internal void CreateObstaclePorts(Obstacle obstacle) {
// Create ObstaclePorts for all Ports of this obstacle. This just creates the
// ObstaclePort object; we don't add its edges/vertices to the graph until we
// do the actual routing.
foreach (var port in obstacle.Ports) {
CreateObstaclePort(obstacle, port);
}
}
protected override bool InsertParallelReflectionSegment(Point start, Point end, Obstacle eventObstacle,
BasicObstacleSide lowNborSide, BasicObstacleSide highNborSide, BasicReflectionEvent action) {
// See notes in InsertPerpendicularReflectionSegment for comments about an existing segment.
// Here, we call AddSegment which adds the segment and continues the reflection staircase.
if (null != ParallelScanSegments.Find(start, end)) {
return false;
}
return AddSegment(start, end, eventObstacle, lowNborSide, highNborSide, action, ScanSegment.ReflectionWeight);
}
internal BasicObstacleSide(Obstacle obstacle, PolylinePoint startVertex, ScanDirection scanDir, bool traverseClockwise)
: base(startVertex)
{
Obstacle = obstacle;
endVertex = traverseClockwise ? startVertex.NextOnPolyline : startVertex.PrevOnPolyline;
if (!scanDir.IsPerpendicular(startVertex.Point, endVertex.Point))
{
Slope = StaticGraphUtility.Slope(startVertex.Point, endVertex.Point, scanDir);
SlopeInverse = 1.0 / Slope;
}
}
internal GroupBoundaryCrossing AddIntersection(Point intersection, Obstacle group, Directions dirToInside) {
List<GroupBoundaryCrossing> crossings;
if (!pointCrossingMap.TryGetValue(intersection, out crossings)) {
crossings = new List<GroupBoundaryCrossing>();
pointCrossingMap[intersection] = crossings;
}
// We may hit the same point on neighbor traversal in multiple directions. We will have more than one item
// in this list only if there are multiple group boundaries at this point, which should be unusual.
var crossingsCount = crossings.Count; // cache for perf
for (int ii = 0; ii < crossingsCount; ++ii) {
var crossing = crossings[ii];
if (crossing.Group == group) {
// At a given location for a given group, there is only one valid dirToInside.
Debug.Assert(dirToInside == crossing.DirectionToInside, "Mismatched dirToInside");
return crossing;
}
}
var newCrossing = new GroupBoundaryCrossing(group, dirToInside);
crossings.Add(newCrossing);
return newCrossing;
}
private ObstaclePort CreateObstaclePort(Obstacle obstacle, Port port) {
// This will replace any previous specification for the port (last one wins).
Debug.Assert(!obstaclePortMap.ContainsKey(port), "Port is used by more than one obstacle");
if (null == port.Curve) {
return null;
}
var roundedLocation = ApproximateComparer.Round(port.Location);
if (PointLocation.Outside == Curve.PointRelativeToCurveLocation(roundedLocation, obstacle.InputShape.BoundaryCurve)) {
// Obstacle.Port is outside Obstacle.Shape; handle it as a FreePoint.
return null;
}
if ((obstacle.InputShape.BoundaryCurve != port.Curve)
&& (PointLocation.Outside == Curve.PointRelativeToCurveLocation(roundedLocation, port.Curve))) {
// Obstacle.Port is outside port.Curve; handle it as a FreePoint.
