public bool PullEvent()
{
if (!_events.MoveNext())
{
return(false);
}
_pq.Add(_events.Current);
return(true);
}
public static bool FTestSimplePolygon(IEnumerable <Vector> poly)
{
var polyList = poly?.ToList();
var sweep = T.MinValue;
if (polyList == null)
{
throw new ArgumentException($"poly is null in {nameof(FTestSimplePolygon)}");
}
if (polyList.Count == 0)
{
return(true);
}
if (polyList[0].Rank != 2)
{
throw new ArgumentException("Calling FTestSimplePolygon with non-2D points");
}
var edgeList = new List <RbLineSegment>();
var eventQueue = new BinaryPriorityQueue <SimplePolygonEvent>((e1, e2) => CmpVectors(e1.Vertex, e2.Vertex));
for (var iVtx = 0; iVtx < polyList.Count; iVtx++)
{
var vtxLow = polyList[iVtx];
var vtxHigh = polyList[(iVtx + 1) % polyList.Count];
var cmp = CmpVectors(vtxLow, vtxHigh);
if (cmp == 0)
{
// We ignore zero length sides
continue;
}
if (cmp > 0)
{
(vtxLow, vtxHigh) = (vtxHigh, vtxLow);
}
// ReSharper disable once AccessToModifiedClosure
edgeList.Add(new RbLineSegment(vtxLow, vtxHigh, () => sweep));
eventQueue.Add(new SimplePolygonEvent(vtxLow, iVtx, false));
eventQueue.Add(new SimplePolygonEvent(vtxHigh, iVtx, true));
}
var segTable = new MeshNavRbTree();
while (eventQueue.Count != 0)
{
var nextEvent = eventQueue.Pop();
if (nextEvent.IsRightEndpoint)
{
// We have to remove the corresponding line segment from consideration
segTable.DeleteBracketed(edgeList[nextEvent.SegIndex]);
}
else
{
sweep = nextEvent.Vertex.X;
var lsCur = edgeList[nextEvent.SegIndex];
// Insert the corresponding line segment
(RbLineSegment high, RbLineSegment low) = segTable.InsertBracketed(lsCur);
if (lsCur.Intersects(low) || lsCur.Intersects(high))
{
return(false);
}
}
}
return(true);
int CmpVectors(Vector v1, Vector v2)
{
var cmp = v1.X.CompareTo(v2.X);
if (cmp == 0)
{
cmp = v1.Y.CompareTo(v2.Y);
}
return(cmp);
}
}
