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This is for Fedora on the M1. It would be amazing to get this for macOS. What's involved in pulling something like that off?

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Ultimately they build command buffers and send them to the GPU. You'd need a way to do that from macOS.

The original Mesa drivers for the M1 GPU were bootstrapped by doing just that, sending command buffers to the AGX driver in macOS using IOKit.

https://rosenzweig.io/blog/asahi-gpu-part-2.html

https://github.com/AsahiLinux/gpu/blob/main/demo/iokit.c

So you'd need a bit more glue in Mesa to get the surfaces from the GPU into something you can composite onto the screen in macOS.

According to the devs, it isn't really possible due to Apple not having a stable public kernel API: https://social.treehouse.systems/@AsahiLinux/111930744188229...

Perhaps already possible via MoltenVK -> Vulkan -> Zink?

Probably needs one or two more layers just to be sure.

I think Apple bans third party kernel drivers? To write a proper Vulkan or OpenGL implementation you need a kernel counterpart for handling the GPU if I understand correctly. That's probably the reason no one bothers implementing native Vulkan for macOS.

But if it's doable with Apple's driver - then not sure.

You can implement an OpenGL driver on top of Metal. But why bother dedicating so many resources for the sake of a suboptimal legacy API?

Because it's a cross-platform framework that thousands of programs (including Mac exclusives) rely on? There's so much OpenGL-only software that it should be Apple's moral imperative to support it anyways. I don't think anyone can honestly say that the graphics situation on Mac has improved in the absence of cross-platform APIs. Even Apple admits it with the Game Porting Toolkit.

And any of those Mac programs need anything more recent than 4.1? GL is legacy tech and Apple does offer legacy support. I just don’t see any reason to invest more work into this area. We should encourage people to stop using GL, not use it more. It’s bad technology.

Ideally we encourage people to port to Vulkan instead of Metal and DirectX, so porting is easier and more people can run common software. Unfortunately, certain vendors have a reputation against third party Open standards.

Legacy or not, OpenGL is the best cross platform graphics API we have that's actually practical for people to write directly. Metal is reasonable to write directly but not cross platform, Vulkan is cross platform but you need thousands of LoC to put a triangle on the screen.

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