void btLemkeAlgorithm::GaussJordanEliminationStep(btMatrixXu& A, int pivotRowIndex, int pivotColumnIndex, const btAlignedObjectArray<int>& basis)
{
btScalar a = -1 / A(pivotRowIndex, pivotColumnIndex);
#ifdef BT_DEBUG_OSTREAM
cout << A << std::endl;
#endif
for (int i = 0; i < A.rows(); i++)
{
if (i != pivotRowIndex)
{
for (int j = 0; j < A.cols(); j++)
{
if (j != pivotColumnIndex)
{
btScalar v = A(i, j);
v += A(pivotRowIndex, j) * A(i, pivotColumnIndex) * a;
A.setElem(i, j, v);
}
}
}
}
#ifdef BT_DEBUG_OSTREAM
cout << A << std::endl;
#endif //BT_DEBUG_OSTREAM
for (int i = 0; i < A.cols(); i++)
{
A.mulElem(pivotRowIndex, i,-a);
}
#ifdef BT_DEBUG_OSTREAM
cout << A << std::endl;
#endif //#ifdef BT_DEBUG_OSTREAM
for (int i = 0; i < A.rows(); i++)
{
if (i != pivotRowIndex)
{
A.setElem(i, pivotColumnIndex,0);
}
}
#ifdef BT_DEBUG_OSTREAM
cout << A << std::endl;
#endif //#ifdef BT_DEBUG_OSTREAM
}
void btMLCPSolver::createMLCPFast(const btContactSolverInfo& infoGlobal)
{
int numContactRows = interleaveContactAndFriction ? 3 : 1;
int numConstraintRows = m_allConstraintArray.size();
int n = numConstraintRows;
{
BT_PROFILE("init b (rhs)");
m_b.resize(numConstraintRows);
m_bSplit.resize(numConstraintRows);
m_b.setZero();
m_bSplit.setZero();
for (int i=0;i<numConstraintRows ;i++)
{
btScalar jacDiag = m_allConstraintArray[i].m_jacDiagABInv;
if (!btFuzzyZero(jacDiag))
{
btScalar rhs = m_allConstraintArray[i].m_rhs;
btScalar rhsPenetration = m_allConstraintArray[i].m_rhsPenetration;
m_b[i]=rhs/jacDiag;
m_bSplit[i] = rhsPenetration/jacDiag;
}
}
}
btScalar* w = 0;
int nub = 0;
m_lo.resize(numConstraintRows);
m_hi.resize(numConstraintRows);
{
BT_PROFILE("init lo/ho");
for (int i=0;i<numConstraintRows;i++)
{
if (0)//m_limitDependencies[i]>=0)
{
m_lo[i] = -BT_INFINITY;
m_hi[i] = BT_INFINITY;
} else
{
m_lo[i] = m_allConstraintArray[i].m_lowerLimit;
m_hi[i] = m_allConstraintArray[i].m_upperLimit;
}
}
}
//
int m=m_allConstraintArray.size();
int numBodies = m_tmpSolverBodyPool.size();
btAlignedObjectArray<int> bodyJointNodeArray;
{
BT_PROFILE("bodyJointNodeArray.resize");
bodyJointNodeArray.resize(numBodies,-1);
}
btAlignedObjectArray<btJointNode> jointNodeArray;
{
BT_PROFILE("jointNodeArray.reserve");
jointNodeArray.reserve(2*m_allConstraintArray.size());
}
static btMatrixXu J3;
{
BT_PROFILE("J3.resize");
J3.resize(2*m,8);
}
static btMatrixXu JinvM3;
{
BT_PROFILE("JinvM3.resize/setZero");
JinvM3.resize(2*m,8);
JinvM3.setZero();
J3.setZero();
}
int cur=0;
int rowOffset = 0;
static btAlignedObjectArray<int> ofs;
{
BT_PROFILE("ofs resize");
ofs.resize(0);
ofs.resizeNoInitialize(m_allConstraintArray.size());
}
{
