From 80e5401c94022f1b537fb5fa715403f06be3c924 Mon Sep 17 00:00:00 2001
From: Kevin Ngo <me@ngokevin.com>
Date: Tue, 3 Oct 2017 16:47:16 +0200
Subject: [PATCH] throttle updateControllerList while keeping getGamepads call

---
 src/systems/tracked-controls.js | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/systems/tracked-controls.js b/src/systems/tracked-controls.js
index 983a7756b06..6dae79764fc 100644
--- a/src/systems/tracked-controls.js
+++ b/src/systems/tracked-controls.js
@@ -1,4 +1,5 @@
 var registerSystem = require('../core/system').registerSystem;
+var utils = require('../utils');
 
 /**
  * Tracked controls system.
@@ -10,7 +11,8 @@ module.exports.System = registerSystem('tracked-controls', {
 
     this.controllers = [];
 
-    this.updateControllerList();
+    this.updateControllerList(navigator.getGamepads && navigator.getGamepads());
+    this.throttledUpdateControllerList = utils.throttle(this.updateControllerList, 500, this);
 
     if (!navigator.getVRDisplays) { return; }
 
@@ -22,20 +24,21 @@ module.exports.System = registerSystem('tracked-controls', {
   },
 
   tick: function () {
-    this.updateControllerList();
+    var gamepads;
+    // Call getGamepads for Chrome.
+    gamepads = navigator.getGamepads && navigator.getGamepads();
+    this.throttledUpdateControllerList(gamepads);
   },
 
   /**
    * Update controller list.
    */
-  updateControllerList: function () {
+  updateControllerList: function (gamepads) {
     var controllers = this.controllers;
     var gamepad;
-    var gamepads;
     var i;
     var prevCount;
 
-    gamepads = navigator.getGamepads && navigator.getGamepads();
     if (!gamepads) { return; }
 
     prevCount = controllers.length;