/// <summary>
/// Transforms point from screen coordinates to data coordinates.
/// </summary>
/// <param name="screenPoint">The point in screen coordinates.</param>
/// <returns></returns>
public Point ScreenToData(Point screenPoint)
{
Point viewportPoint = new Point(screenPoint.X * rxToData - cxToData, cyToData - screenPoint.Y * ryToData);
Point dataPoint = dataTransform.ViewportToData(viewportPoint);
return(dataPoint);
}
