backspace makeupwidth tradeoff

backspace makeupwidth tradeoff

[M.guravage]

Hi,

I'd like to increase the backspace at the expense of the makeupwidth. I
like to do this by adding either a scalar or a percentage of the
backspace. In the following bit of code I'd expect both sets of
\mybackspace and \mywidth macros to yield identical results, but the
don't. The scalar approach seems to work correctly, and the percentage
not.

I'd appreciate it if somebody could show me where I've gone wrong. It must
be embarrassingly simple, but I can't see it - yet. Thanks in advance.

Cheers,

Michael


\showgrid
\showframe
%\showlayout

\def\abcor{1.25cm} % absolute binding correction
\def\pbcor{0.5}    % percentage binding correction

% default backspace is 2.5cm
%\def\mybackspace{\dimexpr(\backspace + \abcor)}
\def\mybackspace{\dimexpr(\backspace + \pbcor\backspace)}

% default makeupwidth is 15cm
%\def\mywidth{\dimexpr(\makeupwidth - \abcor)}
\def\mywidth{\dimexpr(\makeupwidth - \pbcor\backspace)}

\setuplayout
  [location=middle,
   backspace=\mybackspace,
   width=\mywidth]

\starttext
  \dorecurse{10}{\input tufte \par}
\stoptext

Re: backspace makeupwidth tradeoff

[Hans Hagen]

M.guravage wrote:

>% default makeupwidth is 15cm
>%\def\mywidth{\dimexpr(\makeupwidth - \abcor)}
>\def\mywidth{\dimexpr(\makeupwidth - \pbcor\backspace)}
>
>\setuplayout
>  [location=middle,
>   backspace=\mybackspace,
>   width=\mywidth]
>  
>

you refer to \backspace but you cannot say whether it;s set already; 
layout calculations are a bit complex and the order of key=values is not 
related to the calculations

you can try to use:  \layoutparameter{backspace}

\def\mywidth{\dimexpr(\makeupwidth - \pbcor\layoutparameter{backspace})}



Hans