/*
 * $Id: AbstractFilter.java,v 1.1 2008/05/02 06:18:20 kirillcool Exp $
 *
 * Dual-licensed under LGPL (Sun and Romain Guy) and BSD (Romain Guy).
 *
 * Copyright 2005 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * Copyright (c) 2006 Romain Guy <romain.guy@mac.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.jvnet.substance.utils.filters;

import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.*;

/**
 * <p>
 * Provides an abstract implementation of the <code>BufferedImageOp</code>
 * interface. This class can be used to created new image filters based on
 * <code>BufferedImageOp</code>.
 * </p>
 * 
 * @author Romain Guy <romain.guy@mac.com>
 */

public abstract class AbstractFilter implements BufferedImageOp {
	public abstract BufferedImage filter(BufferedImage src, BufferedImage dest);

	/**
	 * {@inheritDoc}
	 */
	public Rectangle2D getBounds2D(BufferedImage src) {
		return new Rectangle(0, 0, src.getWidth(), src.getHeight());
	}

	/**
	 * {@inheritDoc}
	 */
	public BufferedImage createCompatibleDestImage(BufferedImage src,
			ColorModel destCM) {
		if (destCM == null) {
			destCM = src.getColorModel();
		}

		return new BufferedImage(destCM, destCM.createCompatibleWritableRaster(
				src.getWidth(), src.getHeight()),
				destCM.isAlphaPremultiplied(), null);
	}

	/**
	 * {@inheritDoc}
	 */
	public Point2D getPoint2D(Point2D srcPt, Point2D dstPt) {
		return (Point2D) srcPt.clone();
	}

	/**
	 * {@inheritDoc}
	 */
	public RenderingHints getRenderingHints() {
		return null;
	}

	protected int[] getPixels(BufferedImage img, int x, int y, int w, int h,
			int[] pixels) {
		if (w == 0 || h == 0) {
			return new int[0];
		}

		if (pixels == null) {
			pixels = new int[w * h];
		} else if (pixels.length < w * h) {
			throw new IllegalArgumentException(
					"pixels array must have a length" + " >= w*h");
		}

		int imageType = img.getType();
		if (imageType == BufferedImage.TYPE_INT_ARGB
				|| imageType == BufferedImage.TYPE_INT_RGB) {
			Raster raster = img.getRaster();
			return (int[]) raster.getDataElements(x, y, w, h, pixels);
		}

		// Unmanages the image
		return img.getRGB(x, y, w, h, pixels, 0, w);
	}

	/**
	 * <p>
	 * Writes a rectangular area of pixels in the destination
	 * <code>BufferedImage</code>. Calling this method on an image of type
	 * different from <code>BufferedImage.TYPE_INT_ARGB</code> and
	 * <code>BufferedImage.TYPE_INT_RGB</code> will unmanage the image.
	 * </p>
	 * 
	 * @param img
	 *            the destination image
	 * @param x
	 *            the x location at which to start storing pixels
	 * @param y
	 *            the y location at which to start storing pixels
	 * @param w
	 *            the width of the rectangle of pixels to store
	 * @param h
	 *            the height of the rectangle of pixels to store
	 * @param pixels
	 *            an array of pixels, stored as integers
	 * @throws IllegalArgumentException
	 *             is <code>pixels</code> is non-null and of length &lt; w*h
	 */
	protected void setPixels(BufferedImage img, int x, int y, int w, int h,
			int[] pixels) {
		if (pixels == null || w == 0 || h == 0) {
			return;
		} else if (pixels.length < w * h) {
			throw new IllegalArgumentException(
					"pixels array must have a length" + " >= w*h");
		}

		int imageType = img.getType();
		if (imageType == BufferedImage.TYPE_INT_ARGB
				|| imageType == BufferedImage.TYPE_INT_RGB) {
			WritableRaster raster = img.getRaster();
			raster.setDataElements(x, y, w, h, pixels);
		} else {
			// Unmanages the image
			img.setRGB(x, y, w, h, pixels, 0, w);
		}
	}
}
