updated Levels filter and test

src/filters/Levels.js

@@ -4,54 +4,35 @@
    * Levels Filter. Adjusts the channels so that there are no more
    *  than n different values for that channel. This is also applied
    *  to the alpha channel.
-   *  Performs w*h pixel reads and w*h pixel writes.
    * @function
    * @author ippo615
    * @memberof Kinetic.Filters
-   * @param {ImageData} src, the source image data (what will be transformed)
-   * @param {ImageData} dst, the destination image data (where it will be saved)
-   * @param {Object} opt
-   * @param {Number} [opt.quantizationLevels], the number of values allowed for each
-   *  channel. Between 2 and 255. Default is 2. 
+   * @param {Object} imageData
    */
 
-  var Levels = function (src, dst, opt) {
-    var nLevels = Math.round(opt.quantizationLevels || 2);
-    var srcPixels = src.data,
-      dstPixels = dst.data,
-      nPixels = srcPixels.length,
-      scale = (255 / nLevels),
-      i;
-    for (i = 0; i < nPixels; i += 1) {
-      dstPixels[i] = Math.floor(srcPixels[i] / scale) * scale;
+  Kinetic.Filters.Levels = function (imageData) {
+    // level must be between 1 and 255
+    var level = Math.round(this.level() * 254) + 1,
+        data = imageData.data,
+        len = data.length,
+        scale = (255 / level),
+        i;
+
+    for (i = 0; i < len; i += 1) {
+      data[i] = Math.floor(data[i] / scale) * scale;
     }
   };
 
-  Kinetic.Filters.Levels = function(src,dst,opt){
-    if( this === Kinetic.Filters ){
-      Levels(src, dst||src, opt );
-    }else{
-      Levels.call(this, src, dst||src, {
-        quantizationLevels: this.getQuantizationLevels()
-      });
-    }
-  };
-
-  Kinetic.Factory.addFilterGetterSetter(Kinetic.Node, 'quantizationLevels', 4);
+  Kinetic.Factory.addFilterGetterSetter(Kinetic.Node, 'level', 0.5);
 
     /**
-    * get quantization levels.  Returns the number of unique levels for each color
-    * channel. 2 is the minimum, 255 is the maximum. For Kinetic.Filters.Levels
-    * @name getQuantizationLevels
+    * get/set levels.  Must be a number between 0 and 1
+    * @name level
     * @method
-    * @memberof Kinetic.Image.prototype
+    * @memberof Kinetic.Node.prototype
+    * @param {Number} level between 0 and 1
+    * @returns {Number}
     */
 
-    /**
-    * get quantization levels.  Sets the number of unique levels for each color
-    * channel. 2 is the minimum, 255 is the maximum. For Kinetic.Filters.Levels
-    * @name setQuantizationLevels
-    * @method
-    * @memberof Kinetic.Image.prototype
-    */
+
 })();