/*

* 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 org.scijava.java3d;

import java.util.Enumeration;

import org.scijava.vecmath.Color3f;

/**

* Color interpolation behavior. This class defines a behavior that

* modifies the ambient, emissive, diffuse, or specular color of its

* target material object by linearly interpolating between a pair of

* specified colors, using the value generated by the specified Alpha

* object.

* The behavior modifies the color specified by the

* Material's colorTarget attribute, one of: AMBIENT, EMISSIVE,

* DIFFUSE, SPECULAR, or AMBIENT_AND_DIFFUSE.

* The ALLOW_COMPONENT_READ bit must be set in the Material object in

* order for the Material's colorTarget to be read.

* If the Material object's ALLOW_COMPONENT_READ bit is <i>not</i> set, the

* diffuse component will be modified.

*

* @see Material

*/

public class ColorInterpolator extends Interpolator {

Material target;

Color3f startColor = new Color3f();

Color3f endColor = new Color3f();

Color3f newColor = new Color3f();

// We can't use a boolean flag since it is possible

// that after alpha change, this procedure only run

// once at alpha.finish(). So the best way is to

// detect alpha value change.

private float prevAlphaValue = Float.NaN;

private int prevColorTarget = -1;

private WakeupCriterion passiveWakeupCriterion = new WakeupOnElapsedFrames(0, true);

// non-public, no parameter constructor used by cloneNode

ColorInterpolator() {

}

/**

* Constructs a trivial color interpolator with a specified target,

* a starting color of black, and an ending color of white.

* @param alpha the alpha object for this interpolator

* @param target the material component object whose

* color is affected by this color interpolator

*/

public ColorInterpolator(Alpha alpha,

Material target) {

super(alpha);

this.target = target;

this.startColor.set(0.0f, 0.0f, 0.0f);

this.endColor.set(1.0f, 1.0f, 1.0f);

}

/**

* Constructs a color interpolator with the specified target,

* starting color, and ending color.

* @param alpha the alpha object for this interpolator

* @param target the material component object whose

* color is affected by this color interpolator

* @param startColor the starting color

* @param endColor the ending color

*/

public ColorInterpolator(Alpha alpha,

Material target,

Color3f startColor,

Color3f endColor) {

super(alpha);

this.target = target;

this.startColor.set(startColor);

this.endColor.set(endColor);

}

/**

* This method sets the startColor for this interpolator.

* @param color the new start color

*/

public void setStartColor(Color3f color) {

startColor.set(color);

prevAlphaValue = Float.NaN;

}

/**

* This method retrieves this interpolator's startColor.

* @param color the vector that will receive the interpolator's start color

*/

public void getStartColor(Color3f color) {

color.set(startColor);

}

/**

* This method sets the endColor for this interpolator.

* @param color the new end color

*/

public void setEndColor(Color3f color) {

endColor.set(color);

prevAlphaValue = Float.NaN;

}

/**

* This method retrieves this interpolator's endColor.

* @param color the vector that will receive the interpolator's end color

*/

public void getEndColor(Color3f color) {

color.set(endColor);

}

/**

* This method sets the target material component object for

* this interpolator.

* @param target the material component object whose

* color is affected by this color interpolator

*/

public void setTarget(Material target) {

this.target = target;

prevAlphaValue = Float.NaN;

}

/**

* This method retrieves this interpolator's target material

* component object.

* @return the interpolator's target material component object

*/

public Material getTarget() {

return target;

}

// The ColorInterpolator's initialize routine uses the default

// initialization routine.

/**

* This method is invoked by the behavior scheduler every frame.

* It maps the alpha value that corresponds to the current time

* into a color value and updates the ambient, emissive, diffuse,

* or specular color (or both the ambient and diffuse color) of

* the specified target Material object with this new color value.

*

* @param criteria an enumeration of the criteria that caused the

* stimulus

*/

@Override

public void processStimulus(Enumeration criteria) {

// Handle stimulus

WakeupCriterion criterion = passiveWakeupCriterion;

if (alpha != null) {

float value = alpha.value();

int colorTarget = Material.DIFFUSE;

if (target.getCapability(Material.ALLOW_COMPONENT_READ))

colorTarget = target.getColorTarget();

if (value != prevAlphaValue || colorTarget != prevColorTarget) {

newColor.x = (1.0f-value)*startColor.x + value*endColor.x;

newColor.y = (1.0f-value)*startColor.y + value*endColor.y;

newColor.z = (1.0f-value)*startColor.z + value*endColor.z;

switch (colorTarget) {

case Material.AMBIENT:

target.setAmbientColor(newColor);

break;

case Material.AMBIENT_AND_DIFFUSE:

target.setAmbientColor(newColor);

// fall through

case Material.DIFFUSE:

target.setDiffuseColor(newColor);

break;

case Material.EMISSIVE:

target.setEmissiveColor(newColor);

break;

case Material.SPECULAR:

target.setSpecularColor(newColor);

break;

}

prevAlphaValue = value;

prevColorTarget = colorTarget;

}

if (!alpha.finished() && !alpha.isPaused()) {

criterion = defaultWakeupCriterion;

}

}

wakeupOn(criterion);

}

/**

* 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) {

ColorInterpolator ci = new ColorInterpolator();

ci.duplicateNode(this, forceDuplicate);

return ci;

}

/**

* Copies all ColorInterpolator 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);

ColorInterpolator ci = (ColorInterpolator) originalNode;

ci.getStartColor(startColor);

ci.getEndColor(endColor);

// this reference will be updated in updateNodeReferences()

setTarget(ci.getTarget());

}

/**

* Callback used to allow a node to check if any scene graph objects

* referenced

* by that node have been duplicated via a call to <code>cloneTree</code>.

* This method is called by <code>cloneTree</code> after all nodes in

* the sub-graph have been duplicated. The cloned Leaf node's method

* will be called and the Leaf node can then look up any object references

* by using the <code>getNewObjectReference</code> method found in the

* <code>NodeReferenceTable</code> object. If a match is found, a

* reference to the corresponding object in the newly cloned sub-graph

* is returned. If no corresponding reference is found, either a

* DanglingReferenceException is thrown or a reference to the original

* object is returned depending on the value of the

* <code>allowDanglingReferences</code> parameter passed in the

* <code>cloneTree</code> call.

* <p>

* NOTE: Applications should <i>not</i> call this method directly.

* It should only be called by the cloneTree method.

*

* @param referenceTable a NodeReferenceTableObject that contains the

* <code>getNewObjectReference</code> method needed to search for

* new object instances.

* @see NodeReferenceTable

* @see Node#cloneTree

* @see DanglingReferenceException

*/

@Override

public void updateNodeReferences(NodeReferenceTable referenceTable) {

super.updateNodeReferences(referenceTable);

// check Material

NodeComponent nc = getTarget();

if (nc != null) {

setTarget((Material) referenceTable.getNewObjectReference(nc));

}

}

}