updated docs

README.md

@@ -87,6 +87,7 @@ Too many dependencies? Because OpenSCAD doesn't provide namespace management, I
 	- [shape_ellipse](https://openhome.cc/eGossip/OpenSCAD/lib-shape_ellipse.html)
     - [shape_square](https://openhome.cc/eGossip/OpenSCAD/lib-shape_square.html)
     - [shape_pentagram](https://openhome.cc/eGossip/OpenSCAD/lib-shape_pentagram.html)	
+	- [shape_superformula](https://openhome.cc/eGossip/OpenSCAD/lib-shape_superformula.html)	
 	
 - Other
     - [turtle2d](https://openhome.cc/eGossip/OpenSCAD/lib-turtle2d.html)

docs/lib-shape_superformula.md

@@ -0,0 +1,60 @@
+# shape_superformula
+
+Returns shape points and triangle indexes of a [Superformula](https://en.wikipedia.org/wiki/Superformula) shape. They can be used with xxx_extrude modules of dotSCAD. The shape points can be also used with the built-in polygon module. 
+
+## Parameters
+
+- `phi_step` : The radius of the circle.
+- `m1`, `m2`, `n1`, `n2`, `n3`, `a`, `b` : The parameters of [Superformula](https://en.wikipedia.org/wiki/Superformula). The default value of `n2`, `n3`, `a`, and `b` is 1.
+
+## Examples
+
+    include <shape_superformula.scad>;   
+        
+    phi_step = 0.05;
+
+    polygon(shape_superformula(phi_step, 3, 3, 4.5, 10, 10)[0]);
+    translate([3, 0]) 
+        polygon(shape_superformula(phi_step, 4, 4, 12, 15, 15)[0]);
+    translate([6, 0]) 
+        polygon(shape_superformula(phi_step, 7, 7, 10, 6, 6)[0]);
+    translate([9, 0]) 
+        polygon(shape_superformula(phi_step, 5, 5, 4, 4, 4)[0]);
+        
+    translate([0, -4]) 
+        scale(0.8) polygon(shape_superformula(phi_step, 5, 5, 2, 7, 7)[0]);
+    translate([3, -4]) 
+        scale(0.25) polygon(shape_superformula(phi_step, 5, 5, 2, 13, 13)[0]);
+    translate([6, -4]) 
+        polygon(shape_superformula(phi_step, 4, 4, 1, 1, 1)[0]);
+    translate([9, -4]) 
+        scale(0.3) polygon(shape_superformula(phi_step, 4, 4, 1, 7, 8)[0]);
+
+![shape_superformula](images/lib-shape_superformula-1.JPG)
+
+    include <shape_superformula.scad>; 
+    include <circle_path.scad>;
+    include <rotate_p.scad>;
+    include <golden_spiral.scad>;
+    include <cross_sections.scad>;
+    include <polysections.scad>;
+    include <golden_spiral_extrude.scad>;  
+        
+    phi_step = 0.05;
+
+    m = 16;
+    n = 0.5;
+    n3 = 16;
+
+    shape_pts_tris = shape_superformula(phi_step, m, m, n, n, n3);
+
+    golden_spiral_extrude(
+        shape_pts_tris[0], 
+        from = 5, 
+        to = 10, 
+        point_distance = 2,
+        scale = 10,
+        triangles = shape_pts_tris[1]
+    );  
+
+![shape_superformula](images/lib-shape_superformula-2.JPG)

src/shape_superformula.scad

@@ -1,3 +1,17 @@
+/**
+* shape_superformula.scad
+*
+* Returns shape points and triangle indexes of a Superformula shape. 
+* They can be used with xxx_extrude modules of dotSCAD.
+* The shape points can be also used with the built-in polygon module. 
+* 
+* @copyright Justin Lin, 2017
+* @license https://opensource.org/licenses/lgpl-3.0.html
+*
+* @see https://openhome.cc/eGossip/OpenSCAD/lib-shape_superformula.html
+*
+**/ 
+
 include <__private__/__ra_to_xy.scad>;
 include <__private__/__to_degree.scad>;
 include <__private__/__triangles_radial.scad>;