When a graphical object is to be drawn, the points that defines the outline of the graphical object must be specified in some way, i.e. where is the shape supposed to be. Bifrost uses standard Cartesian coordinates for this purpose. Standard Cartesian coordinate subtraction and addition are supported. The Figure above illustrates the coordinate system used.
As shown, an axisparallel rectangle is described by one point (upperleft) and two integers (width and height).
The Bifrost Graphics System  Reference Manual  © 19912004 Mjølner Informatics 
[Modified: Tuesday October 24^{th} 2000 at 15:02]
