Arc Midpoint Calculations

[rkondner]

Hi,
I am plowing through KiCAD footprint generation and I need to handle KiCAD ARCs I need Start, End and Midpoint X,Ys. Instead of Midpoint I have the Center. I can do it using transcendental functions but after looking through the web I see other solutions.

Any graphic gurus out there that can point me to an easy implementation?

Thanks,
Bob K.

[paulvdh]

When I draw an arc in the footprint editor (KiCad V8.0.1) then I also get a control point for the midpoint of the arc (although it’s not listed in the arc properties).

You can draw a line and snap to that midpoint, and then get it’s coordinates from one of the endpoints of the line you drew.

Alternatively, there is: Footprint Editor / New / Create Footprint. This has about 15 footprint wizards, and these are python scripts, that are somewhere in KiCad’s directory (Location depends on your OS). You can study, and modify a copy of these scripts to generate custom footprints.

[rkondner]

Thank you. I am converting in code from another DB to KiCAD. Current DB uses Windows GDI Ellipse function. did find a arctan2 that converts from X/Y to Pi / -Pi radians.

Is the arc always drawn counter clockwise from the star point to the end point?

Thanks,
Bob K