[ft-devel] possibility of optimizing for speed with device metrics

[Hin-Tak Leung]

Hi Werner,

I am going through some of our earlier private e-mails on the
new FT_LOAD_COMPUTE_METRICS introduced in freetpe 2.6.1
and remember something from my testing - I was surprised
that adding that make no noticeable difference to speed.

Then I looked at the code, and see that Freetype does
all the horizontal advance calculations anyway, regardless,
then drop them in preference to available hdmx data.
(to others: the new flag controls the dropping).
Hence the no-difference to speed. So there is a small optimization
one can make moving that check earlier for normal usage, simply
trust the hdmx data and not calculating anything, and make freetype
marginally faster on normal usage.

I thought I should mention this on freetype-devel and
I'll let others put that in as a small evening project or something :-).

Hin-Tak