# Screen-friendly layout for preview

When editing a LaTeX document, I prefer having the source on one display and a live preview (by means of latexmk -pvc or similar) on another display. When the secondary display can be physically rotated, I do -- this allows me to show the preview at original size or even larger. But if the display cannot be rotated, the font size usually becomes too small when a (portrait) document is scaled down to fit the screen.

I'm looking for a way to adapt the page geometry for screen preview while preserving the \textwidth (to make sure that figures still are rendered "somewhat correctly"). How to tell the geometry package to:

• adjust the paperwidth so that the width is maintained as is, adding a small margin
• adjust the paperheight to a given aspect ratio
• remove (or hide) headers and footers

Is there a package that encapsulates this, perhaps including a check if this "screen" mode is active?

Related: Optimising for on-screen viewing.

It turns out that the geometry package accepts length parameters and also supports the calc package, as noted in the manual. This gives the following options:

\geometry{paperwidth=\textwidth+2em,left=1em,right=1em}
\geometry{paperheight=.8\paperwidth}

This uses 1em as margins, an aspect ratio of 5:4 (=1 / 0.8), hides the footer and uses minimal space for the header. The lines may become overly long and difficult to digest, so

\geometry{twocolumn,columnsep=2em}

can be used to generate shorter lines. (I don't know how to enter a "three column" mode.)

These settings are now optimal for text, but the preview of figures might be distorted. I haven't found a package that encapsulates the layout setting -- would such a package be useful?