eq[2] = eqs[0][3]*eqs[1][2] - eqs[1][3]*eqs[0][2];
/* Parametrise x and y in terms of some t. */
- if (abs(eq[0]) < abs(eq[1])) {
+ if (fabs(eq[0]) < fabs(eq[1])) {
/* Parameter is x. */
xt[0] = 1; xt[1] = 0;
yt[0] = -eq[0]/eq[1]; yt[1] = eq[2]/eq[1];
return g;
}
+static void grid_size_greatgreatdodecagonal(int width, int height,
+ int *tilesize, int *xextent, int *yextent)
+{
+ int a = DODEC_A;
+ int b = DODEC_B;
+
+ *tilesize = DODEC_TILESIZE;
+ *xextent = (4*a + 4*b) * (width-1) + 2*(2*a + b) + 2*a + 2*b;
+ *yextent = (6*a + 2*b) * (height-1) + 2*(2*a + b);
+}
+
+static grid *grid_new_greatgreatdodecagonal(int width, int height, const char *desc)
+{
+ int x, y;
+ /* Vector for side of triangle - ratio is close to sqrt(3) */
+ int a = DODEC_A;
+ int b = DODEC_B;
+
+ /* Upper bounds - don't have to be exact */
+ int max_faces = 50 * width * height;
+ int max_dots = 300 * width * height;
+
+ tree234 *points;
+
+ grid *g = grid_empty();
+ g->tilesize = DODEC_TILESIZE;
+ g->faces = snewn(max_faces, grid_face);
+ g->dots = snewn(max_dots, grid_dot);
+
+ points = newtree234(grid_point_cmp_fn);
+
+ for (y = 0; y < height; y++) {
+ for (x = 0; x < width; x++) {
+ grid_dot *d;
+ /* centre of dodecagon */
+ int px = (4*a + 4*b) * x;
+ int py = (6*a + 2*b) * y;
+ if (y % 2)
+ px += 2*a + 2*b;
+
+ /* dodecagon */
+ grid_face_add_new(g, 12);
+ d = grid_get_dot(g, points, px + ( a ), py - (2*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + ( a + b), py - ( a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + (2*a + b), py - ( a )); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px + (2*a + b), py + ( a )); grid_face_set_dot(g, d, 3);
+ d = grid_get_dot(g, points, px + ( a + b), py + ( a + b)); grid_face_set_dot(g, d, 4);
+ d = grid_get_dot(g, points, px + ( a ), py + (2*a + b)); grid_face_set_dot(g, d, 5);
+ d = grid_get_dot(g, points, px - ( a ), py + (2*a + b)); grid_face_set_dot(g, d, 6);
+ d = grid_get_dot(g, points, px - ( a + b), py + ( a + b)); grid_face_set_dot(g, d, 7);
+ d = grid_get_dot(g, points, px - (2*a + b), py + ( a )); grid_face_set_dot(g, d, 8);
+ d = grid_get_dot(g, points, px - (2*a + b), py - ( a )); grid_face_set_dot(g, d, 9);
+ d = grid_get_dot(g, points, px - ( a + b), py - ( a + b)); grid_face_set_dot(g, d, 10);
+ d = grid_get_dot(g, points, px - ( a ), py - (2*a + b)); grid_face_set_dot(g, d, 11);
+
+ /* hexagon on top right of dodecagon */
+ if (y && (x < width - 1 || !(y % 2))) {
+ grid_face_add_new(g, 6);
+ d = grid_get_dot(g, points, px + (a + 2*b), py - (4*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + (a + 2*b), py - (2*a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + (a + b), py - ( a + b)); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px + (a ), py - (2*a + b)); grid_face_set_dot(g, d, 3);
+ d = grid_get_dot(g, points, px + (a ), py - (4*a + b)); grid_face_set_dot(g, d, 4);
+ d = grid_get_dot(g, points, px + (a + b), py - (5*a + b)); grid_face_set_dot(g, d, 5);
+ }
+
+ /* hexagon on right of dodecagon*/
+ if (x < width - 1) {
+ grid_face_add_new(g, 6);
+ d = grid_get_dot(g, points, px + (2*a + 3*b), py - a); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + (2*a + 3*b), py + a); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + (2*a + 2*b), py + 2*a); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px + (2*a + b), py + a); grid_face_set_dot(g, d, 3);
+ d = grid_get_dot(g, points, px + (2*a + b), py - a); grid_face_set_dot(g, d, 4);
+ d = grid_get_dot(g, points, px + (2*a + 2*b), py - 2*a); grid_face_set_dot(g, d, 5);
+ }
+
+ /* hexagon on bottom right of dodecagon */
+ if ((y < height - 1) && (x < width - 1 || !(y % 2))) {
+ grid_face_add_new(g, 6);
+ d = grid_get_dot(g, points, px + (a + 2*b), py + (2*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + (a + 2*b), py + (4*a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + (a + b), py + (5*a + b)); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px + (a ), py + (4*a + b)); grid_face_set_dot(g, d, 3);
