void btConvexPlaneCollisionAlgorithm::processCollision (btCollisionObject* body0,btCollisionObject* body1,const btDispatcherInfo& dispatchInfo,btManifoldResult* resultOut)
{
(void)dispatchInfo;
if (!m_manifoldPtr)
return;
btCollisionObject* convexObj = m_isSwapped? body1 : body0;
btCollisionObject* planeObj = m_isSwapped? body0: body1;
btConvexShape* convexShape = (btConvexShape*) convexObj->getCollisionShape();
btStaticPlaneShape* planeShape = (btStaticPlaneShape*) planeObj->getCollisionShape();
const btVector3& planeNormal = planeShape->getPlaneNormal();
//const btScalar& planeConstant = planeShape->getPlaneConstant();
//first perform a collision query with the non-perturbated collision objects
{
btQuaternion rotq(0,0,0,1);
collideSingleContact(rotq,body0,body1,dispatchInfo,resultOut);
}
if (resultOut->getPersistentManifold()->getNumContacts()<m_minimumPointsPerturbationThreshold)
{
btVector3 v0,v1;
btPlaneSpace1(planeNormal,v0,v1);
//now perform 'm_numPerturbationIterations' collision queries with the perturbated collision objects
const btScalar angleLimit = 0.125f * SIMD_PI;
btScalar perturbeAngle;
btScalar radius = convexShape->getAngularMotionDisc();
perturbeAngle = gContactBreakingThreshold / radius;
if ( perturbeAngle > angleLimit )
perturbeAngle = angleLimit;
btQuaternion perturbeRot(v0,perturbeAngle);
for (int i=0;i<m_numPerturbationIterations;i++)
{
btScalar iterationAngle = i*(SIMD_2_PI/btScalar(m_numPerturbationIterations));
btQuaternion rotq(planeNormal,iterationAngle);
collideSingleContact(rotq.inverse()*perturbeRot*rotq,body0,body1,dispatchInfo,resultOut);
}
}
if (m_ownManifold)
{
if (m_manifoldPtr->getNumContacts())
{
resultOut->refreshContactPoints();
}
}
}
void btConvexPlaneCollisionAlgorithm::processCollision (const btCollisionObjectWrapper* body0Wrap,const btCollisionObjectWrapper* body1Wrap,const btDispatcherInfo& dispatchInfo,btManifoldResult* resultOut)
{
(void)dispatchInfo;
if (!m_manifoldPtr)
return;
const btCollisionObjectWrapper* convexObjWrap = m_isSwapped? body1Wrap : body0Wrap;
const btCollisionObjectWrapper* planeObjWrap = m_isSwapped? body0Wrap: body1Wrap;
btConvexShape* convexShape = (btConvexShape*) convexObjWrap->getCollisionShape();
btStaticPlaneShape* planeShape = (btStaticPlaneShape*) planeObjWrap->getCollisionShape();
bool hasCollision = false;
const btVector3& planeNormal = planeShape->getPlaneNormal();
const btScalar& planeConstant = planeShape->getPlaneConstant();
btTransform planeInConvex;
planeInConvex= convexObjWrap->getWorldTransform().inverse() * planeObjWrap->getWorldTransform();
btTransform convexInPlaneTrans;
convexInPlaneTrans= planeObjWrap->getWorldTransform().inverse() * convexObjWrap->getWorldTransform();
btVector3 vtx = convexShape->localGetSupportingVertex(planeInConvex.getBasis()*-planeNormal);
btVector3 vtxInPlane = convexInPlaneTrans(vtx);
btScalar distance = (planeNormal.dot(vtxInPlane) - planeConstant);
btVector3 vtxInPlaneProjected = vtxInPlane - distance*planeNormal;
btVector3 vtxInPlaneWorld = planeObjWrap->getWorldTransform() * vtxInPlaneProjected;
hasCollision = distance < m_manifoldPtr->getContactBreakingThreshold();
resultOut->setPersistentManifold(m_manifoldPtr);
if (hasCollision)
{
/// report a contact. internally this will be kept persistent, and contact reduction is done
btVector3 normalOnSurfaceB = planeObjWrap->getWorldTransform().getBasis() * planeNormal;
btVector3 pOnB = vtxInPlaneWorld;
resultOut->addContactPoint(normalOnSurfaceB,pOnB,distance);
}
//the perturbation algorithm doesn't work well with implicit surfaces such as spheres, cylinder and cones:
//they keep on rolling forever because of the additional off-center contact points
//so only enable the feature for polyhedral shapes (btBoxShape, btConvexHullShape etc)
if (convexShape->isPolyhedral() && resultOut->getPersistentManifold()->getNumContacts()<m_minimumPointsPerturbationThreshold)
{
btVector3 v0,v1;
btPlaneSpace1(planeNormal,v0,v1);
//now perform 'm_numPerturbationIterations' collision queries with the perturbated collision objects
const btScalar angleLimit = 0.125f * SIMD_PI;
btScalar perturbeAngle;
btScalar radius = convexShape->getAngularMotionDisc();
perturbeAngle = gContactBreakingThreshold / radius;
if ( perturbeAngle > angleLimit )
perturbeAngle = angleLimit;
btQuaternion perturbeRot(v0,perturbeAngle);
for (int i=0;i<m_numPerturbationIterations;i++)
{
btScalar iterationAngle = i*(SIMD_2_PI/btScalar(m_numPerturbationIterations));
btQuaternion rotq(planeNormal,iterationAngle);
collideSingleContact(rotq.inverse()*perturbeRot*rotq,body0Wrap,body1Wrap,dispatchInfo,resultOut);
}
}
if (m_ownManifold)
{
if (m_manifoldPtr->getNumContacts())
{
resultOut->refreshContactPoints();
}
}
}
