/*
* 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.InputCapsule;
import com.jme3.export.JmeExporter;
import com.jme3.export.JmeImporter;
import com.jme3.export.OutputCapsule;
import com.jme3.math.Vector3f;
import com.jme3.scene.Spatial;
import java.io.IOException;
/**
* Represents a point light.
* A point light emits light from a given position into all directions in space.
* E.g a lamp or a bright effect. Point light positions are in world space.
* <p>
* In addition to a position, point lights also have a radius which
* can be used to attenuate the influence of the light depending on the
* distance between the light and the effected object.
*
*/
public class PointLight extends Light {
protected Vector3f position = new Vector3f();
protected float radius = 0;
protected float invRadius = 0;
@Override
public void computeLastDistance(Spatial owner) {
if (owner.getWorldBound() != null) {
BoundingVolume bv = owner.getWorldBound();
lastDistance = bv.distanceSquaredTo(position);
} else {
lastDistance = owner.getWorldTranslation().distanceSquared(position);
}
}
/**
* Returns the world space position of the light.
*
* @return the world space position of the light.
*
* @see PointLight#setPosition(com.jme3.math.Vector3f)
*/
public Vector3f getPosition() {
return position;
}
/**
* Set the world space position of the light.
*
* @param position the world space position of the light.
*/
public void setPosition(Vector3f position) {
this.position.set(position);
}
/**
* Returns the radius of the light influence. A radius of 0 means
* the light has no attenuation.
*
* @return the radius of the light
*/
public float getRadius() {
return radius;
}
/**
* Set the radius of the light influence.
* <p>
* Setting a non-zero radius indicates the light should use attenuation.
* If a pixel's distance to this light's position
* is greater than the light's radius, then the pixel will not be
* effected by this light, if the distance is less than the radius, then
* the magnitude of the influence is equal to distance / radius.
*
* @param radius the radius of the light influence.
*
* @throws IllegalArgumentException If radius is negative
*/
public void setRadius(float radius) {
if (radius < 0) {
throw new IllegalArgumentException("Light radius cannot be negative");
}
this.radius = radius;
if(radius!=0){
this.invRadius = 1 / radius;
}else{
this.invRadius = 0;
}
}
/**
* for internal use only
* @return the inverse of the radius
*/
public float getInvRadius() {
return invRadius;
}
@Override
public Light.Type getType() {
return Light.Type.Point;
}
@Override
public void write(JmeExporter ex) throws IOException {
super.write(ex);
OutputCapsule oc = ex.getCapsule(this);
oc.write(position, "position", null);
oc.write(radius, "radius", 0f);
}
@Override
public void read(JmeImporter im) throws IOException {
super.read(im);
InputCapsule ic = im.getCapsule(this);
position = (Vector3f) ic.readSavable("position", null);
radius = ic.readFloat("radius", 0f);
if(radius!=0){
this.invRadius = 1 / radius;
}else{
this.invRadius = 0;
}
}
}