The following generic functions comprise the bounding rectangle protocol. All classes that participate in this protocol (including all subclasses of region that are bounded regions) implement a method for bounding-rectangle* .
These functions take the argument region , which must be either a bounded region (such as a line or an ellipse) or some other object that obeys the bounding rectangle protocol, such as a sheet or an output record.
bounding-rectangle* [Generic Function]
Summary: Returns the bounding rectangle of region as four real numbers specifying the x and y coordinates of the min point and the x and y coordinates of the max point of the rectangle.
The four returned values min-x , min-y , max-x , and max-y satisfy the inequalities:
bounding-rectangle [Generic Function]
Summary: Returns the bounding rectangle of region as an object that is a subclass of rectangle (described in 2.5.5, Rectangles in CLIM). Since bounding rectangles are volatile, programmers should not depend on the object returned by bounding-rectangle remaining constant.
bounding-rectangle is part of the bounding rectangle Application Programmer Interface, but is not part of the bounding rectangle protocol. CLIM supplies a default method for bounding-rectangle on the protocol class bounding-rectangle that calls bounding-rectangle* .
Common Lisp Interface Manager 2.0 User's Guide - 7 Aug 2017