/// <summary>
/// Returns the normalized vector that is perpendicular to line AB. (Costly method!)
/// </summary>
/// <remarks>
/// <para>
/// The direction of the vector will be to the right when viewed from point A to point B
/// along the line.
/// </para>
/// <para>
/// Special Case: A zero length vector will be returned if the points are collocated.
/// </para>
/// </remarks>
/// <param name="a">Point A on line AB.</param>
/// <param name="b">Point B on line AB.</param>
/// <returns>
/// The normalized vector that is perpendicular to line AB, or a zero length vector if the
/// points are collocated.
/// </returns>
public static Vector2 GetNormalAB(Vector2 a, Vector2 b)
{
if (Vector2Util.SloppyEquals(a, b, MathUtil.Tolerance))
{
// Points do not form a line.
return(new Vector2());
}
Vector2 result = Vector2Util.GetDirectionAB(a, b);
float origX = result.x;
result.x = result.y;
result.y = -origX;
return(result);
}
