On Sun, May 16, 2021 at 10:10 AM Werner LEMBERG <w...@gnu.org> wrote: > > > > We have already discussed 8 Bit SDF earlier and I agree that 8 Bits > > is enough for producing acceptable interpolation for rendering. Here > > is the mail for your reference: > > https://lists.nongnu.org/archive/html/freetype-devel/2020-12/msg00042.html > > Thanks. > > > Back then I was waiting for others opinion and did not add this to > > the renderers however, if everyone agrees now I'll prepare a patch > > to remove 16 Bit support and only allow 8 Bit SDF. It will conserve > > memory and also eliminate the endiness issue that you mentioned > > earlier. > > Since you and Alexei agree on 8bit being enough: Please change to > 8bit!
Anuj, thank you for being open minded on this! Regular FT_PIXEL_MODE_GRAY is very convenient to display in our demo tools. They can look like extra blurry glyphs in ftview and ftgrid ;) Of course ftsdf can do cool stuff like interpolations. Again, I propose normalized SDF with outlide 0 corresponding to −spread and inside 255 corresponding to +spread, rather than 2.6 or 3.5 numbers. This way we use the entire 8-bit range efficiently and, with spread = 1, it will look quite similar to our normal rendering. I think your internal calculations are FT_Fixed and this is just a matter of normalizing output.
