FActorPositionTraceResult FActorPositioning::TraceWorldForPosition(const UWorld& InWorld, const FSceneView& InSceneView, const FVector& RayStart, const FVector& RayEnd, const TArray<AActor*>* IgnoreActors)
{
TArray<FHitResult> Hits;
FCollisionQueryParams Param(TEXT("DragDropTrace"), true);
Param.bTraceAsyncScene = true;
if (IgnoreActors)
{
Param.AddIgnoredActors(*IgnoreActors);
}
FActorPositionTraceResult Results;
if ( InWorld.LineTraceMultiByObjectType(Hits, RayStart, RayEnd, FCollisionObjectQueryParams(FCollisionObjectQueryParams::InitType::AllObjects), Param) )
{
{
// Filter out anything that should be ignored
FSuspendRenderingThread SuspendRendering(false);
Hits.RemoveAll([&](const FHitResult& Hit){
return IsHitIgnored(Hit, InSceneView);
});
}
// Go through all hits and find closest
float ClosestHitDistanceSqr = TNumericLimits<float>::Max();
for (const auto& Hit : Hits)
{
const float DistanceToHitSqr = (Hit.ImpactPoint - RayStart).SizeSquared();
if (DistanceToHitSqr < ClosestHitDistanceSqr)
{
ClosestHitDistanceSqr = DistanceToHitSqr;
Results.Location = Hit.Location;
Results.SurfaceNormal = Hit.Normal.GetSafeNormal();
Results.State = FActorPositionTraceResult::HitSuccess;
Results.HitActor = Hit.Actor;
}
}
}
return Results;
}
/**
* Constructor that flushes and suspends the renderthread
* @param bRecreateThread - Whether the rendering thread should be completely destroyed and recreated, or just suspended.
*/
FSuspendRenderingThread::FSuspendRenderingThread( bool bInRecreateThread )
{
bRecreateThread = bInRecreateThread;
bUseRenderingThread = GUseThreadedRendering;
bWasRenderingThreadRunning = GIsThreadedRendering;
if ( bRecreateThread )
{
GUseThreadedRendering = false;
StopRenderingThread();
FPlatformAtomics::InterlockedIncrement( &GIsRenderingThreadSuspended );
}
else
{
if ( GIsRenderingThreadSuspended == 0 )
{
// First tell the render thread to finish up all pending commands and then suspend its activities.
// this ensures that async stuff will be completed too
FlushRenderingCommands();
if (GIsThreadedRendering)
{
DECLARE_CYCLE_STAT(TEXT("FSimpleDelegateGraphTask.SuspendRendering"),
STAT_FSimpleDelegateGraphTask_SuspendRendering,
STATGROUP_TaskGraphTasks);
FGraphEventRef CompleteHandle = FSimpleDelegateGraphTask::CreateAndDispatchWhenReady(
FSimpleDelegateGraphTask::FDelegate::CreateStatic(&SuspendRendering),
GET_STATID(STAT_FSimpleDelegateGraphTask_SuspendRendering), NULL, ENamedThreads::RenderThread);
// Busy wait while Kismet debugging, to avoid opportunistic execution of game thread tasks
// If the game thread is already executing tasks, then we have no choice but to spin
if (GIntraFrameDebuggingGameThread || FTaskGraphInterface::Get().IsThreadProcessingTasks(ENamedThreads::GameThread) )
{
while (!GIsRenderingThreadSuspended)
{
FPlatformProcess::Sleep(0.0f);
}
}
else
{
FTaskGraphInterface::Get().WaitUntilTaskCompletes(CompleteHandle, ENamedThreads::GameThread);
}
check(GIsRenderingThreadSuspended);
// Now tell the render thread to busy wait until it's resumed
DECLARE_CYCLE_STAT(TEXT("FSimpleDelegateGraphTask.WaitAndResumeRendering"),
STAT_FSimpleDelegateGraphTask_WaitAndResumeRendering,
STATGROUP_TaskGraphTasks);
FSimpleDelegateGraphTask::CreateAndDispatchWhenReady(
FSimpleDelegateGraphTask::FDelegate::CreateStatic(&WaitAndResumeRendering),
GET_STATID(STAT_FSimpleDelegateGraphTask_WaitAndResumeRendering), NULL, ENamedThreads::RenderThread);
}
else
{
SuspendRendering();
}
}
else
{
// The render-thread is already suspended. Just bump the ref-count.
FPlatformAtomics::InterlockedIncrement( &GIsRenderingThreadSuspended );
}
}
}
