/*
* Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
package javax.media.j3d;
import javax.vecmath.Color3f;
import javax.vecmath.Point3f;
/**
* The PointLight object specifies an attenuated light source at a
* fixed point in space that radiates light equally in all directions
* away from the light source. PointLight has the same attributes as
* a Light node, with the addition of location and attenuation
* parameters.
* <p>
* A point light contributes to diffuse and specular reflections,
* which in turn depend on the orientation and position of a
* surface. A point light does not contribute to ambient reflections.
* <p>
* A PointLight is attenuated by multiplying the contribution of the
* light by an attenuation factor. The attenuation factor causes the
* the PointLight's brightness to decrease as distance from the light
* source increases.
* A PointLight's attenuation factor contains three values:
* <P><UL>
* <LI>Constant attenuation</LI>
* <LI>Linear attenuation</LI>
* <LI>Quadratic attenuation</LI></UL>
* <p>
* A PointLight is attenuated by the reciprocal of the sum of:
* <p>
* <ul>
* The constant attenuation factor<br>
* The Linear attenuation factor times the distance between the light
* and the vertex being illuminated<br>
* The quadratic attenuation factor times the square of the distance
* between the light and the vertex
* </ul>
* <p>
* By default, the constant attenuation value is 1 and the other
* two values are 0, resulting in no attenuation.
*/
public class PointLight extends Light {
/**
* Specifies that this PointLight node allows reading its position
* information.
*/
public static final int
ALLOW_POSITION_READ = CapabilityBits.POINT_LIGHT_ALLOW_POSITION_READ;
/**
* Specifies that this PointLight node allows writing its position
* information.
*/
public static final int
ALLOW_POSITION_WRITE = CapabilityBits.POINT_LIGHT_ALLOW_POSITION_WRITE;
/**
* Specifies that this PointLight node allows reading its attenuation
* information.
*/
public static final int
ALLOW_ATTENUATION_READ = CapabilityBits.POINT_LIGHT_ALLOW_ATTENUATION_READ;
/**
* Specifies that this PointLight node allows writing its attenuation
* information.
*/
public static final int
ALLOW_ATTENUATION_WRITE = CapabilityBits.POINT_LIGHT_ALLOW_ATTENUATION_WRITE;
// Array for setting default read capabilities
private static final int[] readCapabilities = {
ALLOW_POSITION_READ,
ALLOW_ATTENUATION_READ
};
/**
* Constructs a PointLight node with default parameters.
* The default values are as follows:
* <ul>
* position : (0,0,0)<br>
* attenuation : (1,0,0)<br>
* </ul>
*/
public PointLight() {
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
}
/**
* Constructs and initializes a point light.
* @param color the color of the light source
* @param position the position of the light in three-space
* @param attenuation the attenutation (constant, linear, quadratic) of the light
*/
public PointLight(Color3f color,
Point3f position,
Point3f attenuation) {
super(color);
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
((PointLightRetained)this.retained).initPosition(position);
((PointLightRetained)this.retained).initAttenuation(attenuation);
}
/**
* Constructs and initializes a point light.
* @param lightOn flag indicating whether this light is on or off
* @param color the color of the light source
* @param position the position of the light in three-space
* @param attenuation the attenuation (constant, linear, quadratic) of the light
*/
public PointLight(boolean lightOn,
Color3f color,
Point3f position,
Point3f attenuation) {
super(lightOn, color);
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
((PointLightRetained)this.retained).initPosition(position);
((PointLightRetained)this.retained).initAttenuation(attenuation);
}
/**
* Creates the retained mode PointLightRetained object that this
* PointLight component object will point to.
*/
@Override
void createRetained() {
this.retained = new PointLightRetained();
this.retained.setSource(this);
}
/**
* Set light position.
* @param position the new position
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void setPosition(Point3f position) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_POSITION_WRITE))
throw new CapabilityNotSetException(J3dI18N.getString("PointLight0"));
if (isLive())
((PointLightRetained)this.retained).setPosition(position);
else
((PointLightRetained)this.retained).initPosition(position);
}
/**
* Set light position.
