/* 
 * Copyright (c) 2002 Lightweight Java Game Library Project
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are 
 * met:
 * 
 * * Redistributions of source code must retain the above copyright 
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'Light Weight Java Game Library' nor the names of 
 *   its contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.lwjgl.opengl;

class VBOTracker {
	private static VBOTracker default_tracker = new VBOTracker();
	private static VBOTracker current_tracker = default_tracker;

	private final StateStack vbo_array_stack;
	private final StateStack vbo_element_stack;
	private final StateStack attrib_stack;

	public static void setCurrent(VBOTracker tracker) {
		current_tracker = tracker;
	}

	public static void releaseCurrent() {
		current_tracker = default_tracker;
	}

	public VBOTracker() {
		int stack_size = Util.getGLInteger(CoreGL11Constants.GL_MAX_CLIENT_ATTRIB_STACK_DEPTH);
		vbo_array_stack = new StateStack(stack_size, 0);
		vbo_element_stack = new StateStack(stack_size, 0);
		attrib_stack = new StateStack(stack_size, 0);
	}

	public static StateStack getVBOArrayStack() {
		return current_tracker.vbo_array_stack;
	}

	public static StateStack getVBOElementStack() {
		return current_tracker.vbo_element_stack;
	}

	public static StateStack getClientAttribStack() {
		return current_tracker.attrib_stack;
	}
}
