> > Most likely FreeType already has a collection of fonts for testing, > > but I cannot find any references. > > Alas, it has not. The test font corpus used for fuzzing is not really > suited for testing the rendering, and collecting commercial fonts is > problematic...
We do not need much to test the rendering itself. The test patterns in ftstring (ft2-demos) with a bunch of tight curves are very sensitive to any errors in the algorithm including insufficient flattening. There are expected to be one-off or two-off differences because of rounding: the 64-bit solutions might differ from the 32-bit once. Any issues with auto hinting also do not need much to show up in blinkl tests: just a few glyphs with slightly curvy stems. To test native hinting, you might need considerably more: https://en.wikipedia.org/wiki/Core_fonts_for_the_Web. A.
