From 0d4a6f400086ee535fabcf1c73e10d634931ccee Mon Sep 17 00:00:00 2001
From: liabru <liambrum@gmail.com>
Date: Fri, 28 Mar 2014 18:36:14 +0000
Subject: [PATCH] replaced "in" operator usage with access checks, it's a
 little faster

---
 src/collision/Detector.js | 4 ++--
 src/collision/Pair.js     | 7 ++++---
 src/collision/Pairs.js    | 8 ++++----
 src/core/Events.js        | 4 ++--
 4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/src/collision/Detector.js b/src/collision/Detector.js
index b737992..e50a8eb 100644
--- a/src/collision/Detector.js
+++ b/src/collision/Detector.js
@@ -41,7 +41,7 @@ var Detector = {};
 
                 // find a previous collision we could reuse
                 var pairId = Pair.id(bodyA, bodyB),
-                    pair = pairId in pairsTable ? pairsTable[pairId] : null,
+                    pair = pairsTable[pairId],
                     previousCollision;
 
                 if (pair && pair.isActive) {
@@ -100,7 +100,7 @@ var Detector = {};
 
                     // find a previous collision we could reuse
                     var pairId = Pair.id(bodyA, bodyB),
-                        pair = pairId in pairsTable ? pairsTable[pairId] : null,
+                        pair = pairsTable[pairId],
                         previousCollision;
 
                     if (pair && pair.isActive) {
diff --git a/src/collision/Pair.js b/src/collision/Pair.js
index 0e089be..12de206 100644
--- a/src/collision/Pair.js
+++ b/src/collision/Pair.js
@@ -56,10 +56,11 @@ var Pair = {};
         if (collision.collided) {
             for (var i = 0; i < supports.length; i++) {
                 var support = supports[i],
-                    contactId = Contact.id(support);
+                    contactId = Contact.id(support),
+                    contact = contacts[contactId];
 
-                if (contactId in contacts) {
-                    activeContacts.push(contacts[contactId]);
+                if (contact) {
+                    activeContacts.push(contact);
                 } else {
                     activeContacts.push(contacts[contactId] = Contact.create(support));
                 }
diff --git a/src/collision/Pairs.js b/src/collision/Pairs.js
index 65b818e..61999d6 100644
--- a/src/collision/Pairs.js
+++ b/src/collision/Pairs.js
@@ -55,11 +55,11 @@ var Pairs = {};
             if (collision.collided) {
                 pairId = Pair.id(collision.bodyA, collision.bodyB);
                 activePairIds.push(pairId);
-                
-                if (pairId in pairsTable) {
-                    // pair already exists (but may or may not be active)
-                    pair = pairsTable[pairId];
 
+                pair = pairsTable[pairId];
+                
+                if (pair) {
+                    // pair already exists (but may or may not be active)
                     if (pair.isActive) {
                         // pair exists and is active
                         collisionActive.push(pair);
diff --git a/src/core/Events.js b/src/core/Events.js
index f7a4469..266ce2c 100644
--- a/src/core/Events.js
+++ b/src/core/Events.js
@@ -67,9 +67,9 @@ var Events = {};
 
             for (var i = 0; i < names.length; i++) {
                 name = names[i];
+                callbacks = object.events[name];
 
-                if (name in object.events) {
-                    callbacks = object.events[name];
+                if (callbacks) {
                     eventClone = Common.clone(event, false);
                     eventClone.name = name;
                     eventClone.source = object;