704: Pipeline layout validation r=cwfitzgerald a=kvark
**Connections**
Implements a solid part of #269
Starts converting the function to return results, related to #638
cc @GabrielMajeri
**Description**
This change matches shader bindings against the pipeline layout. It's *mostly* complete, minus some bugs and not handling the `storage_texture_format` properly.
The risk here is that Naga reflection may have bugs, or our validation may have bugs, and we don't want to break the user content while this is in flux. So the PR introduces an internal `WGPU_SHADER_VALIDATION` environment variable. Switching it to "0" skips Naga shader parsing completely and allows the users to unsafely use the API.
Another aspect of the PR is that some of the functions now return `Result`. The way I see us proceeding is that any errors that we don't expect users to handle should result in panics when `wgpu` is used natively (i.e. not from a browser). These panics would happen in the "direct" backend of wgpu-rs (as well as in wgpu-native), but the `Result` would not be exposed to wgpu-rs, so that it matches the Web behavior.
At the same time, browser implementations (Gecko and Servo) will check the result on their GPU process and implement the WebGPU error model accordingly. This means `wgpu-core` can be super Rusty and safe.
**Testing**
Running on wgpu-rs examples. Most of them fail to get parsed by Naga, but `boids` succeeds and passes validation 🎉
Co-authored-by: Dzmitry Malyshau <kvarkus@gmail.com>
480: Implement `enumerate_adapters`. r=kvark a=daxpedda
This is take two of #478, it's a much smaller change with less abstraction.
- implement `internal_enumerate_adapters`, which refactors `instance.{BACKEND}.enumerate_adapters()` out of `pick_adapter`
- implement `enumerate_adapters`, which just returns a vector of all GPUs in the form of `AdapterId`
Co-authored-by: daxpedda <daxpedda@gmail.com>
PowerPreference::Default will now prefer discrete GPUs
when on AC power and will prefer integrated GPUs while
on battery power (i.e. the battery is discharging).
