Method MapForWriting

trinityal/dx12/Tr2TextureALDx12.cpp:1361–1423

}

ALResult Tr2TextureAL::MapForWriting( const Tr2TextureSubresource& region, void*& data, uint32_t& pitch, Tr2RenderContextAL& renderContext )
{
	if( !IsValid() || !HasFlag( m_cpuUsage, Tr2CpuUsage::WRITE ) )
	{
		return E_INVALIDCALL;
	}
	if( !renderContext.IsValid() )
	{
		return E_INVALIDARG;
	}
	if( !region.IsValidForBitmap( m_desc ) )
	{
		return E_INVALIDARG;
	}
	if( !region.IsSingleSubresource() )
	{
		return E_INVALIDARG;
	}
	if( region.HasBox() && Tr2RenderContextEnum::IsCompressedFormat( m_desc.GetFormat() ) )
	{
		return E_INVALIDARG;
	}

	uint64_t requiredSize = 0;
	uint32_t myPitch = 0;
	GetRegionSize( region, myPitch, requiredSize );

	auto completed = m_owner->GetRenderedFrameNumber();
	m_mappedScratch = m_writeScratches.end();
	for( auto it = begin( m_writeScratches ); it != end( m_writeScratches ); ++it )
	{
		if( completed >= it->frameIndex && requiredSize <= it->size )
		{
			m_mappedScratch = it;
			break;
		}
	}

	if( m_mappedScratch == m_writeScratches.end() )
	{
		auto scratchHeap = HeapDesc( D3D12_HEAP_TYPE_UPLOAD );
		auto scratchDesc = BufferDesc( requiredSize );
		WriteScratch scratch;
		CR_RETURN_HR( m_owner->m_device->CreateCommittedResource(
			&scratchHeap,
			D3D12_HEAP_FLAG_NONE,
			&scratchDesc,
			D3D12_RESOURCE_STATE_GENERIC_READ,
			nullptr,
			IID_PPV_ARGS( &scratch.scratch ) ) );
		scratch.size = requiredSize;
		scratch.frameIndex = m_owner->GetRecordingFrameNumber();
		m_writeScratches.push_back( scratch );
		m_mappedScratch = m_writeScratches.begin() + ( m_writeScratches.size() - 1 );
	}

	D3D12_RANGE range = { 0, 0 };
	CR_RETURN_HR( m_mappedScratch->scratch->Map( 0, &range, &data ) );