/// <summary>
/// Calculates the distance between the two given points.
/// </summary>
protected virtual float GetDistance(float x1, float y1, float x2, float y2)
{
//return Math.abs(y1 - y2);
//return Math.abs(x1 - x2);
return(ChartUtil.Hypot(x1 - x2, y1 - y2));
}