/*
* 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;
/**
* The LinearFog leaf node defines fog distance parameters for
* linear fog.
* LinearFog extends the Fog node by adding a pair of distance values,
* in Z, at which the fog should start obscuring the scene and should maximally
* obscure the scene.
* <P>
* The front and back fog distances are defined in the local coordinate system of
* the node, but the actual fog equation will ideally take place in eye
* coordinates.
* <P>
* The linear fog blending factor, <code>f</code>, is computed as follows:
* <ul>
* <code>f = (backDistance - z) / (backDistance - frontDistance)</code>
* </ul>
* where:
* <ul>
* <code>z</code> is the distance from the viewpoint.<br>
* <code>frontDistance</code> is the distance at which fog starts obscuring objects.<br>
* <code>backDistance</code> is the distance at which fog totally obscurs objects.
* </ul>
*/
public class LinearFog extends Fog {
/**
* Specifies that this LinearFog node allows read access to its distance
* information.
*/
public static final int
ALLOW_DISTANCE_READ = CapabilityBits.LINEAR_FOG_ALLOW_DISTANCE_READ;
/**
* Specifies that this LinearFog node allows write access to its distance
* information.
*/
public static final int
ALLOW_DISTANCE_WRITE = CapabilityBits.LINEAR_FOG_ALLOW_DISTANCE_WRITE;
// Array for setting default read capabilities
private static final int[] readCapabilities = {
ALLOW_DISTANCE_READ
};
/**
* Constructs a LinearFog node with default parameters.
* The default values are as follows:
* <ul>
* front distance : 0.1<br>
* back distance : 1.0<br>
* </ul>
*/
public LinearFog() {
// Just use the defaults
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
}
/**
* Constructs a LinearFog node with the specified fog color.
* @param color the fog color
*/
public LinearFog(Color3f color) {
super(color);
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
}
/**
* Constructs a LinearFog node with the specified fog color and distances.
* @param color the fog color
* @param frontDistance the front distance for the fog
* @param backDistance the back distance for the fog
*/
public LinearFog(Color3f color, double frontDistance, double backDistance) {
super(color);
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
((LinearFogRetained)this.retained).initFrontDistance(frontDistance);
((LinearFogRetained)this.retained).initBackDistance(backDistance);
}
/**
* Constructs a LinearFog node with the specified fog color.
* @param r the red component of the fog color
* @param g the green component of the fog color
* @param b the blue component of the fog color
*/
public LinearFog(float r, float g, float b) {
super(r, g, b);
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
}
/**
* Constructs a LinearFog node with the specified fog color and distances.
* @param r the red component of the fog color
* @param g the green component of the fog color
* @param b the blue component of the fog color
* @param frontDistance the front distance for the fog
* @param backDistance the back distance for the fog
*/
public LinearFog(float r, float g, float b,
double frontDistance, double backDistance) {
super(r, g, b);
// set default read capabilities
setDefaultReadCapabilities(readCapabilities);
((LinearFogRetained)this.retained).initFrontDistance(frontDistance);
((LinearFogRetained)this.retained).initBackDistance(backDistance);
}
/**
* Sets front distance for fog.
* @param frontDistance the distance at which fog starts obscuring objects
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void setFrontDistance(double frontDistance) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_DISTANCE_WRITE))
throw new CapabilityNotSetException(J3dI18N.getString("LinearFog0"));
if (isLive())
((LinearFogRetained)this.retained).setFrontDistance(frontDistance);
else
((LinearFogRetained)this.retained).initFrontDistance(frontDistance);
}
/**
* Gets front distance for fog.
* @return the distance at which fog starts obscuring objects
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public double getFrontDistance() {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_DISTANCE_READ))
throw new CapabilityNotSetException(J3dI18N.getString("LinearFog1"));
return ((LinearFogRetained)this.retained).getFrontDistance();
}
/**
* Sets back distance for fog.
* @param backDistance the distance at which fog totally obscurs objects
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public void setBackDistance(double backDistance) {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_DISTANCE_WRITE))
throw new CapabilityNotSetException(J3dI18N.getString("LinearFog0"));
if (isLive())
((LinearFogRetained)this.retained).setBackDistance(backDistance);
else
((LinearFogRetained)this.retained).initBackDistance(backDistance);
}
/**
* Gets back distance for fog.
* @return the distance at which fog totally obscurs objects
* @exception CapabilityNotSetException if appropriate capability is
* not set and this object is part of live or compiled scene graph
*/
public double getBackDistance() {
if (isLiveOrCompiled())
if(!this.getCapability(ALLOW_DISTANCE_READ))
throw new CapabilityNotSetException(J3dI18N.getString("LinearFog1"));
return ((LinearFogRetained)this.retained).getBackDistance();
}
/**
* Creates the retained mode LinearFogRetained object that this
* LinearFog node will point to.
*/
@Override
void createRetained() {
this.retained = new LinearFogRetained();
this.retained.setSource(this);
}
/**
* 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) {
LinearFog lf = new LinearFog();
lf.duplicateNode(this, forceDuplicate);
return lf;
}
/**
* Copies all LinearFog 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);
LinearFogRetained attr = (LinearFogRetained) originalNode.retained;
LinearFogRetained rt = (LinearFogRetained) retained;
rt.initFrontDistance(attr.getFrontDistance());
rt.initBackDistance(attr.getBackDistance());
}
}