BT_PROFILE("Compute J and JinvM");
int c=0;
int numRows = 0;
for (int i=0;i<m_allConstraintArray.size();i+=numRows,c++)
{
ofs[c] = rowOffset;
int sbA = m_allConstraintArray[i].m_solverBodyIdA;
int sbB = m_allConstraintArray[i].m_solverBodyIdB;
btRigidBody* orgBodyA = m_tmpSolverBodyPool[sbA].m_originalBody;
btRigidBody* orgBodyB = m_tmpSolverBodyPool[sbB].m_originalBody;
numRows = i<m_tmpSolverNonContactConstraintPool.size() ? m_tmpConstraintSizesPool[c].m_numConstraintRows : numContactRows ;
if (orgBodyA)
{
{
int slotA=-1;
//find free jointNode slot for sbA
slotA =jointNodeArray.size();
jointNodeArray.expand();//NonInitializing();
int prevSlot = bodyJointNodeArray[sbA];
bodyJointNodeArray[sbA] = slotA;
jointNodeArray[slotA].nextJointNodeIndex = prevSlot;
jointNodeArray[slotA].jointIndex = c;
jointNodeArray[slotA].constraintRowIndex = i;
jointNodeArray[slotA].otherBodyIndex = orgBodyB ? sbB : -1;
}
for (int row=0;row<numRows;row++,cur++)
{
btVector3 normalInvMass = m_allConstraintArray[i+row].m_contactNormal1 * orgBodyA->getInvMass();
btVector3 relPosCrossNormalInvInertia = m_allConstraintArray[i+row].m_relpos1CrossNormal * orgBodyA->getInvInertiaTensorWorld();
for (int r=0;r<3;r++)
{
J3.setElem(cur,r,m_allConstraintArray[i+row].m_contactNormal1[r]);
J3.setElem(cur,r+4,m_allConstraintArray[i+row].m_relpos1CrossNormal[r]);
JinvM3.setElem(cur,r,normalInvMass[r]);
JinvM3.setElem(cur,r+4,relPosCrossNormalInvInertia[r]);
}
J3.setElem(cur,3,0);
JinvM3.setElem(cur,3,0);
J3.setElem(cur,7,0);
JinvM3.setElem(cur,7,0);
}
} else
{
cur += numRows;
}
if (orgBodyB)
{
{
int slotB=-1;
//find free jointNode slot for sbA
slotB =jointNodeArray.size();
jointNodeArray.expand();//NonInitializing();
int prevSlot = bodyJointNodeArray[sbB];
bodyJointNodeArray[sbB] = slotB;
jointNodeArray[slotB].nextJointNodeIndex = prevSlot;
jointNodeArray[slotB].jointIndex = c;
jointNodeArray[slotB].otherBodyIndex = orgBodyA ? sbA : -1;
jointNodeArray[slotB].constraintRowIndex = i;
}
for (int row=0;row<numRows;row++,cur++)
{
btVector3 normalInvMassB = m_allConstraintArray[i+row].m_contactNormal2*orgBodyB->getInvMass();
btVector3 relPosInvInertiaB = m_allConstraintArray[i+row].m_relpos2CrossNormal * orgBodyB->getInvInertiaTensorWorld();
for (int r=0;r<3;r++)
{
J3.setElem(cur,r,m_allConstraintArray[i+row].m_contactNormal2[r]);
J3.setElem(cur,r+4,m_allConstraintArray[i+row].m_relpos2CrossNormal[r]);
JinvM3.setElem(cur,r,normalInvMassB[r]);
JinvM3.setElem(cur,r+4,relPosInvInertiaB[r]);
}
J3.setElem(cur,3,0);
JinvM3.setElem(cur,3,0);
J3.setElem(cur,7,0);
JinvM3.setElem(cur,7,0);
}
}
else
{
cur += numRows;
}
rowOffset+=numRows;
}
}
//compute JinvM = J*invM.
