PC Plus SuperCD 45/SuperCD45.iso/talleres/java/stage2/HawkRay.java

Java Source | 2000-01-30 | 4.2 KB | 161 lines

/*
 * @(#)HawkRay.java    1.0 98/04/12
 *
 * Copyright (c) 1998, David Griffiths. All Rights Reserved.
 *
 * This software is the proprietary information of David Griffiths.
 * This source code may not be published or redistributed without the
 * express permission of the author.
 *
 * THE AUTHOR MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY
 * OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. THE AUTHOR SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 *
 */

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
import java.awt.image.PixelGrabber;
import java.awt.image.MemoryImageSource;

public class HawkRay extends Applet implements Runnable {
    protected int w, h, dispx = 0, dispz = 0, m_sw, m_sh, texel[], m_cos1, m_sin1, xres, yres;
    protected int m_alti = 120, d = 1, viewA = 180, dViewA = 3;
    protected int screenPixel[];
    protected MemoryImageSource screenMem;
    protected Image screenImage;

    private int garbageCnt = 0;
    private Thread theThread;
    private boolean m_tAnimate = true;

//  Initialisation code

    public void init() {
        addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e){
                m_tAnimate = !m_tAnimate;
            }
        });

        MediaTracker tracker = new MediaTracker(this);
        Image piccy = getImage(getDocumentBase(), getParameter("image"));
        m_sh = getSize().height << 2; m_sw = getSize().width;
        screenPixel = new int[m_sw * m_sh >> 2];
        screenMem = new MemoryImageSource(m_sw, m_sh >> 2, screenPixel, 0, m_sw);
        tracker.addImage(piccy, 0);
        try {
            tracker.waitForID(0);
        }
        catch(Exception e) {}
        w = piccy.getWidth(this); h = piccy.getHeight(this);
        texel = new int[w * h];
        PixelGrabber pixelGrabber = new PixelGrabber(piccy.getSource(),
            0, 0, w, h, texel, 0, w);
        try {
            pixelGrabber.grabPixels();
        }
        catch(Exception e) {
            return;
        }
        piccy = null;
    }

// Running section

    public void start() {
        (theThread = new Thread(this)).start();
    }

    public void stop() {
        if (theThread != null) {
            theThread = null;
        }
    }

    public void run() {
        Graphics myGraphics = getGraphics();
        while ((theThread != null) && m_tAnimate) {
            if (viewA > 720)
                dViewA = -1;
            else if (viewA < 360)
                dViewA = 1;
            viewA += dViewA;

            renderImage();

            Thread.yield();
            paint(myGraphics);

            if (garbageCnt++ > 120) {
                System.gc ();
                garbageCnt = 0;
            }
        }
    }

// Painting section

    public void update(Graphics g) {
        paint(g);
    }

    public void paint(Graphics g) {
        if (screenImage != null)
            g.drawImage(screenImage, 0, 0, this);
    }

//  Rendering section

    protected void renderImage() {
        double x1, y1, x2, y2, x3, y3, x4, y4, va, xinc, yinc;
        int p = 0;
        m_alti = (int)(240.0 - 120.0 * Math.sin((double)viewA * 3.1415926 / 180.0));
        m_sin1 = (int)((1 << 10) * Math.sin((double)viewA * 3.1415926 / 180.0));
        m_cos1 = (int)((1 << 10) * Math.cos((double)viewA * 3.1415926 / 180.0));
        va = (w * (viewA % 360) / 360);
        dispz += m_cos1 << 3;
        dispx += m_sin1 << 3;
        for (int y = ((3 * m_sh) >> 2) + 1; y <= m_sh; y++) {
            planePoint (0, y); x1 = xres; y1 = yres;
            planePoint (m_sw - 1, y); x2 = xres; y2 = yres;
            xinc = (x2 - x1) / (m_sw - 1);
            yinc = (y2 - y1) / (m_sw - 1);
            xinc = ((xinc % (w << 10)) + (w << 10)) % (w << 10);
            yinc = ((yinc % (h << 10)) + (h << 10)) % (h << 10);
            for (int x = 0; x < m_sw; x++) {
                setTexel(p++, (int)x1, (int)y1);
                x1 += xinc; y1 += yinc;
            }
        }
        screenImage = createImage(screenMem);
    }

    void setTexel(int p, int u, int v) {
        int x3 = modIt((w - u) >> 10, w);
        int y3 = modIt(v >> 10, h);
        screenPixel[p] = texel[y3 * w + x3];
    }

    int modIt(int a, int b) {
        int result = (a) % b;
        if (result < 0)
            result += b;
        return result;
    }

    protected void planePoint (int i, int j) {
        double x1, y1, y2, x2;
        y1 = ((double)(j << 1) / (double)m_sh) - 1.0;
        y2 = (double)(d * (m_alti - y1)) / y1;
        x1 = (double)(i - (m_sw >> 1)) / (double)m_sw;
        x2 = x1 * (y2 + d) / (double)d;
        xres = (int)(m_cos1 * x2 + m_sin1 * y2) + dispx;
        yres = (int)(-m_sin1 * x2 + m_cos1 * y2) + dispz;
    }
}