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.light;
34
35import com.jme3.export.InputCapsule;
36import com.jme3.export.JmeExporter;
37import com.jme3.export.JmeImporter;
38import com.jme3.export.OutputCapsule;
39import com.jme3.math.Vector3f;
40import com.jme3.scene.Spatial;
41import java.io.IOException;
42
43/**
44 * <code>DirectionalLight</code> is a light coming from a certain direction in world space.
45 * E.g sun or moon light.
46 * <p>
47 * Directional lights have no specific position in the scene, they always
48 * come from their direction regardless of where an object is placed.
49 */
50public class DirectionalLight extends Light {
51
52    protected Vector3f direction = new Vector3f(0f, -1f, 0f);
53
54    @Override
55    public void computeLastDistance(Spatial owner) {
56        lastDistance = 0; // directional lights are always closest to their owner
57    }
58
59    /**
60     * Returns the direction vector of the light.
61     *
62     * @return The direction vector of the light.
63     *
64     * @see DirectionalLight#setDirection(com.jme3.math.Vector3f)
65     */
66    public Vector3f getDirection() {
67        return direction;
68    }
69
70    /**
71     * Sets the direction of the light.
72     * <p>
73     * Represents the vector direction the light is coming from.
74     * (1, 0, 0) would represent a directional light coming from the X axis.
75     *
76     * @param dir the direction of the light.
77     */
78    public void setDirection(Vector3f dir){
79        direction.set(dir);
80        if (!direction.isUnitVector()) {
81            direction.normalizeLocal();
82        }
83    }
84
85    @Override
86    public Type getType() {
87        return Type.Directional;
88    }
89
90    @Override
91    public void write(JmeExporter ex) throws IOException {
92        super.write(ex);
93        OutputCapsule oc = ex.getCapsule(this);
94        oc.write(direction, "direction", null);
95    }
96
97    @Override
98    public void read(JmeImporter im) throws IOException {
99        super.read(im);
100        InputCapsule ic = im.getCapsule(this);
101        direction = (Vector3f) ic.readSavable("direction", null);
102    }
103
104}
105