[Scribus] Linux's font system

[Craig Ringer]

wtb41 wrote:
> I am no expert on fonts or computers, but I am interested in learning. As I
> understand fonts,
> they are divisible into 2 sets: (1) system fonts, which are loaded into
> memory as part of the 
> boot process and (2) personal fonts, which are not loaded into memory as
> part of the boot 
> process; instead, personal fonts are moved into and out of memory as the
> need arises and 
> ends.

I don't think that's really true except on Mac OS 9 with a font manager
like Suitcase or ATM installed. Most other OSes don't really draw the
distinction to the same extent.

How fonts work varies with the OS and sometimes the application. On most
UNIXes there are no system fonts any more - everything is loaded on
demand by applications. On Mac OS X it depends on what the app is and
what font APIs are used. Windows ... no idea.

> If every system font is loaded into memory at boot time, where it
> remains until the 
> computer is powered down, then is there really any need for more than one
> folder for system 
> fonts?
> 
> Here is a related question: Is anything more involved in "installing" a font
> than putting the font
> files in a folder where they can be found when the need to load them arises?

Again, this depends on the OS and sometimes the application. In most
cases just putting it where the font system can find it is enough, but
some platforms need more (for example, X11 core fonts need a run of
ttmkfdir to build the font database, and most "font manager" apps need a
database update).

> In other words, 
> does font installation involve any internal housekeeping beyond putting the
> font files in a folder
> where they can be found when the need for them arises?  

The OS and applications generally need to cache information about the
fonts so that they don't have to open and examine every font just to
build a list of what fonts are available. The OS often does this to some
extent (sometimes  with explicit updates required, sometimes
automatically rebuilding it - it depends on the OS, and both methods
have advantages). Some apps need more information than the OS's cache
can provide and - like Scribus - must build their own more complete cache.

--
Craig Ringer