// ctor
internal void Update(Point start, Point end)
{
Debug.Assert(PointComparer.Equal(start, end) ||
StaticGraphUtility.IsAscending(PointComparer.GetPureDirection(start, end))
, "non-ascending segment");
startPoint = start;
endPoint = end;
}
private void SpliceGroupBoundaryCrossings(PointAndCrossingsList crossingList, VisibilityVertex startVertex, LineSegment maxSegment)
{
if ((null == crossingList) || (0 == crossingList.Count))
{
return;
}
crossingList.Reset();
var start = maxSegment.Start;
var end = maxSegment.End;
var dir = PointComparer.GetPureDirection(start, end);
// Make sure we are going in the ascending direction.
if (!StaticGraphUtility.IsAscending(dir))
{
start = maxSegment.End;
end = maxSegment.Start;
dir = CompassVector.OppositeDir(dir);
}
// We need to back up to handle group crossings that are between a VisibilityBorderIntersect on a sloped border and the
// incoming startVertex (which is on the first ScanSegment in Perpendicular(dir) that is outside that padded border).
startVertex = TraverseToFirstVertexAtOrAbove(startVertex, start, CompassVector.OppositeDir(dir));
// Splice into the Vertices between and including the start/end points.
for (var currentVertex = startVertex; null != currentVertex; currentVertex = StaticGraphUtility.FindNextVertex(currentVertex, dir))
{
bool isFinalVertex = (PointComparer.Compare(currentVertex.Point, end) >= 0);
while (crossingList.CurrentIsBeforeOrAt(currentVertex.Point))
{
PointAndCrossings pac = crossingList.Pop();
// If it's past the start and at or before the end, splice in the crossings in the descending direction.
if (PointComparer.Compare(pac.Location, startVertex.Point) > 0)
{
if (PointComparer.Compare(pac.Location, end) <= 0)
{
SpliceGroupBoundaryCrossing(currentVertex, pac, CompassVector.OppositeDir(dir));
}
}
// If it's at or past the start and before the end, splice in the crossings in the descending direction.
if (PointComparer.Compare(pac.Location, startVertex.Point) >= 0)
{
if (PointComparer.Compare(pac.Location, end) < 0)
{
SpliceGroupBoundaryCrossing(currentVertex, pac, dir);
}
}
}
if (isFinalVertex)
{
break;
}
}
}
// Use the internal static xxxInstance properties to get an instance.
private ScanDirection(Directions directionAlongScanLine)
{
System.Diagnostics.Debug.Assert(StaticGraphUtility.IsAscending(directionAlongScanLine),
"directionAlongScanLine must be ascending");
Direction = directionAlongScanLine;
DirectionAsPoint = CompassVector.ToPoint(Direction);
PerpDirection = (Directions.North == directionAlongScanLine) ? Directions.East : Directions.North;
PerpDirectionAsPoint = CompassVector.ToPoint(PerpDirection);
OppositeDirection = CompassVector.OppositeDir(directionAlongScanLine);
}
internal bool HasGroupCrossingBeforePoint(Point point)
{
if (!this.HasGroupCrossings)
{
return(false);
}
var pac = StaticGraphUtility.IsAscending(this.OutwardDirection) ? this.pointAndCrossingsList.First : this.pointAndCrossingsList.Last;
return(PointComparer.GetDirections(this.MaxVisibilitySegment.Start, pac.Location) == PointComparer.GetDirections(pac.Location, point));
}
internal void SetSides(Directions dir, RBNode <BasicObstacleSide> neighborNode, RBNode <BasicObstacleSide> overlapEndNode,
BasicObstacleSide interveningGroupSide)
{
if (StaticGraphUtility.IsAscending(dir))
{
HighNeighbor = neighborNode;
HighOverlapEnd = overlapEndNode;
this.GroupSideInterveningBeforeHighNeighbor = interveningGroupSide;
return;
}
LowNeighbor = neighborNode;
LowOverlapEnd = overlapEndNode;
this.GroupSideInterveningBeforeLowNeighbor = interveningGroupSide;
}
internal RBNode <BasicObstacleSide> Next(Directions dir, RBNode <BasicObstacleSide> sideNode)
{
var succ = (StaticGraphUtility.IsAscending(dir)) ? SideTree.Next(sideNode) : SideTree.Previous(sideNode);
return(succ);
}