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#include "ContactJoint.h"
#include "RigidBody.h"
#include "NarrowPhaseCollision/PersistentManifold.h"
//this constant needs to be set up so different solvers give 'similar' results
#define FRICTION_CONSTANT 120.f
ContactJoint::ContactJoint(PersistentManifold* manifold,int index,bool swap,RigidBody* body0,RigidBody* body1)
:m_manifold(manifold),
m_index(index),
m_swapBodies(swap),
m_body0(body0),
m_body1(body1)
{
}
int m_numRows = 3;
void ContactJoint::GetInfo1(Info1 *info)
{
info->m = m_numRows;
//friction adds another 2...
info->nub = 0;
}
#define dCROSS(a,op,b,c) \
(a)[0] op ((b)[1]*(c)[2] - (b)[2]*(c)[1]); \
(a)[1] op ((b)[2]*(c)[0] - (b)[0]*(c)[2]); \
(a)[2] op ((b)[0]*(c)[1] - (b)[1]*(c)[0]);
#define M_SQRT12 SimdScalar(0.7071067811865475244008443621048490)
#define dRecipSqrt(x) ((float)(1.0f/SimdSqrt(float(x)))) /* reciprocal square root */
void dPlaneSpace1 (const dVector3 n, dVector3 p, dVector3 q)
{
if (SimdFabs(n[2]) > M_SQRT12) {
// choose p in y-z plane
SimdScalar a = n[1]*n[1] + n[2]*n[2];
SimdScalar k = dRecipSqrt (a);
p[0] = 0;
p[1] = -n[2]*k;
p[2] = n[1]*k;
// set q = n x p
q[0] = a*k;
q[1] = -n[0]*p[2];
q[2] = n[0]*p[1];
}
else {
// choose p in x-y plane
SimdScalar a = n[0]*n[0] + n[1]*n[1];
SimdScalar k = dRecipSqrt (a);
p[0] = -n[1]*k;
p[1] = n[0]*k;
p[2] = 0;
// set q = n x p
q[0] = -n[2]*p[1];
q[1] = n[2]*p[0];
q[2] = a*k;
}
}
void ContactJoint::GetInfo2(Info2 *info)
{
int s = info->rowskip;
int s2 = 2*s;
float swapFactor = m_swapBodies ? -1.f : 1.f;
// get normal, with sign adjusted for body1/body2 polarity
dVector3 normal;
ManifoldPoint& point = m_manifold->GetContactPoint(m_index);
normal[0] = swapFactor*point.m_normalWorldOnB[0];
normal[1] = swapFactor*point.m_normalWorldOnB[1];
normal[2] = swapFactor*point.m_normalWorldOnB[2];
normal[3] = 0; // @@@ hmmm
// if (GetBody0())
SimdVector3 ccc1;
{
ccc1 = point.GetPositionWorldOnA() - m_body0->getCenterOfMassPosition();
dVector3 c1;
c1[0] = ccc1[0];
c1[1] = ccc1[1];
c1[2] = ccc1[2];
// set jacobian for normal
info->J1l[0] = normal[0];
info->J1l[1] = normal[1];
info->J1l[2] = normal[2];
dCROSS (info->J1a,=,c1,normal);
}
// if (GetBody1())
SimdVector3 ccc2;
{
dVector3 c2;
ccc2 = point.GetPositionWorldOnB() - m_body1->getCenterOfMassPosition();
// for (i=0; i<3; i++) c2[i] = j->contact.geom.pos[i] -
// j->node[1].body->pos[i];
c2[0] = ccc2[0];
c2[1] = ccc2[1];
c2[2] = ccc2[2];
info->J2l[0] = -normal[0];
info->J2l[1] = -normal[1];
info->J2l[2] = -normal[2];
dCROSS (info->J2a,= -,c2,normal);
}
SimdScalar k = info->fps * info->erp;
float depth = -point.GetDistance();
// if (depth < 0.f)
// depth = 0.f;
info->c[0] = k * depth;
float maxvel = .2f;
// if (info->c[0] > maxvel)
// info->c[0] = maxvel;
//can override it, not necessary
// info->cfm[0] = 0.f;
// info->cfm[1] = 0.f;
// info->cfm[2] = 0.f;
// set LCP limits for normal
info->lo[0] = 0;
info->hi[0] = 1e30f;//dInfinity;
info->lo[1] = 0;
info->hi[1] = 0.f;
info->lo[2] = 0.f;
info->hi[2] = 0.f;
#define DO_THE_FRICTION_2
#ifdef DO_THE_FRICTION_2
// now do jacobian for tangential forces
dVector3 t1,t2; // two vectors tangential to normal
dVector3 c1;
c1[0] = ccc1[0];
c1[1] = ccc1[1];
c1[2] = ccc1[2];
dVector3 c2;
c2[0] = ccc2[0];
c2[1] = ccc2[1];
c2[2] = ccc2[2];
float friction = 10.1f;//FRICTION_CONSTANT*m_body0->getFriction() * m_body1->getFriction();
// first friction direction
if (m_numRows >= 2)
{
dPlaneSpace1 (normal,t1,t2);
info->J1l[s+0] = t1[0];
info->J1l[s+1] = t1[1];
info->J1l[s+2] = t1[2];
dCROSS (info->J1a+s,=,c1,t1);
if (1) { //j->node[1].body) {
info->J2l[s+0] = -t1[0];
info->J2l[s+1] = -t1[1];
info->J2l[s+2] = -t1[2];
dCROSS (info->J2a+s,= -,c2,t1);
}
// set right hand side
if (0) {//j->contact.surface.mode & dContactMotion1) {
//info->c[1] = j->contact.surface.motion1;
}
// set LCP bounds and friction index. this depends on the approximation
// mode
//1e30f
info->lo[1] = -friction;//-j->contact.surface.mu;
info->hi[1] = friction;//j->contact.surface.mu;
if (1)//j->contact.surface.mode & dContactApprox1_1)
info->findex[1] = 0;
// set slip (constraint force mixing)
if (0)//j->contact.surface.mode & dContactSlip1)
{
// info->cfm[1] = j->contact.surface.slip1;
} else
{
//info->cfm[1] = 0.f;
}
}
// second friction direction
if (m_numRows >= 3) {
info->J1l[s2+0] = t2[0];
info->J1l[s2+1] = t2[1];
info->J1l[s2+2] = t2[2];
dCROSS (info->J1a+s2,=,c1,t2);
if (1) { //j->node[1].body) {
info->J2l[s2+0] = -t2[0];
info->J2l[s2+1] = -t2[1];
info->J2l[s2+2] = -t2[2];
dCROSS (info->J2a+s2,= -,c2,t2);
}
// set right hand side
if (0){//j->contact.surface.mode & dContactMotion2) {
//info->c[2] = j->contact.surface.motion2;
}
// set LCP bounds and friction index. this depends on the approximation
// mode
if (0){//j->contact.surface.mode & dContactMu2) {
//info->lo[2] = -j->contact.surface.mu2;
//info->hi[2] = j->contact.surface.mu2;
}
else {
info->lo[2] = -friction;
info->hi[2] = friction;
}
if (0)//j->contact.surface.mode & dContactApprox1_2)
{
info->findex[2] = 0;
}
// set slip (constraint force mixing)
if (0) //j->contact.surface.mode & dContactSlip2)
{
//info->cfm[2] = j->contact.surface.slip2;
}
}
#endif //DO_THE_FRICTION_2
}
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