Re: FT_Get_Advance() too slow?

[Behdad Esfahbod]

Hi Werner,

Regarding this thread:

https://lists.nongnu.org/archive/html/freetype-devel/2022-05/msg00004.html

I finally spent enough time on it to have a clue. I wrote up my findings in a document:

https://docs.google.com/document/d/1wskYbA-czBt57oH9gEuGf3sWbTx7bfOiEIcDs36-heo

The short answer is that basically fetching advances from hmtx is such a small bit of work, that HarfBuzz does it in just a few operations because of inlining, but all the function call and other overheads in FreeType add up...

hb-ft is also not asking FreeType for NO_SCALE where it, in theory, can. That's contributing to this as well, but only 10%.

Regards,

behdad
http://behdad.org/