private static unsafe Span <byte> CreateBlob(out ID3DBlob *ppBlob, UIntPtr size)
{
ID3DBlob *p;
ThrowIfFailed(D3DCompiler.D3DCreateBlob(size, &p));
ppBlob = p;
return(new Span <byte>(ppBlob->GetBufferPointer(), (int)ppBlob->GetBufferSize()));
}