Java tutorial
/* * Copyright 1996-2008 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.Vector3d; /** * Position interpolator behavior. This class defines a behavior * that modifies the translational component of its target * TransformGroup by linearly interpolating between a pair of * specified positions (using the value generated by the * specified Alpha object). The interpolated position is used * to generate a translation transform along the local X-axis * of this interpolator. */ public class PositionInterpolator extends TransformInterpolator { private Transform3D translation = new Transform3D(); private Vector3d transv = new Vector3d(); float startPosition; float endPosition; // 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 PositionInterpolator() { } /** * Constructs a trivial position interpolator with a specified target, * an axisOfTranslation set to Identity, a startPosition of 0.0f, and * an endPosition of 1.0f. * @param alpha The alpha object for this Interpolator * @param target The target for this position Interpolator */ public PositionInterpolator(Alpha alpha, TransformGroup target) { super(alpha, target); this.startPosition = 0.0f; this.endPosition = 1.0f; } /** * Constructs a new position interpolator that varies the target * TransformGroup's translational component (startPosition and endPosition). * @param alpha the alpha object for this interpolator * @param target the transformgroup node effected by this positionInterpolator * @param axisOfTransform the transform that defines the local coordinate * system in which this interpolator operates. The translation is * done along the X-axis of this local coordinate system. * @param startPosition the starting position * @param endPosition the ending position */ public PositionInterpolator(Alpha alpha, TransformGroup target, Transform3D axisOfTransform, float startPosition, float endPosition) { super(alpha, target, axisOfTransform); this.startPosition = startPosition; this.endPosition = endPosition; } /** * This method sets the startPosition for this interpolator. * @param position The new start position */ public void setStartPosition(float position) { this.startPosition = position; } /** * This method retrieves this interpolator's startPosition. * @return the interpolator's start position value */ public float getStartPosition() { return this.startPosition; } /** * This method sets the endPosition for this interpolator. * @param position The new end position */ public void setEndPosition(float position) { this.endPosition = position; } /** * This method retrieves this interpolator's endPosition. * @return the interpolator's end position vslue */ public float getEndPosition() { return this.endPosition; } /** * @deprecated As of Java 3D version 1.3, replaced by * <code>TransformInterpolator.setTransformAxis(Transform3D)</code> */ public void setAxisOfTranslation(Transform3D axisOfTranslation) { setTransformAxis(axisOfTranslation); } /** * @deprecated As of Java 3D version 1.3, replaced by * <code>TransformInterpolator.getTransformAxis()</code> */ public Transform3D getAxisOfTranslation() { return getTransformAxis(); } /** * 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 * * @since Java 3D 1.3 */ @Override public void computeTransform(float alphaValue, Transform3D transform) { double val = (1.0 - alphaValue) * startPosition + alphaValue * endPosition; // construct a Transform3D from: axis * translation * axisInverse transv.set(val, 0.0, 0.0); translation.setTranslation(transv); transform.mul(axis, translation); transform.mul(transform, axisInverse); } /** * 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) { PositionInterpolator pi = new PositionInterpolator(); pi.duplicateNode(this, forceDuplicate); return pi; } /** * Copies all PositionInterpolator 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); PositionInterpolator pi = (PositionInterpolator) originalNode; setStartPosition(pi.getStartPosition()); setEndPosition(pi.getEndPosition()); } }