/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License,
* Version 2.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package pivot.wtk.effects;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import pivot.wtk.Component;
import pivot.wtk.Bounds;
/**
* Decorator that applies a blur to a component.
* <p>
* Blurs are given an integer magnitude, which represents the intensity of
* the blur. This value translates to a grid of pixels (<tt>blurMagnitude^2</tt>),
* where each pixel value is calculated by consulting its neighboring pixels
* according to the grid. Because of this, note that you will get "prettier"
* blurring if you choose odd values for the blur magnitude; this allows the
* pixel in question to reside at the center of the grid, thus preventing any
* arbitrary shifting of pixels. Also note that the greater the intensity of
* the blur, the greater the intensity of the calculations necessary to
* accomplish the blur (and the longer it will take to perform the blur).
* <p>
* TODO Increase size of buffered image to account for edge conditions of the
* blur.
* <p>
* TODO Use unequal values in the blur kernel to make pixels that are farther
* away count less towards the blur.
*
* @author tvolkert
*/
public class BlurDecorator implements Decorator {
private int blurMagnitude;
private Graphics2D graphics = null;
private BufferedImage bufferedImage = null;
private Graphics2D bufferedImageGraphics = null;
/**
* Creates a <tt>BlurDecorator</tt> with the default blur magnitude.
*
* @see #BlurDecorator(int)
*/
public BlurDecorator() {
this(9);
}
/**
* Creates a <tt>BlurDecorator</tt> with the specified blur magnitude.
*
* @param blurMagnitude
* The intensity of the blur.
*/
public BlurDecorator(int blurMagnitude) {
this.blurMagnitude = blurMagnitude;
}
public Graphics2D prepare(Component component, Graphics2D graphics) {
this.graphics = graphics;
int width = component.getWidth();
int height = component.getHeight();
if (bufferedImage == null
|| bufferedImage.getWidth() != width
|| bufferedImage.getHeight() != height) {
bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
}
bufferedImageGraphics = bufferedImage.createGraphics();
bufferedImageGraphics.setClip(graphics.getClip());
return bufferedImageGraphics;
}
public void update() {
bufferedImageGraphics.dispose();
bufferedImage.flush();
float[] kernel = new float[blurMagnitude * blurMagnitude];
for (int i = 0, n = kernel.length; i < n; i++) {
kernel[i] = 1f / n;
}
ConvolveOp blur = new ConvolveOp(new Kernel(blurMagnitude, blurMagnitude,
kernel), ConvolveOp.EDGE_NO_OP, null);
bufferedImage = blur.filter(bufferedImage, null);
this.graphics.drawImage(bufferedImage, 0, 0, null);
}
public Bounds getBounds(Component component) {
return new Bounds(0, 0, component.getWidth(), component.getHeight());
}
public AffineTransform getTransform(Component component) {
return new AffineTransform();
}
}