Files
UnrealEngine/Engine/Source/Runtime/TimeManagement/Private/GenlockedCustomTimeStep.cpp
2025-05-18 13:04:45 +08:00

45 lines
1.4 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "GenlockedCustomTimeStep.h"
#include "Misc/App.h"
#include UE_INLINE_GENERATED_CPP_BY_NAME(GenlockedCustomTimeStep)
TAutoConsoleVariable<int32> UGenlockedCustomTimeStep::CVarExperimentalFieldFlipFix(
TEXT("MediaIO.PreventFieldFlipping"), 1,
TEXT("Whether to enable an interlace field flipping fix. (Experimental)"),
ECVF_RenderThreadSafe);
void UGenlockedCustomTimeStep::UpdateAppTimes(const double& TimeBeforeSync, const double& TimeAfterSync) const
{
// Use fixed delta time to update FApp times.
double ActualDeltaTime;
{
// Multiply sync time by valid SyncCountDelta to know ActualDeltaTime
if (IsLastSyncDataValid() && (GetLastSyncCountDelta() > 0))
{
ActualDeltaTime = GetLastSyncCountDelta() * GetSyncRate().AsInterval();
}
else
{
// optimistic default
ActualDeltaTime = GetFixedFrameRate().AsInterval();
}
}
FApp::SetCurrentTime(TimeAfterSync);
FApp::SetIdleTime((TimeAfterSync - TimeBeforeSync) - (ActualDeltaTime - GetFixedFrameRate().AsInterval()));
FApp::SetDeltaTime(ActualDeltaTime);
}
uint32 UGenlockedCustomTimeStep::GetExpectedSyncCountDelta() const
{
//Depending on format, sync count per frame will not be 1.
//For example, PsF will have 2 sync counts
const FFrameRate DeltaFrameRate = GetSyncRate() / GetFixedFrameRate();
return FMath::RoundToInt32(DeltaFrameRate.AsDecimal());
}