Macro

Summary

Binds the mask slot of a graphics port to a rectangular area across the execution of a body of code.

Package

graphics-ports

Signature

with-graphics-mask (port
 mask
 mask-x
 mask-y
 &key)
                   &body body
 => result

Arguments

port

A graphics port.

mask

A list of the form ( x y width height ) or nil .

mask-x

An integer.

mask-y

An integer.

body

A body of Lisp code.

Values

result

The return value of the last form executed in body .

Description

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. These values are used only on Motif.

Example

For a mask value of ( x y width height ) drawing is limited to the rectangular region whose X coordinate is in the range

mask-x + x to mask-x + x + width

and whose Y coordinate is in the range

mask-y + y to mask-y + y + height