package Experiment1;

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

public class X2 extends Applet{
    public X2 (){
	setLayout(new BorderLayout());
	GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
	Canvas3D canvas = new Canvas3D(config);
	add("Center", canvas);
	BranchGroup scene = createSceneGraph();
	scene.compile();
	
	SimpleUniverse su = new SimpleUniverse(canvas);
	su.getViewingPlatform().setNominalViewingTransform();
	
	su.addBranchGraph(scene);
    }
    
    public BranchGroup createSceneGraph() {
	BranchGroup objRoot = new BranchGroup();
	TransformGroup objSpin = new TransformGroup();
	objSpin.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
	objRoot.addChild(objSpin);
	objSpin.addChild(new Shape3D(yoyoGeometry()));
	Alpha rotationAlpha = new Alpha(-1, 4000);
	RotationInterpolator rotator = 
	    new RotationInterpolator(rotationAlpha, objSpin);
	
	BoundingSphere bounds = new BoundingSphere();
	rotator.setSchedulingBounds(bounds);
	objSpin.addChild(rotator);
	return objRoot;
    }
    
    private Geometry yoyoGeometry(){
	TriangleFanArray tfa;
	int N = 21;
	int totalN = 4*(N+1);
	
	Point3f coords [] = new Point3f[totalN];
	Color3f colors [] = new Color3f[totalN];
	Color3f red = new Color3f(1.0f, 0.0f, 0.0f);
	Color3f yellow = new Color3f(0.7f, 0.5f, 0.0f);
	int stripCounts[] = {N+1,N+1,N+1,N+1};
	float r = 0.6f;
	float w = 0.4f;
	int n;
	double a;
	float x, y;
	
	coords[0*(N+1)] = new Point3f (0.0f, 0.0f, w);
	coords[1*(N+1)] = new Point3f (0.0f, 0.0f, 0.0f);
	coords[2*(N+1)] = new Point3f (0.0f, 0.0f, 0.0f);
	coords[3*(N+1)] = new Point3f (0.0f, 0.0f, -w);
	
	colors[0*(N+1)] = red;
	colors[1*(N+1)] = yellow;
	colors[2*(N+1)] = yellow;
	colors[3*(N+1)] = red;
	
	for(a=0, n=0;n<N;a=2.0*Math.PI/(N-1)*++n){
	    x = (float) (r * Math.cos(a));
	    y = (float) (r * Math.sin(a));
	    
	    coords[0*(N+1)+n+1] = new Point3f (x, y, w);
	    coords[1*(N+1)+N-n] = new Point3f (x, y, w);
	    coords[2*(N+1)+n+1] = new Point3f (x, y, -w);
	    coords[3*(N+1)+N-n] = new Point3f (x, y, -w);
	    
	    colors[0*(N+1)+N-n] = red;
	    colors[1*(N+1)+n+1] = yellow;
	    colors[2*(N+1)+N-n] = yellow;
	    colors[3*(N+1)+n+1] = red;
	}
	tfa = new TriangleFanArray (totalN, 
		    TriangleFanArray.COORDINATES|TriangleFanArray.COLOR_3,
		    stripCounts);
	
	tfa.setCoordinates(0, coords);
	tfa.setColors(0, colors);
	
	return tfa;
	
    }
    
    public static void main (String[] args){
	Frame frame = new MainFrame(new X2(), 256, 256);
    }
}