From aedca84aa2f7bee7e6d2838c7137411facbbdce6 Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Fri, 19 May 2017 11:14:09 +0800
Subject: [PATCH] auto-calculating angles when angles is undef

---
 src/along_with.scad | 47 +++++++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 12 deletions(-)

diff --git a/src/along_with.scad b/src/along_with.scad
index 3e3e3e89..d685e810 100644
--- a/src/along_with.scad
+++ b/src/along_with.scad
@@ -11,25 +11,48 @@
 *
 **/ 
 
+include <__private__/__angy_angz.scad>;
+
 module along_with(points, angles) {
-    module rotOrNot(i) {
-        if(angles == undef) {
-            children(0);
-        } else {
-            rotate(angles[i]) 
-                children(0);
-        }        
-    }
+    function _path_angles(path_pts, leng_path_pts, i = 0) = 
+        i == leng_path_pts - 1 ?
+                [] : 
+                concat(
+                    [__angy_angz(path_pts[i], path_pts[i + 1])], 
+                    _path_angles(path_pts, leng_path_pts, i + 1)
+                );
+            
+    function path_angles(path_pts) = 
+       let(
+           leng_path_pts = len(path_pts),
+           angs = _path_angles(path_pts, leng_path_pts)
+       )
+       concat(
+           [[0, -angs[0][0], angs[0][1]]], 
+           [for(a = angs) [0, -a[0], a[1]]]
+       );
+       
+    angles_defined = angles != undef;
+    angs = angles_defined ? angles : path_angles(path_pts);
+
+    module align(i) {
+        translate(points[i]) 
+            rotate(angs[i])
+                if(angles_defined) {
+                    children(0);
+                } else {
+                    rotate([90, 0, -90])  
+                        children(0);                    
+                }
+        }
 
     if($children == 1) { 
         for(i = [0:len(points) - 1]) {
-            translate(points[i])  
-                rotOrNot(i) children(0);
+            align(i) children(0);
         }
     } else {
         for(i = [0:min(len(points), $children) - 1]) {
-            translate(points[i]) 
-                rotOrNot(i) children(i);
+            align(i) children(i);
         }
     }
 }
\ No newline at end of file