From dbf6df4dff1a5ea2bcfa34291bb86f9616e9975a Mon Sep 17 00:00:00 2001
From: Justin Lin <justin.sdk@gmail.com>
Date: Thu, 11 Feb 2021 14:31:28 +0800
Subject: [PATCH] add angle_threshold param

---
 src/_impl/_bezier_smooth_impl.scad | 17 ++++++++++-------
 src/bezier_smooth.scad             |  4 ++--
 test/test_bezier_smooth.scad       | 18 +++++++++++++++++-
 3 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/src/_impl/_bezier_smooth_impl.scad b/src/_impl/_bezier_smooth_impl.scad
index 834477e3..b56572d2 100644
--- a/src/_impl/_bezier_smooth_impl.scad
+++ b/src/_impl/_bezier_smooth_impl.scad
@@ -2,6 +2,7 @@ use <../__comm__/__to3d.scad>;
 use <../__comm__/__to2d.scad>;
 use <../__comm__/__angy_angz.scad>;
 use <../bezier_curve.scad>;
+use <../angle_between.scad>;
 
 function _corner_ctrl_pts(round_d, p1, p2, p3) =
     let(
@@ -24,32 +25,34 @@ function _corner_ctrl_pts(round_d, p1, p2, p3) =
         p2 - [dx2, dy2, dz2]
     ];
     
-    
 function _bezier_corner(round_d, t_step, p1, p2, p3) =
     bezier_curve(t_step, _corner_ctrl_pts(round_d, p1, p2, p3));
 
-function _recursive_bezier_smooth(pts, round_d, t_step, leng) =
+function _recursive_bezier_smooth(pts, round_d, t_step, leng, angle_threshold) =
     let(end_i = leng - 2)
     [
         for(i = 0; i < end_i; i = i + 1) 
-            each _bezier_corner(round_d, t_step, pts[i], pts[i + 1], pts[i + 2])
+            each 
+                angle_between(pts[i] - pts[i + 1], pts[i + 1] - pts[i + 2]) > angle_threshold  ? 
+                    _bezier_corner(round_d, t_step, pts[i], pts[i + 1], pts[i + 2]) :
+                    [pts[i + 1]]
     ];
 
-function _bezier_smooth_impl(path_pts, round_d, t_step, closed) =
+function _bezier_smooth_impl(path_pts, round_d, t_step, closed, angle_threshold) =
     let(
         pts = len(path_pts[0]) == 3 ? path_pts : [for(p = path_pts) __to3d(p)],
         leng = len(pts),
-        middle_pts = _recursive_bezier_smooth(pts, round_d, t_step, leng),
+        middle_pts = _recursive_bezier_smooth(pts, round_d, t_step, leng, angle_threshold),
         pth_pts = closed ?
             concat(
                 _recursive_bezier_smooth(
                     [pts[leng - 1], pts[0], pts[1]],
-                    round_d, t_step, 3
+                    round_d, t_step, 3, angle_threshold
                 ),
                 middle_pts,
                 _recursive_bezier_smooth(
                     [pts[leng - 2], pts[leng - 1], pts[0]],
-                    round_d, t_step, 3
+                    round_d, t_step, 3, angle_threshold
                 )  
             ) :
             concat(
diff --git a/src/bezier_smooth.scad b/src/bezier_smooth.scad
index 9ea01a34..baba9243 100644
--- a/src/bezier_smooth.scad
+++ b/src/bezier_smooth.scad
@@ -10,5 +10,5 @@
 
 use <_impl/_bezier_smooth_impl.scad>;
     
-function bezier_smooth(path_pts, round_d, t_step = 0.1, closed = false) =
-    _bezier_smooth_impl(path_pts, round_d, t_step, closed);
\ No newline at end of file
+function bezier_smooth(path_pts, round_d, t_step = 0.1, closed = false, angle_threshold = 0) =
+    _bezier_smooth_impl(path_pts, round_d, t_step, closed, angle_threshold);
\ No newline at end of file
diff --git a/test/test_bezier_smooth.scad b/test/test_bezier_smooth.scad
index f30cac66..83c2ad0c 100644
--- a/test/test_bezier_smooth.scad
+++ b/test/test_bezier_smooth.scad
@@ -39,5 +39,21 @@ module test_bezier_smooth_closed() {
     assertEqualPoints(expected, actual);
 }
 
+module test_bezier_smooth_angle_threshold() {
+    echo("==== test_bezier_smooth_angle_threshold ====");
+
+    round_d = 15;
+
+    path_pts = [
+        [0, 0, 0],
+        [0, 40, 0],
+        [0, 60, 0],
+        [0, 70, 1]
+    ];
+
+    assert(path_pts == bezier_smooth(path_pts, round_d, angle_threshold = 15));
+}
+
 test_bezier_smooth_no_closed();
-test_bezier_smooth_closed();
\ No newline at end of file
+test_bezier_smooth_closed();
+test_bezier_smooth_angle_threshold();
\ No newline at end of file