🚀 go-pugleaf

| Does anyone have a good explanation how the numbers are derived for the
|bitmaped fonts. For instances for for a pxl font with a design size of
|10pt at 300dp corresponds to the 1500 directory. But the same font in 
|pk format is located at 300, while the font magstep1 is at 360 for pk and
|1800 for pxl.

It's not too complicated, fortunately.

Magsteps form a geometric series. Magstep0 = 1, magstep1 = 1.2,
magstep2 = 1.2 * 1.2 = 1.44, etc. Magstephalf = sqrt(1.2).

For gf and pk files, the number is resolution * factor. Thus
a magstep1 font for a 300 dpi device is 360gf.

For pxl files (who uses them anymore? :-)), the number is
resolution * factor * 5. This was so that a magstep0 font
for a 200 dpi device had a number of 1000.

In some drivers and the TeXbook you will find references to
``magnification''. This is just the magstep factor * 1000.
Thus 1728 is magstep3. For the 200 dpi device mentioned and
pxl fonts, the magnification was reflected in the suffix.

A final note. I've mentioned 360gf, but on some systems the
components are arranged differently to satisfy pathname limitations.
E.g. gf/360/cmr10.