Mostly font editors use Bézier curves with four control points, so the effect of moving an off-curve point is limited to that portion of the curve from the associated on-curve node up towards the opposing on-curve node as affected by the other on-curve node.
It is my understanding that only a couple of very expensive font editors use B-splines where there are three control points which ripple as I noted, however it seems that FontForge supports order2 (quadratic, TrueType) or order3 (cubic, PostScript).
Comments
Mostly font editors use Bézier curves with four control points, so the effect of moving an off-curve point is limited to that portion of the curve from the associated on-curve node up towards the opposing on-curve node as affected by the other on-curve node.
It is my understanding that only a couple of very expensive font editors use B-splines where there are three control points which ripple as I noted, however it seems that FontForge supports order2 (quadratic, TrueType) or order3 (cubic, PostScript).