001/*
002Copyright 2006 Jerry Huxtable
003
004Licensed under the Apache License, Version 2.0 (the "License");
005you may not use this file except in compliance with the License.
006You may obtain a copy of the License at
007
008   http://www.apache.org/licenses/LICENSE-2.0
009
010Unless required by applicable law or agreed to in writing, software
011distributed under the License is distributed on an "AS IS" BASIS,
012WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013See the License for the specific language governing permissions and
014limitations under the License.
015*/
016
017package com.jhlabs.image;
018
019import java.awt.*;
020import java.awt.image.*;
021import com.jhlabs.math.*;
022
023/**
024 * This filter diffuses an image by moving its pixels in random directions.
025 */
026public class DiffuseFilter extends TransformFilter {
027
028        private float[] sinTable, cosTable;
029        private float scale = 4;
030        
031        public DiffuseFilter() {
032                setEdgeAction(CLAMP);
033        }
034        
035        /**
036     * Specifies the scale of the texture.
037     * @param scale the scale of the texture.
038     * @min-value 1
039     * @max-value 100+
040     * @see #getScale
041     */
042        public void setScale(float scale) {
043                this.scale = scale;
044        }
045
046        /**
047     * Returns the scale of the texture.
048     * @return the scale of the texture.
049     * @see #setScale
050     */
051        public float getScale() {
052                return scale;
053        }
054
055        protected void transformInverse(int x, int y, float[] out) {
056                int angle = (int)(Math.random() * 255);
057                float distance = (float)Math.random();
058                out[0] = x + distance * sinTable[angle];
059                out[1] = y + distance * cosTable[angle];
060        }
061
062    public BufferedImage filter( BufferedImage src, BufferedImage dst ) {
063                sinTable = new float[256];
064                cosTable = new float[256];
065                for (int i = 0; i < 256; i++) {
066                        float angle = ImageMath.TWO_PI*i/256f;
067                        sinTable[i] = (float)(scale*Math.sin(angle));
068                        cosTable[i] = (float)(scale*Math.cos(angle));
069                }
070                return super.filter( src, dst );
071        }
072
073        public String toString() {
074                return "Distort/Diffuse...";
075        }
076}