void CreateScanSegments(Obstacle obstacle, NeighborSides neighborSides, BasicVertexEvent vertexEvent)
{
this.CreateScanSegments(obstacle, (HighObstacleSide)neighborSides.LowNeighbor.Item
, (null == neighborSides.LowOverlapEnd) ? null : neighborSides.LowOverlapEnd.Item
, (null == neighborSides.HighOverlapEnd) ? null : neighborSides.HighOverlapEnd.Item
, (LowObstacleSide)neighborSides.HighNeighbor.Item, vertexEvent);
}
void SkipToNeighbor(Directions nborSearchDir, BasicObstacleSide side, Point sideReferencePoint,
RBNode<BasicObstacleSide> nborNode, NeighborSides neighborSides) {
// Find the first neighbor side (LowObstacleSide if going high, HighObstacleSide if going low) and
// the side of opposite type (which would potentially end overlap), that that we cross *through*, if any.
RBNode<BasicObstacleSide> overlapSideNode = null;
BasicObstacleSide interveningGroupSide = null;
for (; ; nborNode = scanLine.Next(nborSearchDir, nborNode)) {
// Ignore the opposite side of the current obstacle.
if (nborNode.Item.Obstacle == side.Obstacle) {
continue;
}
if (nborNode.Item.Obstacle.IsGroup) {
if (ProcessGroupSideEncounteredOnTraversalToNeighbor(nborNode, sideReferencePoint, nborSearchDir)) {
// Keep the first one (outermost) encountered.
if (null == interveningGroupSide) {
interveningGroupSide = nborNode.Item;
}
}
continue;
}
// Check for overlap-ending obstacle.
if ((nborNode.Item is HighObstacleSide) == StaticGraphUtility.IsAscending(nborSearchDir)) {
if (ScanLineCrossesObstacle(sideReferencePoint, nborNode.Item.Obstacle)) {
overlapSideNode = nborNode;
interveningGroupSide = null;
}
continue;
}
// If we're here, we found the neighbor we were looking for.
break;
}
neighborSides.SetSides(nborSearchDir, nborNode, overlapSideNode, interveningGroupSide);
}
protected void FindNeighbors(BasicVertexEvent vertexEvent, RBNode<BasicObstacleSide> sideNode, NeighborSides neighborSides) {
// vertexEvent.Site is on one of vertexEvent.Obstacle.Active(Low|High)Side, so we must get the
// appropriate vertex on whichever one of those Active*Sides is sideNode.
var sideReferencePoint = (vertexEvent is OpenVertexEvent) ? sideNode.Item.Start : sideNode.Item.End;
RBNode<BasicObstacleSide> initialLowNbor, initialHighNbor;
this.FindInitialNeighborSides(sideNode, out initialLowNbor, out initialHighNbor);
this.SkipToNeighbor(this.ScanDirection.OppositeDirection, sideNode.Item, sideReferencePoint, initialLowNbor, neighborSides);
this.SkipToNeighbor(this.ScanDirection.Direction, sideNode.Item, sideReferencePoint, initialHighNbor, neighborSides);
}
void CreateScanSegments(Obstacle obstacle, NeighborSides neighborSides, BasicVertexEvent vertexEvent) {
this.CreateScanSegments(obstacle, (HighObstacleSide)neighborSides.LowNeighbor.Item
, (null == neighborSides.LowOverlapEnd) ? null : neighborSides.LowOverlapEnd.Item
, (null == neighborSides.HighOverlapEnd) ? null : neighborSides.HighOverlapEnd.Item
, (LowObstacleSide)neighborSides.HighNeighbor.Item, vertexEvent);
}