/*
* Copyright (c) 2009-2012 jMonkeyEngine
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of 'jMonkeyEngine' nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jme3.renderer.queue;
import com.jme3.math.Vector3f;
import com.jme3.renderer.Camera;
import com.jme3.scene.Geometry;
public class TransparentComparator implements GeometryComparator {
private Camera cam;
private final Vector3f tempVec = new Vector3f();
public void setCamera(Camera cam){
this.cam = cam;
}
/**
* Calculates the distance from a spatial to the camera. Distance is a
* squared distance.
*
* @param spat
* Spatial to distancize.
* @return Distance from Spatial to camera.
*/
private float distanceToCam2(Geometry spat){
if (spat == null)
return Float.NEGATIVE_INFINITY;
if (spat.queueDistance != Float.NEGATIVE_INFINITY)
return spat.queueDistance;
Vector3f camPosition = cam.getLocation();
Vector3f viewVector = cam.getDirection();
Vector3f spatPosition = null;
if (spat.getWorldBound() != null){
spatPosition = spat.getWorldBound().getCenter();
}else{
spatPosition = spat.getWorldTranslation();
}
spatPosition.subtract(camPosition, tempVec);
spat.queueDistance = tempVec.dot(tempVec);
float retval = Math.abs(tempVec.dot(viewVector)
/ viewVector.dot(viewVector));
viewVector.mult(retval, tempVec);
spat.queueDistance = tempVec.length();
return spat.queueDistance;
}
private float distanceToCam(Geometry spat){
// NOTE: It is best to check the distance
// to the bound's closest edge vs. the bound's center here.
return spat.getWorldBound().distanceToEdge(cam.getLocation());
}
public int compare(Geometry o1, Geometry o2) {
float d1 = distanceToCam(o1);
float d2 = distanceToCam(o2);
if (d1 == d2)
return 0;
else if (d1 < d2)
return 1;
else
return -1;
}
}