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| Allegro CL version 10.1 Unrevised from 10.0 to 10.1. 10.0 version

## radial-line-box-intersection-x-y

Arguments: point-x point-y box-left box-top box-right box-bottom &key margin

Returns as multiple values the coordinates of the point on the edge of a box where it is crossed by a line that passes through the center of the box and through an arbitrary point. Returns `nil` if the box center and the arbitrary point are the same.

The first two arguments are real numbers for the X and Y coordinates of the arbitrary point. The remaining required arguments are real numbers that specify the sides of a box. Returns two real numbers for the X and Y coordinates of the intersection point, or `nil`.

The margin argument is somewhat obscure. If specified, it should be a real number indicating a distance. If the real intersection point is less than this distance from a corner of the box, then the returned point will be adjusted so that it is this distance from the corner. (This is used by one application to avoid drawing a connecting line to a rounded corner of a rounded box.)

See also radial-line-box-intersection and radial-line-circle-intersection-x-y.

Copyright (c) 1998-2022, Franz Inc. Lafayette, CA., USA. All rights reserved.
This page was not revised from the 10.0 page.
Created 2019.8.20.

|  | ToC | DocOverview | CGDoc | RelNotes | FAQ | Index | PermutedIndex
| Allegro CL version 10.1 Unrevised from 10.0 to 10.1. 10.0 version