From 7a2e20caac9db6f789a7b3fab344b9758af45335 Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Sun, 19 Apr 2015 21:02:06 -0700 Subject: j3dcore: flatten the directory structure a bit Signed-off-by: Harvey Harrison --- src/javax/media/j3d/NodeReferenceTable.java | 135 ++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 src/javax/media/j3d/NodeReferenceTable.java (limited to 'src/javax/media/j3d/NodeReferenceTable.java') diff --git a/src/javax/media/j3d/NodeReferenceTable.java b/src/javax/media/j3d/NodeReferenceTable.java new file mode 100644 index 0000000..1bab869 --- /dev/null +++ b/src/javax/media/j3d/NodeReferenceTable.java @@ -0,0 +1,135 @@ +/* + * Copyright 1997-2008 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 java.util.Hashtable; + +/** + * The NodeReferenceTable object is used by a leaf node's + * updateNodeReferences method called by the + * cloneTree method. + * The NodeReferenceTable maps nodes from the original subgraph + * to the new nodes in the cloned subgraph. This information + * can then be used to update any cloned leaf node references + * to reference nodes in the cloned subgraph. + *

+ * During a cloneTree call, after all nodes have been duplicated, + * each SceneGraphObject's updateNodeReferences method is called. + * This method takes a NodeReferenceTable object as a parameter. The + * SceneGraphObject's updateNodeReferences method can then use the + * getNewObjectReference method from this object to get updated + * references to objects that have been duplicated in the new cloneTree + * sub-graph. If a match is found, a + * reference to the corresponding SceneGraphObject in the newly cloned sub-graph + * is returned. If no corresponding reference is found, either a + * DanglingReferenceException is thrown by the cloneTree + * method or a reference to the original + * SceneGraphObject is returned depending on the value of the + * allowDanglingReferences parameter passed in the + * cloneTree call. + * @see SceneGraphObject#updateNodeReferences + * @see Node#cloneTree + * @see DanglingReferenceException + */ +public class NodeReferenceTable extends Object { + + Hashtable objectHashtable; + boolean allowDanglingReferences; + + /** + * Constructs an empty NodeReferenceTable. + * @since Java 3D 1.2 + */ + public NodeReferenceTable() { + } + + // Constructor - this is NOT public! + NodeReferenceTable(boolean allowDanglingReferences, + Hashtable objectHashtable) { + set(allowDanglingReferences, objectHashtable); + } + + void set(boolean allowDanglingReferences, + Hashtable objectHashtable) { + this.objectHashtable = objectHashtable; + this.allowDanglingReferences = allowDanglingReferences; + } + + + /** + * This method is used in conjunction with the cloneTree + * method. It can be used by the updateNodeReferences + * method to see if a SceneGraphObject that is being referenced has been duplicated + * in the new cloneTree sub-graph. + *

+ * A SceneGraphObject's updateNodeReferences method would use this + * method by calling it with the reference to the old (existed before + * the cloneTree operation) object. If the object has been duplicated + * in the cloneTree sub-graph, the corresponding object in the cloned + * sub-graph is returned. If no corresponding reference is found, either + * a DanglingReferenceException is thrown or a reference to the original + * SceneGraphObject is returned depending on the value of the + * allowDanglingReferences parameter passed in the + * cloneTree call. + * + * @param oldReference the reference to the object in + * the original sub-graph. + * + * @return A reference to the corresponding object in the cloned + * sub-graph. If no corresponding object exists, either a + * DanglingReferenceException will be generated by the + * cloneTree method or a reference to the original object + * is returned depending on the value of the + * allowDanglingReferences parameter passed in the + * cloneTree call. + * + * @see SceneGraphObject#updateNodeReferences + * @see Node#cloneTree + * @see DanglingReferenceException + */ + public final SceneGraphObject + getNewObjectReference(SceneGraphObject oldReference) { + + // look up original SceneGraphObject in hash table + SceneGraphObject newObject = + (SceneGraphObject)objectHashtable.get(oldReference); + + if (newObject != null) { + // found new reference + return newObject; + } + + // dangling reference found! + if (allowDanglingReferences == true) { + return oldReference; + } + + // dangling references not allowed + throw new DanglingReferenceException(); + } + +} -- cgit v1.2.3