/// <summary>
/// iterates all the edges of the polygon and gets the closest point on any edge to point. Returns via out the squared distance
/// to the closest point and the normal of the edge it is on. point should be in the space of the Polygon (point - poly.position)
/// </summary>
/// <returns>The closest point on polygon to point.</returns>
/// <param name="point">Point.</param>
/// <param name="distanceSquared">Distance squared.</param>
/// <param name="edgeNormal">Edge normal.</param>
public static Vector2 GetClosestPointOnPolygonToPoint(Vector2[] points, Vector2 point, out float distanceSquared, out Vector2 edgeNormal)
{
distanceSquared = float.MaxValue;
edgeNormal = Vector2.Zero;
var closestPoint = Vector2.Zero;
float tempDistanceSquared;
for (var i = 0; i < points.Length; i++)
{
var j = i + 1;
if (j == points.Length)
{
j = 0;
}
var closest = ShapeCollisions.ClosestPointOnLine(points[i], points[j], point);
Vector2.DistanceSquared(ref point, ref closest, out tempDistanceSquared);
if (tempDistanceSquared < distanceSquared)
{
distanceSquared = tempDistanceSquared;
closestPoint = closest;
// get the normal of the line
var line = points[j] - points[i];
edgeNormal.X = -line.Y;
edgeNormal.Y = line.X;
}
}
Vector2Ext.Normalize(ref edgeNormal);
return(closestPoint);
}