001: /*
002: * $RCSfile: MultiTransformGroup.java,v $
003: *
004: * Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: *
010: * - Redistribution of source code must retain the above copyright
011: * notice, this list of conditions and the following disclaimer.
012: *
013: * - Redistribution in binary form must reproduce the above copyright
014: * notice, this list of conditions and the following disclaimer in
015: * the documentation and/or other materials provided with the
016: * distribution.
017: *
018: * Neither the name of Sun Microsystems, Inc. or the names of
019: * contributors may be used to endorse or promote products derived
020: * from this software without specific prior written permission.
021: *
022: * This software is provided "AS IS," without a warranty of any
023: * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
024: * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
025: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
026: * EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL
027: * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF
028: * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
029: * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR
030: * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
031: * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
032: * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
033: * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
034: * POSSIBILITY OF SUCH DAMAGES.
035: *
036: * You acknowledge that this software is not designed, licensed or
037: * intended for use in the design, construction, operation or
038: * maintenance of any nuclear facility.
039: *
040: * $Revision: 1.4 $
041: * $Date: 2007/02/09 17:20:44 $
042: * $State: Exp $
043: */
044:
045: package com.sun.j3d.utils.universe;
046:
047: import javax.media.j3d.*;
048: import javax.vecmath.*;
049:
050: /**
051: * A convenience class that effectively creates a series of TransformGroup
052: * nodes connected one to another hierarchically. For most applications,
053: * creating a MultiTransformGroup containing one transform will suffice.
054: * More sophisticated applications that use a complex portal/head tracking
055: * viewing system may find that more transforms are needed.
056: * <P>
057: * When more than one transform is needed, transform[0] is considered the
058: * "top most" transform with repsect to the scene graph, (attached to the
059: * ViewingPlatform node) and transform[numTransforms - 1] is the "bottom
060: * most" transform (the ViewPlatorm object is attached to this transform).
061: */
062: public class MultiTransformGroup {
063:
064: // For now just have an array of TransformGroup nodes.
065: TransformGroup[] transforms;
066:
067: /**
068: * Creates a MultiTransformGroup node that contains a single transform.
069: * This is effectively equivalent to creating a single TransformGroup
070: * node.
071: */
072: public MultiTransformGroup() {
073: this (1);
074: }
075:
076: /**
077: * Creates a MultiTransformGroup node that contains the specified
078: * number of transforms.
079: * <P>
080: * When more than one transform is needed, transform[0] is considered the
081: * "top most" transform with repsect to the scene graph, (attached to the
082: * ViewingPlatform node) and transform[numTransforms - 1] is the "bottom
083: * most" transform (the ViewPlatorm object is attached to this transform).
084: *
085: * @param numTransforms The number of transforms for this node to
086: * contain. If this number is less than one, one is assumed.
087: */
088: public MultiTransformGroup(int numTransforms) {
089: if (numTransforms < 1)
090: numTransforms = 1;
091:
092: transforms = new TransformGroup[numTransforms];
093:
094: // there is always at least one TransformGroup
095: transforms[0] = new TransformGroup();
096: transforms[0]
097: .setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
098: transforms[0]
099: .setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
100: transforms[0]
101: .setCapability(TransformGroup.ALLOW_CHILDREN_WRITE);
102: transforms[0]
103: .setCapability(TransformGroup.ALLOW_CHILDREN_EXTEND);
104:
105: for (int i = 1; i < numTransforms; i++) {
106: transforms[i] = new TransformGroup();
107: transforms[i]
108: .setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
109: transforms[i]
110: .setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
111: transforms[i]
112: .setCapability(TransformGroup.ALLOW_CHILDREN_WRITE);
113: transforms[i]
114: .setCapability(TransformGroup.ALLOW_CHILDREN_EXTEND);
115: transforms[i - 1].addChild(transforms[i]);
116: }
117: }
118:
119: /**
120: * Returns the selected TransformGroup node.
121: *
122: * @param transform The index of the transform to return. The indices
123: * are in the range [0..(n - 1)] - where n was the number of transforms
124: * created. transform[0] is considered the
125: * "top most" transform with repsect to the scene graph, (attached to the
126: * ViewingPlatform node) and transform[numTransforms - 1] is the "bottom
127: * most" transform (the ViewPlatorm object is attached to this transform).
128: *
129: * @return The TransformGroup node at the designated index. If an out of
130: * range index is given, null is returned.
131: */
132: public TransformGroup getTransformGroup(int transform) {
133: if (transform >= transforms.length || transform < 0)
134: return null;
135:
136: return transforms[transform];
137: }
138:
139: /**
140: * Returns the number of transforms in this MultiTransformGroup object.
141: *
142: * @return The number of transforms in this object.
143: */
144: public int getNumTransforms() {
145: return transforms.length;
146: }
147:
148: }
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