org.deegree.rendering.r3d.opengl.display
Class TrackBall

java.lang.Object
  java.awt.event.MouseAdapter
      org.deegree.rendering.r3d.opengl.display.TrackBall

All Implemented Interfaces:

MouseListener, MouseMotionListener, MouseWheelListener, EventListener

public class TrackBall
extends MouseAdapter

The TrackBall pretends that a ball encloses the 3d view. You roll this ball with the mouse. For example, if you click on the center of the ball and move the ball directly right, you rotate around y. Click on edge of ball and roll to get a z rotation. The idea isn't too hard. Start with a vector from the first mouse click to the center of the 3d view. Set the radius of the ball to the smaller dimension of the 3d view. As you drag around, a second vector is determined from the surface to center of the ball. Axis of rotation is cross-product of those two vectors, and the angle is the angle between the vectors. This class was copied from a cpp file I once used in my Computer Graphic classes. I don't know who the original author was, but since I only created the java representation of the working code, I would like to thank him/her.

Version:

$Revision: 29127 $, $Date: 2011-01-10 16:13:35 +0100 (Mon, 10 Jan 2011) $

Author:

Rutger Bezema, last edited by: $Author: aschmitz $

Constructor Summary

TrackBall()
Set the rotation matrices to the initial state (0,1,0,0)

Method Summary

void	mouseDragged(MouseEvent e)
void	mousePressed(MouseEvent e)
void	mouseReleased(MouseEvent e)
void	mouseWheelMoved(MouseWheelEvent e)
void	multModelMatrix(javax.media.opengl.GL context, float[] worldTranslation) Multiply the rotation vectors on top of the current context, the multiplication also uses the translation
void	reset() Reset the rotation vectors

Methods inherited from class java.awt.event.MouseAdapter

mouseClicked, mouseEntered, mouseExited, mouseMoved

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TrackBall

public TrackBall()

Set the rotation matrices to the initial state (0,1,0,0)

Method Detail

mousePressed

public void mousePressed(MouseEvent e)

Specified by:

mousePressed in interface MouseListener

Overrides:

mousePressed in class MouseAdapter

mouseWheelMoved

public void mouseWheelMoved(MouseWheelEvent e)

Specified by:

mouseWheelMoved in interface MouseWheelListener

Overrides:

mouseWheelMoved in class MouseAdapter

mouseReleased

public void mouseReleased(MouseEvent e)

Specified by:

mouseReleased in interface MouseListener

Overrides:

mouseReleased in class MouseAdapter

mouseDragged

public void mouseDragged(MouseEvent e)

Specified by:

mouseDragged in interface MouseMotionListener

Overrides:

mouseDragged in class MouseAdapter

multModelMatrix

public void multModelMatrix(javax.media.opengl.GL context,
                            float[] worldTranslation)

Multiply the rotation vectors on top of the current context, the multiplication also uses the translation

Parameters:

context - to multiply the rotations upon.

worldTranslation - a float[3] which contains a translation vector (normally the center of the scene ), if null or length != 3 no translation will be done.

reset

public void reset()

Reset the rotation vectors