|
From: | Behdad Esfahbod |
Subject: | Re: GSOC - Distance Fields |
Date: | Wed, 3 Jun 2020 15:32:56 -0700 |
Hi Jim, others,Thanks for your input. I've been meaning to get into the discussion as well but didn't get to.I support your suggestions: generate from vector instead of bitmap, as well as 8-bit 3.5 fixed point or similar at least as an option. In your 3.5 fixed-point, does one unit reflect 1em, or 1 pixel at the SDF size?I think we do want a 8bit representation at least, and possible a higher one.On Wed, Jun 3, 2020 at 10:26 AM Jim Van Verth <jvanverth@google.com> wrote:Forgive me for coming into this late -- a colleague pointed me to this thread a couple of days ago and I'm just catching up. I work on Skia, and we've been generating SDFs from glyphs for quite some time now, so the possibility of just getting them from Freetype is pretty exciting.I hope you don't mind some comments on what we have now. We currently use the Gustavson algorithm to generate them from bitmaps but it produces slightly fuzzy results. I have wanted to move to use this algorithm to generate them directly from the outline which might be useful to you:We use it to store atlased paths at the moment and it produces much better results.As far as format, we use an 8-bit 3.5 fixed point format, because it allows us to combine the SDF and bitmap glyphs into the same atlas to conserve space. There is a sacrifice in quality, but we only use the SDFs for larger glyphs so it's acceptable.If you would like more details on our implementation please let me know. I'm looking forward to seeing how this turns out.--behdad
http://behdad.org/
[Prev in Thread] | Current Thread | [Next in Thread] |