/*************************************************************************

 *                                                                       *

 * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith.       *

 * All rights reserved.  Email: russ@q12.org   Web: www.q12.org          *

 *                                                                       *

 * This library is free software; you can redistribute it and/or         *

 * modify it under the terms of EITHER:                                  *

 *   (1) The GNU Lesser General Public License as published by the Free  *

 *       Software Foundation; either version 2.1 of the License, or (at  *

 *       your option) any later version. The text of the GNU Lesser      *

 *       General Public License is included with this library in the     *

 *       file LICENSE.TXT.                                               *

 *   (2) The BSD-style license that is included with this library in     *

 *       the file LICENSE-BSD.TXT.                                       *

 *                                                                       *

 * This library 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 files    *

 * LICENSE.TXT and LICENSE-BSD.TXT for more details.                     *

 *                                                                       *

 *************************************************************************/

/*

given (A,b,lo,hi), solve the LCP problem: A*x = b+w, where each x(i),w(i)

satisfies one of

	(1) x = lo, w >= 0

	(2) x = hi, w <= 0

	(3) lo < x < hi, w = 0

A is a matrix of dimension n*n, everything else is a vector of size n*1.

lo and hi can be +/- dInfinity as needed. the first `nub' variables are

unbounded, i.e. hi and lo are assumed to be +/- dInfinity.

we restrict lo(i) <= 0 and hi(i) >= 0.

the original data (A,b) may be modified by this function.

if the `findex' (friction index) parameter is nonzero, it points to an array

of index values. in this case constraints that have findex[i] >= 0 are

special. all non-special constraints are solved for, then the lo and hi values

for the special constraints are set:

  hi[i] = abs( hi[i] * x[findex[i]] )

  lo[i] = -hi[i]

and the solution continues. this mechanism allows a friction approximation

to be implemented. the first `nub' variables are assumed to have findex < 0.

*/

#ifndef _ODE_LCP_H_

#define _ODE_LCP_H_

void dSolveLCP (int n, dReal *A, dReal *x, dReal *b, dReal *w,

		int nub, dReal *lo, dReal *hi, int *findex);

#endif