From 39d90f8d8bf33e40150fe4fb603c02d6e6830ea0 Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Wed, 17 May 2017 10:13:56 +0800
Subject: [PATCH] supported closed sections

---
 src/polysections.scad | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/src/polysections.scad b/src/polysections.scad
index 3b142126..5c28d1b0 100644
--- a/src/polysections.scad
+++ b/src/polysections.scad
@@ -49,23 +49,30 @@ module polysections(sections, triangles = "SOLID") {
         leng_sects = len(sects);
         leng_pts_sect = len(sects[0]);
   
-        first_idxes = [for(i = [0:leng_pts_sect - 1]) leng_pts_sect - 1 - i];  
-
-        last_idxes = [
-            for(i = [0:leng_pts_sect - 1]) 
-                i + leng_pts_sect * (leng_sects - 1)
-        ];    
-
         v_pts = [
             for(sect = sects) 
                 for(pt = sect) 
                     pt
-        ];
+        ];      
 
-        polyhedron(
-            v_pts, 
-            concat([first_idxes], side_indexes(sects), [last_idxes])
-        );    
+        if(sects[0] == sects[leng_sects - 1]) {
+            polyhedron(
+                v_pts, 
+                side_indexes(sects)
+            ); 
+        } else {
+            first_idxes = [for(i = [0:leng_pts_sect - 1]) leng_pts_sect - 1 - i];  
+
+            last_idxes = [
+                for(i = [0:leng_pts_sect - 1]) 
+                    i + leng_pts_sect * (leng_sects - 1)
+            ];       
+
+            polyhedron(
+                v_pts, 
+                concat([first_idxes], side_indexes(sects), [last_idxes])
+            );    
+        }
     }
 
     module hollow_sections(sects) {