[Alephmodular-devel] Font Musings (different)

[Br'fin <br...@ma...>]

A Font (CFontSpec) encapsulates choice of font family, style, and size. 
For instance, Monaco, Bold, 10pt. A CFontSpec is a relatively 
lightweight class.

You can ask CDisplay if a font is available.

You can pass a font to CDContext->draw_text to select the font to draw 
with.

If a font is unavailable, then drawing in that font is undefined (It 
may have a default font, or may just decline drawing anything at all)

 From a CFontSpec, you can ask for variants (Such as different sizes or 
different styles)

Before drawing with a font, you should prepare a buffer for receiving 
it. This allows the buffer to prepare and cache any information it 
needs for the font. Such as preloading bitmap definitions or setting up 
OpenGL drawing lists for each glyph. Draw_text will prepare the font 
itself, but for efficiency reasons, you may wish to precache these 
things when beginning a level or switching graphic modes.

Preparing a buffer with a font that it has already been prepared with 
should be a no-op.

CFontSpec's should test for equality (Does CFontSpec A == CFontSpec B?)


Implementation musings:

Internally, I'm thinking of some kind of hash_map within a CBuffer for 
storing prepared font info. How wary should I be that hash_map is a SGI 
extension to the C++ STL? (gcc appears to support it, as does 
microsoft) and it seems to have been originally extended as far back as 
Hewlett Packard, so may be in the most generally available STL 
downloads. (at the very least, gcc+MS covers a good chunk of our 
expected targets anyhow)

I think I'm finally getting somewhere conceptually. Yay!

-Jeremy Parsons