Re: WebGPU on the Raspberry Pi 4

Hi Doug,

We've been discussing the possibility of defining a reduced WebGPU spec 
targeting OpenGL ES and D3D11 (distantly similar to how Vulkan 
Portability is a reduced spec of Vulkan). There is strong desire from 
both Mozilla and Google to make it work on OpenGL ES, at least, given 
that there is a lot of platforms still (especially in Android space) 
that don't have Vulkan/Metal/D3D12. So far, the working group hasn't 
agreed on how the spec will be extended/"subtended" for OpenGL ES, and 
it's not the goal of the whole group. We may end up with a reduced 
profile specified outside of the group.

In terms of implementation, Google's NXT prototype had OpenGL support 
from the start.

"gfx-rs" does have an OpenGL ES backend that is very rough (not 
production ready) but we are serious about getting it work, in 
particular by looking for a GSoC student to help with this. "wgpu" used 
to support OpenGL, and that was cut out, hopefully temporarily. There is 
a high chance Firefox will be able to run *some* WebGPU applications on 
OpenGL ES 3.1 in the future, but we have more important work right now 
than chasing this.


Hope this is helpful.

Regards,

Dzmitry

On 12/21/19 5:45 PM, Doug Moen wrote:
> I wonder if there is hope for WebGPU in a web browser running on the 
> Raspberry Pi 4?
>
> There is no Vulkan driver available, nor is there OpenGL. Instead, 
> there is an OpenGL ES 3.1 driver (compute shaders) in the final stages 
> of development, and work has begun to support OpenGL ES 3.2 (geometry 
> shaders). So my question is whether OpenGL ES 3.1/3.2 is good enough 
> to support WebGPU?
>
> https://www.raspberrypi.org/blog/vc4-and-v3d-opengl-drivers-for-raspberry-pi-an-update/
>
> Mozilla's gfx-rs/wgpu project says nothing about OpenGL ES 3.1 
> support. I do see some kind of OpenGL support in the underlying 
> gfx-hal library, but nothing is being promised for wgpu. So maybe 
> there will be no Firefox support.
>
> Google's Dawn project says "OpenGL as best effort where available". 
> There is no mention of version numbers, though. Will Dawn support 
> OpenGL ES 3.1/3.2?
>
>