From d4bec583753d65ad09eb402f3f434a547801e2fc Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Thu, 19 Sep 2019 17:41:24 +0800
Subject: [PATCH] refactor

---
 src/helix.scad | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/helix.scad b/src/helix.scad
index b54650e7..40771806 100644
--- a/src/helix.scad
+++ b/src/helix.scad
@@ -12,20 +12,20 @@ include <__comm__/__frags.scad>;
 
 function helix(radius, levels, level_dist, vt_dir = "SPI_DOWN", rt_dir = "CT_CLK") = 
     let(
+        is_SPI_DOWN = vt_dir == "SPI_DOWN",
         is_flt = is_num(radius),
         r1 = is_flt ? radius : radius[0],
         r2 = is_flt ? radius : radius[1],
-        init_r = vt_dir == "SPI_DOWN" ? r2 : r1,
-        _frags = __frags(init_r),
         h = level_dist * levels,
-        vt_d = vt_dir == "SPI_DOWN" ? 1 : -1,
+        begin_r = is_SPI_DOWN ? r2 : r1,
+        begin_h = is_SPI_DOWN ? h : 0,
+        _frags = __frags(begin_r),        
+        vt_d = is_SPI_DOWN ? 1 : -1,
         rt_d = rt_dir == "CT_CLK" ? 1 : -1,
         r_diff = (r1 - r2) * vt_d,
         h_step = level_dist / _frags * vt_d,
         r_step = r_diff / (levels * _frags),
         a_step = 360 / _frags * rt_d,
-        begin_r = vt_dir == "SPI_DOWN" ? r2 : r1,
-        begin_h = vt_dir == "SPI_DOWN" ? h : 0,
         end_i = _frags * levels
     )
     [