BitmapUtil added cache

haxework/gui/utils/BitmapUtil.hx

@@ -7,14 +7,31 @@ import flash.display.BitmapData;
 
 class BitmapUtil {
 
+  private static var cache:Map<BitmapData, Map<String, BitmapData>> = new Map<BitmapData, Map<String, BitmapData>>();
+
+  private static function fromCache(image:BitmapData, key:String):Null<BitmapData> {
+    return cache.exists(image) && cache.get(image).exists(key) ? cache.get(image).get(key) : null;
+  }
+
+  private static function toCache(image:BitmapData, key:String, value:BitmapData):Void {
+    if (!cache.exists(image)) cache.set(image, new Map<String, BitmapData>());
+    cache.get(image).set(key, value);
+  }
+
+
   public static function multiply(image:BitmapData, m:Float):BitmapData {
+    var result = fromCache(image, "multiply:" + m);
+    if (result != null) return result;
     var ct:ColorTransform = new ColorTransform(m, m, m, 1.0, 0, 0, 0);
     var out:BitmapData = image.clone();
     out.colorTransform(out.rect, ct);
+    toCache(image, "multiply:" + m, out);
     return out;
   }
 
   public static function grayscale(image:BitmapData, m:Float):BitmapData {
+    var result = fromCache(image, "grayscale:" + m);
+    if (result != null) return result;
     var matrix:Array<Float> = [];
     matrix = matrix.concat([m, m, m, 0, 0]);
     matrix = matrix.concat([m, m, m, 0, 0]);
@@ -23,6 +40,7 @@ class BitmapUtil {
     var cmf:ColorMatrixFilter = new ColorMatrixFilter(matrix);
     var out:BitmapData = image.clone();
     out.applyFilter(out, out.rect, new Point(0,0), cmf);
+    toCache(image, "grayscale:" + m, out);
     return out;
   }
 }