get-bounding-box in dc-path%
Returns a rectangle that encloses the path's points. The return values are the left, top, width, and height of the rectangle.
For curves within the path, the bounding box enclosed the two control points as well as the start and end points. Thus, the bounding box does not always tightly bound the path.
A path is not connected to any particular dc<%> object, so
setting a dc<%> origin or scale does not affect path
operations. Instead, a dc<%>'s origin and scale apply at the
time that the path is drawn or used to set a region.