// UNEXPOSED
void CPhysicsObject::ComputeDragBasis(bool isStatic) {
m_dragBasis.setZero();
m_angDragBasis.setZero();
if (!isStatic && GetCollide()) {
btCollisionShape *shape = m_pObject->getCollisionShape();
btVector3 min, max, delta;
btTransform ident = btTransform::getIdentity();
shape->getAabb(ident, min, max);
delta = max - min;
delta = delta.absolute();
m_dragBasis.setX(delta.y() * delta.z());
m_dragBasis.setY(delta.x() * delta.z());
m_dragBasis.setZ(delta.x() * delta.y());
m_dragBasis *= GetInvMass();
btVector3 ang = m_pObject->getInvInertiaDiagLocal();
delta *= 0.5;
m_angDragBasis.setX(AngDragIntegral(ang[0], delta.x(), delta.y(), delta.z()) + AngDragIntegral(ang[0], delta.x(), delta.z(), delta.y()));
m_angDragBasis.setY(AngDragIntegral(ang[1], delta.y(), delta.x(), delta.z()) + AngDragIntegral(ang[1], delta.y(), delta.z(), delta.x()));
m_angDragBasis.setZ(AngDragIntegral(ang[2], delta.z(), delta.x(), delta.y()) + AngDragIntegral(ang[2], delta.z(), delta.y(), delta.x()));
}
}
void CPhysicsObject::Init(CPhysicsEnvironment* pEnv, btRigidBody* pObject, int materialIndex, float volume, float drag, float angDrag, const Vector *massCenterOverride) {
m_pEnv = pEnv;
m_materialIndex = materialIndex;
m_pObject = pObject;
pObject->setUserPointer(this);
m_pGameData = NULL;
m_gameFlags = 0;
m_iLastActivationState = pObject->getActivationState();
m_callbacks = CALLBACK_GLOBAL_COLLISION|CALLBACK_GLOBAL_FRICTION|CALLBACK_FLUID_TOUCH|CALLBACK_GLOBAL_TOUCH|CALLBACK_GLOBAL_COLLIDE_STATIC|CALLBACK_DO_FLUID_SIMULATION;
m_fVolume = volume;
float matdensity;
g_SurfaceDatabase.GetPhysicsProperties(materialIndex, &matdensity, NULL, NULL, NULL);
m_fBuoyancyRatio = (GetMass()/(GetVolume()*METERS_PER_INCH*METERS_PER_INCH*METERS_PER_INCH))/matdensity;
surfacedata_t *surface = g_SurfaceDatabase.GetSurfaceData(materialIndex);
if (surface)
{
m_pObject->setFriction(surface->physics.friction);
// Note to self: using these dampening values = breakdancing fridges http://dl.dropbox.com/u/4838268/gm_construct%202012-4-24%2004-50-26.webm
//m_pObject->setDamping(surface->physics.dampening, surface->physics.dampening);
}
// Drag calculations converted from 2003 source code
if (!IsStatic() && GetCollide() )
{
btCollisionShape * shape = m_pObject->getCollisionShape();
btVector3 min, max, delta;
btTransform t;
delta = min, max;
delta = delta.absolute();
shape->getAabb( t, min, max);
m_dragBasis.setX(delta.y() * delta.z());
m_dragBasis.setY(delta.x() * delta.z());
m_dragBasis.setZ(delta.x() * delta.y());
btVector3 ang = m_pObject->getInvInertiaDiagLocal();
delta *= 0.5;
m_angDragBasis.setX(AngDragIntegral( ang[0], delta.x(), delta.y(), delta.z() ) + AngDragIntegral( ang[0], delta.x(), delta.z(), delta.y() ));
m_angDragBasis.setY(AngDragIntegral( ang[1], delta.y(), delta.x(), delta.z() ) + AngDragIntegral( ang[1], delta.y(), delta.z(), delta.x() ));
m_angDragBasis.setZ(AngDragIntegral( ang[2], delta.z(), delta.x(), delta.y() ) + AngDragIntegral( ang[2], delta.z(), delta.y(), delta.x() ));
} else {
drag = 0;
angDrag = 0;
}
m_dragCoefficient = drag;
m_angDragCoefficient = angDrag;
}
void CPhysicsObject::Init( IVP_Real_Object *pObject, int materialIndex, float volume, float drag, float angDrag, const Vector *massCenterOverride )
{
m_materialIndex = materialIndex;
m_pObject = pObject;
pObject->client_data = (void *)this;
m_pGameData = NULL;
m_gameFlags = 0;
m_sleepState = OBJ_SLEEP; // objects start asleep
m_callbacks = CALLBACK_GLOBAL_COLLISION|CALLBACK_GLOBAL_FRICTION|CALLBACK_FLUID_TOUCH|CALLBACK_GLOBAL_TOUCH|CALLBACK_GLOBAL_COLLIDE_STATIC|CALLBACK_DO_FLUID_SIMULATION;
m_activeIndex = 0xFFFF;
m_pShadow = NULL;
m_shadowTempGravityDisable = false;
m_dragBasis = vec3_origin;
m_angDragBasis = vec3_origin;
if ( massCenterOverride )
{
m_massCenterOverride = *massCenterOverride;
}
if ( !IsStatic() && GetCollide() )
{
// Basically we are computing drag as an OBB. Get OBB extents for projection
// scale those extents by appropriate mass/inertia to compute velocity directly (not force)
// in the controller
// NOTE: Compute these even if drag coefficients are zero, because the drag coefficient could change later
// Get an AABB for this object and use the area of each side as a basis for approximating cross-section area for drag
Vector dragMins, dragMaxs;
// NOTE: coordinates in/out of physcollision are in HL units, not IVP
physcollision->CollideGetAABB( dragMins, dragMaxs, GetCollide(), vec3_origin, vec3_angle );
Vector delta = dragMaxs - dragMins;
ConvertPositionToIVP( delta.x, delta.y, delta.z );
delta.x = fabsf(delta.x);
delta.y = fabsf(delta.y);
delta.z = fabsf(delta.z);
// dragBasis is now the area of each side
m_dragBasis.x = delta.y * delta.z;
m_dragBasis.y = delta.x * delta.z;
m_dragBasis.z = delta.x * delta.y;
m_dragBasis *= GetInvMass();
const IVP_U_Float_Point *pInvRI = m_pObject->get_core()->get_inv_rot_inertia();
// This angular basis is the integral of each differential drag area's torque over the whole OBB
// need half lengths for this integral
delta *= 0.5;
// rotation about the x axis
m_angDragBasis.x = AngDragIntegral( pInvRI->k[0], delta.x, delta.y, delta.z ) + AngDragIntegral( pInvRI->k[0], delta.x, delta.z, delta.y );
// rotation about the y axis
m_angDragBasis.y = AngDragIntegral( pInvRI->k[1], delta.y, delta.x, delta.z ) + AngDragIntegral( pInvRI->k[1], delta.y, delta.z, delta.x );
// rotation about the z axis
m_angDragBasis.z = AngDragIntegral( pInvRI->k[2], delta.z, delta.x, delta.y ) + AngDragIntegral( pInvRI->k[2], delta.z, delta.y, delta.x );
}
else
{
drag = 0;
angDrag = 0;
}
m_dragCoefficient = drag;
m_angDragCoefficient = angDrag;
SetVolume( volume );
}
