From 3dc1877dbdfb460a5a8457c500824dbcb0587e80 Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Sat, 6 May 2017 13:50:49 +0800
Subject: [PATCH] added two shapes

---
 src/shape_pentagram.scad | 22 ++++++++++++++++++++++
 src/shape_square.scad    | 30 ++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 src/shape_pentagram.scad
 create mode 100644 src/shape_square.scad

diff --git a/src/shape_pentagram.scad b/src/shape_pentagram.scad
new file mode 100644
index 00000000..685355e0
--- /dev/null
+++ b/src/shape_pentagram.scad
@@ -0,0 +1,22 @@
+function shape_pentagram(r) =
+    [
+        // shape points
+        [
+            [0, 1], [-0.224514, 0.309017], 
+            [-0.951057, 0.309017], [-0.363271, -0.118034], 
+            [-0.587785, -0.809017], [0, -0.381966], 
+            [0.587785, -0.809017], [0.363271, -0.118034], 
+            [0.951057, 0.309017], [0.224514, 0.309017]
+        ] * r,
+        // triangles
+        [   
+            [0, 1, 9],
+            [2, 3, 1],
+            [4, 5, 3],
+            [6, 7, 5],
+            [8, 9, 7],
+            [1, 3, 5],
+            [1, 5, 7],
+            [1, 7, 9]
+        ]
+    ];
\ No newline at end of file
diff --git a/src/shape_square.scad b/src/shape_square.scad
new file mode 100644
index 00000000..f07499b8
--- /dev/null
+++ b/src/shape_square.scad
@@ -0,0 +1,30 @@
+function shape_square(size, corner_r = 0) = 
+    let(
+        frags = $fn > 0 ? 
+            ($fn >= 3 ? $fn : 3) : 
+            max(min(360 / $fa, corner_r * 6.28318 / $fs), 5),
+        remain = frags % 4,
+        corner_frags = (remain / 4) > 0.5 ? frags - remain + 4 : frags - remain,
+        step_a = 360 / corner_frags,
+        x = len(size) == undef ? size : size[0],
+        y = len(size) == undef ? size : size[1],
+        half_x = x / 2,
+        half_y = y / 2, 
+        half_w = half_x - corner_r,
+        half_h = half_y - corner_r,
+        shape_pts = concat(
+            [[half_x, -half_h], [half_x, half_h]],
+            [for(a = [step_a:step_a:90 - step_a]) [corner_r * cos(a) + half_w, corner_r * sin(a) + half_h]],
+            [[half_w, half_y], [-half_w, half_y]],
+            [for(a = [90 + step_a:step_a:180 - step_a]) [corner_r * cos(a) - half_w, corner_r * sin(a) + half_h]], 
+            [[-half_x, half_h], [-half_x, -half_h]],
+            [for(a = [180 + step_a:step_a:270 - step_a]) [corner_r * cos(a) - half_w, corner_r * sin(a) - half_h]],
+            [[-half_w, -half_y], [half_w, -half_y]],
+            [for(a = [270 + step_a:step_a:360 - step_a]) [corner_r * cos(a) + half_w, corner_r * sin(a) - half_h]]
+        ),
+        triangles = [for(i = [1:len(shape_pts) - 2]) [0, i, i + 1]]
+    )
+    [
+       shape_pts,
+       triangles
+    ];
\ No newline at end of file