with-transformed-area

with-transformed-area Macro

Summary

Transforms a rectangle using a port's transform, and binds the resulting values to a variable across the evaluation of the macro's body.

Package

graphics-ports

Signature

with-transformed-area (points port left top right bottom) &body body => result

Arguments

`points`⇩	A variable.
`port`⇩	A graphics port.
`left`⇩	A real number.
`top`⇩	A real number.
`right`⇩	A real number.
`bottom`⇩	A real number.
`body`⇩	A body of Lisp code.

Values

result

The return value of the last form executed in body.

Description

The macro with-transformed-area uses port's transform to transform a rectangle specified by left, top, right AND bottom. Then points is bound to the resulting list of eight values (alternating x and y values for four corner points) while the forms of body are evaluated as an implicit progn.