Hello Severin,
i have a general question to the use of fonts in context.
Your question applies to TeX in general (LaTeX as well as other formats).
is that true that i always need a *.tfm and *.pfb file of a font to use it in context??
if you use pdftex: yes. If you use Knuth's TeX: only *tfm files are used. But as soon as you generate a ps or pdf file for viewing/printing, the pfb file gets used.
if i generate some *.tfm (from afm files) with "texfont" context complains about not finding the *.pfb files.
I don't know anything about texfont, but this looks slightly odd at first sight.
when I use texfont *.tfm and *.vf are generated. what are the *.vf files good for??
vf stands for virtual font. These fonts are normally used to change the encoding of an original font. You use the vf without noticing it, when switching to ec encoding for example. The dvi driver (or pdftex) is mapping the special characters (8-bit characters) to the position really used in the font (well, not completely true) by looking at the virtual font. For example when you request a ß (germandbls) and have ec encoding activated, TeX looks for a glyph in position 255 (decimal). But the real font is 8r encoded and the germandbls is in position 223. There is a virtual font (phvr8t.vf for example) that has the mapping 255 -> 223 (377 -> 337 octal): (CHARACTER O 377 (CHARWD R 0.610999) (CHARHT R 0.735498) (CHARDP R 0.011493) (MAP (SETCHAR O 337) ) ) So TeX gets the dimensions from the vf as above, but the dvi/pdf driver looks inside the vf and sees "the charcter 377 (octal) is really character 337 (octal)". But there is much *more* that can be done with vf. See Knuth's "More fun for grand wizards" article about virtual fonts. Patrick -- Morgen gibts kein ABC mehr...