Using installed version OpenCASCADE

[katyo]

This PR adds support installed version of OpenCASCADE library when it found and fits prerequisites. This drastically speeds up build. You can use builtin feature to prefer builtin version and skip detecting installed one.

Also added support for dynamic linking via using dynamic feature so this PR also superseeds #26.

[katyo]

@bschwind What do you think?

[bschwind]

Hey @katyo, thanks for the PR! I think once we figure out where opencascade-sys is going (being discussed in #86), we can then add these changes on top (or vice-versa).

I should also see if this helps resolve #27.

In any case, please give me a bit of time to test and review :)

[strohel]

Thanks @katyo, this is indeed a very useful change. I posted some thoughts/suggestions for the implementation. We've also working on #86 with @bschwind. I'm happy to rebase/adapt this if #86 lands sooner.

BTW this could be even a solution for slow CI - at least the Ubuntu runner provides opencascade in the repository.

[katyo]

@bschwind I rebased this PR to current master.
@strohel I changed it as you suggested before but I have some doubts.

Maybe we should enable builtin feature by default or remove it in favor of external feature which will enable using installed OpenCASCADE libraries instead of compiling builtin one. But it seems cargo does not provide a way to disable optional dependency (occt-sys) conditionally when some feature is enabled.

[bschwind]

I've been delayed in reviewing this but I'll give it a try soon!

[strohel]

Looking good! Just adding some nits.

Maybe we should enable builtin feature by default

Yes, please, on opencascade level.

[bschwind]

This is looking good, just need a few tweaks:

• Fix the build errors
• Fix the clippy warnings (we run cargo clippy --release --all-targets -- -D warnings in CI)

Could you also add a bit of documentation in the README on how to use the bundled OCCT, vs. using the system-installed one?

[katyo]

@bschwind @strohel I thought a more proper solution is using cmake in both cases (when builtin feature is enabled and also when it is disabled).

[strohel]

@bschwind @strohel I thought a more proper solution is using cmake in both cases (when builtin feature is enabled and also when it is disabled).

Yeah this should work! We'd just need to provide a good error message in case the version doesn't check with the builtin feature (basically say that the developers are to blame, that's not on the user side).

[bschwind]

@katyo could you please rebase this on the latest main (which is now based on opencascade 7.7.1)?

[katyo]

@bschwind Does this mean that OCCT 7.7.1 is a minimum supported version?

[katyo]

@bschwind Currently CI won't work as expected when occt-sys needs to be updated too. Hope such behavior was predictable.

[bschwind]

@katyo that's okay! I see what you mean, we need to update occt-sys first with the changes, and then publish that to 0.3.

@bschwind Does this mean that OCCT 7.7.1 is a minimum supported version?

Unfortunately yes. We could go back and see when exactly the ComputeNormals function was added and use that version I suppose, but it was a nightmare to get the crate size down to 10MB, and that later version was needed so I didn't have to depend on the StdPrs package.

I can help to support this PR and get it through, as I currently have the publishing rights to occt-sys, just give me some time to complete that.

[katyo]

@bschwind Any chance that this PR will be merged soon?
Seems currently development stuck. I would like add many more changes.

[bschwind]

Hi @katyo , yes I still want to get to this for sure. I've been on a two week trip so development and review has been a bit slow. This PR is the next one I want to test so I'll update you here when I've done so. Sorry for the wait!

[bschwind]

@strohel could I get another review from you on this? Especially concerning the newly added builtin feature flags on the examples and viewer crates, I wasn't sure if that was the right approach or not.

Also, I excluded occt-sys from the workspace in c59c037 and 96a6634, does that seem logical to you?

[bschwind]

@katyo I'm back from the trip I was on. I pushed some changes to your branch and published 0.3 of occt-sys to get this building. Thanks so much for your patience! Please take a look at the changes and let me know if you agree with them.

I've tested this fairly thoroughly and things are working well!

Interestingly, I seem to get better performance when using the builtin version of OCCT. Anecdotally on my mac mini m1, the keycap model takes:

• ~1.58 seconds using the statically-linked OCCT
• ~2.01 seconds using the dynamically-linked, system-provided OCCT

[katyo]

@bschwind

Are you sure that this works as expected?
Because I tested it with linux only maybe something went wrong.
Please look at ldd output in both cases to check which OCCT libs actually used.

