From b62906a2c93cdea4456bc8f13d53dc13d37278e6 Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Sun, 25 May 2014 01:27:40 -0700
Subject: [PATCH] Rings alternate twirl directions

---
 medusa.html | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/medusa.html b/medusa.html
index 87e9301..7a4babd 100644
--- a/medusa.html
+++ b/medusa.html
@@ -3,10 +3,10 @@
     <title>Medusa</title>
     <script type="text/javascript" src="nt3d.js"></script>
     <script type="text/javascript">
-      function finger(params, finger_crosssection, ring_radius, finger_angle) {
+      function finger(params, finger_crosssection, ring_num, ring_radius, finger_angle) {
         var path = [];
-        var twirl_angle = params.finger_twirl_distance / (ring_radius * 2 * Math.PI);
-        console.log(twirl_angle);
+        var twirl_amplitute = Math.cos((ring_num * 2 * Math.PI) / params.finger_twirl_period);
+        var twirl_angle = twirl_amplitute * params.finger_twirl_distance / (ring_radius * 2 * Math.PI);
         for (var finger_point = 0; finger_point <= params.finger_points; finger_point++) {
           var angle = (finger_angle + twirl_angle * finger_point / params.finger_points) * 2 * Math.PI;
           var x = ring_radius * Math.cos(angle);
@@ -23,7 +23,7 @@
           var num_fingers = Math.round((ring_radius * 2 * Math.PI) / params.finger_spacing);
           for (var finger_num = 0; finger_num < num_fingers; finger_num++) {
             var finger_angle = finger_num / num_fingers;
-            fingers = fingers.concat(finger(params, finger_crosssection, ring_radius, finger_angle));
+            fingers = fingers.concat(finger(params, finger_crosssection, ring_num, ring_radius, finger_angle));
           }
         }
 
@@ -37,6 +37,7 @@
                     ["finger_faces", 3],
                     ["finger_points", 20],
                     ["finger_twirl_distance", 50],
+                    ["finger_twirl_period", 2, "Finger Twirl Period (1=same, 2=alternating)"],
                     ["finger_height", 100]];
     </script>
   </head>
-- 
2.44.1