`MTLAccelerationStructureTypes` feature guards the packed floats instead

[Lichtso]

See https://github.com/madsmtm/objc2/blob/master/framework-crates/objc2-metal/src/lib.rs#L46

Thus https://docs.rs/objc2-metal/0.3.0/src/objc2_metal/generated/MTLAccelerationStructure.rs.html is not exported.

[madsmtm]

Hmm, I'm not sure what you mean? The things in MTLAccelerationStructure.rs are guarded by the feature flag of the same name? Or for the case of e.g. MTLAccelerationStructureInstanceDescriptor, it is guarded by both the "MTLAccelerationStructure" and "MTLAccelerationStructureTypes" feature flags.

[Lichtso]

That is the issue. The things in MTLAccelerationStructure.rs are not guarded by the feature flag of the same name. Instead the feature flag guards something completely unrelated (packed floats). This is not a question, it is a bug.

[MarijnS95]

MTLPackedFloat3 is the only type defined in mod packed;. This type is (currently?) exclusively used by the acceleration structures (MTLPackedFloat4x3, MTLAxisAlignedBoundingBox and MTLComponentTransform), and is a type alias that Apple's Metal headers themselves define inside MTLAccelerationStructureTypes.h, that is why the header translator wraps it behind a cfg of the same name:

https://github.com/search?q=mtlpackedfloat3+path%3A**%2FMTLAccelerationStructureTypes.h&type=code

[MarijnS95]

Thus https://docs.rs/objc2-metal/0.3.0/src/objc2_metal/generated/MTLAccelerationStructure.rs.html is not exported.

In addition, what are you meaning with this? This link points to the entire source file of the MTLAccelerationStructure module. Did you mean to link to a specific item inside that module instead?

[MarijnS95]

Maybe since the handwritten linked packed.rs file/module is being disputed, perhaps it should simply be renamed to acceleration_structure_types - despite currently only defining one manual type - to clear up some confusion?

[Lichtso]

I think my confusion is that there are two features "MTLAccelerationStructure" and "MTLAccelerationStructureTypes", and one needs both to do anything useful.

Also, yes packed.rs should be renamed acceleration_structure_types.rs to match the feature name, otherwise there is no way to make the mental connection between those two.

[MarijnS95]

I concur that the current way of having certain types behind seemingly differently named features makes for a quite annoying experience when looking up a missing type. The best workaround is to just enable default-features especially now that the bindings are split out into a relatively small objc2-metal crate.

[madsmtm]

I think my confusion is that there are two features "MTLAccelerationStructure" and "MTLAccelerationStructureTypes", and one needs both to do anything useful.

I also agree that the feature selection is annoying, but the headers simply do not provide enough information to make a better choice. We could, for example, have the MTLAccelerationStructure feature automatically activate the MTLAccelerationStructureTypes feature since it references #import <Metal/MTLAccelerationStructureTypes.h> - but even then, another user might (theoretically) not want that enabled, since they only use e.g. MTLPrimitiveAccelerationStructureDescriptor (contrived example, but hopefully you get the idea).

I've chosen the current approach since it allows the user to fully minimize the amount of code (at the cost of being harder to use, which is why the default has everything enabled).

If you can come up with different schemes (maybe some sort of name matching, e.g. feature Xyz also enables feature XyzAbc?), then I'm all ears!

Maybe since the handwritten linked packed.rs file/module is being disputed, perhaps it should simply be renamed to acceleration_structure_types - despite currently only defining one manual type - to clear up some confusion?

Good suggestion, I have renamed the file in 35ec315.