dhewm3/neo/idlib/math/Lcp.h

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

Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.

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

Doom 3 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 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 Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 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 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 __MATH_LCP_H__
#define __MATH_LCP_H__

#include "idlib/math/Matrix.h"
#include "framework/Common.h"
#include "framework/CVarSystem.h"

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

  Box Constrained Mixed Linear Complementarity Problem solver

  A is a matrix of dimension n*n and x, b, lo, hi are vectors of dimension n

  Solve: Ax = b + t, where t is a vector of dimension n, with
  complementarity condition: (x[i] - lo[i]) * (x[i] - hi[i]) * t[i] = 0
  such that for each 0 <= i < n one of the following holds:

	1. lo[i] < x[i] < hi[i], t[i] == 0
	2. x[i] == lo[i], t[i] >= 0
	3. x[i] == hi[i], t[i] <= 0

  Partly bounded or unbounded variables can have lo[i] and/or hi[i]
  set to negative/positive idMath::INFITITY respectively.

  If boxIndex != NULL and boxIndex[i] != -1 then

	lo[i] = - fabs( lo[i] * x[boxIndex[i]] )
	hi[i] = fabs( hi[i] * x[boxIndex[i]] )
	boxIndex[boxIndex[i]] must be -1

  Before calculating any of the bounded x[i] with boxIndex[i] != -1 the
  solver calculates all unbounded x[i] and all x[i] with boxIndex[i] == -1.

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

class idLCP {
public:
	static idLCP *	AllocSquare( void );		// A must be a square matrix
	static idLCP *	AllocSymmetric( void );		// A must be a symmetric matrix

	virtual			~idLCP( void );

	virtual bool	Solve( const idMatX &A, idVecX &x, const idVecX &b, const idVecX &lo, const idVecX &hi, const int *boxIndex = NULL ) = 0;
	virtual void	SetMaxIterations( int max );
	virtual int		GetMaxIterations( void );

protected:
	int				maxIterations;
};

#endif /* !__MATH_LCP_H__ */