freelistmanager.java

JAVA3D矩陈的相关类

/*
 * $RCSfile: FreeListManager.java,v $
 *
 * Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved.
 *
 * Use is subject to license terms.
 *
 * $Revision: 1.7 $
 * $Date: 2007/04/12 17:34:04 $
 * $State: Exp $
 */

package javax.media.j3d;


class FreeListManager {

    private static final boolean DEBUG = false;

    // constants that represent the freelists managed by the Manager
    static final int DISPLAYLIST = 0;
    static final int TEXTURE2D = 1;
    static final int TEXTURE3D = 2;       
    
    private static int maxFreeListNum = 2;
    
    // what list we are going to shrink next
    private static int currlist = 0;

    static MemoryFreeList[] freelist = null;
    
    static void createFreeLists() {
        maxFreeListNum = 2;
        freelist = new MemoryFreeList[maxFreeListNum+1];
        freelist[DISPLAYLIST] = new IntegerFreeList();
        freelist[TEXTURE2D] = new IntegerFreeList();
        freelist[TEXTURE3D] = new IntegerFreeList();
        
    }

    // see if the current list can be shrunk
    static void manageLists() {
// 	System.err.println("manageLists");
	if (freelist[currlist] != null) {
	    freelist[currlist].shrink();
	}
	
	currlist++;
	if (currlist > maxFreeListNum) currlist = 0;
    }

    // return the freelist specified by the list param
    static MemoryFreeList getFreeList(int list) {
	if (list < 0 || list > maxFreeListNum) {
	    if (DEBUG) System.err.println("illegal list");
	    return null;
	}
	else {
	    return freelist[list];
	}
    }

    static Object getObject(int listId) {
	return freelist[listId].getObject();
    }

    static void freeObject(int listId, Object obj) {
	freelist[listId].add(obj);
    }

    static void clearList(int listId) {
	freelist[listId].clear();
    }

}