add shape2wire

examples/shape2wire.scad

@@ -0,0 +1,36 @@
+use <ptf/ptf_rotate.scad>;
+use <hull_polyline2d.scad>;
+use <hull_polyline3d.scad>;
+use <shape_superformula.scad>; 
+
+function shape2wire(shape, r) = 
+	let(
+	    leng_shape = len(shape),
+	    a = 360 / leng_shape
+	)
+	[
+		for(i = [0:len(shape) - 1])
+		let(p = shape[i])	
+		ptf_rotate(
+		    ptf_rotate([p[0], p[1], 0], [90, 0, 0]) + [r, 0, 0], 
+		    a * i
+		)
+	];
+
+phi_step = 0.05;
+m = 16;
+n = 0.5;
+n3 = 16;
+shape = shape_superformula(phi_step, m, m, n, n, n3) * 30;
+
+translate([150, 0])
+rotate([90, 0, 0])
+linear_extrude(1, center = true)
+difference() {
+	square(120, center = true);
+	hull_polyline2d(concat(shape, [shape[0]]), width = 5);
+}
+
+wire = shape2wire(shape, 150);
+rotate(-$t * 360)
+    hull_polyline3d(concat(wire, [wire[0]]), 3);