angle VS MoltenVK

It's using MoltenVK on Mac for Vulkan compatibility, and ANGLE for OpenGL compatibility on Windows and Linux. Makes you wonder what it's actually doing itself.

Can't they use https://github.com/google/angle?

BTW. For the last 15 years, all web browsers on Windows do WebGL on top of DirectX (using the Angle library https://github.com/google/angle).

You can still use OpenGL. Just not the vendor provided drivers. They are indeed horrible. There are libraries like:

* ANGLE ( https://github.com/google/angle ) - An OpenGL ES implementation with Direct3D 9, Direct3D 11, Desktop GL, GL ES, Vulkan and Metal backends. This is what we used to use for shipping our Qt 3D application, that used a bunch of OpenGL Shaders. We used to get bug reports about various shaders not working properly on various hardware. After switching to this, all those bug reports vanished.

* Zinc ( https://www.supergoodcode.com/do-not/ ) - A more recent, OpenGL implementation on top of Vulkan. I haven't used this one yet. But they are making a lot of progress and it is almost as performant as vendor provided OpenGL Drivers these days. So if I ever have to ship a desktop app, needing opengl, I'd strongly consider using this.

Another option if perf isn't a big concern is to try using Google's angle OpenGL ES 3.0 implementation, there's backends for it to be supported on Vulkan, Direct3D 11, and (work in progress) Metal. Disclosure, haven't tried it myself, just looking at their feature descriptions: https://github.com/google/angle

I don't believe Chrome uses OpenGL directly- any OpenGL usage it does have (e.g. for WebGL) is actually going through ANGLE which translates it all to D3D on Windows.

RTFM, have you read their instruction

https://github.com/KhronosGroup/MoltenVK

Translating between rendering APIs is not really the problem. The GPU design is more different than the API is.

Khronos maintains MoltenVk though, which is "official" as it gets: https://github.com/KhronosGroup/MoltenVK

...technically, Vulkan on Windows is also only supported via 3rd-parties (the GPU vendors), Microsoft doesn't support Vulkan either ;)

MoltenVK implements large parts of Vulkan on top of Metal for Apple systems. It isn't full Vulkan but it makes porting Vulkan games to OS X easier.

That's cool. Maybe I haven't thought enough about this. Let me check it out. FWIW it's this PR that you are referring to I think: https://github.com/KhronosGroup/MoltenVK/pull/1815/

For Metal specifically, they could adopt and contribute to Vulkan and get access to a lot more software. Right now you need to use a compatibility layer, and surely Apple could just support both APIs natively with much lower overhead. But they don't, because it nudges developers to stick to the Apple ecosystem instead of being able to support multiple platforms.

At the moment the most promising thing is MoltenVK (DX12 -> DXVK -> Vulkan -> MoltenVK -> Metal), but the development is not that quick mainly because there aren't tons of developer that works at the same time on the project. It's not actually a Metal related problem at the moment (they have a road map of things that they can be achieved with Metal 3 like Mesh shader and Geometry shader).

What you asked is already existed for at least 8 years. Yeah EIGHT years. It's called "MoltenVK". So far it's the only implementation of Vulkan for macOS. Basically it's a wrapper that runs on top of Metal API.