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Diffstat (limited to 'thirdparty/bullet/BulletDynamics/MLCPSolvers/btDantzigLCP.h')
| -rw-r--r-- | thirdparty/bullet/BulletDynamics/MLCPSolvers/btDantzigLCP.h | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/thirdparty/bullet/BulletDynamics/MLCPSolvers/btDantzigLCP.h b/thirdparty/bullet/BulletDynamics/MLCPSolvers/btDantzigLCP.h new file mode 100644 index 0000000000..903832770a --- /dev/null +++ b/thirdparty/bullet/BulletDynamics/MLCPSolvers/btDantzigLCP.h @@ -0,0 +1,77 @@ +/************************************************************************* + * * + * 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 * + * 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 _BT_LCP_H_ +#define _BT_LCP_H_ + +#include <stdlib.h> +#include <stdio.h> +#include <assert.h> + + +#include "LinearMath/btScalar.h" +#include "LinearMath/btAlignedObjectArray.h" + +struct btDantzigScratchMemory +{ + btAlignedObjectArray<btScalar> m_scratch; + btAlignedObjectArray<btScalar> L; + btAlignedObjectArray<btScalar> d; + btAlignedObjectArray<btScalar> delta_w; + btAlignedObjectArray<btScalar> delta_x; + btAlignedObjectArray<btScalar> Dell; + btAlignedObjectArray<btScalar> ell; + btAlignedObjectArray<btScalar*> Arows; + btAlignedObjectArray<int> p; + btAlignedObjectArray<int> C; + btAlignedObjectArray<bool> state; +}; + +//return false if solving failed +bool btSolveDantzigLCP (int n, btScalar *A, btScalar *x, btScalar *b, btScalar *w, + int nub, btScalar *lo, btScalar *hi, int *findex,btDantzigScratchMemory& scratch); + + + +#endif //_BT_LCP_H_ |