Re: Shadow demo for WebGPU-native

Hi Dzmitry,

Great job putting this sample together! Good to see real-world examples of
how the API should be used. I think we should aim to create many more such
samples in order to expose usability issues with WebGPU before it's set in
stone.

-Ken


On Mon, Feb 25, 2019 at 2:43 AM Corentin Wallez <cwallez@google.com> wrote:

> Hey Dzmitry,
>
> Thanks for sharing this, demos like this show that the API is starting to
> be well-rounded and your feedback is very valuable given your background in
> rendering engines for games! Can you file a bug / add an item in the
> snapshot tracker for the usability issues you found?
>
> Cheers,
>
> Corentin
>
> On Sat, Feb 23, 2019 at 5:04 AM Dzmitry Malyshau <dmalyshau@mozilla.com>
> wrote:
>
>> Hi WebGPU!
>>
>> I've been working ([1]) on an example to test and polish our native
>> WebGPU implementation, called "shadow". See the attached screenshot to get
>> the idea. Just wanted to share a bit of feedback, now that I got a slight
>> idea about what it is to *use* the API as opposed to designing it:
>>
>>    1. Overall, the experience was very pleasant ([2]). I believe we are
>>    aiming for the right level of abstraction for the web: low enough to be
>>    efficient, high enough to actually be able to write the demo and not drown
>>    in details.
>>    2. Some of the structures are unbalanced. For example,
>>    GPURasterizationStateDescriptor has most of the fields related to depth
>>    biasing. It would be cleaner to have all the depth biasing in a dedicated
>>    structure instead.
>>    3. I find GLSL with Vulkan syntax to be pretty nice to use. It
>>    addresses the biggest problem GLSL has - separating textures and samplers
>>    ([3]), along with specifying all the bind group/binding registers
>>    explicitly. I see value in it being well supported by WebGPU (not a as
>>    digested format), given that the current users of WebGL would have easier
>>    time moving to that syntax than to HLSL.
>>
>>
>>
>> Note: the example is written in Rust, but it's just a light wrapper over
>> C API library (wgpu-native). The idea is for it to be compatible with Dawn,
>> and also to gain the ability to target WASM in the future.
>>
>> Links:
>>
>> [1] https://github.com/gfx-rs/wgpu/pull/71
>>
>> [2]
>> https://github.com/kvark/wgpu/blob/616a3dd849c87db72db37d534bb21ddc700a2165/gfx-examples/src/shadow.rs
>>
>> [3]
>> https://github.com/kvark/wgpu/blob/616a3dd849c87db72db37d534bb21ddc700a2165/gfx-examples/data/shadow-forward.frag#L45
>>
>>
>> Regards,
>>
>> Dzmitry
>>
>