public override void Run(List <CGUtilities.Point> points, List <CGUtilities.Line> lines, List <CGUtilities.Polygon> polygons, ref List <CGUtilities.Point> outPoints, ref List <CGUtilities.Line> outLines, ref List <CGUtilities.Polygon> outPolygons)
{
Event.lines = lines;
OrderedSet <Event> Q = new OrderedSet <Event>(EventComparer.CompareX);
OrderedSet <Event> L = new OrderedSet <Event>(EventComparer.CompareY);
for (int i = 0; i < lines.Count; i++)
{
if (lines[i].Start > lines[i].End)
{
HelperMethods.Swap(lines[i].Start, lines[i].End);
}
Q.Add(new Event(lines[i].Start, i, Enums.EventType.StartPoint));
Q.Add(new Event(lines[i].End, i, Enums.EventType.EndPoint));
}
while (Q.Count != 0)
{
Event e = Q.GetFirst();
Q.Remove(e);
#region Start Point
if (e.eventType == Enums.EventType.StartPoint)
{
Point intersection = null;
if (HelperMethods.IsVertical(lines[e.index]))
{
IList <Event> toBeCompared = L.AsList();
for (int i = 0; i < toBeCompared.Count; i++)
{
intersection = HelperMethods.GetIntersection(lines[toBeCompared[i].index], lines[e.index]);
if (intersection != null)
{
outPoints.Add(intersection);
}
}
continue;
}
L.Add(e);
KeyValuePair <Event, Event> KVP = L.DirectUpperAndLower(e);
Event prev = KVP.Key;
Event next = KVP.Value;
if (prev != null)
{
intersection = HelperMethods.GetIntersection(lines[prev.index], lines[e.index]);
if (intersection != null)
{
Q.Add(new Event(intersection, prev, e, Enums.EventType.Intersection));
}
}
if (next != null)
{
intersection = HelperMethods.GetIntersection(lines[e.index], lines[next.index]);
if (intersection != null)
{
Q.Add(new Event(intersection, e, next, Enums.EventType.Intersection));
}
}
}
#endregion
#region End Point
else if (e.eventType == Enums.EventType.EndPoint)
{
KeyValuePair <Event, Event> KVP = L.DirectUpperAndLower(e);
Event prev = KVP.Key;
Event next = KVP.Value;
if (prev != null && next != null)
{
Point intersection = HelperMethods.GetIntersection(lines[prev.index], lines[next.index]);
if (intersection != null)
{
Q.Add(new Event(intersection, prev, next, Enums.EventType.Intersection));
}
}
L.RemoveAll(p => p.index == e.index);
}
#endregion
#region Intersection Point
else
{
if (!outPoints.Contains(e.point))
{
outPoints.Add(e.point);
}
Event prev = e.prev;
Event next = e.next;
Event prev_prev = L.DirectUpperAndLower(prev).Key;
Event next_next = L.DirectUpperAndLower(next).Value;
Point intersection = null;
if (prev_prev != null)
{
intersection = HelperMethods.GetIntersection(lines[prev_prev.index], lines[next.index]);
if (intersection != null)
{
Q.Add(new Event(intersection, prev_prev, next, Enums.EventType.Intersection));
}
}
if (next_next != null)
{
intersection = HelperMethods.GetIntersection(lines[prev.index], lines[next_next.index]);
if (intersection != null)
{
Q.Add(new Event(intersection, prev, next_next, Enums.EventType.Intersection));
}
}
prev.point = next.point = e.point;
L.RemoveAll(p => p.index == prev.index);
L.RemoveAll(p => p.index == next.index);
L.Add(next);
L.Add(prev);
}
#endregion
}
}