From b4aef1195a0623723bd639ee4f34b5d28276b28f Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Mon, 15 May 2017 08:46:18 +0800
Subject: [PATCH] refactored

---
 src/__private__/__half_trapezium.scad | 46 ++++++++++++++++-----------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/src/__private__/__half_trapezium.scad b/src/__private__/__half_trapezium.scad
index 45d2a0d2..b5911acd 100644
--- a/src/__private__/__half_trapezium.scad
+++ b/src/__private__/__half_trapezium.scad
@@ -1,27 +1,37 @@
+function __tr_corner(frags, l1, l2, h, round_r) = 
+    let(
+        t_sector_angle = atan2(h, l1 - l2),
+        t_leng = l2 - round_r * tan(t_sector_angle / 2),
+        t_round_frags = frags * t_sector_angle / 360,
+        half_h = h / 2
+    )
+    [
+        for(pt = __pie_for_rounding(round_r, 90 - t_sector_angle, 90, t_round_frags))
+            [pt[0] + t_leng, pt[1] + h - round_r - half_h]
+    ];
+
+function __br_corner(frags, l1, l2, h, round_r) = 
+    let(
+        b_ang = atan2(h, l1 - l2),
+        b_sector_angle = 180 - b_ang,
+        b_leng = l1 - round_r / tan(b_ang / 2),
+        b_round_frags = frags * b_sector_angle / 360,
+        b_end_angle = -90 + b_sector_angle,
+        half_h = h / 2
+    ) 
+    [
+        for(pt = __pie_for_rounding(round_r, -90, b_end_angle, b_round_frags))
+            [pt[0] + b_leng, pt[1] + round_r - half_h]
+    ];
+
 function __half_trapezium(length, h, round_r) =
     let(
         is_vt = __is_vector(length),
         l1 = is_vt ? length[0] : length,
         l2 = is_vt ? length[1] : length,
         frags = __frags(round_r),
-        b_ang = atan2(h, l1 - l2),
-        b_sector_angle = 180 - b_ang,
-        b_leng = l1 - round_r / tan(b_ang / 2),
-        b_round_frags = frags * b_sector_angle / 360,
-        b_end_angle = -90 + b_sector_angle,
-        t_sector_angle = b_ang,
-        t_leng = l2 - round_r * tan(t_sector_angle / 2),
-        t_round_frags = frags * t_sector_angle / 360,
-        half_h = h / 2,
-        br_corner = [
-            for(pt = __pie_for_rounding(round_r, -90, b_end_angle, b_round_frags))
-                [pt[0] + b_leng, pt[1] + round_r - half_h]
-        ],
-
-        tr_corner = [
-            for(pt = __pie_for_rounding(round_r, 90 - t_sector_angle, 90, t_round_frags))
-                [pt[0] + t_leng, pt[1] + h - round_r - half_h]
-        ]
+        br_corner = __br_corner(frags, l1, l2, h, round_r),
+        tr_corner = __tr_corner(frags, l1, l2, h, round_r)
     )    
     concat(
         br_corner,