Binds the mask slot of a graphics port to a rectangular area across the execution of a body of code.
A graphics port
A list of the form
(
x
y
width
height
)
or
nil
An integer
An integer
A body of Lisp code
The
with-graphics-mask
macro binds the
mask
slot of
port
's graphic state to a rectangular area across the execution of
body
. By default,
mask-x
and
mask-y
are both 0.