Sometimes it is useful to specify a “window” through which drawings are viewed. Parts of a figure extending outside the window are not drawn. A rectangular window is specified by giving the lower left and upper right corners of the desired window:

The corners could also be given in coarse-grid coordinates, as in “window 1524;1248”.

Drawings constructed from the various -draw- commands and -circle- commands are affected by a preceding -window- command. Line-drawn text (size non-zero) produced by -write-, -writec-, -show-, etc., will also be windowed. Like -size- and -rotate-, windowing is not reset upon entering a new main unit. Be sure to use a blank -windowcommand (blank tag) to turn off windowing operations. It is quite common for an author to forget to turn off windowing and then wonder why some of the drawings aren't showing up! The correct structure is shown below. (See Figures 9-9 and 9-10.)

More on Erasing: The -eraseu- Command