For the most part truetypetracer produces valid and nice input data for testing openvoronoi. But sometimes I see wiggles, and now this:
It is frustrating to try to track down bugs in downstream algorithms that take this as input, and assume all line-segments are non-intersecting when in fact the are not!
I seem to have only 13 .ttf files in my
/usr/share/fonts/truetype/freefont folder, but maybe there are more elsewhere. I should find a font that is properly designed without wiggles and without overlaps. The other approach is to write a pre-processor that looks at input data and either rejects or cleans it. Looking for all pair-wise intersections of N line-segments is a slow N^2 algorithm - at least for a naive implementation (without bounding-boxes or binning or other tricks).
Here is G-code generated with ttt-4.0 and drawn in LinuxCNC: