javax.media.j3d.TransparencyInterpolator Maven / Gradle / Ivy
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*
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package javax.media.j3d;
import java.util.Enumeration;
/**
* TransparencyInterpolator behavior. This class defines a behavior
* that modifies the transparency of its target TransparencyAttributes
* object by linearly interpolating between a pair of specified
* transparency values (using the value generated by the specified
* Alpha object).
*
* There are two forms of constructor to specify the
* type of transparency interpolation. The first constructor takes
* an Alpha and a TransparencyAttributes object and creates a transparency
* interpolator that maps an Alpha value of 1.0 to a transparency
* value of 1.0, and an Alpha value of 0.0 and maps it to a
* transparency value of 0.0. The second constructor takes an Alpha,
* a TransparencyAttributes object, a minimum transparency value and a
* maximum transparency value. This constructor provides more
* flexibility by specifying how the Alpha values are mapped
* to the transparency values - an Alpha of 1.0 maps to the
* maximum transparency value and an Alpha of 0.0 maps to the
* minimum transparency value.
*
* @see Alpha
* @see TransparencyAttributes
*/
public class TransparencyInterpolator extends Interpolator {
TransparencyAttributes target;
float minimumTransparency;
float maximumTransparency;
// 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 WakeupCriterion passiveWakeupCriterion = new WakeupOnElapsedFrames(0, true);
// non-public, default constructor used by cloneNode
TransparencyInterpolator() {
}
/**
* Constructs a trivial transparency interpolator with a specified target,
* a minimum transparency of 0.0f and a maximum transparency of 1.0f.
* @param alpha the alpha object for this interpolator
* @param target the TransparencyAttributes component object affected
* by this interpolator
*/
public TransparencyInterpolator(Alpha alpha,
TransparencyAttributes target) {
super(alpha);
this.target = target;
this.minimumTransparency = 0.0f;
this.maximumTransparency = 1.0f;
}
/**
* Constructs a new transparency interpolator that varies the target
* material's transparency between the two transparency values.
* @param alpha the alpha object for this Interpolator
* @param target the TransparencyAttributes component object affected
* by this interpolator
* @param minimumTransparency the starting transparency
* @param maximumTransparency the ending transparency
*/
public TransparencyInterpolator(Alpha alpha,
TransparencyAttributes target,
float minimumTransparency,
float maximumTransparency) {
super(alpha);
this.target = target;
this.minimumTransparency = minimumTransparency;
this.maximumTransparency = maximumTransparency;
}
/**
* This method sets the minimumTransparency for this interpolator.
* @param transparency the new minimum transparency
*/
public void setMinimumTransparency(float transparency) {
this.minimumTransparency = transparency;
}
/**
* This method retrieves this interpolator's minimumTransparency.
* @return the interpolator's minimum transparency value
*/
public float getMinimumTransparency() {
return this.minimumTransparency;
}
/**
* This method sets the maximumTransparency for this interpolator.
* @param transparency the new maximum transparency
*/
public void setMaximumTransparency(float transparency) {
this.maximumTransparency = transparency;
}
/**
* This method retrieves this interpolator's maximumTransparency.
* @return the interpolator's maximal transparency vslue
*/
public float getMaximumTransparency() {
return this.maximumTransparency;
}
/**
* This method sets the target TransparencyAttributes object
* for this interpolator.
* @param target the target TransparencyAttributes object
*/
public void setTarget(TransparencyAttributes target) {
this.target = target;
}
/**
* This method retrieves this interpolator's target reference.
* @return the interpolator's target TransparencyAttributes object
*/
public TransparencyAttributes getTarget() {
return target;
}
// The TransparencyInterpolator'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
* transparency value and updates the specified TransparencyAttributes
* object with this new transparency 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();
if (value != prevAlphaValue) {
float val = (float)((1.0-value)*minimumTransparency +
value*maximumTransparency);
target.setTransparency(val);
prevAlphaValue = value;
}
if (!alpha.finished() && !alpha.isPaused()) {
criterion = defaultWakeupCriterion;
}
}
wakeupOn(criterion);
}
/**
* Used to create a new instance of the node. This routine is called
* by cloneTree to duplicate the current node.
* @param forceDuplicate when set to true, causes the
* duplicateOnCloneTree flag to be ignored. When
* false, the value of each node's
* duplicateOnCloneTree 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) {
TransparencyInterpolator ti = new TransparencyInterpolator();
ti.duplicateNode(this, forceDuplicate);
return ti;
}
/**
* Copies all TransparencyInterpolator information from
* originalNode into
* the current node. This method is called from the
* cloneNode method which is, in turn, called by the
* cloneTree method.
*
* @param originalNode the original node to duplicate.
* @param forceDuplicate when set to true, causes the
* duplicateOnCloneTree flag to be ignored. When
* false, the value of each node's
* duplicateOnCloneTree 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);
TransparencyInterpolator ti =
(TransparencyInterpolator) originalNode;
setMinimumTransparency(ti.getMinimumTransparency());
setMaximumTransparency(ti.getMaximumTransparency());
// this reference will be updated in updateNodeReferences()
setTarget(ti.getTarget());
}
/**
* Callback used to allow a node to check if any nodes referenced
* by that node have been duplicated via a call to cloneTree.
* This method is called by cloneTree 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 node references
* by using the getNewObjectReference method found in the
* NodeReferenceTable object. If a match is found, a
* reference to the corresponding Node 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
* node is returned depending on the value of the
* allowDanglingReferences parameter passed in the
* cloneTree call.
*
* NOTE: Applications should not call this method directly.
* It should only be called by the cloneTree method.
*
* @param referenceTable a NodeReferenceTableObject that contains the
* getNewObjectReference 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 TransparencyAttributes
NodeComponent nc = getTarget();
if (nc != null) {
setTarget((TransparencyAttributes) referenceTable.getNewObjectReference(nc));
}
}
}