Re: Analysis of redisplay performance on Windows

[Adrian Robert]

Chong Yidong <cyd <at> stupidchicken.com> writes:

> 
> Jason Rumney <jasonr <at> gnu.org> writes:
> 
> > As I suggested in my earlier email, new functions in the
> > font backend interface to select a font for working with and releasing
> > it when done, would help, as we could then skip doing this in
> > functions like encode_char and text_extents.

In the NS font driver (nsfont.m) these two functions cache info
for each font by block of 256 (stored in nsfont_info -- nsterm.h).
This made a significant different in rendering speed when I
implemented it, and the memory cost is not high unless lots of different
char ranges are being rendered in lots of different fonts.  Moving this code
up to font.c would be another option to consider.