add tiled_line_ring

examples/tiles/tiled_line_ring.scad

@@ -0,0 +1,48 @@
+use <experimental/tile_truchet.scad>;
+use <polyline_join.scad>;
+
+radius = 15;
+height = 10;
+line_diameter = 2;
+$fn = 4;
+
+module tiled_line_ring(radius, height, line_diameter) {
+    half_line_diameter = line_diameter / 2;
+    size = [
+	    round(2 * radius * PI / line_diameter), 
+		round(height / line_diameter)
+	];
+    lines = concat(
+        [
+            for(tile = tile_truchet(size)) 
+            let(
+			    x = tile[0],
+				y = tile[1],
+				i = tile[2]
+			)
+            i <= 1 ? 
+			    [
+				    [x * half_line_diameter, y * line_diameter], 
+					[(x + 1) * half_line_diameter, (y + 1) * line_diameter]
+				] 
+				: 
+				[
+				    [(x + 1) * half_line_diameter, y * line_diameter],
+					[x * half_line_diameter, (y + 1) * line_diameter]
+				]  
+        ]
+    );
+            
+
+	a = 360 / size[0];
+    for(line = lines) {
+	    pts = [
+		    for(p = line) 
+		        [radius * cos(a * p[0]), radius * sin(a * p[0]), p[1]]
+		];
+        polyline_join(pts) 
+		    sphere(half_line_diameter);
+    }
+}
+
+tiled_line_ring(radius, height, line_diameter);