Re: Help Required

[Noah Levitt <nlevitt columbia edu>]

On Fri, Sep 19, 2003 at 10:56:21 -0700, Spundun Bhatt wrote:
> 1) Does font config have database of all fonts used by all (open source) 
> apps? If not what are the examples of common apps not using fontconfig 
> on X? and where do they get their fonts from?

You tell fontconfig where to look for fonts on your system.
Nothing has a database of anything. Old apps, such as gtk+
1.2 apps, don't use fontconfig, they use the old X font system.

> 2) Is there a difference between fonts and glyphs? If yes, then since 
> pango gives sequence of glyphs and font config has database of fonts(I 
> hope) where/when does the conversion take place?

Fonts are collections of glyphs with information about the
glyphs. A glyph is just a little picture.

> 3) If pango only gives back a sequence of glyphs then Are we (app using 
> pango) responsible for making Xft calls?

No, pango helps you out with that, you call pango_xft_render.

> 4) Are we also responsible for making  fontconfig calls? (how do you use 
> fonconfig anyway? is it a library as in -lfontconfig?)

No, you don't have to make fontconfig calls. Yes, fontconfig
is a library.

> 5) specific example: If I do "ls" in my gnome terminal, in a directory 
> that has files with unicode names. Is ls responsible for making calls to 
> any of the libraries mentioned above? 

No.

> Can ls just output 
> unicode to stdout and is the gnome-terminal responsible for rendering 
> the unicode? 

Yes. (Except the output from ls isn't necessarily unicode.)

> Does gnome-terminal use pango,fontconfig and Xft? or does 
> it use something else?

It uses fontconfig and Xft, but not pango (usually), because
terminals emulators have special needs that pango doesn't
fill well.

> 6) If I set fonts to arial or something in my brwser or something, and 
> that app tries to render some non english characters, how does it 
> successfully render them? how are non english charactes associated with 
> these standard fonts? Can I have just one font for say hindi on my 
> system and associate that with all fonts, like times new roman, arial, 
> courier etc..?

If the font you choose doesn't have glyphs for the
characters you're trying to render, pango, with help from
fontconfig, falls back on fonts that _do_ have those glyphs,
if there are any.

Noah