void DrawEdge(Graphics g, Edge item, PointF p1, PointF p2, bool selected)
{
string distance = GetDistance(Point.Round(p1), Point.Round(p2)).ToString();
p1.X += NODE_RADIUS;
p1.Y += NODE_RADIUS;
p2.X += NODE_RADIUS;
p2.Y += NODE_RADIUS;
Vector2D v1 = new Vector2D(p1.X - p2.X, p1.Y - p2.Y);
if (v1.Length - NODE_RADIUS > 0)
{
v1.Contract(NODE_RADIUS);
p1.X = p2.X + v1.X;
p1.Y = p2.Y + v1.Y;
}
Vector2D v = new Vector2D(p2.X - p1.X, p2.Y - p1.Y);
if (v.Length - NODE_RADIUS > 0)
{
v.Contract(NODE_RADIUS);
p2.X = p1.X + v.X;
p2.Y = p1.Y + v.Y;
}
if (!IsUndirectedGraph && item.IsUndirected)
{
_penEdge.StartCap = LineCap.ArrowAnchor;
}
else
{
_penEdge.StartCap = LineCap.NoAnchor;
}
if (item.IsRemoving)
{
Pen p = new Pen(Color.Red, 4);
g.DrawLine(p, p1, p2);
}
else
{
if (_path != null && (_path.Contains(new Point(item.Start, item.End)) || _path.Contains(new Point(item.End, item.Start))))
{
Pen p = (Pen)_penEdge.Clone();
p.Color = Color.Green;
p.DashStyle = DashStyle.Dash;
g.DrawLine(p, p1, p2);
}
else if (selected)
{
var hPen = (Pen)_penEdge.Clone();
hPen.Color = Color.Red;
g.DrawLine(hPen, p1, p2);
}
else
{
g.DrawLine(_penEdge, p1, p2);
}
}
// draw distance
SizeF size = g.MeasureString(distance, this.Font);
PointF pp = p1;
pp.X += p2.X;
pp.Y += p2.Y;
pp.X /= 2;
pp.Y /= 2;
pp.X -= size.Width / 2;
pp.Y -= size.Height / 2;
g.FillEllipse(Brushes.Yellow, pp.X - 5, pp.Y - 5, size.Width + 10, size.Height + 5);
g.DrawString(distance.ToString(), this.Font, Brushes.Blue, pp);
}