void FindMoreRemovedFromFrontElements()
{
foreach (var triangle in removedTriangles)
{
foreach (var e in triangle.Edges)
{
if (e.CcwTriangle == null && e.CwTriangle == null)
{
var site = e.upperSite.Point.X < e.lowerSite.Point.X ? e.upperSite : e.lowerSite;
var frontNode = CdtSweeper.FindNodeInFrontBySite(front, site);
if (frontNode.Item.Edge == e)
{
elementsToBeRemovedFromFront.Add(frontNode.Item);
}
}
}
}
}
void Init()
{
// if (CdtSweeper.D)
// CdtSweeper.ShowFront(triangles, front, new[] {new LineSegment(a.Point, b.Point)},null);
//new[] {new LineSegment(piercedEdge.upperSite.Point, piercedEdge.lowerSite.Point)});
var frontElemNodeRightOfA = CdtSweeper.FindNodeInFrontBySite(front, a);
var frontElemNodeLeftOfA = front.Previous(frontElemNodeRightOfA);
if (Point.PointToTheLeftOfLine(b.Point, frontElemNodeLeftOfA.Item.LeftSite.Point, frontElemNodeLeftOfA.Item.RightSite.Point))
{
piercedToTheLeftFrontElemNode = frontElemNodeLeftOfA;
}
else if (Point.PointToTheRightOfLine(b.Point, frontElemNodeRightOfA.Item.RightSite.Point, frontElemNodeRightOfA.Item.LeftSite.Point))
{
piercedToTheRightFrontElemNode = frontElemNodeRightOfA;
}
else
{
foreach (var e in a.Edges)
{
var t = e.CcwTriangle;
if (t == null)
{
continue;
}
if (Point.PointToTheLeftOfLine(b.Point, e.lowerSite.Point, e.upperSite.Point))
{
continue;
}
var eIndex = t.Edges.Index(e);
var site = t.Sites[eIndex + 2];
if (Point.PointToTheLeftOfLineOrOnLine(b.Point, site.Point, e.upperSite.Point))
{
piercedEdge = t.Edges[eIndex + 1];
piercedTriangle = t;
// CdtSweeper.ShowFront(triangles, front, new[] { new LineSegment(e.upperSite.Point, e.lowerSite.Point) },
// new[] { new LineSegment(piercedEdge.upperSite.Point, piercedEdge.lowerSite.Point) });
break;
}
}
}
}
void PrepareNextStateAfterPiercedEdge()
{
var t = piercedEdge.CwTriangle ?? piercedEdge.CcwTriangle;
var eIndex = t.Edges.Index(piercedEdge);
for (int i = 1; i <= 2; i++)
{
var e = t.Edges[i + eIndex];
var signedArea0 = ApproximateComparer.Sign(Point.SignedDoubledTriangleArea(e.lowerSite.Point, a.Point, b.Point));
var signedArea1 = ApproximateComparer.Sign(Point.SignedDoubledTriangleArea(e.upperSite.Point, a.Point, b.Point));
if (signedArea1 * signedArea0 <= 0)
{
if (e.CwTriangle != null && e.CcwTriangle != null)
{
piercedTriangle = t;
piercedEdge = e;
break;
}
//e has to belong to the front, and its triangle has to be removed
piercedTriangle = null;
piercedEdge = null;
var leftSite = e.upperSite.Point.X < e.lowerSite.Point.X ? e.upperSite : e.lowerSite;
var frontElem = CdtSweeper.FindNodeInFrontBySite(front, leftSite);
Debug.Assert(frontElem != null);
if (leftSite.Point.X < a.Point.X)
{
piercedToTheLeftFrontElemNode = frontElem;
}
else
{
piercedToTheRightFrontElemNode = frontElem;
}
RemovePiercedTriangle(e.CwTriangle ?? e.CcwTriangle);
break;
}
}
}
void SweepAndFinalize()
{
sweeper = new CdtSweeper(allInputSites, P1, P2, GetOrCreateEdge);
sweeper.Run();
}
void SweepAndFinalize() {
sweeper = new CdtSweeper(allInputSites, P1, P2, GetOrCreateEdge);
sweeper.Run();
}
static bool LocalInCircle(CdtSite v, CdtSite a, CdtSite b, CdtSite c, bool reverseTrangleWhenCompare)
{
return(reverseTrangleWhenCompare ? CdtSweeper.InCircle(v, a, c, b) : CdtSweeper.InCircle(v, a, b, c));
}