Re: XeConTeXt bug report I: strange benchmark

[Hans Hagen <pragma@wxs.nl>]

Yue Wang wrote:
> On Tue, May 12, 2009 at 8:54 PM, Hans Hagen <pragma@wxs.nl> wrote:
>> Yue Wang wrote:
>>
>>
>>> moreover, can you tell me why pdftex load these fonts so fast? (also 6
>>> families * 3 sizes)
>> i don't know; as the same code is used so it must be xetex itself then
> 
> Then let me tell you why: ConTeXt tries to load lmmono10-regular at
> least 6 times, failed after two testing, then succeed in the end.
> However, try to testing whether a loaded font is \nullfont or not is
> quite slow in XeTeX (Jonathan already mentioned that in
> \testFontIsAvailable). we should definately avoid that.
> But why pdftex is so fast? because it does not involve font testing.
> 
> So why XeTeX is spending 6 seconds aimlessly? since ConTeXt asked it
> to search for a non-existed font.

well, even locating a font 6 times should be no big deal

btw, you can try to change the following into

\def\defaultfontfile{file:lmmono10-regular}

but even then ... if that one is used then there is something else going 
on so best find out what happens ... in context we can have 4 extra math 
families and in most cases only two are used (MathAlpha and MathBeta) 
while (just in onder to catch errors) MathGamma etc then automatically 
will trigger the default font to be used (other approached would demand 
more definitions at the user end and/or a more low level 
implementation); the only optimization i can imagine is more clever 
sharing of the default font but as in other cases one expects the 
default to be properly scaled it not that simple; after all, users also 
expect proper error recovery (and in many cases missing some specific 
fonts is no real problem until it's used); so, you can hardly blame 
context for the fact that xetex has a certain logix on locating fonts 
that happens to be not that good a match for context

The fact that xetex uses this mixture of "" en [] does not help either 
as context uses [] itself so parsing is somewhat complicated (the 
file/name prefix was introduced to circumvent this problem);

Hans

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