Function

Summary

Invalidates a rectangle specified by two points, causing it to be redisplayed.

Package

graphics-ports

Signature

invalidate-rectangle-from-points port x1 y1 x2 y2 &key extend extend-x extend-y

Arguments

port

A graphics port.

x1 , y1 , x2 , y2

Real numbers.

extend , extend-x , extend-y

Real numbers.

Description

The function invalidate-rectangle-from-points invalidates a rectangle (by calling invalidate-rectangle) specified by two points. The coordinates of one point are ( x1 , y1 ) and the other ( x2 , y2 ) The points do not have to be ordered.

The keyword arguments specify extending the rectangle: extend-x extends the rectangle in the x dimension in both directions, and extend-y extends the rectangle in the y dimension in both directions. Both extend-x and extend-y default to extend , which itself defaults to 0 (that is, no extension).

invalidate-rectangle-from-points does not return a useful value.

See also

invalidate-rectangle