Alan W. Irwin wrote:
> On 2009-04-04 22:49-0400 Hazen Babcock wrote:
>>> I have a slightly more recent version of pangocairo (1.22.2) and I also get
>>> pretty much identical rendering speeds with text_clipping on or off.
>> And now I'm not so sure about this result. Alan, can you try with the xcairo
>> driver? It seems noticeably slower to me now with text_clipping on. Slow
>> enough that I can almost see it drawing each string.
> I measure no significant difference. I held down the return key (to go
> through the pages as quickly as possible) and got consistent timings (using
> the time command) with text clipping and consistent timings without text
> clipping. And without was consistently faster. But the difference was only
> 0.01 seconds, i.e., negligible. So device xcairo is consistent with the
> other cairo devices (none of which showed large changes in speed between
> text clipping on or off).
> I wonder if your recent rewrite of text handling in cairo is a factor. The
> above test was without your recent changes, i.e., revision 9774 of cairo.c.
> You might want to repeat your test with that revision. Also, I would highly
> advise using the time command (or whatever is equivalent on Mac OS X) to
> measure your timing results.
I thought that might be the issue but the speed was the same with &
without this change. Instead it looks like the issue is somehow related
to X forwarding with SSH. If I run the examples directly on my linux box
the text rendering speed is pretty much the same with and without
clipping, but if I use X forwarding to display the examples on my OS-X
box then I can see a significant difference. A little puzzling, but
probably not a reason to go back to the no text clipping default.