From 6297bd86f77c699e8e0d1b4a2cf495e9c9ba8bb2 Mon Sep 17 00:00:00 2001
From: Mark Finkle <mfinkle@mozilla.com>
Date: Wed, 15 Apr 2009 01:51:10 -0400
Subject: [PATCH] Bug 488418: Simplify kinetic averaging code, r=stuart

---
 mobile/chrome/content/InputHandler.js | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/mobile/chrome/content/InputHandler.js b/mobile/chrome/content/InputHandler.js
index 1509d14fd71b..cee7cd7668c3 100644
--- a/mobile/chrome/content/InputHandler.js
+++ b/mobile/chrome/content/InputHandler.js
@@ -524,30 +524,23 @@ KineticData.prototype = {
     if (mblen < 2)
       return false;
 
-    let speedBufX = [];
-    let speedBufY = [];
+    let tempX = 0;
+    let tempY = 0;
 
     // build arrays of each movement's speed in pixels/ms
     let prev = mb[0];
     for (let i = 1; i < mblen; i++) {
       let me = mb[i];
 
-      let speedX = (me.sx - prev.sx) / (me.t - prev.t);
-      speedBufX.push(speedX);
-
-      let speedY = (me.sy - prev.sy) / (me.t - prev.t);
-      speedBufY.push(speedY);
+      tempX += (me.sx - prev.sx) / (me.t - prev.t);
+      tempY += (me.sy - prev.sy) / (me.t - prev.t);
 
       prev = me;
     }
 
-    function average(buf) {
-      return buf.reduce(function(a,b) a+b) / buf.length;
-    }
-
-    // average the speeds out (This could probably be a bit smarter)
-    this._speedX = average(speedBufX);
-    this._speedY = average(speedBufY);
+    // average the speeds out (this could probably be a bit smarter)
+    this.speedX = tempX / mblen;
+    this.speedY = tempY / mblen;
 
     // fire off our kinetic timer which will do all the work
     this._startKineticTimer();