




A graphics port.
A real number.
A real number.
A real number.
General graphics port drawing arguments.
A boolean.
The 
draw-circle
 function draws a circle of the given radius centered on (
x
 
y
).  The 
transform
, 
foreground
, 
background
, 
operation
, 
thickness
, 
scale-thickness
, and 
mask
 from the port's graphics state (see make-graphics-state) are all used. When 
filled
 is non-
nil
, the circle is filled with the foreground color.
(gp:draw-circle port 100 100 20)
(gp:draw-circle port 100 100 50
:filled t
:foreground :green)