RippleFilter.java

package com.hphoto.image;

import java.awt.*;
import java.awt.image.*;


/**
 * A filter which distorts an image by rippling it in the X or Y directions.
 * The amplitude and wavelength of rippling can be specified as well as whether 
 * pixels going off the edges are wrapped or not.
 */
public class RippleFilter extends TransformFilter {
	
    /**
     * Sine wave ripples.
     */
	public final static int SINE = 0;

    /**
     * Sawtooth wave ripples.
     */
	public final static int SAWTOOTH = 1;

    /**
     * Triangle wave ripples.
     */
	public final static int TRIANGLE = 2;

    /**
     * Noise ripples.
     */
	public final static int NOISE = 3;

	private float xAmplitude, yAmplitude;
	private float xWavelength, yWavelength;
	private int waveType;

	/**
	 * Construct a RippleFilter.
	 */
	public RippleFilter() {
		xAmplitude = 5.0f;
		yAmplitude = 0.0f;
		xWavelength = yWavelength = 16.0f;
	}

	/**
	 * Set the amplitude of ripple in the X direction.
	 * @param xAmplitude the amplitude (in pixels).
     * @see #getXAmplitude
	 */
	public void setXAmplitude(float xAmplitude) {
		this.xAmplitude = xAmplitude;
	}

	/**
	 * Get the amplitude of ripple in the X direction.
	 * @return the amplitude (in pixels).
     * @see #setXAmplitude
	 */
	public float getXAmplitude() {
		return xAmplitude;
	}

	/**
	 * Set the wavelength of ripple in the X direction.
	 * @param xWavelength the wavelength (in pixels).
     * @see #getXWavelength
	 */
	public void setXWavelength(float xWavelength) {
		this.xWavelength = xWavelength;
	}

	/**
	 * Get the wavelength of ripple in the X direction.
	 * @return the wavelength (in pixels).
     * @see #setXWavelength
	 */
	public float getXWavelength() {
		return xWavelength;
	}

	/**
	 * Set the amplitude of ripple in the Y direction.
	 * @param yAmplitude the amplitude (in pixels).
     * @see #getYAmplitude
	 */
	public void setYAmplitude(float yAmplitude) {
		this.yAmplitude = yAmplitude;
	}

	/**
	 * Get the amplitude of ripple in the Y direction.
	 * @return the amplitude (in pixels).
     * @see #setYAmplitude
	 */
	public float getYAmplitude() {
		return yAmplitude;
	}

	/**
	 * Set the wavelength of ripple in the Y direction.
	 * @param yWavelength the wavelength (in pixels).
     * @see #getYWavelength
	 */
	public void setYWavelength(float yWavelength) {
		this.yWavelength = yWavelength;
	}

	/**
	 * Get the wavelength of ripple in the Y direction.
	 * @return the wavelength (in pixels).
     * @see #setYWavelength
	 */
	public float getYWavelength() {
		return yWavelength;
	}


	/**
	 * Set the wave type.
	 * @param waveType the type.
     * @see #getWaveType
	 */
	public void setWaveType(int waveType) {
		this.waveType = waveType;
	}

	/**
	 * Get the wave type.
	 * @return the type.
     * @see #setWaveType
	 */
	public int getWaveType() {
		return waveType;
	}

	protected void transformSpace(Rectangle r) {
		if (edgeAction == ZERO) {
			r.x -= (int)xAmplitude;
			r.width += (int)(2*xAmplitude);
			r.y -= (int)yAmplitude;
			r.height += (int)(2*yAmplitude);
		}
	}

	protected void transformInverse(int x, int y, float[] out) {
		float nx = (float)y / xWavelength;
		float ny = (float)x / yWavelength;
		float fx, fy;
		switch (waveType) {
		case SINE:
		default:
			fx = (float)Math.sin(nx);
			fy = (float)Math.sin(ny);
			break;
		case SAWTOOTH:
			fx = ImageMath.mod(nx, 1);
			fy = ImageMath.mod(ny, 1);
			break;
		case TRIANGLE:
			fx = ImageMath.triangle(nx);
			fy = ImageMath.triangle(ny);
			break;
		case NOISE:
			fx = Noise.noise1(nx);
			fy = Noise.noise1(ny);
			break;
		}
		out[0] = x + xAmplitude * fx;
		out[1] = y + yAmplitude * fy;
	}

	public String toString() {
		return "Distort/Ripple...";
	}

}