On Thu, May 16, 2019 at 2:11 PM Dominik Röttsches <
address@hidden> wrote:
b) I would prefer 7a81b63abc2b3da0d7f0950f69377d2b3f54b0fb to be reworked so it doesn't cause pixel differences if possible, or reverted. Similarly with the current reasoning, I do not find 2ea511eed81770f423544525adebf7f954b8be93 a change that is strictly required or justified.
Dominik,
I have just committed the benchmarking numbers: Bezier bisections are faster by 20-30%, which ultimately translates to 2-3% of rendering speed. The other change gives 1% more. Not much right? I have been squeezing these percentage points over past 6 years and it adds up to about 30% by now. Considering that FT_Render_Glyph is called at least 10^12 times globally daily, it is important.
IMHO, the bit-level consistency that you are asking is flawed in the case of font rasterization. For what it is worth, rasterization is approximation, i.e, Bézier curves are flattened. There is so many *correct* ways to do it looking for that performance. Not everything has to be a bug fix, not every bit matters.
Alexei