Switch to ttf fonts in SDL port

[d_m]

Some of the SDL fonts don't support the new character used for the floor glyph (the dot) and many more don't support Latin-1 characters, which breaks xchars.

Given that there are currently a ton of these fonts, and that most users will assume that the size of a font shouldn't change it's appearance, I think we should do at least one of the following:

1. prune or update the "bad" fonts

2. separate out the different font faces (serif, sans) and styles (bold) from the size (making sure that we can support bold/non-bold versions of the different fonts)

3. move to truetype fonts for SDL which can be displayed at different point sizes.

I am not a font expert so maybe I have misused some of the font terms, but I think the point should be clear.

[magnate]

Not confirmed: all SDL fonts support both xchars and centred dots IME. Changing this ticket to an aspiration to use sdl-ttf. (In the meantime, point 2 can be dealt with in #1267).

I think Sangband (which is SDL-only) handles TTFs, so we could look at that implementation.

[takkaria]

we already use sdl-ttf2 -- just need a UI for selecting font sizes for TTF fonts.

[magnate]

Missed this one, but it's not an "experimental" issue.

[noz]

I'm going to stick my neck out here, and argue against using TTF fonts (under some circumstances). Hard-coded font sizes cannot be beaten for sheer readable information density, particularly in the small sizes. When you only have say 5 pixels by 9 pixels, no amount of clever scaling of a single glyph will do better than a pixel-optimised arrangement.

I've still not got rid of the old X-fonts on my system for precisely that reason - I can get about 25% more on the screen using them.

[noz]

(Damn, that was meant to be a comment, not a Description change...)