1/*
2 * Copyright (c) 2009-2010 jMonkeyEngine
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 * * Redistributions of source code must retain the above copyright
10 *   notice, this list of conditions and the following disclaimer.
11 *
12 * * Redistributions in binary form must reproduce the above copyright
13 *   notice, this list of conditions and the following disclaimer in the
14 *   documentation and/or other materials provided with the distribution.
15 *
16 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
17 *   may be used to endorse or promote products derived from this software
18 *   without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33package com.jme3.renderer.queue;
34
35import com.jme3.material.Material;
36import com.jme3.math.Vector3f;
37import com.jme3.renderer.Camera;
38import com.jme3.scene.Geometry;
39
40public class OpaqueComparator implements GeometryComparator {
41
42    private Camera cam;
43    private final Vector3f tempVec  = new Vector3f();
44    private final Vector3f tempVec2 = new Vector3f();
45
46    public void setCamera(Camera cam){
47        this.cam = cam;
48    }
49
50    public float distanceToCam(Geometry spat){
51        if (spat == null)
52            return Float.NEGATIVE_INFINITY;
53
54        if (spat.queueDistance != Float.NEGATIVE_INFINITY)
55                return spat.queueDistance;
56
57        Vector3f camPosition = cam.getLocation();
58        Vector3f viewVector = cam.getDirection(tempVec2);
59        Vector3f spatPosition = null;
60
61        if (spat.getWorldBound() != null){
62            spatPosition = spat.getWorldBound().getCenter();
63        }else{
64            spatPosition = spat.getWorldTranslation();
65        }
66
67        spatPosition.subtract(camPosition, tempVec);
68        spat.queueDistance = tempVec.dot(viewVector);
69
70        return spat.queueDistance;
71    }
72
73    public int compare(Geometry o1, Geometry o2) {
74        Material m1 = o1.getMaterial();
75        Material m2 = o2.getMaterial();
76
77        int sortId = m1.compareTo(m2);
78
79        if (sortId == 0){
80            // use the same shader.
81            // sort front-to-back then.
82            float d1 = distanceToCam(o1);
83            float d2 = distanceToCam(o2);
84
85            if (d1 == d2)
86                return 0;
87            else if (d1 < d2)
88                return -1;
89            else
90                return 1;
91        }else{
92            return sortId;
93        }
94    }
95
96}
97