import javax.media.j3d.*;
import javax.vecmath.*;

// Origin at center of solid. Sides of length 2.

public class ColorTetra extends Shape3D {
	private static final float ycenter = (float)Math.sqrt(1.0/6.0);
	private static final float zcenter = (float)Math.sqrt(1.0/3.0);
	private static final float sqrt3 = (float)Math.sqrt(3.0);
	private static final float sqrt24_3 = (float)Math.sqrt ( 8.0/3.0);

	private static final Point3f p1 = new Point3f ( -1.0f, -ycenter, zcenter );
	private static final Point3f p2 = new Point3f ( 1.0f, -ycenter, zcenter );
	private static final Point3f p3
		= new Point3f ( 0.0f, -ycenter, -sqrt3 + zcenter );
	private static final Point3f p4
		= new Point3f ( 0.0f, sqrt24_3 -ycenter, 0.0f );

	private static final Point3f[] verts = {
		p1, p2, p4, // front face
		p1, p4, p3, // left back face
		p2, p3, p4, // right back face
		p1, p3, p2, // bottom face
	};

	private static final Color3f c1 = new Color3f ( 1.0f, 0.0f, 0.0f );
	private static final Color3f c2 = new Color3f ( 0.0f, 1.0f, 0.0f );
	private static final Color3f c3 = new Color3f ( 1.0f, 1.0f, 1.0f );
	private static final Color3f c4 = new Color3f ( 0.0f, 0.0f, 1.0f );

	private static final Color3f[] colors = {
		c1, c2, c4,
		c1, c4, c3,
		c2, c3, c4,
		c1, c3, c2,
	};

	public ColorTetra() {
		TriangleArray tetra = new TriangleArray ( 12, 
			TriangleArray.COORDINATES | TriangleArray.COLOR_3 );
		tetra.setCoordinates (0, verts );
		tetra.setColors (0, colors );
		this.setGeometry ( tetra );
		this.setAppearance ( null );
	}
}