Minor optimisation and clean up.

Author: pjbaron

src/tilemap/TilemapLayerGL.js

@@ -464,12 +464,14 @@ Phaser.TilemapLayerGL.prototype.renderRegion = function (scrollX, scrollY, left,
     // x/y - is cell location, normalized [0..width/height) in loop
     // xmax/ymax - remaining cells to render on column/row
     var tx, ty, x, y, xmax, ymax;
+    var tileset = this._mc.tileset;
 
     for (y = normStartY, ymax = bottom - top, ty = baseY; ymax >= 0; y++, ymax--, ty += th)
     {
         if (y >= height)
         {
-            y -= height;
+            // wrap around if coordinates go out of range 0..height
+            y %= height;
         }
 
         var row = this.layer.data[y];
@@ -478,7 +480,8 @@ Phaser.TilemapLayerGL.prototype.renderRegion = function (scrollX, scrollY, left,
         {
             if (x >= width)
             {
-                x -= width;
+                // wrap around if coordinates go out of range 0..width
+                x %= width;
             }
 
             var tile = row[x];
@@ -487,23 +490,23 @@ Phaser.TilemapLayerGL.prototype.renderRegion = function (scrollX, scrollY, left,
             if (!tile || tile.index < this._mc.tileset.firstgid || tile.index > this._mc.lastgid)
             {
                 // skipping some tiles, add a degenerate marker into the batch list
-                this._mc.tileset.addDegenerate(this.glBatch);
+                tileset.addDegenerate(this.glBatch);
                 continue;
             }
 
             var index = tile.index;
 
-            this._mc.tileset.drawGl(this.glBatch, tx + offx, ty + offy, index, tile.alpha, tile.flippedVal);
+            tileset.drawGl(this.glBatch, tx + offx, ty + offy, index, tile.alpha, tile.flippedVal);
         }
 
         // at end of each row, add a degenerate marker into the batch drawing list
-        this._mc.tileset.addDegenerate(this.glBatch);
+        tileset.addDegenerate(this.glBatch);
     }
 
 };
 
 /**
-* Clear and render the entire canvas.
+* Render the entire visible region of the map.
 *
 * @method Phaser.TilemapLayerGL#renderFull
 * @private

src/tilemap/Tileset.js

@@ -39,14 +39,6 @@ Phaser.Tileset = function (name, firstgid, width, height, margin, spacing, prope
     */
     this.firstgid = firstgid | 0;
 
-    /**
-    * This is the ending index of the last tile index this Tileset can contain.
-    * This is populated automatically by Phaser.TilemapParser.parseTiledJSON.
-    * For a single tileset map it should be left as the default value.
-    * @property {integer} lastgid
-    */
-    this.lastgid = Infinity;
-
     /**
     * The width of each tile (in pixels).
     * @property {integer} tileWidth
@@ -162,10 +154,10 @@ Phaser.Tileset.prototype = {
     },
 
     /**
-    * Sets the GL Batch data to draw a tile from this Tileset at the given coordinates 
-    * using a WebGL renderer.
+    * Draws a tile from this Tileset at the given coordinates using a WebGL renderer.
     *
     * @method Phaser.Tileset#drawGl
+    * @public
     * @param {Array} glBatch - A list of WebGL batch objects to draw later.
     * @param {number} x - The x coordinate to draw to.
     * @param {number} y - The y coordinate to draw to.
@@ -230,16 +222,16 @@ Phaser.Tileset.prototype = {
     },
 
     /**
-    * Adds a marker for the WebGL batch display to insert a degenerate 
-    * triangle (eg. at the end of each row of tiles)
+    * Adds a marker for the WebGl batch display to insert a degenerate triangle (eg. at the end of each row of tiles)
     *
     * @method Phaser.Tileset#addDegenerate
-    * @param {array} glBatch - The GL Batch data array.
+    * @public
+    * @param {[type]} glBatch [description]
     */
     addDegenerate: function (glBatch) {
 
-        //  Don't insert multiple degenerate markers in a row
-        if (glBatch[glBatch.length - 1])
+        // don't insert multiple degenerate markers in a row
+        if (glBatch.length > 0 && glBatch[glBatch.length - 1])
         {
             glBatch.push(null);
         }