DOOM-3-BFG/neo/idlib/containers/Stack.h

/*
===========================================================================

Doom 3 BFG Edition GPL Source Code
Copyright (C) 1993-2012 id Software LLC, a ZeniMax Media company. 

This file is part of the Doom 3 BFG Edition GPL Source Code ("Doom 3 BFG Edition Source Code").  

Doom 3 BFG Edition Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Doom 3 BFG Edition Source 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 for more details.

You should have received a copy of the GNU General Public License
along with Doom 3 BFG Edition Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 BFG Edition Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 BFG Edition Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/

#ifndef __STACK_H__
#define __STACK_H__

/*
===============================================================================

	Stack template

===============================================================================
*/

#define idStack( type, next )		idStackTemplate<type, (int)&(((type*)NULL)->next)>

template< class type, int nextOffset >
class idStackTemplate {
public:
							idStackTemplate();

	void					Add( type *element );
	type *					Get();

private:
	type *					top;
	type *					bottom;
};

#define STACK_NEXT_PTR( element )		(*(type**)(((byte*)element)+nextOffset))

template< class type, int nextOffset >
idStackTemplate<type,nextOffset>::idStackTemplate() {
	top = bottom = NULL;
}

template< class type, int nextOffset >
void idStackTemplate<type,nextOffset>::Add( type *element ) {
	STACK_NEXT_PTR(element) = top;
	top = element;
	if ( !bottom ) {
		bottom = element;
	}
}

template< class type, int nextOffset >
type *idStackTemplate<type,nextOffset>::Get() {
	type *element;

	element = top;
	if ( element ) {
		top = STACK_NEXT_PTR(top);
		if ( bottom == element ) {
			bottom = NULL;
		}
		STACK_NEXT_PTR(element) = NULL;
	}
	return element;
}

#endif /* !__STACK_H__ */