Open Dynamics Engine
lcp.h
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3  * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
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22 
23 /*
24 
25 given (A,b,lo,hi), solve the LCP problem: A*x = b+w, where each x(i),w(i)
26 satisfies one of
27  (1) x = lo, w >= 0
28  (2) x = hi, w <= 0
29  (3) lo < x < hi, w = 0
30 A is a matrix of dimension n*n, everything else is a vector of size n*1.
31 lo and hi can be +/- dInfinity as needed. the first `nub' variables are
32 unbounded, i.e. hi and lo are assumed to be +/- dInfinity.
33 
34 we restrict lo(i) <= 0 and hi(i) >= 0.
35 
36 the original data (A,b) may be modified by this function.
37 
38 if the `findex' (friction index) parameter is nonzero, it points to an array
39 of index values. in this case constraints that have findex[i] >= 0 are
40 special. all non-special constraints are solved for, then the lo and hi values
41 for the special constraints are set:
42  hi[i] = abs( hi[i] * x[findex[i]] )
43  lo[i] = -hi[i]
44 and the solution continues. this mechanism allows a friction approximation
45 to be implemented. the first `nub' variables are assumed to have findex < 0.
46 
47 */
48 
49 
50 #ifndef _ODE_LCP_H_
51 #define _ODE_LCP_H_
52 
54 
55 void dSolveLCP (dxWorldProcessMemArena *memarena,
56  int n, dReal *A, dReal *x, dReal *b, dReal *w,
57  int nub, dReal *lo, dReal *hi, int *findex);
58 
59 size_t dEstimateSolveLCPMemoryReq(int n, bool outer_w_avail);
60 
61 #endif
Definition: util.h:114