javax.media.j3d.TransformInterpolator Maven / Gradle / Ivy
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package javax.media.j3d;
import java.util.Enumeration;
/**
* TransformInterpolator is an abstract class that extends
* Interpolator to provide common methods used by various transform
* related interpolator subclasses. These include methods to set/get
* the target of TransformGroup, and set/get transform of axis.
*
* @since Java 3D 1.3
*/
public abstract class TransformInterpolator extends Interpolator {
/**
* The TransformGroup node affected by this transformInterpolator
*/
protected TransformGroup target = null;
/**
* The transform that defines the local coordinate
*/
protected Transform3D axis = new Transform3D();
/**
* The inverse transform that defines the local coordinate
*/
protected Transform3D axisInverse = new Transform3D();
/**
* The transform which is passed into computeTransform() when computeTransform()
* is called implicitly from processStimulus()
*/
private Transform3D currentTransform = new Transform3D();
// 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);
/**
* Constructs a TransformInterpolator node with a null alpha value and
* a null target of TransformGroup
*/
public TransformInterpolator() {
}
/**
* Constructs a trivial transform interpolator with a specified alpha,
* a specified target and an default axis set to Identity.
* @param alpha The alpha object for this transform Interpolator
* @param target The target TransformGroup for this TransformInterpolator
*/
public TransformInterpolator(Alpha alpha, TransformGroup target) {
super(alpha);
this.target = target;
axis.setIdentity();
axisInverse.setIdentity();
}
/**
* Constructs a new transform interpolator that set an specified alpha,
* a specified targe and a specified axisOfTransform.
* @param alpha the alpha object for this interpolator
* @param target the transformGroup node affected by this transformInterpolator
* @param axisOfTransform the transform that defines the local coordinate
* system in which this interpolator operates.
*/
public TransformInterpolator(Alpha alpha,
TransformGroup target,
Transform3D axisOfTransform){
super(alpha);
this.target = target;
axis.set(axisOfTransform);
axisInverse.invert(axis);
}
/**
* This method sets the target TransformGroup node for this
* interpolator.
* @param target The target TransformGroup
*/
public void setTarget(TransformGroup target) {
this.target = target;
}
/**
* This method retrieves this interpolator's TransformGroup
* node reference.
* @return the Interpolator's target TransformGroup
*/
public TransformGroup getTarget() {
return target;
}
/**
* This method sets the axis of transform for this interpolator.
* @param axisOfTransform the transform that defines the local coordinate
* system in which this interpolator operates
*/
public void setTransformAxis(Transform3D axisOfTransform) {
this.axis.set(axisOfTransform);
this.axisInverse.invert(this.axis);
}
/**
* This method retrieves this interpolator's axis of transform.
* @return the interpolator's axis of transform
*/
public Transform3D getTransformAxis() {
return new Transform3D(this.axis);
}
/**
* Computes the new transform for this interpolator for a given
* alpha value.
*
* @param alphaValue alpha value between 0.0 and 1.0
* @param transform object that receives the computed transform for
* the specified alpha value
*/
public abstract void computeTransform(float alphaValue,
Transform3D transform);
/**
* This method is invoked by the behavior scheduler every frame.
* First it gets the alpha value that corresponds to the current time.
* Then it calls computeTransform() method to computes the transform based on this
* alpha vaule, and updates the specified TransformGroup node with this new transform.
* @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) {
computeTransform(value, currentTransform);
target.setTransform(currentTransform);
prevAlphaValue = value;
}
if (!alpha.finished() && !alpha.isPaused()) {
criterion = defaultWakeupCriterion;
}
}
wakeupOn(criterion);
}
/**
* Copies all TransformInterpolator 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);
TransformInterpolator ti = (TransformInterpolator) originalNode;
setTransformAxis(ti.getTransformAxis());
// this reference will be updated in updateNodeReferences()
setTarget(ti.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 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 object references
* by using the getNewObjectReference method found in the
* NodeReferenceTable 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
* 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 TransformGroup
Node n = getTarget();
if (n != null) {
setTarget((TransformGroup) referenceTable.getNewObjectReference(n));
}
}
}