C++ TRefCountPtr::EnumOutputs方法代码示例

static uint32 CountAdapterOutputs(TRefCountPtr<IDXGIAdapter>& Adapter)
{
	uint32 OutputCount = 0;
	for(;;)
	{
		TRefCountPtr<IDXGIOutput> Output;
		HRESULT hr = Adapter->EnumOutputs(OutputCount, Output.GetInitReference());
		if(FAILED(hr))
		{
			break;
		}
		++OutputCount;
	}

	return OutputCount;
}

/**
 * Returns a supported screen resolution that most closely matches the input.
 * @param Width - Input: Desired resolution width in pixels. Output: A width that the platform supports.
 * @param Height - Input: Desired resolution height in pixels. Output: A height that the platform supports.
 */
void FD3D11DynamicRHI::RHIGetSupportedResolution( uint32 &Width, uint32 &Height )
{
	uint32 InitializedMode = false;
	DXGI_MODE_DESC BestMode;
	BestMode.Width = 0;
	BestMode.Height = 0;

	{
		HRESULT hr = S_OK;
		TRefCountPtr<IDXGIAdapter> Adapter;
		hr = DXGIFactory->EnumAdapters(ChosenAdapter,Adapter.GetInitReference());
		if( DXGI_ERROR_NOT_FOUND == hr )
		{
			return;
		}
		if( FAILED(hr) )
		{
			return;
		}

		// get the description of the adapter
		DXGI_ADAPTER_DESC AdapterDesc;
		VERIFYD3D11RESULT(Adapter->GetDesc(&AdapterDesc));
	  
		// Enumerate outputs for this adapter
		// TODO: Cap at 1 for default output
		for(uint32 o = 0;o < 1; o++)
		{
			TRefCountPtr<IDXGIOutput> Output;
			hr = Adapter->EnumOutputs(o,Output.GetInitReference());
			if(DXGI_ERROR_NOT_FOUND == hr)
				break;
			if(FAILED(hr))
				return;

			// TODO: GetDisplayModeList is a terribly SLOW call.  It can take up to a second per invocation.
			//  We might want to work around some DXGI badness here.
			DXGI_FORMAT Format = DXGI_FORMAT_R8G8B8A8_UNORM;
			uint32 NumModes = 0;
			hr = Output->GetDisplayModeList(Format,0,&NumModes,NULL);
			if(hr == DXGI_ERROR_NOT_FOUND)
			{
				return;
			}
			else if(hr == DXGI_ERROR_NOT_CURRENTLY_AVAILABLE)
			{
				UE_LOG(LogD3D11RHI, Fatal,
					TEXT("This application cannot be run over a remote desktop configuration")
					);
				return;
			}
			DXGI_MODE_DESC* ModeList = new DXGI_MODE_DESC[ NumModes ];
			VERIFYD3D11RESULT(Output->GetDisplayModeList(Format,0,&NumModes,ModeList));

			for(uint32 m = 0;m < NumModes;m++)
			{
				// Search for the best mode
				
				// Suppress static analysis warnings about a potentially out-of-bounds read access to ModeList. This is a false positive - Index is always within range.
				CA_SUPPRESS( 6385 );
				bool IsEqualOrBetterWidth = FMath::Abs((int32)ModeList[m].Width - (int32)Width) <= FMath::Abs((int32)BestMode.Width - (int32)Width);
				bool IsEqualOrBetterHeight = FMath::Abs((int32)ModeList[m].Height - (int32)Height) <= FMath::Abs((int32)BestMode.Height - (int32)Height);
				if(!InitializedMode || (IsEqualOrBetterWidth && IsEqualOrBetterHeight))
				{
					BestMode = ModeList[m];
					InitializedMode = true;
				}
			}

			delete[] ModeList;
		}
	}

	check(InitializedMode);
	Width = BestMode.Width;
	Height = BestMode.Height;
}