RippleImageOp.java

/*
 * Copyright (c) 2009 Piotr Piastucki
 * 
 * This file is part of Patchca CAPTCHA library.
 * 
 *  Patchca is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *  
 *  Patchca is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with Patchca. If not, see <http://www.gnu.org/licenses/>.
 */
package com.xiongyingqi.captcha.filter.library;


public class RippleImageOp extends AbstractTransformImageOp {

    protected double xWavelength;
    protected double yWavelength;
    protected double xAmplitude;
    protected double yAmplitude;
    protected double xRandom;
    protected double yRandom;

    public RippleImageOp() {
        xWavelength = 20;
        yWavelength = 10;
        xAmplitude = 5;
        yAmplitude = 5;
        xRandom = 5 * Math.random();
        yRandom = 5 * Math.random();
    }

    public double getxWavelength() {
        return xWavelength;
    }

    public void setxWavelength(double xWavelength) {
        this.xWavelength = xWavelength;
    }

    public double getyWavelength() {
        return yWavelength;
    }

    public void setyWavelength(double yWavelength) {
        this.yWavelength = yWavelength;
    }

    public double getxAmplitude() {
        return xAmplitude;
    }

    public void setxAmplitude(double xAmplitude) {
        this.xAmplitude = xAmplitude;
    }

    public double getyAmplitude() {
        return yAmplitude;
    }

    public void setyAmplitude(double yAmplitude) {
        this.yAmplitude = yAmplitude;
    }

    @Override
    protected void transform(int x, int y, double[] t) {
        double tx = Math.sin((double) y / yWavelength + yRandom);
        double ty = Math.cos((double) x / xWavelength + xRandom);
        t[0] = x + xAmplitude * tx;
        t[1] = y + yAmplitude * ty;
    }

}