warpimage.java

java2d的源码分析

/*
 * @(#)WarpImage.java	1.16 99/04/23
 *
 * Copyright (c) 1998, 1999 by Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 * 
 * 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 AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE 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 SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 * 
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

package demos.Images;

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.CubicCurve2D;
import java.awt.geom.Point2D;
import java.awt.geom.FlatteningPathIterator;
import java.awt.geom.PathIterator;
import AnimatingContext;
import DemoSurface;
import DemoPanel;


/**
 * Warps a image on a CubicCurve2D flattened path.
 */
public class WarpImage extends DemoSurface implements AnimatingContext {

    private static int iw, ih, iw2, ih2;
    private static Image img;
    private static final int FORWARD = 0;
    private static final int BACK = 1;
    private Point2D pts[];
    private int direction = FORWARD;
    private int pNum;
    private int x, y;


    public WarpImage() {
        setBackground(Color.white);
        img = getImage("surfing.gif");
        iw = img.getWidth(this);
        ih = img.getHeight(this);
        iw2 = iw/2;
        ih2 = ih/2;
    }


    public void reset(int w, int h) {
        pNum = 0;
        direction = FORWARD;
        CubicCurve2D cc = new CubicCurve2D.Float(
                        w*.2f, h*.5f, w*.4f,0, w*.6f,h,w*.8f,h*.5f);
        PathIterator pi = cc.getPathIterator(null, 0.1);
        Point2D tmp[] = new Point2D[200];
        int i = 0;
        while ( !pi.isDone() ) {
            float[] coords = new float[6];
            switch ( pi.currentSegment(coords) ) {
                case pi.SEG_MOVETO:
                case pi.SEG_LINETO:
                        tmp[i] = new Point2D.Float(coords[0], coords[1]);
            }
            i++;
            pi.next();
        }
        pts = new Point2D[i];
        System.arraycopy(tmp,0,pts,0,i);
    }


    public void step(int w, int h) {
        if (pts == null) {
            return;
        }
        x = (int) pts[pNum].getX();
        y = (int) pts[pNum].getY();
        if (direction == FORWARD)
            if (++pNum == pts.length)
                direction = BACK;
        if (direction == BACK)
            if (--pNum == 0)
                direction = FORWARD;
    }


    public void drawDemo(int w, int h, Graphics2D g2) {
        g2.drawImage(img,
                        0,              0,              x,              y,
                        0,              0,              iw2,            ih2,
                        this);
        g2.drawImage(img,
                        x,              0,              w,              y,
                        iw2,            0,              iw,             ih2,
                        this);
        g2.drawImage(img,
                        0,              y,              x,              h,
                        0,              ih2,            iw2,            ih,
                        this);
        g2.drawImage(img,
                        x,              y,              w,              h,
                        iw2,            ih2,            iw,             ih,
                        this);
    }


    public static void main(String argv[]) {
        final DemoPanel dp = new DemoPanel(new WarpImage());
        Frame f = new Frame("Java2D Demo - WarpImage");
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {System.exit(0);}
            public void windowDeiconified(WindowEvent e) { 
                dp.surface.start(); 
            }
            public void windowIconified(WindowEvent e) { 
                dp.surface.stop(); 
            }
        });
        f.add("Center", dp);
        f.pack();
        f.setSize(new Dimension(400,300));
        f.show();
        dp.surface.start();
    }
}