General ⇒ Box height from given width (TeX?)

[ogtifs]

Hello
I am interested in developing a package for a specific type of tabular layout which cannot be implemented on top of existing table packages. I expect to start with perlTeX and perhaps eventually remove the dependency if I feel masochistic enough to learn TeX internals.
Central to this plan is the need to determine the height of a (fixed-width) parbox for a given text block, as the number is needed for further dimensional calculations - ideally without actually outputting anything as multiple iterations are necessary. I expect this is fairly low level TeX - does anyone know how to do this?

[josephwright]

You could perhaps fill us in on what type of layout you need! Developing table-related stuff needs a good understanding of TeX low-level stuff, so you should first be sure you know enough TeX.

Anything which is boxed up can in principle be measured using the \ht, \wd and \dp primitives:

Code: Select all

\newbox\tempbox
\tempbox=\hbox{abc}
\newdimen\tempdimen
\tempdimen\ht\tempbox\relax

Most of this work is done using TeX primitives rather than LaTeX wrappers. However, you can apply the same to anything which is a box (for example, if it's created using LaTeX's \newsavebox).