From 58c0bcca59a6a267436ecd0c7da6dcf85ab006e8 Mon Sep 17 00:00:00 2001
From: Renato Cordeiro Ferreira <renato.cferreira@hotmail.com>
Date: Mon, 11 May 2015 21:18:38 -0300
Subject: [PATCH] Normalize trackball quartenion

---
 App/quaternion.js | 10 ++++++++++
 App/trackball.js  |  2 +-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/App/quaternion.js b/App/quaternion.js
index 23d9b10..e068a67 100644
--- a/App/quaternion.js
+++ b/App/quaternion.js
@@ -62,6 +62,16 @@ Quaternion.prototype.norm = function() {
     return dot(this.toVec4(), this.toVec4());
 }
 
+/**
+ * @return Normalized version of this quartenion
+ */
+Quaternion.prototype.normalize = function() {
+    return new this.constructor(
+        this.s/this.norm(),
+        scalar(1/this.norm(), this.v)
+    );
+}
+
 /**
  * Operator q()q^-1
  * Use quartenion properties to represent a rotation in IR³
diff --git a/App/trackball.js b/App/trackball.js
index 4632c29..6fb34a1 100644
--- a/App/trackball.js
+++ b/App/trackball.js
@@ -38,7 +38,7 @@ Trackball.prototype.rotation = function(x1, y1, x2, y2, mORq) {
     if (N[0] == 0 && N[1] == 0 && N[2] == 0) theta = 0;
 
     if (mORq == 'q') // return a quaternion
-        return createRotationQuaternionFromAngleAndAxis(theta, N);
+        return createRotationQuaternionFromAngleAndAxis(theta, N).normalize();
     else // return a matrix
         return rotate(theta, N);
 }