bool FPhysScene::SubstepSimulation(uint32 SceneType, FGraphEventRef &InOutCompletionEvent)
{
#if WITH_PHYSX
check(SceneType != PST_Cloth); //we don't bother sub-stepping cloth
float UseDelta = UseSyncTime(SceneType)? SyncDeltaSeconds : DeltaSeconds;
float SubTime = PhysSubSteppers[SceneType]->UpdateTime(UseDelta);
PxScene* PScene = GetPhysXScene(SceneType);
if(SubTime <= 0.f)
{
return false;
}else
{
//we have valid scene and subtime so enqueue task
PhysXCompletionTask* Task = new PhysXCompletionTask(InOutCompletionEvent, PScene->getTaskManager());
ENamedThreads::Type NamedThread = PhysSingleThreadedMode() ? ENamedThreads::GameThread : ENamedThreads::AnyThread;
DECLARE_CYCLE_STAT(TEXT("FSimpleDelegateGraphTask.SubstepSimulationImp"),
STAT_FSimpleDelegateGraphTask_SubstepSimulationImp,
STATGROUP_TaskGraphTasks);
FSimpleDelegateGraphTask::CreateAndDispatchWhenReady(
FSimpleDelegateGraphTask::FDelegate::CreateRaw(PhysSubSteppers[SceneType], &FPhysSubstepTask::StepSimulation, Task),
GET_STATID(STAT_FSimpleDelegateGraphTask_SubstepSimulationImp), NULL, NamedThread
);
return true;
}
#endif
}
bool FPhysScene::SubstepSimulation(uint32 SceneType, FGraphEventRef &InOutCompletionEvent)
{
float UseDelta = UseSyncTime(SceneType)? SyncDeltaSeconds : DeltaSeconds;
float SubTime = PhysSubSteppers[SceneType]->UpdateTime(UseDelta);
PxScene* PScene = GetPhysXScene(SceneType);
#if WITH_APEX
NxApexScene* ApexScene = GetApexScene(SceneType);
if(!ApexScene || SubTime <= 0.f)
{
return false;
}else
{
//we have valid scene and subtime so enqueue task
PhysXCompletionTask* Task = new PhysXCompletionTask(InOutCompletionEvent, PScene->getTaskManager());
FSimpleDelegateGraphTask::CreateAndDispatchWhenReady(FSimpleDelegateGraphTask::FDelegate::CreateRaw(PhysSubSteppers[SceneType], &FPhysSubstepTask::StepSimulation, ApexScene, Task), TEXT("SubstepSimulationImp"));
return true;
}
#endif
}
/** Exposes ticking of physics-engine scene outside Engine. */
void FPhysScene::TickPhysScene(uint32 SceneType, FGraphEventRef& InOutCompletionEvent)
{
SCOPE_CYCLE_COUNTER(STAT_TotalPhysicsTime);
SCOPE_CYCLE_COUNTER(STAT_PhysicsKickOffDynamicsTime);
check(SceneType < NumPhysScenes);
if (bPhysXSceneExecuting[SceneType] != 0)
{
// Already executing this scene, must call WaitPhysScene before calling this function again.
UE_LOG(LogPhysics, Log, TEXT("TickPhysScene: Already executing scene (%d) - aborting."), SceneType);
return;
}
#if WITH_SUBSTEPPING
if (IsSubstepping(SceneType)) //we don't bother sub-stepping cloth
{
//We're about to start stepping so swap buffers. Might want to find a better place for this?
PhysSubSteppers[SceneType]->SwapBuffers();
}
#endif
/**
* clamp down... if this happens we are simming physics slower than real-time, so be careful with it.
* it can improve framerate dramatically (really, it is the same as scaling all velocities down and
* enlarging all timesteps) but at the same time, it will screw with networking (client and server will
* diverge a lot more.)
*/
float UseDelta = FMath::Min(UseSyncTime(SceneType) ? SyncDeltaSeconds : DeltaSeconds, MaxPhysicsDeltaTime);
// Only simulate a positive time step.
if (UseDelta <= 0.f)
{
if (UseDelta < 0.f)
{
// only do this if negative. Otherwise, whenever we pause, this will come up
UE_LOG(LogPhysics, Warning, TEXT("TickPhysScene: Negative timestep (%f) - aborting."), UseDelta);
}
return;
}
#if WITH_PHYSX
GatherPhysXStats(GetPhysXScene(SceneType), SceneType);
#endif
/**
* Weight frame time according to PhysScene settings.
*/
AveragedFrameTime[SceneType] *= FrameTimeSmoothingFactor[SceneType];
AveragedFrameTime[SceneType] += (1.0f - FrameTimeSmoothingFactor[SceneType])*UseDelta;
// Set execution flag
bPhysXSceneExecuting[SceneType] = true;
check(!InOutCompletionEvent.GetReference()); // these should be gone because nothing is outstanding
InOutCompletionEvent = FGraphEvent::CreateGraphEvent();
bool bTaskOutstanding = false;
#if WITH_PHYSX
#if WITH_VEHICLE
if (VehicleManager && SceneType == PST_Sync)
{
float TickTime = AveragedFrameTime[SceneType];
#if WITH_SUBSTEPPING
if (IsSubstepping(SceneType))
{
TickTime = UseSyncTime(SceneType) ? SyncDeltaSeconds : DeltaSeconds;
}
#endif
VehicleManager->PreTick(TickTime);
#if WITH_SUBSTEPPING
if (IsSubstepping(SceneType) == false)
#endif
{
VehicleManager->Update(AveragedFrameTime[SceneType]);
}
}
#endif
#if !WITH_APEX
PxScene* PScene = GetPhysXScene(SceneType);
if (PScene && (UseDelta > 0.f))
{
PhysXCompletionTask* Task = new PhysXCompletionTask(InOutCompletionEvent, PScene->getTaskManager());
PScene->lockWrite();
PScene->simulate(AveragedFrameTime[SceneType], Task);
PScene->unlockWrite();
Task->removeReference();
bTaskOutstanding = true;
}
#else // #if !WITH_APEX
// The APEX scene calls the simulate function for the PhysX scene, so we only call ApexScene->simulate().
NxApexScene* ApexScene = GetApexScene(SceneType);
if(ApexScene && UseDelta > 0.f)
{
#if WITH_SUBSTEPPING
if (IsSubstepping(SceneType)) //we don't bother sub-stepping cloth
{
bTaskOutstanding = SubstepSimulation(SceneType, InOutCompletionEvent);
}else
#endif
{
PhysXCompletionTask* Task = new PhysXCompletionTask(InOutCompletionEvent, ApexScene->getTaskManager());
ApexScene->simulate(AveragedFrameTime[SceneType], true, Task);
Task->removeReference();
bTaskOutstanding = true;
}
}
#endif // #if !WITH_APEX
#endif // WITH_PHYSX
if (!bTaskOutstanding)
{
InOutCompletionEvent->DispatchSubsequents(); // nothing to do, so nothing to wait for
}
#if WITH_SUBSTEPPING
bSubstepping = UPhysicsSettings::Get()->bSubstepping;
bSubsteppingAsync = UPhysicsSettings::Get()->bSubsteppingAsync;
#endif
}
