Tidy up - remove old skipIndexZero property on layers

Author: mikewesthad

v3/src/gameobjects/tilemap/components/CullTiles.js

@@ -30,7 +30,7 @@ var CullTiles = function (layer, camera, outputArray)
         {
             var tile = mapData[row][col];
 
-            if (tile === null || (tile.index <= 0 && tilemapLayer.skipIndexZero)) { continue; }
+            if (tile === null || tile.index === -1) { continue; }
 
             var tileX = tile.pixelX * sx - left;
             var tileY = tile.pixelY * sy - top;

v3/src/gameobjects/tilemap/dynamiclayer/DynamicTilemapLayer.js

@@ -87,8 +87,6 @@ var DynamicTilemapLayer = new Class({
         this.setSizeToFrame();
         this.setOrigin();
         this.setSize(this.layer.tileWidth * this.layer.width, this.layer.tileHeight * this.layer.height);
-
-        this.skipIndexZero = false;
     },
 
     /**

v3/src/gameobjects/tilemap/staticlayer/StaticTilemapLayer.js

@@ -97,8 +97,6 @@ var StaticTilemapLayer = new Class({
         this.setOrigin();
         this.setSize(this.layer.tileWidth * this.layer.width, this.layer.tileHeight * this.layer.height);
 
-        this.skipIndexZero = false;
-
         scene.sys.game.renderer.addContextRestoredCallback(this.contextRestore.bind(this));
     },
 
@@ -166,7 +164,7 @@ var StaticTilemapLayer = new Class({
                     for (col = 0; col < mapWidth; ++col)
                     {
                         tile = mapData[row][col];
-                        if (tile === null || (tile.index <= 0 && this.skipIndexZero)) { continue; }
+                        if (tile === null || tile.index === -1) { continue; }
 
                         var tx = tile.pixelX;
                         var ty = tile.pixelY;