/// <summary>
/// Creates a new instance of <see cref="Line2D"/>.
/// </summary>
/// <param name="p1">The first point.</param>
/// <param name="p2">The second point.</param>
public Line2D(Point2D p1, Point2D p2)
{
Point1 = p1;
Point2 = p2;
p1.Changed += OnPointChanged;
p2.Changed += OnPointChanged;
}
/// <summary>
/// Invoked when a point has changed.
/// </summary>
/// <param name="source">The source of the event.</param>
/// <param name="args">The event arguments.</param>
void OnPointChanged(Point2D source, PointChangedEventArgs args)
{
OnChanged();
}
internal static Line2D GetParallelLine(Point p1, Point p2, Point directionPoint, double offset)
{
Point2D linePoint1 = new Point2D();
Point2D linePoint2 = new Point2D();
double dx = p1.X - p2.X;
double dy = p1.Y - p2.Y;
double leght = Math.Sqrt((dx) * (dx) + (dy) * (dy));
// Determine the direction of the offset.
offset *= GetPointPosition(p1, p2, directionPoint);
// This is the parallel line
linePoint1.X = (p1.X - offset * (dy) / leght);
linePoint2.X = (p2.X - offset * (dy) / leght);
linePoint1.Y = (p1.Y + offset * (dx) / leght);
linePoint2.Y = (p2.Y + offset * (dx) / leght);
Line2D parallelLine = new Line2D(linePoint1, linePoint2);
return parallelLine;
}