[WIP] Metal Backend

[fkaa]

Done:

• gfx_window_metal
• Metal backend in gfx_app
• PSO
• Reflection
• Texture/Samplers
• Command buffer/encoder
• Depth/stencil things

Almost done:

• Bunch of factory methods for updating data etc.

Not started:

• Instancing
• Fixing memory leaks – the thing i'm looking forward to the least (i'm saving .retain(), .release() for last)

Probably bunch of other stuff i missed mentioning, but should crop up eventually

[fkaa]

We have clear color now 🔨

[bvssvni]

Can you rebase? I want to try it on my computer.

[fkaa]

@bvssvni that should do it! (Only the cube example "works" at the moment though)

[bvssvni]

I'm getting this error:

src/backend/metal/src/command.rs:68:1: 68:30 error: the trait `Copy` may not be implemented for this type; variant `SetViewport` does not implement `Copy` [E0205]
src/backend/metal/src/command.rs:68 #[derive(Clone, Copy, Debug)]
                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[fkaa]

Sorry, was working with local cargo override. Pushed the changes now.

[bvssvni]

@fkaa Still getting same error.

[fkaa]

cargo update -p metal?

[bvssvni]

@fkaa Yay! It works!

[fkaa]

We have cube!

[kvark]

Thanks @fkaa! Proceeding with merge.
The biggest problem here would be supporting the code base, given that it grows faster than our contributor base.

[kvark]

@homu r+

[homu]

📌 Commit 7a3d257 has been approved by kvark

[homu]

⚡️ Test exempted - status

[kvark]

@fkaa was able to get the shadow example kinda working with some tweaking:

The backend is not ready for adoption, but it's getting close to it!