Element: graphic_window.save_under

Type

numeric

Description

Whether graphic_window has save-under capabilities. Such capabilities enable fast redrawing of window contents when graphic_window is exposed. Exposure occurs when parts or all of a window become visible after being obscured by other windows or popups.

This resource is by default off (value 0) for new windows and is usually only required to be on (value 1) when window contents are unusually complex, e.g. a graphic window with many vectors and polygons.

Leaving the resource off conserves memory but at the expense of slower redraws.

Graphic windows with scrollbars automatically have this element set to on at window creation time and cannot have it turned off.

The interactive pan and zoom commands (pan -im, and blow -im) require that save-unders be turned on.