dynamically modify a worker and provide per-execution options

[BrianWiz]

Before looking at this plugin I had a very manual setup, and what I was doing was running some compute passes that modify a heightmap in a storage buffer. The thing is, the user would add a layer (like you would in photoshop) and you end up with a one-to-one relationship between layers and compute passes. Then after user input it would run all the passes in order.

I would like to flesh out this issue more, but I'll just start with my requirements for now:

• I need to be able to dynamically add and remove passes on a worker at any point during the app's lifetime
• I need to specify the x, y, z args in pass.dispatch_workgroups() per execution since this is tied to what the user's request is
• I may also need to call pass.set_push_constants() per execution, tbh its not super clear to me the need of it atm, but I have old code that does so, will get back to this
• I also needed to specify shader defs on pipelines when calling pipeline_cache.queue_compute_pipeline(), this may be worthy of another ticket but I'll keep here for now

Could have some kind of ExecutionSettings struct that you pass into worker.execute(). Will look deeper at this soon.

I'm willing to do the work here

[ivanceras]

I need to specify the x, y, z args in pass.dispatch_workgroups() per execution since this is tied to what the user's request is

+1 for this, I also need this capability.

I may also need to call pass.set_push_constants() per execution, tbh its not super clear to me the need of it atm, but I have old code that does so, will get back to this

This can be achieve using the write or write_slice function. Which works for changing the uniform or a storage value.