return null;
}
var oport = new ObstaclePort(port, obstacle);
obstaclePortMap[port] = oport;
return oport;
}
internal BasicVertexEvent(Obstacle obstacle, PolylinePoint p) : base(p)
{
this.Obstacle = obstacle;
}
internal static bool ObstaclesIntersect(Obstacle first, Obstacle second)
{
if (first == second)
{
return false;
}
return Curve.CurvesIntersect(first.VisibilityPolyline, second.VisibilityPolyline);
}
private void CreatePaddedObstacle(Shape shape) {
var obstacle = new Obstacle(shape, this.UseObstacleRectangles, this.Padding);
this.ShapeToObstacleMap[shape] = obstacle;
this.PortManager.CreateObstaclePorts(obstacle);
}
internal CloseVertexEvent(Obstacle obstacle, PolylinePoint p) : base(obstacle, p)
{
}
internal HighObstacleSide(Obstacle obstacle, PolylinePoint startVertex, ScanDirection scanDir)
: base(obstacle, startVertex, scanDir, scanDir.IsVertical /*traverseClockwise*/)
{
}
protected override bool InsertParallelReflectionSegment(Point start, Point end, Obstacle eventObstacle,
BasicObstacleSide lowNborSide, BasicObstacleSide highNborSide, BasicReflectionEvent action)
{
Debug.Assert(false, "base.wantReflections is false in Sparse mode so this should never be called");
// ReSharper disable HeuristicUnreachableCode
return(false);
// ReSharper restore HeuristicUnreachableCode
}
// If true, we have a staircase situation.
internal bool IsStaircaseStep(Obstacle reflectionTarget) {
return (this.InitialObstacle == reflectionTarget);
}
// obstacleToIgnore is the event obstacle if we're looking at intersections along its boundary.
private bool IntersectionAtSideIsInsideAnotherObstacle(BasicObstacleSide side, Obstacle eventObstacle, Point intersect)
{
// See if the intersection with an obstacle side is inside another obstacle (that encloses
// at least the part of side.Obstacle containing the intersection). This will only happen
// if side.Obstacle is overlapped and in the same clump (if it's not the same clump, we must
// be hitting it from the outside).
if (!side.Obstacle.IsOverlapped)
{
return(false);
}
if (!side.Obstacle.IsGroup && !eventObstacle.IsGroup && (side.Obstacle.Clump != eventObstacle.Clump))
{
return(false);
}
return(ObstacleTree.IntersectionIsInsideAnotherObstacle(side.Obstacle, eventObstacle, intersect, ScanDirection));
}
// Return value is whether or not we added a new segment.
bool AddSegment(Point start, Point end, Obstacle eventObstacle
, BasicObstacleSide lowNborSide, BasicObstacleSide highNborSide
, SweepEvent action, double weight)
{
DevTraceInfoVgGen(1, "Adding Segment [{0} -> {1} {2}] weight {3}", start, end, weight);
DevTraceInfoVgGen(2, " side {0}", lowNborSide);
DevTraceInfoVgGen(2, " -> side {0}", highNborSide);
if (PointComparer.Equal(start, end))
{
return(false);
}
// See if the new segment subsumes or can be subsumed by the last one. gbcList may be null.
PointAndCrossingsList gbcList = CurrentGroupBoundaryCrossingMap.GetOrderedListBetween(start, end);
bool extendStart, extendEnd;
bool wasSubsumed = ScanSegment.Subsume(ref hintScanSegment, start, end, weight, gbcList, ScanDirection
, ParallelScanSegments, out extendStart, out extendEnd);
if (!wasSubsumed)
{
Debug.Assert((weight != ScanSegment.ReflectionWeight) || (ParallelScanSegments.Find(start, end) == null),
"Reflection segments already in the ScanSegmentTree should should have been detected before calling AddSegment");
hintScanSegment = ParallelScanSegments.InsertUnique(new ScanSegment(start, end, weight, gbcList)).Item;
}
else if (weight == ScanSegment.ReflectionWeight)
{
// Do not continue this; it is probably a situation where a side is at a tiny angle from the axis,
// resulting in an initial reflection segment that is parallel and very close to the extreme-vertex-derived
// segment, so as the staircase progresses they eventually converge due to floating-point rounding.
// See RectilinearFilesTest.ReflectionStaircasesConverge.
return(false);
}
// Do reflections only if the new segment is not overlapped.
if (ScanSegment.OverlappedWeight != weight)
{
// If these fire, it's probably an indication that isOverlapped is not correctly set
// and one of the neighbors is an OverlapSide from CreateScanSegments.
