Merge pull request phaserjs#3153 from halgorithm/weighted-randomize-index-arrays

Weighted randomize index arrays

Author: photonstorm

src/gameobjects/tilemap/components/WeightedRandomize.js

@@ -20,7 +20,8 @@ var GetTilesWithin = require('./GetTilesWithin');
  * @param {integer} [width=max width based on tileX] - [description]
  * @param {integer} [height=max height based on tileY] - [description]
  * @param {object[]} [weightedIndexes] - An array of objects to randomly draw from during
- * randomization. They should be in the form: { index: 0, weight: 4 }.
+ * randomization. They should be in the form: { index: 0, weight: 4 } or
+ * { index: [0, 1], weight: 4 } if you wish to draw from multiple tile indexes.
  * @param {LayerData} layer - [description]
  */
 var WeightedRandomize = function (tileX, tileY, width, height, weightedIndexes, layer)
@@ -48,7 +49,10 @@ var WeightedRandomize = function (tileX, tileY, width, height, weightedIndexes,
             sum += weightedIndexes[j].weight;
             if (rand <= sum)
             {
-                randomIndex = weightedIndexes[j].index;
+                var chosen = weightedIndexes[j].index;
+                randomIndex = Array.isArray(chosen)
+                    ? chosen[Math.floor(Math.random() * chosen.length)]
+                    : chosen;
                 break;
             }
         }