fixed variable problem and refactored

docs/lib-along_with.md

@@ -5,7 +5,7 @@ Puts children along the given path. If there's only one child, it will put the c
 ## Parameters
 
 - `points` : The points along the path. 
-- `angles` : If it's given, rotate before translate each child.
+- `angles` : Rotate before translate each child. If not given, `angles` will be calculated automatically according to `points`.
 
 ## Examples
 
@@ -60,4 +60,44 @@ Puts children along the given path. If there's only one child, it will put the c
 			linear_extrude(1, center = true) 
 				text("A", valign = "center", halign = "center");
 
-![along_with](images/lib-along_with-3.JPG)
+![along_with](images/lib-along_with-3.JPG)
+
+	include <bezier_curve.scad>;
+	include <along_with.scad>;
+
+	module scales() {
+		module one_scale() {
+			rotate([0, 60, 0]) 
+				linear_extrude(1, center = true) 
+					scale([2, 1]) 
+						circle(1.25, $fn = 24);    
+		}
+		
+		for(a = [0:30:360 - 15]) {
+		rotate(a) 
+			translate([5, 0, 0]) 
+				one_scale();
+		rotate(a + 15) 
+			translate([5, 0, 1.75]) 
+				one_scale();
+		}
+
+	}
+
+	t_step = 0.01;
+
+	p0 = [0, 0, 0];
+	p1 = [0, 50, 35];
+	p2 = [-100, 70, 0];
+	p3 = [30, 120, -35];
+	p4 = [30, 150, -40];
+	p5 = [0, 200, -3];
+
+	path_pts = bezier_curve(t_step, 
+		[p0, p1, p2, p3, p4, p5]
+	);
+
+	along_with(path_pts)  
+		scales();
+
+![along_with](images/lib-along_with-4.JPG)

src/along_with.scad

@@ -14,26 +14,25 @@
 include <__private__/__angy_angz.scad>;
 
 module along_with(points, angles) {
-    function _path_angles(path_pts, leng_path_pts, i = 0) = 
+    leng_points = len(points);
-        i == leng_path_pts - 1 ?
+
+    function _path_angles(i = 0) = 
+        i == leng_points - 1 ?
                 [] : 
                 concat(
-                    [__angy_angz(path_pts[i], path_pts[i + 1])], 
+                    [__angy_angz(points[i], points[i + 1])], 
-                    _path_angles(path_pts, leng_path_pts, i + 1)
+                    _path_angles(i + 1)
                 );
             
-    function path_angles(path_pts) = 
+    function path_angles(points) = 
-       let(
+       let(angs = _path_angles())
-           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);
+    angs = angles_defined ? angles : path_angles(points);
 
     module align(i) {
         translate(points[i])