/*
 *	@(#)PureImmediate.java 1.7 98/04/09 15:33:37
 *
 * Copyright (c) 1996-1998 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
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 *
 * 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.
 */

import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.GraphicsConfiguration;
import java.awt.event.*;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.geometry.ColorCube;
import com.sun.j3d.utils.universe.*;
import javax.media.j3d.*;
import javax.vecmath.*;

/**
 * Pure immediate mode example program.  In pure immediate mode, the
 * renderer must be stopped on the Canvas being rendered into. In our
 * example, this is done immediately after the canvas is created. A
 * separate thread is started up to do the immediate mode rendering.
 */
public class PureImmediate extends Applet implements Runnable {

    private Canvas3D canvas;
    private Thread t = null;

    private GraphicsContext3D gc = null;
    private Geometry cube = null;
    private long startTime = 0L;
    private Transform3D cmt = new Transform3D();

    // 1/6 revolution (60 degrees) of rotation per second
    private static final double rotationPerSecond = (2.0 * Math.PI) / 6.0;

    //
    // Renders a single frame by clearing the canvas, drawing the
    // geometry, and swapping the draw and display buffer.
    //
    public void render() {
	if (gc == null) {
	    // Set up Graphics context
	    gc = canvas.getGraphicsContext3D();
	    gc.setAppearance(new Appearance());

	    // Set up geometry
	    cube = new ColorCube(0.4).getGeometry();
	}

	// Get current system time
	long currTime = System.currentTimeMillis();
	if (startTime == 0)
	    startTime = currTime;

	// Compute angle of rotation based on elapsed time since startup
	long elapsedTime = currTime - startTime;
	double angle = (double)elapsedTime / 1000.0 * rotationPerSecond;
	cmt.rotY(angle);
 
	// Render the geometry for this frame
	gc.clear();
	gc.setModelTransform(cmt);
	gc.draw(cube);
	canvas.swap();
    }


    //
    // Run method for our immediate mode rendering thread.
    //
    public void run() {
	System.out.println("PureImmediate.run: starting main loop");
	while (true) {
	    render();
	    Thread.yield();
	}
    }


    //
    //Applet init routine (called by browser or by MainFrame)
    //
    public void init() {
	setLayout(new BorderLayout());

	canvas = new Canvas3D(null);
        canvas.stopRenderer();
	add("Center", canvas);

	// Create a simple scene and attach it to the virtual universe
	SimpleUniverse u = new SimpleUniverse(canvas);

        // This will move the ViewPlatform back a bit so the
        // objects in the scene can be viewed.
        u.getViewingPlatform().setNominalViewingTransform();

	// Start a new thread that will continuously render
	t = new Thread(this);
	t.start();
    }

    //
    // The following allows PureImmediate to be run as an application
    // as well as an applet
    //
    public static void main(String[] args) {
	new MainFrame(new PureImmediate(), 256, 256);
    }
}