Fix native dylib location on Mac

[roeyskoe]

Currently ImGui.NET places native mac dylib to runtimes/osx-universal, which is not a valid location for DllImport to load it.
Imgui.NET 1.87.3 does not work with MacOs, without manually moving the libcimgui.dylib to a correct location.

This pr renamesosx-universal to osx, which works with both Intel and Arm platforms.

See also accepted names for runtimes folders: https://github.com/dotnet/runtime/blob/main/src/libraries/Microsoft.NETCore.Platforms/src/runtime.json

[miwarnec]

this currently blocks usage of IMGUI on apple silicon.
fix would be greatly appreciated :)

[frenzibyte]

So far, the osx RID has worked well on both Intel and Apple Silicon platforms, and can confirm that in the approach I noted at veldrid/veldrid-spirv#24. Gonna try testing this and see if it's working on osx as well.

[frenzibyte]

After testing in a similar manner to veldrid/veldrid-spirv#24, the osx RID also works here on M1, and osx-arm64 is not required.

[roeyskoe]

Yes osx should work according to the runtime.json I linked, but it didn't on my machine (M1, Monterey 12.3.1, .NET 6.0.201).

Please tell if just the first commit of this PR works on your machine, it was made with an Intel Mac.

[roeyskoe]

Good timing :P

But this raises a question, why did it not work when I tested?

[frenzibyte]

I would be curious about your way of testing it, can you fill in the steps? for me I just created a local nuget package and referenced it on a fresh project, and the osx RID is working there.

[roeyskoe]

That is exactly what I did.
When it didn't work, I just copied the libcimgui.dylib to osx-arm64 in the output directory and then it ran properly.

[frenzibyte]

As a sanity check, on a fresh console app project, can you reference this package and test with this code:

// See https://aka.ms/new-console-template for more information

using Veldrid.SPIRV;

Veldrid.SPIRV.SpirvCompilation.CompileVertexFragment(Array.Empty<byte>(), Array.Empty<byte>(), CrossCompileTarget.MSL, new CrossCompileOptions());

and see if it finds the native library or not?

[roeyskoe]

It does.

But I figured out why osx did not work when I tested.

In the output folder there is projectName.deps.json. In my test project it had a reference to runtimes/osx-universal/native/libcimgui.dylib. Because of that, osx or osx-universal does not work, but osx-arm64 does work.

This does not really make sense in my mind...

[frenzibyte]

Well, I'm surprised as well, but at least it's discovered now. I think the latest changes can be reverted now and only keep the first two, yeah?

[roeyskoe]

Reverted and tested with fully clean project that it works. Its is possible that this may cause small issues with some users when updating, but I think that we can ignore that since clean output directory fixes this.

Thanks @frenzibyte :D

[sergey-tihon]

Should build scripts be updated as well?

1. https://github.com/mellinoe/ImGui.NET/blob/65e1442134347e8f9bb24be979de38474a7eda3f/download-native-deps.ps1#L18
2. https://github.com/mellinoe/ImGui.NET/blob/65e1442134347e8f9bb24be979de38474a7eda3f/download-native-deps.ps1#L63
3. https://github.com/mellinoe/ImGui.NET/blob/b196a86359a0d5d33fed32854fca470ea392e7dd/download-native-deps.sh#L28