### Will this ever be a fully functional VK driver?
As far as I know the PI is NOT fully VK capable on the hardware level. I can already see that some things will need to be emulated and others won't ever be emulated. The compiler is also a huge unknown at this point as I plan to write one from scratch.
### What performance should you expect?
Performance wise, the Pi is quite capable. The specs and architecture is close to the GPU in the iPhone 4s. The only problem I see is bandwidth as you only have about 7GB/s compared to 12-25GB/s on typical mobile phones. So post processing is a huge no and you'd need to be very careful about the techniques that you use. Eg. you'd need to stay on chip at all times.
- I already plan to emulate a couple of the basics such as copy commands using compute
- Tessellation and geometry shaders won't be considered, it just doesn't make sense
- Sparse resources might be implemented, but I don't think performance would be great
- Compute shaders could also be implemented, though I think I would need to modify the kernel side for that, no LDS or any of the fancy stuff though...
- As far as I know the PI doesn't support occlusion queries (https://github.com/anholt/mesa/wiki/VC4-OpenGL-support)
- Indirect draws are probably out of scope
- I already added support (to be polished) to load shader assembly. This will enable devs to optimise shaders to the last cycle.
- I'll probably add something to indicate towards the developer that things are emulated or not supported at all.