// Simulate one timestep
public override float Simulate(float timeStep)
{
int updatedEntityCount;
IntPtr updatedEntitiesPtr;
int collidersCount;
IntPtr collidersPtr;
// prevent simulation until we've been initialized
if (!m_initialized)
{
return(10.0f);
}
// update the prim states while we know the physics engine is not busy
ProcessTaints();
// Some of the prims operate with special vehicle properties
ProcessVehicles(timeStep);
ProcessTaints(); // the vehicles might have added taints
// step the physical world one interval
m_simulationStep++;
int numSubSteps = BulletSimAPI.PhysicsStep(m_worldID, timeStep, m_maxSubSteps, m_fixedTimeStep,
out updatedEntityCount, out updatedEntitiesPtr, out collidersCount, out collidersPtr);
// Don't have to use the pointers passed back since we know it is the same pinned memory we passed in
// Get a value for 'now' so all the collision and update routines don't have to get their own
m_simulationNowTime = Util.EnvironmentTickCount();
// If there were collisions, process them by sending the event to the prim.
// Collisions must be processed before updates.
if (collidersCount > 0)
{
for (int ii = 0; ii < collidersCount; ii++)
{
uint cA = m_collisionArray[ii].aID;
uint cB = m_collisionArray[ii].bID;
Vector3 point = m_collisionArray[ii].point;
Vector3 normal = m_collisionArray[ii].normal;
SendCollision(cA, cB, point, normal, 0.01f);
SendCollision(cB, cA, point, -normal, 0.01f);
}
}
// If any of the objects had updated properties, tell the object it has been changed by the physics engine
if (updatedEntityCount > 0)
{
for (int ii = 0; ii < updatedEntityCount; ii++)
{
EntityProperties entprop = m_updateArray[ii];
// m_log.DebugFormat("{0}: entprop[{1}]: id={2}, pos={3}", LogHeader, ii, entprop.ID, entprop.Position);
BSCharacter actor;
if (m_avatars.TryGetValue(entprop.ID, out actor))
{
actor.UpdateProperties(entprop);
continue;
}
BSPrim prim;
if (m_prims.TryGetValue(entprop.ID, out prim))
{
prim.UpdateProperties(entprop);
}
}
}
if (m_detailedStatsStep > 0)
{
if ((m_simulationStep % m_detailedStatsStep) == 0)
{
BulletSimAPI.DumpBulletStatistics();
}
}
// TODO: FIX THIS: fps calculation wrong. This calculation always returns about 1 in normal operation.
return(timeStep / (numSubSteps * m_fixedTimeStep) * 1000f);
}