There are some nice texture-based solutions out there for drawing text in XNA. I've used the font code in XNAExtras a couple times, and it works fine. There's another font utility on Ziggyware that looks nice, and I believe there are others too. There's also talk of an official font solution being added to XNA at some point.
For the kinds of XNA programs I'm playing with, I would prefer a font solution that is resolution-independent and shader-based. All my other game elements are specified in world space coordinates, so I don't want to switch over to screen space coordinates to draw text, or have the text look relatively tiny when my game is at high resolution. And I want to be able to do the same kind of "fun" effects with text that I can do with everything else.
So I have a couple ideas on how to do scalable fonts, but today's post is about using stroke fonts as opposed to other kinds. Stroke fonts are pretty rare these days; I think they were primarily designed for use with pen-based plotters. The idea is to draw the font's glyphs with a series of strokes of a virtual (or actual) pen. Since I've written some XNA code to do thick, rounded lines, stroke fonts sounded like a natural match.
With a binary editor, I opened up the "modern.fon" file, one of the three stroke fonts that (still) ship with Windows, and with help from this page I was able to extract most of the font information. But I couldn't find any documentation on how to interpret the stroke data, so I had to put my little brain to work to figure that out. If you want a little puzzle, see if you can crack the code from a couple examples:
(See StrokeFont.AddCharacter() in StrokeFont.cs for the solution.) Anyway, I got it working and I'm fairly happy with the result.
I added one thing to my Line class: the Draw method now takes a transformation matrix that applies to the entire lineList. So you can build a lineList representing some text, then easily transform that whole block to size/position it in worldspace.
If you don't need the characters from 0x80 to 0xff (accented characters and some less-used symbols), you can cut down the size of StrokeFont.cs even further. Search the code for "0x80+" to see tips on what lines to delete.
The StrokeFontDemo program (attached) has the same controls as the LinesDemo program, with one addition: use the Y axis of the right stick (or D/C keys) to change the line thickness.
I'm still working on a game based on the Microbes code...I'm hoping to wrap it up soon and post it here.