Re: inheriting size characteristics

["Adam Lindsay" <atl@comp.lancs.ac.uk>]

Idris Samawi Hamid said this at Tue, 19 Apr 2005 10:04:28 -0600:

>Given predefined switches like \tf and \bf, one inherits the size 
>characteristics of the one already declared. But for user-defined switches 
>this does not work. The following minimal files (typescript and test) is
>a bit 
>long, but it accurately illustrates the problem and uses the default
>fonts. My 
>user-defined switch works, but does not inherit from, e.g., \tfc. But \bf
>does 
>inherit.

Idris,

I don't have time to really delve into the implementation details, but it
looks like the difference is that ConTeXt isn't so responsive with user-
defined alternatives with more than two characters. Compare the stripped
down version with your own. Your \scsb has been changed to \SB, effectively. 

Note the tricks that can happen behind the scenes: \SBc isn't defined,
but still \SB gets scaled at `c'. \SBb is defined as scaled to something
different, and the switch picks up that fact. In short, there's a lot of
subtle, tricky stuff going on behind the scenes that I don't understand fully:


%D The in-file typescript requires a recent beta!
\starttypescript[serif]                 [lm][default]
  \definefontsynonym [LM]               [texnansi-lmr12]
  \definefontsynonym [LMBold]           [texnansi-lmbx12]
  \definefontsynonym [LMSemiboldCaps]   [texnansi-lmro12]
\stoptypescript

\starttypescript[serif] [lm] [size]
  \definebodyfont [12pt]
  [rm]
  [tf=LM             sa 1,
   bf= LMBold         sa 1,
   SB= LMSemiboldCaps        sa 1,
   SBa=LMSemiboldCaps        sa a,
   SBb=LMSemiboldCaps        sa d, % !!!
%  SBc=LMSemiboldCaps        sa c, % !!!
   SBd=LMSemiboldCaps        sa d]
\stoptypescript

  \definetypeface [lmtest] [rm] [serif] [lm] [lm] 

  \setupbodyfont[lmtest,12pt]

\starttext

\tfc    This is a test of stacking font commands. 123467689

\bf     This is a test of stacking font commands. 123467689

\SB     This is a test of stacking font commands. 123467689

\textrule
\tfb    This is a test of stacking font commands. 123467689

\SB     This picks up the unusual size implicitly. 123467689

\bf     This is a test of stacking font commands. 123467689
\stoptext


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 Adam T. Lindsay, Computing Dept.     atl@comp.lancs.ac.uk
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