Posted by dxli on Apr 03, 2012; 11:30pm
URL: https://forum.librecad.org/Tangent-arcs-circles-or-ellips-tp5604952p5616611.html

draw a tangential circle for three existing entities:

currently we have "draw circle inscribed", need to get combinations of:

line/circle (arcs are treated as circles here, ellipse will be added after line/circle)

One way to do it:

find intersections between parabola and hyperbola. LibreCAD has its own quartic equation solver, so, this can be done by algebraic methods.

I wonder whether there's an easier algorithm by approximate methods.

dxli