001: /*
002: * $RCSfile: TransformInterpolator.java,v $
003: *
004: * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved.
005: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
006: *
007: * This code is free software; you can redistribute it and/or modify it
008: * under the terms of the GNU General Public License version 2 only, as
009: * published by the Free Software Foundation. Sun designates this
010: * particular file as subject to the "Classpath" exception as provided
011: * by Sun in the LICENSE file that accompanied this code.
012: *
013: * This code is distributed in the hope that it will be useful, but WITHOUT
014: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
015: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
016: * version 2 for more details (a copy is included in the LICENSE file that
017: * accompanied this code).
018: *
019: * You should have received a copy of the GNU General Public License version
020: * 2 along with this work; if not, write to the Free Software Foundation,
021: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
022: *
023: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
024: * CA 95054 USA or visit www.sun.com if you need additional information or
025: * have any questions.
026: *
027: * $Revision: 1.5 $
028: * $Date: 2008/02/28 20:17:32 $
029: * $State: Exp $
030: */
031:
032: package javax.media.j3d;
033:
034: import java.util.Enumeration;
035:
036: /**
037: * TransformInterpolator is an abstract class that extends
038: * Interpolator to provide common methods used by various transform
039: * related interpolator subclasses. These include methods to set/get
040: * the target of TransformGroup, and set/get transform of axis.
041: *
042: * @since Java 3D 1.3
043: */
044:
045: public abstract class TransformInterpolator extends Interpolator {
046: /**
047: * The TransformGroup node affected by this transformInterpolator
048: */
049: protected TransformGroup target = null;
050:
051: /**
052: * The transform that defines the local coordinate
053: */
054: protected Transform3D axis = new Transform3D();
055:
056: /**
057: * The inverse transform that defines the local coordinate
058: */
059: protected Transform3D axisInverse = new Transform3D();
060:
061: /**
062: * The transform which is passed into computeTransform() when computeTransform()
063: * is called implicitly from processStimulus()
064: */
065: private Transform3D currentTransform = new Transform3D();
066:
067: // We can't use a boolean flag since it is possible
068: // that after alpha change, this procedure only run
069: // once at alpha.finish(). So the best way is to
070: // detect alpha value change.
071: private float prevAlphaValue = Float.NaN;
072: private WakeupCriterion passiveWakeupCriterion = (WakeupCriterion) new WakeupOnElapsedFrames(
073: 0, true);
074:
075: /**
076: * Constructs a TransformInterpolator node with a null alpha value and
077: * a null target of TransformGroup
078: */
079: public TransformInterpolator() {
080: }
081:
082: /**
083: * Constructs a trivial transform interpolator with a specified alpha,
084: * a specified target and an default axis set to Identity.
085: * @param alpha The alpha object for this transform Interpolator
086: * @param target The target TransformGroup for this TransformInterpolator
087: */
088: public TransformInterpolator(Alpha alpha, TransformGroup target) {
089: super (alpha);
090: this .target = target;
091: axis.setIdentity();
092: axisInverse.setIdentity();
093: }
094:
095: /**
096: * Constructs a new transform interpolator that set an specified alpha,
097: * a specified targe and a specified axisOfTransform.
098: * @param alpha the alpha object for this interpolator
099: * @param target the transformGroup node affected by this transformInterpolator
100: * @param axisOfTransform the transform that defines the local coordinate
101: * system in which this interpolator operates.
102: */
103: public TransformInterpolator(Alpha alpha, TransformGroup target,
104: Transform3D axisOfTransform) {
105:
106: super (alpha);
107: this .target = target;
108: axis.set(axisOfTransform);
109: axisInverse.invert(axis);
110: }
111:
112: /**
113: * This method sets the target TransformGroup node for this
114: * interpolator.
115: * @param target The target TransformGroup
116: */
117: public void setTarget(TransformGroup target) {
118: this .target = target;
119: }
120:
121: /**
122: * This method retrieves this interpolator's TransformGroup
123: * node reference.
124: * @return the Interpolator's target TransformGroup
125: */
126: public TransformGroup getTarget() {
127: return target;
128: }
129:
130: /**
131: * This method sets the axis of transform for this interpolator.
132: * @param axisOfTransform the transform that defines the local coordinate
133: * system in which this interpolator operates
134: */
135: public void setTransformAxis(Transform3D axisOfTransform) {
136: this .axis.set(axisOfTransform);
137: this .axisInverse.invert(this .axis);
138: }
139:
140: /**
141: * This method retrieves this interpolator's axis of transform.
