static
__inline
void solveFriction(b3GpuConstraint4& cs,
const b3Vector3& posA, b3Vector3& linVelA, b3Vector3& angVelA, float invMassA, const b3Matrix3x3& invInertiaA,
const b3Vector3& posB, b3Vector3& linVelB, b3Vector3& angVelB, float invMassB, const b3Matrix3x3& invInertiaB,
float maxRambdaDt[4], float minRambdaDt[4])
{
if( cs.m_fJacCoeffInv[0] == 0 && cs.m_fJacCoeffInv[0] == 0 ) return;
const b3Vector3& center = (const b3Vector3&)cs.m_center;
b3Vector3 n = -(const b3Vector3&)cs.m_linear;
b3Vector3 tangent[2];
#if 1
b3PlaneSpace1 (n, tangent[0],tangent[1]);
#else
b3Vector3 r = cs.m_worldPos[0]-center;
tangent[0] = cross3( n, r );
tangent[1] = cross3( tangent[0], n );
tangent[0] = normalize3( tangent[0] );
tangent[1] = normalize3( tangent[1] );
#endif
b3Vector3 angular0, angular1, linear;
b3Vector3 r0 = center - posA;
b3Vector3 r1 = center - posB;
for(int i=0; i<2; i++)
{
setLinearAndAngular( tangent[i], r0, r1, linear, angular0, angular1 );
float rambdaDt = calcRelVel(linear, -linear, angular0, angular1,
linVelA, angVelA, linVelB, angVelB );
rambdaDt *= cs.m_fJacCoeffInv[i];
{
float prevSum = cs.m_fAppliedRambdaDt[i];
float updated = prevSum;
updated += rambdaDt;
updated = b3Max( updated, minRambdaDt[i] );
updated = b3Min( updated, maxRambdaDt[i] );
rambdaDt = updated - prevSum;
cs.m_fAppliedRambdaDt[i] = updated;
}
b3Vector3 linImp0 = invMassA*linear*rambdaDt;
b3Vector3 linImp1 = invMassB*(-linear)*rambdaDt;
b3Vector3 angImp0 = (invInertiaA* angular0)*rambdaDt;
b3Vector3 angImp1 = (invInertiaB* angular1)*rambdaDt;
#ifdef _WIN32
b3Assert(_finite(linImp0.getX()));
b3Assert(_finite(linImp1.getX()));
#endif
linVelA += linImp0;
angVelA += angImp0;
linVelB += linImp1;
angVelB += angImp1;
}
{ // angular damping for point constraint
b3Vector3 ab = ( posB - posA ).normalized();
b3Vector3 ac = ( center - posA ).normalized();
if( b3Dot( ab, ac ) > 0.95f || (invMassA == 0.f || invMassB == 0.f))
{
float angNA = b3Dot( n, angVelA );
float angNB = b3Dot( n, angVelB );
angVelA -= (angNA*0.1f)*n;
angVelB -= (angNB*0.1f)*n;
}
}
}
void setConstraint4( const b3Vector3& posA, const b3Vector3& linVelA, const b3Vector3& angVelA, float invMassA, const b3Matrix3x3& invInertiaA,
const b3Vector3& posB, const b3Vector3& linVelB, const b3Vector3& angVelB, float invMassB, const b3Matrix3x3& invInertiaB,
b3Contact4* src, float dt, float positionDrift, float positionConstraintCoeff, float countA, float countB,
b3GpuConstraint4* dstC )
{
dstC->m_bodyA = abs(src->m_bodyAPtrAndSignBit);
dstC->m_bodyB = abs(src->m_bodyBPtrAndSignBit);
float dtInv = 1.f/dt;
for(int ic=0; ic<4; ic++)
{
dstC->m_appliedRambdaDt[ic] = 0.f;
}
dstC->m_fJacCoeffInv[0] = dstC->m_fJacCoeffInv[1] = 0.f;
dstC->m_linear = src->m_worldNormalOnB;
dstC->m_linear[3] = 0.7f ;//src->getFrictionCoeff() );
for(int ic=0; ic<4; ic++)
{
b3Vector3 r0 = src->m_worldPosB[ic] - posA;
b3Vector3 r1 = src->m_worldPosB[ic] - posB;
if( ic >= src->m_worldNormalOnB[3] )//npoints
{
dstC->m_jacCoeffInv[ic] = 0.f;
continue;
}
float relVelN;
{
b3Vector3 linear, angular0, angular1;
setLinearAndAngular(src->m_worldNormalOnB, r0, r1, linear, angular0, angular1);
dstC->m_jacCoeffInv[ic] = calcJacCoeff(linear, -linear, angular0, angular1,
invMassA, &invInertiaA, invMassB, &invInertiaB ,countA,countB);
relVelN = calcRelVel(linear, -linear, angular0, angular1,
linVelA, angVelA, linVelB, angVelB);
float e = 0.f;//src->getRestituitionCoeff();
if( relVelN*relVelN < 0.004f )
{
e = 0.f;
}
dstC->m_b[ic] = e*relVelN;
//float penetration = src->m_worldPos[ic].w;
dstC->m_b[ic] += (src->m_worldPosB[ic][3] + positionDrift)*positionConstraintCoeff*dtInv;
dstC->m_appliedRambdaDt[ic] = 0.f;
}
}
if( src->m_worldNormalOnB[3] > 0 )//npoints
{ // prepare friction
b3Vector3 center = make_float4(0.f);
for(int i=0; i<src->m_worldNormalOnB[3]; i++)
center += src->m_worldPosB[i];
center /= (float)src->m_worldNormalOnB[3];
b3Vector3 tangent[2];
b3PlaneSpace1(src->m_worldNormalOnB,tangent[0],tangent[1]);
b3Vector3 r[2];
r[0] = center - posA;
r[1] = center - posB;
for(int i=0; i<2; i++)
{
b3Vector3 linear, angular0, angular1;
setLinearAndAngular(tangent[i], r[0], r[1], linear, angular0, angular1);
dstC->m_fJacCoeffInv[i] = calcJacCoeff(linear, -linear, angular0, angular1,
invMassA, &invInertiaA, invMassB, &invInertiaB ,countA,countB);
dstC->m_fAppliedRambdaDt[i] = 0.f;
}
dstC->m_center = center;
}
for(int i=0; i<4; i++)
{
if( i<src->m_worldNormalOnB[3] )
{
dstC->m_worldPos[i] = src->m_worldPosB[i];
}
else
{
dstC->m_worldPos[i] = make_float4(0.f);
}
}
}
