Notify users about quality of Martin fonts

[wipfli]

Should we notify users about the quality of fonts served with Martin? I think many will not be aware that fonts generated with Martin are more pixelated than the ones generated with font-maker...

[nyurik]

@wipfli I am not certain why this might be the case - shouldn't Martin generate the same font types, with the same resolution? Martin uses pbf_font_tools by @lseelenbinder and @ianthetechie which internally handles all that.

[ianthetechie]

Yeah, nobody has ever complained to us about it yet, but TL;DR the crate currently uses the methodology from TinySDF whereby it rasterizes to a bitmap first and generates the SDF from that. This is faster but slightly lower quality.

There is an open issue to add support for the other method. PRs welcome; it’s not hard to port the C++ code. Just hasn’t been high on my priority queue. stadiamaps/sdf_font_tools#16