Ammendment: Change to definition of limits for maxdrift (App E)
Ammendment number: 07
Submitted by: Joachim Schrod <xitijsch@ddathd21.bitnet>
Date: 02 August 1990


Currently says:

   For a horizontal movement from any other command, ${\it hh}$
   should be set to be ${\it hh}+{\it pixel\_round}(x)$ if
   $x<0.2{\it quad}$ for a horizontal movement to the right or if
   $x>-0.9{\it quad}$ for a horizontal movement to the left. $\it
   quad$ is defined to be the design size of the current font in the
   \DVI\ file (after all necessary magnifications have been
   applied). If $x$ exceeds the bounds outlined above, ${\it hh}$ is
   set to be ${\it pixel\_round}(h+x)$. In this way, rounding
   errors are absorbed by interword spaces.


Change to read:

   For a horizontal movement from any other command, ${\it hh}$
   should be set to be ${\it hh}+{\it pixel\_round}(x)$ if
|  $x < {\it word\_space}$ for a horizontal movement to the right or if
|  $x > -{\it back\_space}$ for a horizontal movement to the left. {\it
|  word\_space\/} is defined as $\it space - space_shrink$, and {\it
|  back\_space\/} is defined as $\it 0.9 quad$ if the driver uses {\tt
|  TFM} files. If the driver does not use {\tt TFM} files the design
|  size of the current font in the {\tt DVI} file (after all necessary
|  magnifications have been applied) may be used for a {\it quad}, and
|  {\it word\_space\/} may be approximated by $\it 0.2 quad$.
   If $x$ exceeds the bounds outlined above, ${\it hh}$ is
   set to be ${\it pixel\_round}(h+x)$. In this way, rounding
   errors are absorbed by interword spaces.
 
[vertical bars indicate the changed portion]

 
Reason for change:

A driver should not be forced to read TFM files (perhaps they are not
available there at all). But if it wants to it may -- and then it
should use the most precise information available.