inline UINT64 UpdateSubresources()

in Tools/WinMLRunner/src/d3dx12.h [1893:1947]
51 lines of code
12 McCabe index (conditional complexity)

inline UINT64 UpdateSubresources(
    _In_ ID3D12GraphicsCommandList* pCmdList,
    _In_ ID3D12Resource* pDestinationResource,
    _In_ ID3D12Resource* pIntermediate,
    _In_range_(0,D3D12_REQ_SUBRESOURCES) UINT FirstSubresource,
    _In_range_(0,D3D12_REQ_SUBRESOURCES-FirstSubresource) UINT NumSubresources,
    UINT64 RequiredSize,
    _In_reads_(NumSubresources) const D3D12_PLACED_SUBRESOURCE_FOOTPRINT* pLayouts,
    _In_reads_(NumSubresources) const UINT* pNumRows,
    _In_reads_(NumSubresources) const UINT64* pRowSizesInBytes,
    _In_reads_(NumSubresources) const D3D12_SUBRESOURCE_DATA* pSrcData)
{
    // Minor validation
    auto IntermediateDesc = pIntermediate->GetDesc();
    auto DestinationDesc = pDestinationResource->GetDesc();
    if (IntermediateDesc.Dimension != D3D12_RESOURCE_DIMENSION_BUFFER || 
        IntermediateDesc.Width < RequiredSize + pLayouts[0].Offset || 
        RequiredSize > SIZE_T(-1) || 
        (DestinationDesc.Dimension == D3D12_RESOURCE_DIMENSION_BUFFER && 
            (FirstSubresource != 0 || NumSubresources != 1)))
    {
        return 0;
    }
    
    BYTE* pData;
    HRESULT hr = pIntermediate->Map(0, nullptr, reinterpret_cast<void**>(&pData));
    if (FAILED(hr))
    {
        return 0;
    }
    
    for (UINT i = 0; i < NumSubresources; ++i)
    {
        if (pRowSizesInBytes[i] > SIZE_T(-1)) return 0;
        D3D12_MEMCPY_DEST DestData = { pData + pLayouts[i].Offset, pLayouts[i].Footprint.RowPitch, SIZE_T(pLayouts[i].Footprint.RowPitch) * SIZE_T(pNumRows[i]) };
        MemcpySubresource(&DestData, &pSrcData[i], static_cast<SIZE_T>(pRowSizesInBytes[i]), pNumRows[i], pLayouts[i].Footprint.Depth);
    }
    pIntermediate->Unmap(0, nullptr);
    
    if (DestinationDesc.Dimension == D3D12_RESOURCE_DIMENSION_BUFFER)
    {
        pCmdList->CopyBufferRegion(
            pDestinationResource, 0, pIntermediate, pLayouts[0].Offset, pLayouts[0].Footprint.Width);
    }
    else
    {
        for (UINT i = 0; i < NumSubresources; ++i)
        {
            CD3DX12_TEXTURE_COPY_LOCATION Dst(pDestinationResource, i + FirstSubresource);
            CD3DX12_TEXTURE_COPY_LOCATION Src(pIntermediate, pLayouts[i]);
            pCmdList->CopyTextureRegion(&Dst, 0, 0, 0, &Src, nullptr);
        }
    }
    return RequiredSize;
}