# 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}
``````\geometry{twocolumn,columnsep=2em}