In LibreCAD v3, 2d integrals are estimated to find the area
In LibreCAD v2, the area is found by contour integrals.
While it's straightforward to consider a local weight function to get various physical functions, it's not really what we are focusing on. Any help is welcome though
ginghis wrote
In the case of 2D it would be second moment of area instead of center of gravity. Multiplying by thickness and density gives weight which is centered at the center of second moment of the area.