From 3ea790985381aa433627385388537751ea141140 Mon Sep 17 00:00:00 2001
From: Justin Lin <justin.sdk@gmail.com>
Date: Sat, 10 Jul 2021 09:39:28 +0800
Subject: [PATCH] refactor

---
 src/__comm__/_face_normal.scad    | 3 +++
 src/__comm__/_vertex_normals.scad | 6 ++----
 src/surface/sf_thickenT.scad      | 8 +++-----
 3 files changed, 8 insertions(+), 9 deletions(-)
 create mode 100644 src/__comm__/_face_normal.scad

diff --git a/src/__comm__/_face_normal.scad b/src/__comm__/_face_normal.scad
new file mode 100644
index 00000000..a72b482e
--- /dev/null
+++ b/src/__comm__/_face_normal.scad
@@ -0,0 +1,3 @@
+function _face_normal(points) =
+	let(v = cross(points[2] - points[0], points[1] - points[0])) v / norm(v); 
+	
\ No newline at end of file
diff --git a/src/__comm__/_vertex_normals.scad b/src/__comm__/_vertex_normals.scad
index 2d8f0853..c475be86 100644
--- a/src/__comm__/_vertex_normals.scad
+++ b/src/__comm__/_vertex_normals.scad
@@ -1,4 +1,5 @@
 
+use <_face_normal.scad>;
 use <../util/slice.scad>;
 use <../util/sort.scad>;
 use <../util/find_index.scad>;
@@ -23,9 +24,6 @@ function _connected_faces(faces, leng, leng_pts, cnt_faces, i = 0) =
 		]
 	)
 	_connected_faces(faces, leng, leng_pts, n_cnt_faces, i + 1);
-
-function face_normal(points) =
-	let(v = cross(points[2] - points[0], points[1] - points[0])) v / norm(v); 
 	
 function _vertex_normals(points, faces) = 
     let(
@@ -37,7 +35,7 @@ function _vertex_normals(points, faces) =
 		let(
 			face_normals = [
 				for(face = cnn_faces[i])
-					face_normal([for(i = face) points[i]])
+					_face_normal([for(i = face) points[i]])
 			]
 		)
 		sum(face_normals) / len(face_normals)
diff --git a/src/surface/sf_thickenT.scad b/src/surface/sf_thickenT.scad
index 35dfceb6..fa207f8d 100644
--- a/src/surface/sf_thickenT.scad
+++ b/src/surface/sf_thickenT.scad
@@ -8,6 +8,7 @@
 *
 **/ 
 
+use <../__comm__/_face_normal.scad>;
 use <../util/sort.scad>;
 use <../util/find_index.scad>;
 use <../util/sum.scad>;
@@ -40,9 +41,6 @@ module sf_thickenT(points, thickness, triangles = undef, direction = "BOTH") {
 		)
 		_connected_tris(triangles, leng, leng_pts, n_cnt_tris, i + 1);
 
-	function tri_normal(tri) =
-		let(v = cross(tri[2] - tri[0], tri[1] - tri[0])) v / norm(v); 
-
     leng_pts = len(points);
     cnn_tris = connected_tris(leng_pts, tris);
 
@@ -50,7 +48,7 @@ module sf_thickenT(points, thickness, triangles = undef, direction = "BOTH") {
         dir_v = direction / norm(direction);
         mid = sort(points)[leng_pts / 2];
         tri = cnn_tris[find_index(points, function(p) p == mid)][0];
-        nv = tri_normal([points[tri[0]], points[tri[1]], points[tri[2]]]);
+        nv = _face_normal([points[tri[0]], points[tri[1]], points[tri[2]]]);
         pts = [for(p = points) p + dir_v * thickness];
 
         if(nv * dir_v > 0) {
@@ -66,7 +64,7 @@ module sf_thickenT(points, thickness, triangles = undef, direction = "BOTH") {
             let(
                 normals = [
                     for(tri = cnn_tris[i])
-                    tri_normal([
+                    _face_normal([
                         points[tri[0]], 
                         points[tri[1]], 
                         points[tri[2]]]