142: * @return the interpolator's axis of transform
143: */
144: public Transform3D getTransformAxis() {
145: return new Transform3D(this .axis);
146: }
147:
148: /**
149: * Computes the new transform for this interpolator for a given
150: * alpha value.
151: *
152: * @param alphaValue alpha value between 0.0 and 1.0
153: * @param transform object that receives the computed transform for
154: * the specified alpha value
155: */
156: public abstract void computeTransform(float alphaValue,
157: Transform3D transform);
158:
159: /**
160: * This method is invoked by the behavior scheduler every frame.
161: * First it gets the alpha value that corresponds to the current time.
162: * Then it calls computeTransform() method to computes the transform based on this
163: * alpha vaule, and updates the specified TransformGroup node with this new transform.
164: * @param criteria an enumeration of the criteria that caused the
165: * stimulus
166: */
167: public void processStimulus(Enumeration criteria) {
168: // Handle stimulus
169: WakeupCriterion criterion = passiveWakeupCriterion;
170:
171: if (alpha != null) {
172: float value = alpha.value();
173: if (value != prevAlphaValue) {
174: computeTransform(value, currentTransform);
175: target.setTransform(currentTransform);
176: prevAlphaValue = value;
177: }
178: if (!alpha.finished() && !alpha.isPaused()) {
179: criterion = defaultWakeupCriterion;
180: }
181: }
182: wakeupOn(criterion);
183: }
184:
185: /**
186: * Copies all TransformInterpolator information from
187: * <code>originalNode</code> into
188: * the current node. This method is called from the
189: * <code>cloneNode</code> method which is, in turn, called by the
190: * <code>cloneTree</code> method.<P>
191: *
192: * @param originalNode the original node to duplicate.
193: * @param forceDuplicate when set to <code>true</code>, causes the
194: * <code>duplicateOnCloneTree</code> flag to be ignored. When
195: * <code>false</code>, the value of each node's
196: * <code>duplicateOnCloneTree</code> variable determines whether
197: * NodeComponent data is duplicated or copied.
198: *
199: * @exception RestrictedAccessException if this object is part of a live
200: * or compiled scenegraph.
201: *
202: * @see Node#duplicateNode
203: * @see Node#cloneTree
204: * @see NodeComponent#setDuplicateOnCloneTree
205: */
206: void duplicateAttributes(Node originalNode, boolean forceDuplicate) {
207: super .duplicateAttributes(originalNode, forceDuplicate);
208:
209: TransformInterpolator ti = (TransformInterpolator) originalNode;
210:
211: setTransformAxis(ti.getTransformAxis());
212:
213: // this reference will be updated in updateNodeReferences()
214: setTarget(ti.getTarget());
215: }
216:
217: /**
218: * Callback used to allow a node to check if any scene graph objects
219: * referenced
220: * by that node have been duplicated via a call to <code>cloneTree</code>.
221: * This method is called by <code>cloneTree</code> after all nodes in
222: * the sub-graph have been duplicated. The cloned Leaf node's method
223: * will be called and the Leaf node can then look up any object references
224: * by using the <code>getNewObjectReference</code> method found in the
225: * <code>NodeReferenceTable</code> object. If a match is found, a
226: * reference to the corresponding object in the newly cloned sub-graph
227: * is returned. If no corresponding reference is found, either a
228: * DanglingReferenceException is thrown or a reference to the original
229: * object is returned depending on the value of the
230: * <code>allowDanglingReferences</code> parameter passed in the
231: * <code>cloneTree</code> call.
232: * <p>
233: * NOTE: Applications should <i>not</i> call this method directly.
234: * It should only be called by the cloneTree method.
235: *
236: * @param referenceTable a NodeReferenceTableObject that contains the
237: * <code>getNewObjectReference</code> method needed to search for
238: * new object instances.
239: * @see NodeReferenceTable
240: * @see Node#cloneTree
241: * @see DanglingReferenceException
242: */
243: public void updateNodeReferences(NodeReferenceTable referenceTable) {
244: super .updateNodeReferences(referenceTable);
245:
246: // check TransformGroup
247: Node n = getTarget();
248:
249: if (n != null) {
250: setTarget((TransformGroup) referenceTable
251: .getNewObjectReference(n));
252: }
253: }
254: }
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