Embedding native surface while still using Avalonia as host

[jp2masa]

Use case

Veldrid doesn't seem to like OpenGL, so OpenGlControlBase can't be used. So I changed to a NativeControlHost where I create a SDL2 window from native API and pass it to Veldrid, which works just fine, but I'd like to use an Avalonia Window and not from SDL2, to make it easier to handle inputs and have less dependencies.

Is this possible?

[maxkatz6]

I think var window = new EmbeddableControlRoot() is what you need.

See:
https://github.com/AvaloniaUI/Avalonia/blob/master/src/Avalonia.Controls/Embedding/EmbeddableControlRoot.cs#L18
And

Avalonia/src/Windows/Avalonia.Win32/EmbeddedWindowImpl.cs

Line 11 in 8b5f97e

protected override IntPtr CreateWindowOverride(ushort atom)

[maxkatz6]

You can also use NativeControlHost.CreateDefaultChild() it won't return full window impl, but can be used to host content in the NativeControlHost itself. For reference, that's Win implementation with WM_CHILD https://github.com/AvaloniaUI/Avalonia/blob/master/src/Windows/Avalonia.Win32/Win32NativeControlHost.cs#L84 and parent.

[jp2masa]

It's actually INativeControlHostImpl.CreateDefaultChild(), and I think that doesn't help much, because it returns a handle to a new native window, and I would need an impl object to pass to embedded control root.

[maxkatz6]

This method is available on the NativeControlHost too (different name though, haven't noticed before - base.CreateNativeControlCore()), you don't need implementation.

because it returns a handle to a new native window

But doesn't it work as a replacement for SDL2 window? You can pass this handle to the Veldrid from what I understand.

[jp2masa]

Yes, but I'm no longer using SDL2, I'm trying to use Avalonia only, and passing the handle to Veldrid for rendering. Unfortunately the embedded control root exposes the platform impl as a top level impl (makes sense considering not all platforms use windows for embedding), but top level impl doesn't give me a handle.

The main problem is that pointer input doesn't work.

[anose001]

@jp2masa, did this ever work out for you?