - the edge might be - * "off to one side". So we insist that the triangle with (x,y) has - * acute angles at the edge's dots. + * Just judging edges by perpendicular distance is not quite right - + * the edge might be "off to one side". So we insist that the triangle + * with (x,y) has acute angles at the edge's dots. * * edge1 * *---------*------ @@ -116,50 +107,14 @@ static double point_line_distance(long px, long py, */ grid_edge *grid_nearest_edge(grid *g, int x, int y) { - grid_dot *cur; grid_edge *best_edge; double best_distance = 0; int i; - cur = g->middle_face->dots[0]; - - for (;;) { - /* Target to beat */ - long dist = SQ((long)cur->x - (long)x) + SQ((long)cur->y - (long)y); - /* Look for nearer dot - if found, store in 'new'. */ - grid_dot *new = cur; - int i; - /* Search all dots in all faces touching this dot. Some shapes - * (such as in Cairo) don't quite work properly if we only search - * the dot's immediate neighbours. */ - for (i = 0; i < cur->order; i++) { - grid_face *f = cur->faces[i]; - int j; - if (!f) continue; - for (j = 0; j < f->order; j++) { - long new_dist; - grid_dot *d = f->dots[j]; - if (d == cur) continue; - new_dist = SQ((long)d->x - (long)x) + SQ((long)d->y - (long)y); - if (new_dist < dist) { /* found closer dot */ - new = d; - dist = new_dist; - } - } - } - - if (new == cur) { - /* Didn't find a closer dot among the neighbours of 'cur' */ - break; - } else { - cur = new; - } - } - /* 'cur' is nearest dot, so find which of the dot's edges is closest. */ best_edge = NULL; - for (i = 0; i < cur->order; i++) { - grid_edge *e = cur->edges[i]; + for (i = 0; i < g->num_edges; i++) { + grid_edge *e = &g->edges[i]; long e2; /* squared length of edge */ long a2, b2; /* squared lengths of other sides */ double dist; @@ -222,7 +177,6 @@ static void grid_print_basic(grid *g) } printf("]\n"); } - printf("Middle face: %d\n", (int)(g->middle_face - g->faces)); } /* Show the derived grid information, computed by grid_make_consistent */ static void grid_print_derived(grid *g) @@ -724,7 +678,6 @@ grid *grid_new_square(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + (height/2) * width + (width/2); grid_make_consistent(g); return g; @@ -779,7 +732,6 @@ grid *grid_new_honeycomb(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + (height/2) * width + (width/2); grid_make_consistent(g); return g; @@ -858,10 +810,6 @@ grid *grid_new_triangular(int width, int height) } } - /* "+ width" takes us to the middle of the row, because each row has - * (2*width) faces. */ - g->middle_face = g->faces + (height / 2) * 2 * width + width; - grid_make_consistent(g); return g; } @@ -960,7 +908,6 @@ grid *grid_new_snubsquare(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + (height/2) * width + (width/2); grid_make_consistent(g); return g; @@ -1053,7 +1000,6 @@ grid *grid_new_cairo(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + (height/2) * width + (width/2); grid_make_consistent(g); return g; @@ -1169,7 +1115,6 @@ grid *grid_new_greathexagonal(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + (height/2) * width + (width/2); grid_make_consistent(g); return g; @@ -1238,7 +1183,6 @@ grid *grid_new_octagonal(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + (height/2) * width + (width/2); grid_make_consistent(g); return g; @@ -1344,7 +1288,6 @@ grid *grid_new_kites(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + 6 * ((height/2) * width + (width/2)); grid_make_consistent(g); return g; @@ -1433,7 +1376,6 @@ grid *grid_new_floret(int width, int height) freetree234(points); assert(g->num_faces <= max_faces); assert(g->num_dots <= max_dots); - g->middle_face = g->faces + 6 * ((height/2) * width + (width/2)); grid_make_consistent(g); return g; |