/*
* 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.light;
import com.jme3.bounding.BoundingVolume;
import com.jme3.export.*;
import com.jme3.math.FastMath;
import com.jme3.math.Vector3f;
import com.jme3.scene.Spatial;
import java.io.IOException;
/**
* Represents a spot light.
* A spot light emmit a cone of light from a position and in a direction.
* It can be used to fake torch lights or car's lights.
* <p>
* In addition to a position and a direction, spot lights also have a range which
* can be used to attenuate the influence of the light depending on the
* distance between the light and the effected object.
* Also the angle of the cone can be tweaked by changing the spot inner angle and the spot outer angle.
* the spot inner angle determin the cone of light where light has full influence.
* the spot outer angle determin the cone global cone of light of the spot light.
* the light intensity slowly decrease between the inner cone and the outer cone.
* @author Nehon
*/
public class SpotLight extends Light implements Savable {
protected Vector3f position = new Vector3f();
protected Vector3f direction = new Vector3f(0,-1,0);
protected float spotInnerAngle = FastMath.QUARTER_PI / 8;
protected float spotOuterAngle = FastMath.QUARTER_PI / 6;
protected float spotRange = 100;
protected float invSpotRange = 1 / 100;
protected float packedAngleCos=0;
public SpotLight() {
super();
computePackedCos();
}
private void computePackedCos() {
float innerCos=FastMath.cos(spotInnerAngle);
float outerCos=FastMath.cos(spotOuterAngle);
packedAngleCos=(int)(innerCos*1000);
//due to approximations, very close angles can give the same cos
//here we make sure outer cos is bellow inner cos.
if(((int)packedAngleCos)== ((int)(outerCos*1000)) ){
outerCos -= 0.001f;
}
packedAngleCos+=outerCos;
}
@Override
protected void computeLastDistance(Spatial owner) {
if (owner.getWorldBound() != null) {
BoundingVolume bv = owner.getWorldBound();
lastDistance = bv.distanceSquaredTo(position);
} else {
lastDistance = owner.getWorldTranslation().distanceSquared(position);
}
}
@Override
public Type getType() {
return Type.Spot;
}
public Vector3f getDirection() {
return direction;
}
public void setDirection(Vector3f direction) {
this.direction.set(direction);
}
public Vector3f getPosition() {
return position;
}
public void setPosition(Vector3f position) {
this.position.set(position);
}
public float getSpotRange() {
return spotRange;
}
/**
* Set the range of the light influence.
* <p>
* Setting a non-zero range indicates the light should use attenuation.
* If a pixel's distance to this light's position
* is greater than the light's range, then the pixel will not be
* effected by this light, if the distance is less than the range, then
* the magnitude of the influence is equal to distance / range.
*
* @param spotRange the range of the light influence.
*
* @throws IllegalArgumentException If spotRange is negative
*/
public void setSpotRange(float spotRange) {
if (spotRange < 0) {
throw new IllegalArgumentException("SpotLight range cannot be negative");
}
this.spotRange = spotRange;
if (spotRange != 0) {
this.invSpotRange = 1 / spotRange;
} else {
this.invSpotRange = 0;
}
}
/**
* for internal use only
* @return the inverse of the spot range
*/
public float getInvSpotRange() {
return invSpotRange;
}
/**
* returns the spot inner angle
* @return the spot inner angle
*/
public float getSpotInnerAngle() {
return spotInnerAngle;
}
/**
* Sets the inner angle of the cone of influence.
* This angle is the angle between the spot direction axis and the inner border of the cone of influence.
* @param spotInnerAngle
*/
public void setSpotInnerAngle(float spotInnerAngle) {
this.spotInnerAngle = spotInnerAngle;
computePackedCos();
}
/**
* returns the spot outer angle
* @return the spot outer angle
*/
public float getSpotOuterAngle() {
return spotOuterAngle;
}
/**
* Sets the outer angle of the cone of influence.
* This angle is the angle between the spot direction axis and the outer border of the cone of influence.
* this should be greater than the inner angle or the result will be unexpected.
* @param spotOuterAngle
*/
public void setSpotOuterAngle(float spotOuterAngle) {
this.spotOuterAngle = spotOuterAngle;
computePackedCos();
}
/**
* for internal use only
* @return the cosines of the inner and outter angle packed in a float
*/
public float getPackedAngleCos() {
return packedAngleCos;
}
@Override
public void write(JmeExporter ex) throws IOException {
super.write(ex);
OutputCapsule oc = ex.getCapsule(this);
oc.write(direction, "direction", new Vector3f());
oc.write(position, "position", new Vector3f());
oc.write(spotInnerAngle, "spotInnerAngle", FastMath.QUARTER_PI / 8);
oc.write(spotOuterAngle, "spotOuterAngle", FastMath.QUARTER_PI / 6);
oc.write(spotRange, "spotRange", 100);
}
@Override
public void read(JmeImporter im) throws IOException {
super.read(im);
InputCapsule ic = im.getCapsule(this);
spotInnerAngle = ic.readFloat("spotInnerAngle", FastMath.QUARTER_PI / 8);
spotOuterAngle = ic.readFloat("spotOuterAngle", FastMath.QUARTER_PI / 6);
computePackedCos();
direction = (Vector3f) ic.readSavable("direction", new Vector3f());
position = (Vector3f) ic.readSavable("position", new Vector3f());
spotRange = ic.readFloat("spotRange", 100);
if (spotRange != 0) {
this.invSpotRange = 1 / spotRange;
} else {
this.invSpotRange = 0;
}
}
}