* @param x the new X position
* @param y the new Y position
* @param z the new Z position
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void setPosition(float x, float y, float z) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_POSITION_WRITE))
throw new CapabilityNotSetException(J3dI18N.getString("PointLight1"));
if (isLive())
((PointLightRetained)this.retained).setPosition(x,y,z);
else
((PointLightRetained)this.retained).initPosition(x,y,z);
}
/**
* Gets this Light's current position and places it in the parameter specified.
* @param position the vector that will receive this node's position
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void getPosition(Point3f position) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_POSITION_READ))
throw new CapabilityNotSetException(J3dI18N.getString("PointLight2"));
((PointLightRetained)this.retained).getPosition(position);
}
/**
* Sets this Light's current attenuation values and places it in the parameter specified.
* @param attenuation the vector that will receive the attenuation values
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void setAttenuation(Point3f attenuation) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_ATTENUATION_WRITE))
throw new CapabilityNotSetException(J3dI18N.getString("PointLight3"));
if (isLive())
((PointLightRetained)this.retained).setAttenuation(attenuation);
else
((PointLightRetained)this.retained).initAttenuation(attenuation);
}
/**
* Sets this Light's current attenuation values and places it in the parameter specified.
* @param constant the light's constant attenuation
* @param linear the light's linear attenuation
* @param quadratic the light's quadratic attenuation
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void setAttenuation(float constant, float linear, float quadratic) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_ATTENUATION_WRITE))
throw new CapabilityNotSetException(J3dI18N.getString("PointLight3"));
if (isLive())
((PointLightRetained)this.retained).setAttenuation(constant, linear, quadratic);
else
((PointLightRetained)this.retained).initAttenuation(constant, linear, quadratic);
}
/**
* Gets this Light's current attenuation values and places it in the parameter specified.
* @param attenuation the vector that will receive the attenuation values
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void getAttenuation(Point3f attenuation) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_ATTENUATION_READ))
throw new CapabilityNotSetException(J3dI18N.getString("PointLight5"));
((PointLightRetained)this.retained).getAttenuation(attenuation);
}
/**
* Used to create a new instance of the node. This routine is called
* by <code>cloneTree</code> to duplicate the current node.
* @param forceDuplicate when set to <code>true</code>, causes the
* <code>duplicateOnCloneTree</code> flag to be ignored. When
* <code>false</code>, the value of each node's
* <code>duplicateOnCloneTree</code> variable determines whether
* NodeComponent data is duplicated or copied.
*
* @see Node#cloneTree
* @see Node#cloneNode
* @see Node#duplicateNode
* @see NodeComponent#setDuplicateOnCloneTree
*/
@Override
public Node cloneNode(boolean forceDuplicate) {
PointLight p = new PointLight();
p.duplicateNode(this, forceDuplicate);
return p;
}
/**
* Copies all PointLight information from
* <code>originalNode</code> into
* the current node. This method is called from the
* <code>cloneNode</code> method which is, in turn, called by the
* <code>cloneTree</code> method.<P>
*
* @param originalNode the original node to duplicate.
* @param forceDuplicate when set to <code>true</code>, causes the
* <code>duplicateOnCloneTree</code> flag to be ignored. When
* <code>false</code>, the value of each node's
* <code>duplicateOnCloneTree</code> variable determines whether
* NodeComponent data is duplicated or copied.
*
* @exception RestrictedAccessException if this object is part of a live
* or compiled scenegraph.
*
* @see Node#duplicateNode
* @see Node#cloneTree
* @see NodeComponent#setDuplicateOnCloneTree
*/
@Override
void duplicateAttributes(Node originalNode, boolean forceDuplicate) {
super.duplicateAttributes(originalNode, forceDuplicate);
PointLightRetained attr = (PointLightRetained) originalNode.retained;
PointLightRetained rt = (PointLightRetained) retained;
Point3f p = new Point3f();
attr.getPosition(p);
rt.initPosition(p);
attr.getAttenuation(p);
rt.initAttenuation(p);
}
}