fixed p2 physics loading format and added the ability to extract a single fixture

Author: georgiee

src/loader/Cache.js

@@ -569,14 +569,15 @@ Phaser.Cache.prototype = {
     },
 
     /**
-    * Get a physics data object from the cache by its key. You can get either the entire data set or just a single object from it.
+    * Get a physics data object from the cache by its key. You can get either the entire data set, a single object or a single fixture of an object from it.
     *
     * @method Phaser.Cache#getPhysicsData
     * @param {string} key - Asset key of the physics data object to retrieve from the Cache.
     * @param {string} [object=null] - If specified it will return just the physics object that is part of the given key, if null it will return them all.
+    * @param {string} fixtureKey - Fixture key of fixture inside an object. This key can be set per fixture with the Phaser Exporter.
     * @return {object} The requested physics object data if found.
     */
-    getPhysicsData: function (key, object) {
+    getPhysicsData: function (key, object, fixtureKey) {
 
         if (typeof object === 'undefined' || object === null)
         {
@@ -594,7 +595,28 @@ Phaser.Cache.prototype = {
         {
             if (this._physics[key] && this._physics[key].data[object])
             {
-                return this._physics[key].data[object];
+                fixtures = this._physics[key].data[object];
+
+                //try to find a fixture by it's fixture key if given
+                if (fixtures && fixtureKey)
+                {
+                    for(var fixture in fixtures)
+                    {
+                        //this contains the fixture data of a polygon or a circle
+                        fixture = fixtures[fixture]
+                        //test the key
+                        if(fixture.fixtureKey === fixtureKey)
+                        {
+                            return fixture;
+                        }
+                    }
+                    
+                    //we did not find the requested fixture
+                    console.warn('Phaser.Cache.getPhysicsData: Could not find given fixtureKey: "' + fixtureKey + ' in ' + key + '"');
+                }else{
+                    return fixtures;
+                }
+                
             }
             else
             {

src/loader/Loader.js

@@ -582,7 +582,7 @@ Phaser.Loader.prototype = {
 
         if (typeof dataURL === "undefined") { dataURL = null; }
         if (typeof jsonData === "undefined") { jsonData = null; }
-        if (typeof format === "undefined") { format = Phaser.Loader.PHYSICS_LIME_CORONA_JSON; }
+        if (typeof format === "undefined") { format = Phaser.Physics.LIME_CORONA_JSON; }
 
         if (dataURL == null && jsonData == null)
         {