/// <summary>
/// Calculates the minimum distance between a point and a line.
/// </summary>
/// <param name="p">A point.</param>
/// <param name="origin">Line origin point.</param>
/// <param name="dir">Line direction.</param>
/// <returns>The minimum distance between the point and the line.</returns>
public static double PointLineDistance(Vector2 p, Vector2 origin, Vector2 dir)
{
double t = Vector2.DotProduct(dir, p - origin);
Vector2 pPrime = origin + t * dir;
Vector2 vec = p - pPrime;
double distanceSquared = Vector2.DotProduct(vec, vec);
return(Math.Sqrt(distanceSquared));
}
/// <summary>
/// Checks if a point is inside a line segment.
/// </summary>
/// <param name="p">A point.</param>
/// <param name="start">Segment start point.</param>
/// <param name="end">Segment end point.</param>
/// <returns>Zero if the point is inside the segment, 1 if the point is after the end point, and -1 if the point is before the start point.</returns>
public static int PointInSegment(Vector2 p, Vector2 start, Vector2 end)
{
Vector2 dir = end - start;
Vector2 pPrime = p - start;
double t = Vector2.DotProduct(dir, pPrime);
if (t <= 0)
{
return(-1);
}
double dot = Vector2.DotProduct(dir, dir);
if (t >= dot)
{
return(1);
}
return(0);
}
