theme_nomask: Show or Hide the Clipping Mask
Description
Convenience Function to Show or Hide the Clipping Mask, theme_showmask is a function that
appends to the current theme a flag to switch ON the clipping mask, whilst, theme_nomask (or theme_hidemask) is a function
that appends to the current theme a flag to switch OFF the clipping mask
Usage
theme_nomask()
theme_hidemask()
theme_showmask()