const btScalar* JinvM = JinvM3.getBufferPointer();
const btScalar* Jptr = J3.getBufferPointer();
{
BT_PROFILE("m_A.resize");
m_A.resize(n,n);
}
{
BT_PROFILE("m_A.setZero");
m_A.setZero();
}
int c=0;
{
int numRows = 0;
BT_PROFILE("Compute A");
for (int i=0;i<m_allConstraintArray.size();i+= numRows,c++)
{
int row__ = ofs[c];
int sbA = m_allConstraintArray[i].m_solverBodyIdA;
int sbB = m_allConstraintArray[i].m_solverBodyIdB;
btRigidBody* orgBodyA = m_tmpSolverBodyPool[sbA].m_originalBody;
btRigidBody* orgBodyB = m_tmpSolverBodyPool[sbB].m_originalBody;
numRows = i<m_tmpSolverNonContactConstraintPool.size() ? m_tmpConstraintSizesPool[c].m_numConstraintRows : numContactRows ;
const btScalar *JinvMrow = JinvM + 2*8*(size_t)row__;
{
int startJointNodeA = bodyJointNodeArray[sbA];
while (startJointNodeA>=0)
{
int j0 = jointNodeArray[startJointNodeA].jointIndex;
int cr0 = jointNodeArray[startJointNodeA].constraintRowIndex;
if (j0<c)
{
int numRowsOther = cr0 < m_tmpSolverNonContactConstraintPool.size() ? m_tmpConstraintSizesPool[j0].m_numConstraintRows : numContactRows;
size_t ofsother = (m_allConstraintArray[cr0].m_solverBodyIdB == sbA) ? 8*numRowsOther : 0;
//printf("%d joint i %d and j0: %d: ",count++,i,j0);
m_A.multiplyAdd2_p8r ( JinvMrow,
Jptr + 2*8*(size_t)ofs[j0] + ofsother, numRows, numRowsOther, row__,ofs[j0]);
}
startJointNodeA = jointNodeArray[startJointNodeA].nextJointNodeIndex;
}
}
{
int startJointNodeB = bodyJointNodeArray[sbB];
while (startJointNodeB>=0)
{
int j1 = jointNodeArray[startJointNodeB].jointIndex;
int cj1 = jointNodeArray[startJointNodeB].constraintRowIndex;
if (j1<c)
{
int numRowsOther = cj1 < m_tmpSolverNonContactConstraintPool.size() ? m_tmpConstraintSizesPool[j1].m_numConstraintRows : numContactRows;
size_t ofsother = (m_allConstraintArray[cj1].m_solverBodyIdB == sbB) ? 8*numRowsOther : 0;
m_A.multiplyAdd2_p8r ( JinvMrow + 8*(size_t)numRows,
Jptr + 2*8*(size_t)ofs[j1] + ofsother, numRows, numRowsOther, row__,ofs[j1]);
}
startJointNodeB = jointNodeArray[startJointNodeB].nextJointNodeIndex;
}
}
}
{
BT_PROFILE("compute diagonal");
// compute diagonal blocks of m_A
int row__ = 0;
int numJointRows = m_allConstraintArray.size();
int jj=0;
for (;row__<numJointRows;)
{
int sbA = m_allConstraintArray[row__].m_solverBodyIdA;
int sbB = m_allConstraintArray[row__].m_solverBodyIdB;
btRigidBody* orgBodyA = m_tmpSolverBodyPool[sbA].m_originalBody;
btRigidBody* orgBodyB = m_tmpSolverBodyPool[sbB].m_originalBody;
const unsigned int infom = row__ < m_tmpSolverNonContactConstraintPool.size() ? m_tmpConstraintSizesPool[jj].m_numConstraintRows : numContactRows;
const btScalar *JinvMrow = JinvM + 2*8*(size_t)row__;
const btScalar *Jrow = Jptr + 2*8*(size_t)row__;
m_A.multiply2_p8r (JinvMrow, Jrow, infom, infom, row__,row__);
if (orgBodyB)
{
m_A.multiplyAdd2_p8r (JinvMrow + 8*(size_t)infom, Jrow + 8*(size_t)infom, infom, infom, row__,row__);
}
row__ += infom;
jj++;
}
}
}
if (1)
{
// add cfm to the diagonal of m_A
for ( int i=0; i<m_A.rows(); ++i)
{
m_A.setElem(i,i,m_A(i,i)+ m_cfm / infoGlobal.m_timeStep);
}
}
///fill the upper triangle of the matrix, to make it symmetric
{
BT_PROFILE("fill the upper triangle ");
m_A.copyLowerToUpperTriangle();
}
{
BT_PROFILE("resize/init x");
m_x.resize(numConstraintRows);
m_xSplit.resize(numConstraintRows);
if (infoGlobal.m_solverMode&SOLVER_USE_WARMSTARTING)
{
for (int i=0;i<m_allConstraintArray.size();i++)
{
const btSolverConstraint& c = m_allConstraintArray[i];
m_x[i]=c.m_appliedImpulse;
m_xSplit[i] = c.m_appliedPushImpulse;
}
} else
{
m_x.setZero();
m_xSplit.setZero();
}
}
}