Add new hololens code (winrt + D3D immersive mode example)

support/hololens/ServoApp/Common/DirectXHelper.h

@@ -0,0 +1,65 @@
+#pragma once
+
+namespace DX {
+// Function that reads from a binary file asynchronously.
+inline std::future<std::vector<byte>>
+ReadDataAsync(const std::wstring_view &filename) {
+  using namespace winrt::Windows::Storage;
+  using namespace winrt::Windows::Storage::Streams;
+
+  IBuffer fileBuffer = co_await PathIO::ReadBufferAsync(filename);
+
+  std::vector<byte> returnBuffer;
+  returnBuffer.resize(fileBuffer.Length());
+  DataReader::FromBuffer(fileBuffer)
+      .ReadBytes(winrt::array_view<uint8_t>(returnBuffer));
+  return returnBuffer;
+}
+
+// Converts a length in device-independent pixels (DIPs) to a length in physical
+// pixels.
+inline float ConvertDipsToPixels(float dips, float dpi) {
+  constexpr float dipsPerInch = 96.0f;
+  return floorf(dips * dpi / dipsPerInch + 0.5f); // Round to nearest integer.
+}
+
+inline winrt::Windows::Graphics::DirectX::Direct3D11::IDirect3DSurface
+CreateDepthTextureInteropObject(
+    const Microsoft::WRL::ComPtr<ID3D11Texture2D> spTexture2D) {
+  // Direct3D interop APIs are used to provide the buffer to the WinRT API.
+  Microsoft::WRL::ComPtr<IDXGIResource1> depthStencilResource;
+  winrt::check_hresult(spTexture2D.As(&depthStencilResource));
+  Microsoft::WRL::ComPtr<IDXGISurface2> depthDxgiSurface;
+  winrt::check_hresult(
+      depthStencilResource->CreateSubresourceSurface(0, &depthDxgiSurface));
+  winrt::com_ptr<::IInspectable> inspectableSurface;
+  winrt::check_hresult(CreateDirect3D11SurfaceFromDXGISurface(
+      depthDxgiSurface.Get(),
+      reinterpret_cast<IInspectable **>(winrt::put_abi(inspectableSurface))));
+
+  return inspectableSurface
+      .as<winrt::Windows::Graphics::DirectX::Direct3D11::IDirect3DSurface>();
+}
+
+#if defined(_DEBUG)
+// Check for SDK Layer support.
+inline bool SdkLayersAvailable() {
+  HRESULT hr = D3D11CreateDevice(
+      nullptr,
+      D3D_DRIVER_TYPE_NULL, // There is no need to create a real hardware
+                            // device.
+      0,
+      D3D11_CREATE_DEVICE_DEBUG, // Check for the SDK layers.
+      nullptr,                   // Any feature level will do.
+      0,
+      D3D11_SDK_VERSION, // Always set this to D3D11_SDK_VERSION for Windows
+                         // Runtime apps.
+      nullptr,           // No need to keep the D3D device reference.
+      nullptr,           // No need to know the feature level.
+      nullptr            // No need to keep the D3D device context reference.
+  );
+
+  return SUCCEEDED(hr);
+}
+#endif
+} // namespace DX