DiffuseImageOp.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;

import java.util.Random;

public class DiffuseImageOp extends AbstractTransformImageOp {

    double[] tx;
    double[] ty;
    double amount;

    public DiffuseImageOp() {
        amount = 1.6;
    }

    public double getAmount() {
        return amount;
    }

    public void setAmount(double amount) {
        this.amount = amount;
    }

    @Override
    protected synchronized void init() {
        tx = new double[256];
        ty = new double[256];
        for (int i = 0; i < 256; i++) {
            double angle = 2 * Math.PI * i / 256;
            tx[i] = amount * Math.sin(angle);
            ty[i] = amount * Math.cos(angle);
        }
    }

    @Override
    protected void transform(int x, int y, double[] t) {
        Random r = new Random();
        int angle = (int) (r.nextFloat() * 255);
        t[0] = x + tx[angle];
        t[1] = y + ty[angle];
    }

}