Add WinUI 3 SwapChainPanel support

[DDRBoxman]

Checklist

• Run cargo clippy.
• Run cargo clippy --target wasm32-unknown-unknown if applicable.
• Add change to CHANGELOG.md. See simple instructions inside file.

Connections

Closes #4187

Description

Currently WinUI3 requires using a SwapChainPanel to render into a widget with directx.

This allows passing down a SwapChainPanel reference and then sets the swap chain on the panel.

Testing

Called from a C# Win UI App and rendered the triangle from the tutorial to the swap chain

[cwfitzgerald]

Code generally looks fine, there's a bit of architectural stuff I want to deal with after this lands, but lets land first.

[DDRBoxman]

Sample code for how to get the correct pointer to send to native code in c#

IntPtr objectAddress = Marshal.GetComInterfaceForObject(swapChainPanel1, typeof(ISwapChainPanelNative));
CsBindgen.NativeMethods.send_swap_chain_panel((void*)objectAddress);

[cwfitzgerald]

Lets do it!

[DDRBoxman]

🎊

[Codentale]

Hi @DDRBoxman, nice work!
btw do you mind to share the C# sample project?
thanks.

Called from a C# Win UI App and rendered the triangle from the tutorial to the swap chain

[DDRBoxman]

@Codentale take a look here

https://github.com/DDRBoxman/Cappy3ds/tree/main/win