/*

  * Copyright (c) 2003, the JUNG Project and the Regents of the University of

  * California All rights reserved.

  * 

  * This software is open-source under the BSD license; see either "license.txt"

  * or http://jung.sourceforge.net/license.txt for a description.

  * 

  */

 package edu.uci.ics.jung.visualization.jai;

 import java.awt.geom.NoninvertibleTransformException;

 import java.awt.geom.Point2D;

 import javax.media.jai.PerspectiveTransform;

 import edu.uci.ics.jung.visualization.transform.MutableAffineTransformer;

 import edu.uci.ics.jung.visualization.transform.MutableTransformer;

 import edu.uci.ics.jung.visualization.transform.MutableTransformerDecorator;

 /**

  * PerspectiveTransformer wraps a MutableAffineTransformer and modifies

  * the transform and inverseTransform methods so that they create a

  * perspective projection of the graph points.

  * 

  * @author Tom Nelson

  *

  */

 public class PerspectiveTransformer extends MutableTransformerDecorator implements MutableTransformer {

     protected PerspectiveTransform perspectiveTransform;

     /**

      * create an instance, setting values from the passed component

      * and registering to listen for size changes on the component

      * @param component

      */

     public PerspectiveTransformer(PerspectiveTransform perspectiveTransform) {

         this(perspectiveTransform, new MutableAffineTransformer());

     }

     /**

      * create an instance with a possibly shared transform

      * @param component

      * @param delegate

      */

     public PerspectiveTransformer(PerspectiveTransform perspectiveTransform, MutableTransformer delegate) {

                     super(delegate);

                     this.perspectiveTransform = perspectiveTransform;

    }

     @Override

     public void setToIdentity() {

         this.perspectiveTransform.setToIdentity();

     }

     public PerspectiveTransform createInverse() {

         try {

             return perspectiveTransform.createInverse();

         } catch (NoninvertibleTransformException e) {

             e.printStackTrace();

         } catch (CloneNotSupportedException e) {

             e.printStackTrace();

         }

         return null;

     }

     /**

      * override base class transform to project the perspective effect

      */

     @Override

     public Point2D transform(Point2D graphPoint) {

         if(graphPoint == null) return null;

         Point2D p2 = super.transform(graphPoint);

         return perspectiveTransform.transform(p2, null);

     }

     /**

      * override base class to un-project the perspective effect

      */

     @Override

     public Point2D inverseTransform(Point2D viewPoint) {

         Point2D p2 = createInverse().transform(viewPoint, null);

         return super.inverseTransform(p2);

     }

     public Point2D perspectiveTransform(Point2D graphPoint) {

         if(graphPoint == null) return null;

         return perspectiveTransform.transform(graphPoint, null);

     }

     /**

      * override base class to un-project the perspective effect

      */

     public Point2D inversePerspectiveTransform(Point2D viewPoint) {

         return createInverse().transform(viewPoint, null);

     }

     public PerspectiveTransform getPerspectiveTransform() {

         return perspectiveTransform;

     }

     public void setPerspectiveTransform(PerspectiveTransform perspectiveTransform) {

         this.perspectiveTransform = perspectiveTransform;

     }

 }