On Fri, Jun 20, 2025 at 10:35 PM Luca Fascione <l.fasci...@gmail.com> wrote: > One thing you said about fonts before caught my eye: > you said that if the glyph definition changes the image might change, I agree > but isn't that an orthogonal problem to this? > In my mind the font content (the look of the glyphs, its metrics, > whathaveyou) and the work done by the > layout engine to decide where these glyphs and other graphics elements should > be placed are separate things to test. > > Also I expect changes to the font definition are a) comparatively rare, and > b) done by different people than > layout algorithm folks. But more importantly isn't it the case that normally > if you alter the glyphs > you're likely to alter the metrics? > > It seems to me this would knock (a bit) around all layouts anyways, no? I'm > thinking it would invalidate all regressions > using that font, I guess (and in a way "for the wrong reason", I might add, > in that the layout engine is just following > new metric definitions without a real algorithmic change). > > Am I thinking about this all upside down?
No. Maybe I have a different angle on the problem, because the bitmap-based comparisons were essential to debugging Cairo backend. But we don't add new backends often enough to support that by default in the regression testing infrastructure. Looking forward to your POC. -- Han-Wen Nienhuys - hanw...@gmail.com - http://www.xs4all.nl/~hanwen
