import javax.media.j3d.*;
import javax.vecmath.*;
import java.util.*; // Vector

/* note the change from Vector3f to Point3f (and similar change Function3f to
Curve3f */
public class ParametricCurve3D extends Shape3D {
	Vector pointList;
	Vector timeList;
	float epsilon;
	float t0;
	float t1;
	Curve3f fun;
	float zmin;
	float zmax;

	public ParametricCurve3D( float tZero, float tOne, float e, Curve3f f ) {
		t0 = tZero;
		t1 = tOne;
		epsilon = e;
		fun = f;
		timeList = new Vector(64);
		timeList.addElement( new Float(t0) );
		pointList = new Vector(64);
		Point3f p = fun.valueAt(t0);
		pointList.addElement( p );
		zmin = p.z;
		zmax = p.z;
		buildVector ( t1 );
		buildGeometry();
	}

	public void buildVector ( float t1 ) {
		float t0 = ((Float)timeList.lastElement()).floatValue();
		while ( Math.abs ( t1 - t0 ) >= epsilon ) {
			buildVector ( (t0 + t1)/2 );
			t0 = ((Float)timeList.lastElement()).floatValue();
		}
		Point3f p0 = (Point3f)pointList.lastElement();
		t0 = ((Float)timeList.lastElement()).floatValue();
		Point3f p1 = fun.valueAt(t1);
		while ( ! p1.epsilonEquals( p0, epsilon ) ) {
			buildVector ( (t0 + t1)/2 );
			t0 = ((Float)timeList.lastElement()).floatValue();
			p0 = (Point3f)pointList.lastElement();
		}
		timeList.addElement(new Float(t1));
		pointList.addElement(p1);
		zmin = (zmin>p1.z)? p1.z : zmin;
		zmax = (zmax<p1.z)? p1.z : zmax;
	}

	private float ScaleColor ( float z ) {
		return (z - zmin)/(zmax - zmin);
	}

	private void buildGeometry() {
		Color3f[] colors = new Color3f[pointList.size()];
		for ( int i = 0; i < pointList.size(); i++ ) {
			float x = ScaleColor ( ((Point3f)pointList.elementAt(i)).z );
			colors[i] = new Color3f ( x, 0, 1 - x );
		}
		int[] count = { pointList.size() };
		LineStripArray curve = new LineStripArray ( pointList.size(),
			LineStripArray.COORDINATES | LineStripArray.COLOR_3, count ); 
		Point3f[] vertices = new Point3f[pointList.size()];
		pointList.toArray( vertices );
		curve.setCoordinates ( 0, vertices );
		curve.setColors ( 0, colors );
		this.setGeometry ( curve );
		this.setAppearance ( null );
	}

	public void print () {
		Enumeration p = pointList.elements();
		Enumeration t = timeList.elements();
		while ( p.hasMoreElements() ) {
			float f = ((Float) t.nextElement()).floatValue();
			Point3f v = (Point3f) p.nextElement();
			System.out.println ( "t = " + f + " v = " + v.toString() );
		}
	}
	/* not used, must delete as there is no WireMesh interface any more
	public void draw ( WireMesh w ) {
		Enumeration p = pointList.elements();
		if ( !p.hasMoreElements() )
			return;
		Vector3f next = (Vector3f) p.nextElement();
		while ( p.hasMoreElements() ) {
			Vector3f prev = next;
			next = (Vector3f) p.nextElement();
			w.lineVector3f ( prev, next );
		}
	}
	*/

	public static void main ( String[] args ) {
		Curve3f function = new Helix ( 1, 1 );
		ParametricCurve3D p = new ParametricCurve3D ( 0, 3, 0.25f, function );
		p.print();
	}
}