SKGLView on .NET MAUI is missing a handler

[praeclarum]

I can’t use SKGLView because its handler is missing. SKCanvasView works fine.

new SKGLView();

Expected Behavior

A working OpenGL view.

Actual Behavior

Runtime error saying no handler found.

Basic Information

• Version with issue: latest
• Last known good version: none
• IDE: VSMPreview
• Platform Target Frameworks:
  • macCatalyst:
• Target Devices:
  • Mac

[mattleibow]

Yeah... Seems the iOS team deleted that. There is no GL view for mac cat. Not sure what to do. Might need to use metal, but this is slightly different.

[praeclarum]

Tell them to put it back. Mac Cat supports OpenGL.

[praeclarum]

I opened an issue. This is mind-blowingly painful. What is going on over there? dotnet/macios#15083

[praeclarum]

@mattleibow I would be willing to test the Metal version. Is that stable? How do I use it from MAUI? I don’t see a Maui.Controls.SKMetalView

I get that the names are weird. Maybe you could introduce an SKGpuView for those of us who need fast renderers.

[praeclarum]

OK, looks like Apple has removed GL from Catalyst. FML :-)

So… How about that MAUI SKGpuView That uses Metal on Apple and GL everywhere else? :-)

[xtuzy]

Hope Skiasharp can have more perfect support😊

platform	ios	android	winui3	maccatalyst
cpu	SKCanvasView	SKCanvasView	SKXamlCanvas	SKCanvasView
gpu	SKGLVIew,SKMetalView	SKGLSurfaceView,SKSurfaceView,SKGLTextureView	✗	SKMetalView

platform	ios	android	winui3	maccatalyst
maui cpu SKCanvasView	✓	✓	✓	✓
maui gpu SKGLVIew	✓	✓	✗	✗

[marcojak]

Does it mean that for MAUI we don't have gpu support on WinUI3 and MacCatalyst?
Is it something that is going to change?

[charlesroddie]

Agreed the SkGpuView is a good idea.

On the subject of ios/maccatalyst naming, ios seems to include maccatalyst which is a bit confusing. Perhaps SkiaSharp.Views.Uikit would be more accurate.

Currently this is regulated by:

SkiaSharp/source/SkiaSharp.Views/SkiaSharp.Views.Apple/SKMetalView.cs

Line 18 in b8efe44

public class SKMetalView : MTKView, IMTKViewDelegate, IComponent

#if __IOS__
namespace SkiaSharp.Views.iOS
#elif __MACOS__
namespace SkiaSharp.Views.Mac
#endif

And catalyst seems to be IOS. For example

SkiaSharp/samples/Gallery/Uno.WinUI/SkiaSharpSample.Mobile/SkiaSharpSample.Mobile.csproj

Line 33 in b8efe44

<DefineConstants>$(DefineConstants);__IOS__</DefineConstants>

<PropertyGroup Condition="'$(TargetFramework)'=='net6.0-ios' or '$(TargetFramework)'=='net6.0-maccatalyst'">