# [luatex] The effect of \pardir on \leftskip versus \parshape

Khaled Hosny khaledhosny at eglug.org
Sat Dec 8 13:43:28 CET 2012

On Sat, Dec 08, 2012 at 10:01:28AM +0000, Joseph Wright wrote:
> On 07/12/2012 13:17, Khaled Hosny wrote:
> > Now, if I understand \left and \rightskip correctly, it seems like
> > something one wants to mirror with directional change, otherwise one
> > would want to explicitly adapt styles depending on text
> > directionality, which is not something I really like (especially
> > when dealing with something like LaTeX styles that are PITA to
> > modify).
>
> I'm not sure that follows at an engine level (LaTeX2e's deficiencies are
> a different matter). If you think about sitting down with a piece of
> paper to design a layout, the text direction does not affect which side
> of the paper is the left, and therefore a design description may well
> refer to 'left' and 'right' of the page whether the dominant direction
> is LTR or RTL.

I can't what a layout used for both RTL and LTR would use an absolute
left and right values for. One of the things I liked about Omega model
is the little changes needed to adapt any existing style to RTL.

> > In general the layout in right to left settings is usually an identical
> > mirror of left to right one (including the position of odd and even
> > pages).
>
> That's only true if you are assuming you are producing both LTR and RTL
> documents from one design spec: seems unlikely.

This is how my multi-lingual documents are produced :)

Regards,
Khaled