FTexture2DRHIRef FOpenGLDynamicRHI::RHIGetViewportBackBuffer(FViewportRHIParamRef ViewportRHI)
{
FOpenGLViewport* Viewport = ResourceCast(ViewportRHI);
return Viewport->GetBackBuffer();
}
void FOpenGLDynamicRHI::RHIEndDrawingViewport(FViewportRHIParamRef ViewportRHI,bool bPresent,bool bLockToVsync)
{
VERIFY_GL_SCOPE();
FOpenGLViewport* Viewport = ResourceCast(ViewportRHI);
SCOPE_CYCLE_COUNTER(STAT_OpenGLPresentTime);
check(DrawingViewport.GetReference() == Viewport);
FOpenGLTexture2D* BackBuffer = Viewport->GetBackBuffer();
bool bNeedFinishFrame = PlatformBlitToViewport(PlatformDevice,
*Viewport,
BackBuffer->GetSizeX(),
BackBuffer->GetSizeY(),
bPresent,
bLockToVsync,
RHIOpenGLConsoleVariables::SyncInterval
);
// Always consider the Framebuffer in the rendering context dirty after the blit
RenderingContextState.Framebuffer = -1;
DrawingViewport = NULL;
// Don't wait on the GPU when using SLI, let the driver determine how many frames behind the GPU should be allowed to get
if (GNumActiveGPUsForRendering == 1)
{
if (bNeedFinishFrame)
{
static const auto CFinishFrameVar = IConsoleManager::Get().FindTConsoleVariableDataInt(TEXT("r.FinishCurrentFrame"));
if (!CFinishFrameVar->GetValueOnRenderThread())
{
// Wait for the GPU to finish rendering the previous frame before finishing this frame.
Viewport->WaitForFrameEventCompletion();
Viewport->IssueFrameEvent();
}
else
{
// Finish current frame immediately to reduce latency
Viewport->IssueFrameEvent();
Viewport->WaitForFrameEventCompletion();
}
}
// If the input latency timer has been triggered, block until the GPU is completely
// finished displaying this frame and calculate the delta time.
if ( GInputLatencyTimer.RenderThreadTrigger )
{
Viewport->WaitForFrameEventCompletion();
uint32 EndTime = FPlatformTime::Cycles();
GInputLatencyTimer.DeltaTime = EndTime - GInputLatencyTimer.StartTime;
GInputLatencyTimer.RenderThreadTrigger = false;
}
}
if (bRevertToSharedContextAfterDrawingViewport)
{
PlatformSharedContextSetup(PlatformDevice);
bRevertToSharedContextAfterDrawingViewport = false;
}
}