# [texhax] font metrics

Philip TAYLOR [PC336/H-XP] P.Taylor at Rhul.Ac.Uk
Thu Jun 5 22:28:57 CEST 2003


Karl Berry wrote:
>
>     I would like to discuss about the slant parameter in the Tex font metric
>     file. As far as i have come to know is that it is equal to the tangent of
>     the angle in degrees from the vertical in the counter-clockwise direction.
>
> It is?  That is not exactly clear to me either.  tftopl.web (et al.) says:
>
>   param[1]=@!slant| is the amount of italic slant, which is used
>   to help position accents. For example, |slant=.25| means that when you go
>   up one unit, you also go .25 units to the right. The |slant| is a pure
>   number; it's the only |fix_word| other than the design size itself that is
>   not scaled by the design size.

I think that, mathematically speaking, these are the almost same thing
(modulo the "counter" in "counter-clockwise", which I think is an error).
If as per Don's text you go up 1 and right 0.25, then you have two
conceptual sides of a right-angled triangle which, in terms of the angle
from the origin to the point reached after going up 1 and right 0.25
represent the opposite and adjacent sides.  Since

$$\tan {theta} = opposite \over adjacent$$

I believe that both jim_938 and DEK are saying the same thing but just
using different terminology.

** Phil.