Add rounded slot feature

[bweissinger]

Adds basic functionality for creating slots. It uses the current point as the center point for the slot. Length is the overall end to end length of the slot, with direction set by angle in degrees. Addresses #158

[codecov]

Codecov Report

Merging #186 into master will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #186      +/-   ##
==========================================
+ Coverage   94.82%   94.86%   +0.03%     
==========================================
  Files          19       19              
  Lines        4116     4144      +28     
==========================================
+ Hits         3903     3931      +28     
  Misses        213      213

Impacted Files	Coverage Δ
cadquery/cq.py	93.2% <100%> (+0.13%)	⬆️
tests/TestCadQuery.py	98.94% <100%> (+0.01%)	⬆️

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[adam-urbanczyk]

Thanks a lot @bweissinger ! Some minor comments in the review.

[bweissinger]

@adam-urbanczyk @jmwright Added changes to address noted issues.

[jmwright]

@bweissinger Looks good. Thanks for implementing this.

[adam-urbanczyk]

Thanks for you work @bweissinger . Before we merge it, I think we need to still discuss the naming. I realized that slot could imply 3D feature. Do you know how other CAD packages name such a 2D thing?

[bweissinger]

Thanks for you work @bweissinger . Before we merge it, I think we need to still discuss the naming. I realized that slot could imply 3D feature. Do you know how other CAD packages name such a 2D thing?

Good catch.

As far as actual function names, the only package I have any idea on would be Freecad. Looking at the Freecad console, the slot sketch command seems to be named Sketcher_CreateSlot.

In my experience, slot usually refers to a 2D sketch feature. If a CAD package does use 3D slots, they don't seem to have a 2D slot features. A notable exception is Solid Works. It has both, but the 3D feature is actually located under Hole Wizard. I think it just depends on the function/industry the software is oriented towards. For instance, Catia has (as far as I know) only a 3D slot function, and it actually uses a path and a profile to cut along that path.

Unfortunately, the above programs all have a GUI to provide context. They could have both 2D and 3D, and name them both slot without much issue. However, 2D sketch slots tend to be named after the way they are defined:

• Center to Center Slot
• Center Point Slot
• Arc Slot
• ...

With everything above in mind, a couple of possibilities includes:

• sketchSlot
• centerPointSlot

[adam-urbanczyk]

@jmwright any thoughts on the name?

[jmwright]

@adam-urbanczyk I'm not sure. sketchSlot would be a break from how we name 2D operations, but it's probably the most accurate, and I think this is a little bit of a different case than we've had before with 2D operations. If it's named sketchSlot or something like slot2D, the user could still call some sort of 3D *Slot operation later that creates the 3D version, cut from the selected face.

[HLevering]

@jmwright I think in AutoCad there is a similar feature called "RoundedRect", but where there is one more degree of freedom namely the height of the rect. Our "slot" would be a special case of a rounded rect, where H = 2 * R. Maybe be it makes sense to generalize our slot to a rounded rect, which can be parameterized by width, height, edge_radius and where height defaults to 2 times egde_radius when not given by the user.

[adam-urbanczyk]

I looked at the newest FreeCAD and in the sketcher UI I can see a Create Slot tool. One day we might want to expose the OCC 3D slot feature so I'm in favor of renaming this to slot2D.

@Hatatister you can create a rounded rectangle by using rect, extruding it and filleting the edges. This is not possible for a slot (due to OCC kernel limitations).

[bweissinger]

Slot2D sounds good to me as well.

[adam-urbanczyk]

I think it is ready to be merged. Anything to add @jmwright @dcowden ?

[dcowden]

@adam-urbanczyk looks great to me!

[jmwright]

+1

[adam-urbanczyk]

Thanks for your contribution @bweissinger !