+ d = grid_get_dot(g, points, px + (a ), py + (2*a + b)); grid_face_set_dot(g, d, 4);
+ d = grid_get_dot(g, points, px + (a + b), py + ( a + b)); grid_face_set_dot(g, d, 5);
+ }
+
+ /* square on top right of dodecagon */
+ if (y && (x < width - 1 )) {
+ grid_face_add_new(g, 4);
+ d = grid_get_dot(g, points, px + ( a + 2*b), py - (2*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + (2*a + 2*b), py - (2*a )); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + (2*a + b), py - ( a )); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px + ( a + b), py - ( a + b)); grid_face_set_dot(g, d, 3);
+ }
+
+ /* square on bottom right of dodecagon */
+ if ((y < height - 1) && (x < width - 1 )) {
+ grid_face_add_new(g, 4);
+ d = grid_get_dot(g, points, px + (2*a + 2*b), py + (2*a )); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + ( a + 2*b), py + (2*a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + ( a + b), py + ( a + b)); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px + (2*a + b), py + ( a )); grid_face_set_dot(g, d, 3);
+ }
+
+ /* square below dodecagon */
+ if ((y < height - 1) && (x < width - 1 || !(y % 2)) && (x > 0 || (y % 2))) {
+ grid_face_add_new(g, 4);
+ d = grid_get_dot(g, points, px + a, py + (2*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + a, py + (4*a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px - a, py + (4*a + b)); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px - a, py + (2*a + b)); grid_face_set_dot(g, d, 3);
+ }
+
+ /* square on bottom left of dodecagon */
+ if (x && (y < height - 1)) {
+ grid_face_add_new(g, 4);
+ d = grid_get_dot(g, points, px - (2*a + b), py + ( a )); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px - ( a + b), py + ( a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px - ( a + 2*b), py + (2*a + b)); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px - (2*a + 2*b), py + (2*a )); grid_face_set_dot(g, d, 3);
+ }
+
+ /* square on top left of dodecagon */
+ if (x && y) {
+ grid_face_add_new(g, 4);
+ d = grid_get_dot(g, points, px - ( a + b), py - ( a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px - (2*a + b), py - ( a )); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px - (2*a + 2*b), py - (2*a )); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px - ( a + 2*b), py - (2*a + b)); grid_face_set_dot(g, d, 3);
+
+ }
+
+ /* square above dodecagon */
+ if (y && (x < width - 1 || !(y % 2)) && (x > 0 || (y % 2))) {
+ grid_face_add_new(g, 4);
+ d = grid_get_dot(g, points, px + a, py - (4*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + a, py - (2*a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px - a, py - (2*a + b)); grid_face_set_dot(g, d, 2);
+ d = grid_get_dot(g, points, px - a, py - (4*a + b)); grid_face_set_dot(g, d, 3);
+ }
+
+ /* upper triangle (v) */
+ if (y && (x < width - 1)) {
+ grid_face_add_new(g, 3);
+ d = grid_get_dot(g, points, px + (3*a + 2*b), py - (2*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + (2*a + 2*b), py - (2*a )); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + ( a + 2*b), py - (2*a + b)); grid_face_set_dot(g, d, 2);
+ }
+
+ /* lower triangle (^) */
+ if ((y < height - 1) && (x < width - 1)) {
+ grid_face_add_new(g, 3);
+ d = grid_get_dot(g, points, px + (3*a + 2*b), py + (2*a + b)); grid_face_set_dot(g, d, 0);
+ d = grid_get_dot(g, points, px + ( a + 2*b), py + (2*a + b)); grid_face_set_dot(g, d, 1);
+ d = grid_get_dot(g, points, px + (2*a + 2*b), py + (2*a )); grid_face_set_dot(g, d, 2);
+ }
+ }
+ }
+
+ freetree234(points);
+ assert(g->num_faces <= max_faces);
+ assert(g->num_dots <= max_dots);
+
+ grid_make_consistent(g);
+ return g;
+}
+
typedef struct setface_ctx
{
int xmin, xmax, ymin, ymax;