[bschwind]

@katyo I tested it with --no-default-features and without --no-default-features:

Dynamic Linking

$ cargo build --release --no-default-features --bin viewer

opencascade $ otool -L target/release/viewer                          
target/release/viewer:
	/System/Library/Frameworks/QuartzCore.framework/Versions/A/QuartzCore (compatibility version 1.2.0, current version 1.11.0)
	/System/Library/Frameworks/Metal.framework/Versions/A/Metal (compatibility version 1.0.0, current version 258.17.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1311.0.0)
	/usr/lib/libobjc.A.dylib (compatibility version 1.0.0, current version 228.0.0)
	/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit (compatibility version 45.0.0, current version 2113.20.111)
	/System/Library/Frameworks/ApplicationServices.framework/Versions/A/ApplicationServices (compatibility version 1.0.0, current version 56.0.0)
	/System/Library/Frameworks/CoreGraphics.framework/Versions/A/CoreGraphics (compatibility version 64.0.0, current version 1557.3.2)
	/System/Library/Frameworks/CoreVideo.framework/Versions/A/CoreVideo (compatibility version 1.2.0, current version 1.5.0)
	/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation (compatibility version 150.0.0, current version 1856.105.0)
	/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation (compatibility version 300.0.0, current version 1856.105.0)
	/opt/homebrew/opt/opencascade/lib/libTKMath.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKernel.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKFeat.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKGeomBase.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKG2d.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKG3d.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKTopAlgo.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKGeomAlgo.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKBRep.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKPrim.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKSTEP.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKSTEPAttr.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKSTEPBase.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKSTEP209.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKSTL.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKMesh.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKShHealing.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKFillet.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKBool.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKBO.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKOffset.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/opt/homebrew/opt/opencascade/lib/libTKXSBase.7.7.dylib (compatibility version 7.7.0, current version 7.7.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 1200.3.0)
	/usr/lib/libiconv.2.dylib (compatibility version 7.0.0, current version 7.0.0)
	/System/Library/Frameworks/ColorSync.framework/Versions/A/ColorSync (compatibility version 1.0.0, current version 4.7.0)

Static Linking

$ cargo build --release --bin viewer

opencascade $ otool -L target/release/viewer 
target/release/viewer:
	/System/Library/Frameworks/QuartzCore.framework/Versions/A/QuartzCore (compatibility version 1.2.0, current version 1.11.0)
	/System/Library/Frameworks/Metal.framework/Versions/A/Metal (compatibility version 1.0.0, current version 258.17.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1311.0.0)
	/usr/lib/libobjc.A.dylib (compatibility version 1.0.0, current version 228.0.0)
	/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit (compatibility version 45.0.0, current version 2113.20.111)
	/System/Library/Frameworks/ApplicationServices.framework/Versions/A/ApplicationServices (compatibility version 1.0.0, current version 56.0.0)
	/System/Library/Frameworks/CoreGraphics.framework/Versions/A/CoreGraphics (compatibility version 64.0.0, current version 1557.3.2)
	/System/Library/Frameworks/CoreVideo.framework/Versions/A/CoreVideo (compatibility version 1.2.0, current version 1.5.0)
	/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation (compatibility version 150.0.0, current version 1856.105.0)
	/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation (compatibility version 300.0.0, current version 1856.105.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 1200.3.0)
	/usr/lib/libiconv.2.dylib (compatibility version 7.0.0, current version 7.0.0)
	/System/Library/Frameworks/ColorSync.framework/Versions/A/ColorSync (compatibility version 1.0.0, current version 4.7.0)

[katyo]

@bschwind Seems it works as expected.

[bschwind]

@katyo were you having trouble making it work on linux? I can test it out on a linux machine today too.

[katyo]

@bschwind No, it works fine for me (NixOS). I think it shouldn't have problems with other distros either.

Maybe we won't get significant speedup using dynamic linking itself but using pre-installed OCCT allows skip building it which takes several minutes on my laptop.

[bschwind]

@strohel I'm going to merge this, but please leave any post-merge reviews you may have and we can always open up new PRs to make any adjustments you might suggest.

@katyo thanks again for your work and patience on this.