highlightfilter.java

此程序是用标准的JAVA2实现的一个图形程序

/*
 * @(#)HighlightFilter.java	1.12 04/07/26
 * 
 * Copyright (c) 2004 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 * 
 * -Redistribution 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.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL 
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST 
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, 
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY 
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, 
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */

/*
 * @(#)HighlightFilter.java	1.12 04/07/26
 */

import java.applet.Applet;
import java.awt.Image;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.StringTokenizer;
import java.util.Vector;
import java.util.Hashtable;
import java.net.URL;
import java.awt.image.*;
import java.net.MalformedURLException;

/**
 * An image filter to highlight an image by brightening or darkening
 * the pixels in the images.
 *
 * @author 	Jim Graham
 * @version 	1.12, 07/26/04
 */
class HighlightFilter extends RGBImageFilter {
    boolean brighter;
    int percent;

    public HighlightFilter(boolean b, int p) {
	brighter = b;
	percent = p;
	canFilterIndexColorModel = true;
    }

    public int filterRGB(int x, int y, int rgb) {
	int r = (rgb >> 16) & 0xff;
	int g = (rgb >> 8) & 0xff;
	int b = (rgb >> 0) & 0xff;
	if (brighter) {
	    r = (255 - ((255 - r) * (100 - percent) / 100));
	    g = (255 - ((255 - g) * (100 - percent) / 100));
	    b = (255 - ((255 - b) * (100 - percent) / 100));
	} else {
	    r = (r * (100 - percent) / 100);
	    g = (g * (100 - percent) / 100);
	    b = (b * (100 - percent) / 100);
	}
	if (r < 0) r = 0;
	if (r > 255) r = 255;
	if (g < 0) g = 0;
	if (g > 255) g = 255;
	if (b < 0) b = 0;
	if (b > 255) b = 255;
	return (rgb & 0xff000000) | (r << 16) | (g << 8) | (b << 0);
    }
}