Added toBitmapData.

git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@720 ed5b42cb-e716-0410-a449-f6a68f950b19

src/as/com/threerings/flash/ImageUtil.as

@@ -67,6 +67,24 @@ public class ImageUtil
         */
     }
 
+    /**
+     * Takes a BitmapData, Bitmap, or Class that will turn into either, and returns
+     * a reference to the BitmapData, or returns null.
+     */
+    public static function toBitmapData (spec :*) :BitmapData
+    {
+        if (spec is Class) {
+            spec = new (Class(spec))();
+        }
+        if (spec is BitmapData) {
+            return BitmapData(spec);
+        } else if (spec is Bitmap) {
+            return Bitmap(spec).bitmapData;
+        } else {
+            return null;
+        }
+    }
+
     /**
      * Create a minimally-sized "error" BitmapData.
      */