add island_maze

examples/maze/island_maze.scad

@@ -0,0 +1,58 @@
+use <maze/mz_square.scad>
+use <maze/mz_squarewalls.scad>
+use <polyline2d.scad>
+use <noise/nz_perlin2.scad>
+use <util/choose.scad>
+
+rows = 30;
+columns = 30;
+cell_width = 3;
+wall_thickness = 1.5;
+moutain_height = 30;
+base_height = 3;
+seed = 35;
+smoothness  = 25;
+
+island_maze();
+
+module island_maze() {
+    dirs = function(x, y, cells, seed) 
+           let(
+               nz = nz_perlin2(x * cell_width / smoothness, y * cell_width / smoothness, seed),
+               sd = y * len(cells[0]) + x + seed,
+               h = choose([[0, 2], [2, 0]], seed = sd),
+               v = choose([[1, 3], [3, 1]], seed = sd)
+           )
+           nz > 0 ? concat(h, v) : concat(v, h);
+
+    cells = mz_square(rows, columns, seed = seed, directions = dirs);
+    walls = mz_squarewalls(cells, cell_width);
+
+    color("green")
+    for(wall = walls) {
+        for(i = [0:len(wall) - 2]) {
+            p1 = wall[i];
+            p2 = wall[i + 1];
+            h1 = nz_perlin2(p1.x / smoothness , p1.y / smoothness , seed);
+            h2 = nz_perlin2(p2.x / smoothness , p2.y / smoothness , seed);
+            hull() {
+               linear_extrude(h1 > 0 ? h1 * moutain_height + base_height : base_height)
+                translate(p1)
+                    square(wall_thickness);
+                
+               linear_extrude(h2 > 0 ? h2 * moutain_height + base_height : base_height)
+                translate(p2)
+                    square(wall_thickness);
+            }
+        }
+    }
+
+    if($preview) {
+        color("blue")
+        translate([wall_thickness, wall_thickness] / 2)
+        for(wall = walls) {
+            linear_extrude(base_height)
+            polyline2d(wall, wall_thickness, joinStyle = "JOIN_MITER");
+        }
+    }
+}