Metric font transformations with dvips

[Lars Hellström <Lars.Hellstrom@math.umu.se>]

My problem is as follows: I've got a PS font and want to tell dvips to
scale this font horizontally by some amount, scale it vertically by some
(different) amount, and to slant it by some amount. This operation is
trivial in postscript, so I should only have to figure out how to put the
right code in the right place. The dvips manual isn't much help here since
it only gives a few examples of what can be done, but it is at least clear
that this should be achieved by putting some suitable piece of PS code
between two double quotes on the corresponding line in psfonts.map. So far,
everything is fine.

Now consider the example that I want to scale horizontally by 1.3 (extend
by 30%), scale vertically by 0.8 (compress by 20%), and slant by 0.167.
This seems like just the kind of task the postscript operator makefont was
made for, so I expect that the right thing to write would be

  [1.3 0 0.167 0.8 0 0] makefont

but this doesn't work. The reason is that it requires the thing on top of
the operand stack to be the font dictionary of the font that is to be
transformed, and this is very far from the case at the point where dvips
inserts PS code from psfonts.map. Instead it seems that what is on the
stack are some selected components from the dictionary, but as I can't make
sense of the code (in particular, the definition of rf), I have failed to
determine exactly which and in exactly which order. I'm not a postscript
hacker, though. Can someone perhaps shed some light on this?

Lars Hellström