Math::PointInConvexPolygon

Defined in: C4Computation.h

Returns a value indicating whether a point lies within the interior of a convex polygon, lies on its boundary, or lies outside the polygon.

Prototype

int32 PointInConvexPolygon(const Point3D& p, int32 vertexCount, const Point3D *vertex, const Vector3D& normal);

Parameters

`p`	The point to test.
`vertexCount`	The number of vertices defining the boundary of the polygon. This must be at least 3.
`vertex`	An array containing the vertices of the polygon, wound in counterclockwise order.
`normal`	The normal direction of the polygon.

Description

The PointInConvexPolygon function determines the location of the point given by the p parameter with respect to the polygon specified by the vertexCount and vertex parameters. The return value is one of the following constants.

`kPolygonInterior`	The point lies in the interior of the polygon.
`kPolygonBoundary`	The point lies on or very near the boundary of the polygon.
`kPolygonExterior`	The point lies outside the polygon.

The vertex parameter should point to an array of Point3D objects of size given by the vertexCount parameter. These vertices should be wound in counterclockwise order about the normal direction specified by the normal parameter. The polygon must be convex and must lie in a plane that is perpendicular to the normal direction. If these requirements are not satisfied, then the result is undefined.