nannou-org/nannou

Link Shaderc Dynamically

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#311 opened on May 12, 2019

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 (3 comments) (1 reaction) (0 assignees)Rust (4,662 stars) (254 forks)batch import
help wanted

Description

I'm opening this issue to investigate the possibility of linking shaderc dynamically. It's by far the biggest time consumer in nannous build times. But all it's doing is compiling a c library which we should be able to install as a system library and just link against. Things to consider:

  • How do we build it the first time? Perhaps we make a small crate that compiles and installs it as a system library.
  • How to check if it's already installed. I think maybe the same crate could check if it's already installed and only compile if it isn't. Something similar to moltenvk_deps.
  • What if shaderc get's an update. We might need a way to check if this happens and recompile. I'm not sure how this is currently handled. I think it's pulling the source as a submodule from git.
  • How to tell vulkano not to just compile shaderc. (And any other crates that use it) We might need a PR to vulkano as well but maybe there is someway to tell shaderc-rs to check for system libraries first.

I'll try and get to this soon but I'm pretty busy with other stuff. This would be a good issue for anyone with cmake experience and I'm happy to help with the build.rs stuff. Probably not a good first issue.

I think the best place to start is to see if there is a way to achieve this with the current setup by passing a feature flag to shaderc-rs or something similar.

Contributor guide

Tech stack
rustc
Domain
build systemdeveloper experienceperformance
Issue type
performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
cmake knowledgeRust build.rslinking conceptsshaderc/SPIR V
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
Investigate shaderc rs features to see if it supports system library linking. Look at moltenvk deps as a pattern for conditional compilation. Determine how to detect installed shaderc version. Check nannou's build.rs and shaderc rs source for integration points.