FunctionPackage: cgToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 9.0
Unrevised from 8.2 to 9.0.
8.2 version

inside-polygon-p

Arguments: position position-vector-or-list

Returns whether position is inside the polygon that is defined by position-vector-or-list. position should be a position instance (as created with make-position), and position-vector-or-list should be either a vector or a list of positions that define a polygon, just as you would pass to draw-polygon or fill-polygon.

The beginning position should not be repeated at the end of the vector or list to "close" the polygon, and so a vector or list of three positions would specify a triangle. A position that is exactly on a line segment is considered to be "inside" the polygon.

This function is used internally by polygonal hotspots (see hotspot-region), but can be used by itself if desired.


Copyright (c) 1998-2015, Franz Inc. Oakland, CA., USA. All rights reserved.
Documentation for Allegro CL version 9.0. This page was not revised from the 8.2 page.
Created 2012.5.30.

ToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 9.0
Unrevised from 8.2 to 9.0.
8.2 version