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 */
32package com.jme3.light;
33
34import com.jme3.bounding.BoundingVolume;
35import com.jme3.export.*;
36import com.jme3.math.FastMath;
37import com.jme3.math.Vector3f;
38import com.jme3.scene.Spatial;
39import java.io.IOException;
40
41/**
42 * Represents a spot light.
43 * A spot light emmit a cone of light from a position and in a direction.
44 * It can be used to fake torch lights or car's lights.
45 * <p>
46 * In addition to a position and a direction, spot lights also have a range which
47 * can be used to attenuate the influence of the light depending on the
48 * distance between the light and the effected object.
49 * Also the angle of the cone can be tweaked by changing the spot inner angle and the spot outer angle.
50 * the spot inner angle determin the cone of light where light has full influence.
51 * the spot outer angle determin the cone global cone of light of the spot light.
52 * the light intensity slowly decrease between the inner cone and the outer cone.
53 *  @author Nehon
54 */
55public class SpotLight extends Light implements Savable {
56
57    protected Vector3f position = new Vector3f();
58    protected Vector3f direction = new Vector3f(0,-1,0);
59    protected float spotInnerAngle = FastMath.QUARTER_PI / 8;
60    protected float spotOuterAngle = FastMath.QUARTER_PI / 6;
61    protected float spotRange = 100;
62    protected float invSpotRange = 1 / 100;
63    protected float packedAngleCos=0;
64
65    public SpotLight() {
66        super();
67        computePackedCos();
68    }
69
70    private void computePackedCos() {
71        float innerCos=FastMath.cos(spotInnerAngle);
72        float outerCos=FastMath.cos(spotOuterAngle);
73        packedAngleCos=(int)(innerCos*1000);
74        packedAngleCos+=outerCos;
75    }
76
77    @Override
78    protected void computeLastDistance(Spatial owner) {
79        if (owner.getWorldBound() != null) {
80            BoundingVolume bv = owner.getWorldBound();
81            lastDistance = bv.distanceSquaredTo(position);
82        } else {
83            lastDistance = owner.getWorldTranslation().distanceSquared(position);
84        }
85    }
86
87    @Override
88    public Type getType() {
89        return Type.Spot;
90    }
91
92    public Vector3f getDirection() {
93        return direction;
94    }
95
96    public void setDirection(Vector3f direction) {
97        this.direction.set(direction);
98    }
99
100    public Vector3f getPosition() {
101        return position;
102    }
103
104    public void setPosition(Vector3f position) {
105        this.position.set(position);
106    }
107
108    public float getSpotRange() {
109        return spotRange;
110    }
111
112    /**
113     * Set the range of the light influence.
114     * <p>
115     * Setting a non-zero range indicates the light should use attenuation.
116     * If a pixel's distance to this light's position
117     * is greater than the light's range, then the pixel will not be
118     * effected by this light, if the distance is less than the range, then
119     * the magnitude of the influence is equal to distance / range.
120     *
121     * @param spotRange the range of the light influence.
122     *
123     * @throws IllegalArgumentException If spotRange is negative
124     */
125    public void setSpotRange(float spotRange) {
126        if (spotRange < 0) {
127            throw new IllegalArgumentException("SpotLight range cannot be negative");
128        }
129        this.spotRange = spotRange;
130        if (spotRange != 0) {
131            this.invSpotRange = 1 / spotRange;
132        } else {
133            this.invSpotRange = 0;
134        }
135    }
136
137    /**
138     * for internal use only
139     * @return the inverse of the spot range
140     */
141    public float getInvSpotRange() {
142        return invSpotRange;
143    }
144
145    /**
146     * returns the spot inner angle
147     * @return the spot inner angle
148     */
149    public float getSpotInnerAngle() {
150        return spotInnerAngle;
151    }
152
153    /**
154     * Sets the inner angle of the cone of influence.
155     * This angle is the angle between the spot direction axis and the inner border of the cone of influence.
156     * @param spotInnerAngle
157     */
158    public void setSpotInnerAngle(float spotInnerAngle) {
159        this.spotInnerAngle = spotInnerAngle;
160        computePackedCos();
161    }
162
163    /**
164     * returns the spot outer angle
165     * @return the spot outer angle
166     */
167    public float getSpotOuterAngle() {
168        return spotOuterAngle;
169    }
170
171    /**
172     * Sets the outer angle of the cone of influence.
173     * This angle is the angle between the spot direction axis and the outer border of the cone of influence.
174     * this should be greater than the inner angle or the result will be unexpected.
175     * @param spotOuterAngle
176     */
177    public void setSpotOuterAngle(float spotOuterAngle) {
178        this.spotOuterAngle = spotOuterAngle;
179        computePackedCos();
180    }
181
182    /**
183     * for internal use only
184     * @return the cosines of the inner and outter angle packed in a float
185     */
186    public float getPackedAngleCos() {
187        return packedAngleCos;
188    }
189
190
191
192    @Override
193    public void write(JmeExporter ex) throws IOException {
194        super.write(ex);
195        OutputCapsule oc = ex.getCapsule(this);
196        oc.write(direction, "direction", new Vector3f());
197        oc.write(position, "position", new Vector3f());
198        oc.write(spotInnerAngle, "spotInnerAngle", FastMath.QUARTER_PI / 8);
199        oc.write(spotOuterAngle, "spotOuterAngle", FastMath.QUARTER_PI / 6);
200        oc.write(spotRange, "spotRange", 100);
201    }
202
203    @Override
204    public void read(JmeImporter im) throws IOException {
205        super.read(im);
206        InputCapsule ic = im.getCapsule(this);
207        spotInnerAngle = ic.readFloat("spotInnerAngle", FastMath.QUARTER_PI / 8);
208        spotOuterAngle = ic.readFloat("spotOuterAngle", FastMath.QUARTER_PI / 6);
209        direction = (Vector3f) ic.readSavable("direction", new Vector3f());
210        position = (Vector3f) ic.readSavable("position", new Vector3f());
211        spotRange = ic.readFloat("spotRange", 100);
212        if (spotRange != 0) {
213            this.invSpotRange = 1 / spotRange;
214        } else {
215            this.invSpotRange = 0;
216        }
217    }
218}
219