added path_extrude.scad

src/path_extrude.scad

@@ -0,0 +1,46 @@
+module path_extrude(shape_pts, points, triangles = "RADIAL") {
+    function first_section() = 
+        let(
+            p1 = points[0],
+            p2 = points[1],
+            dx = p2[0] - p1[0],
+            dy = p2[1] - p1[1],
+            dz = p2[2] - p1[2],
+            ay = 90 - atan2(dz, sqrt(pow(dx, 2) + pow(dy, 2))),
+            az = atan2(dy, dx)
+        )
+        [
+            for(p = shape_pts) 
+                rotate_p(p, [0, ay, az]) + p1
+        ];
+    
+
+    function section(p1, p2) = 
+        let(
+            dx = p2[0] - p1[0],
+            dy = p2[1] - p1[1],
+            dz = p2[2] - p1[2],
+            length = sqrt(pow(dx, 2) + pow(dy, 2) + pow(dz, 2)),
+            ay = 90 - atan2(dz, sqrt(pow(dx, 2) + pow(dy, 2))),
+            az = atan2(dy, dx)
+        )
+        [
+            for(p = shape_pts) 
+                rotate_p(p + [0, 0, length], [0, ay, az]) + p1
+        ];
+    
+
+    len_pts = len(points);
+    
+    function path_extrude_inner(index) =
+       index == len_pts ? [] :
+           concat(
+               [section(points[index - 1], points[index])],
+               path_extrude_inner(index + 1)
+           );
+
+    polysections(
+        concat([first_section()], path_extrude_inner(1)),
+        triangles = triangles
+    );    
+}