wgpu-core: Inform user about possible fix

[hackaugusto]

Connections

None

Description

I'm inexperienced with the API, and wrote a test using Limits::downlevel_webgl2_defaults(). The only reason I realized the validation error for the number of bindings was not a hardware capability issue is because I had gone over an working example on https://webgpufundamentals.org/.

Adding a bit more of context to the error message should help new users realize this is a configuration issue instead of hardware/support and guide them to a possible fix.

This changes the error from:

wgpu error: Validation Error

Caused by:
    In Device::create_bind_group_layout
    Too many bindings of type StorageBuffers in Stage ShaderStages(VERTEX | FRAGMENT), limit is 0, count was 1

To:

wgpu error: Validation Error

Caused by:
    In Device::create_bind_group_layout
    Too many bindings of type StorageBuffers in Stage ShaderStages(VERTEX | FRAGMENT), limit is 0, count was 1. Check the required limit max_storage_buffers_per_shader_stage used on request_device

Testing

With cargo xtask test

Checklist

• Run cargo fmt.
• Run cargo clippy. If applicable, add:
  • --target wasm32-unknown-unknown
  • --target wasm32-unknown-emscripten
• Run cargo xtask test to run tests.
• Add change to CHANGELOG.md. See simple instructions inside file.

[cwfitzgerald]

Love the change, just a few small issues!

[hackaugusto]

Updated the error message and implementation, after changes it looks like this:

wgpu error: Validation Error

Caused by:
    In Device::create_bind_group_layout
    Too many bindings of type StorageBuffers in Stage ShaderStages(VERTEX | FRAGMENT), limit is 0, count was 1. Check the limit `max_storage_buffers_per_shader_stage` passed to `Adapter::request_device`

[cwfitzgerald]

Nice