In addition to the standard operations, a graphics device may support
custom operations. For example, most devices have custom
operations to control color.
graphics-operation is used to
invoke custom operations.
Invokes the graphics operation on graphics-device whose name is
the symbol name, passing it the remaining arguments. This
procedure can be used to invoke the standard operations, as well as
custom operations that are specific to a particular graphics device
type. The names of the standard graphics operations are formed by
graphics- prefix from the corresponding procedure.
For example, the following are equivalent:
(graphics-draw-point device x y) (graphics-operation device 'draw-point x y)
For information on the custom operations for a particular device, see the documentation for its type.