public void AddMpoint(Point point)
{
foreach (Point mp in MPoints)
{
if (!mp.Neq(point))
return;
}
MPoints.Add(point);
}
public Trapezoid(Point leftPoint, Point rightPoint, Edge top, Edge bottom)
{
LeftPoint = leftPoint;
RightPoint = rightPoint;
Top = top;
Bottom = bottom;
UpperLeft = null;
UpperRight = null;
LowerLeft = null;
LowerRight = null;
Inside = true;
Sink = null;
}
public Edge(Point p, Point q)
{
P = p;
Q = q;
if (q.X - p.X != 0)
Slope = (q.Y - p.Y) / (q.X - p.X);
else
Slope = 0;
B = p.Y - (p.X * Slope);
Above = null;
Below = null;
MPoints = new HashSet<Point>();
MPoints.Add(p);
MPoints.Add(q);
}
// Create an AABB around segments
public Trapezoid BoundingBox(List<Edge> edges)
{
Point max = edges[0].P + _margin;
Point min = edges[0].Q - _margin;
foreach (Edge e in edges)
{
if (e.P.X > max.X) max = new Point(e.P.X + _margin, max.Y);
if (e.P.Y > max.Y) max = new Point(max.X, e.P.Y + _margin);
if (e.Q.X > max.X) max = new Point(e.Q.X + _margin, max.Y);
if (e.Q.Y > max.Y) max = new Point(max.X, e.Q.Y + _margin);
if (e.P.X < min.X) min = new Point(e.P.X - _margin, min.Y);
if (e.P.Y < min.Y) min = new Point(min.X, e.P.Y - _margin);
if (e.Q.X < min.X) min = new Point(e.Q.X - _margin, min.Y);
if (e.Q.Y < min.Y) min = new Point(min.X, e.Q.Y - _margin);
}
Edge top = new Edge(new Point(min.X, max.Y), new Point(max.X, max.Y));
Edge bottom = new Edge(new Point(min.X, min.Y), new Point(max.X, min.Y));
Point left = bottom.P;
Point right = top.Q;
return new Trapezoid(left, right, top, bottom);
}
public bool IsBelow(Point point)
{
return P.Orient2D(Q, point) > 0;
}
public bool IsAbove(Point point)
{
return P.Orient2D(Q, point) < 0;
}
// Determines if this point lies inside the trapezoid
public bool Contains(Point point)
{
return (point.X > LeftPoint.X && point.X < RightPoint.X && Top.IsAbove(point) && Bottom.IsBelow(point));
}