Debug.Assert(lowNborSide is HighObstacleSide, "lowNbor is not HighObstacleSide");
Debug.Assert(highNborSide is LowObstacleSide, "highNbor is not LowObstacleSide");
// If we are closing the obstacle then the initial Obstacles of the reflections (the ones it
// will bounce between) are the opposite neighbors. Otherwise, the OpenVertexEvent obstacle
// is the ReflectionEvent initial obstacle.
if (action is CloseVertexEvent)
{
// If both neighbor sides reflect upward, they can't intersect, so we don't need
// to store a lookahead site (if neither reflect upward, StoreLookaheadSite no-ops).
if (!SideReflectsUpward(lowNborSide) || !SideReflectsUpward(highNborSide))
{
// Try to store both; only one will "take" (for the upward-reflecting side).
// The initial Obstacle is the opposite neighbor.
if (extendStart)
{
this.StoreLookaheadSite(highNborSide.Obstacle, lowNborSide, start, wantExtreme: false);
}
if (extendEnd)
{
this.StoreLookaheadSite(lowNborSide.Obstacle, highNborSide, end, wantExtreme: false);
}
}
}
else
{
if (extendStart)
{
StoreLookaheadSite(eventObstacle, LowNeighborSides.GroupSideInterveningBeforeLowNeighbor, lowNborSide, start);
}
if (extendEnd)
{
StoreLookaheadSite(eventObstacle, HighNeighborSides.GroupSideInterveningBeforeHighNeighbor, highNborSide, end);
}
}
}
DevTraceInfoVgGen(2, "HintScanSegment {0}{1}", hintScanSegment, wasSubsumed ? " (subsumed)" : "");
DevTrace_DumpScanSegmentsDuringAdd(3);
return(true);
}
internal LowObstacleSide(Obstacle obstacle, PolylinePoint startVertex, ScanDirection scanDir)
: base(obstacle, startVertex, scanDir, scanDir.IsHorizontal /*traverseClockwise*/)
{
}
internal HighObstacleSide(Obstacle obstacle, PolylinePoint startVertex, ScanDirection scanDir)
: base(obstacle, startVertex, scanDir, scanDir.IsVertical /*traverseClockwise*/)
{
}
internal LowObstacleSide(Obstacle obstacle, PolylinePoint startVertex, ScanDirection scanDir)
: base(obstacle, startVertex, scanDir, scanDir.IsHorizontal /*traverseClockwise*/)
{
}
internal BasicVertexEvent(Obstacle obstacle, PolylinePoint p) : base (p) {
this.Obstacle = obstacle;
}
internal ObstaclePort(Port port, Obstacle obstacle) {
this.Port = port;
this.Obstacle = obstacle;
this.PortEntrances = new List<ObstaclePortEntrance>();
this.Location = ApproximateComparer.Round(this.Port.Location);
}
private static bool ObstaclesAreCloseEnoughToBeConsideredTouching(Obstacle a, Obstacle b, bool aIsInsideB, bool bIsInsideA)
{
// This is only called when the obstacle.VisibilityPolylines don't intersect, thus one is inside the other
// or both are outside. If both are outside then either one's LooseVisibilityPolyline may be used.
if (!aIsInsideB && !bIsInsideA)
{
return(Curve.CurvesIntersect(a.LooseVisibilityPolyline, b.VisibilityPolyline));
}
// Otherwise see if the inner one is close enough to the outer border to consider them touching.
var innerLoosePolyline = aIsInsideB ? a.LooseVisibilityPolyline : b.LooseVisibilityPolyline;
var outerPolyline = aIsInsideB ? b.VisibilityPolyline : a.VisibilityPolyline;
foreach (Point innerPoint in innerLoosePolyline)
{
if (Curve.PointRelativeToCurveLocation(innerPoint, outerPolyline) == PointLocation.Outside)
{
var outerParamPoint = Curve.ClosestPoint(outerPolyline, innerPoint);
if (!ApproximateComparer.CloseIntersections(innerPoint, outerParamPoint))
{
return(true);
}
}
}
return(false);
}
internal HighBendVertexEvent(Obstacle obstacle, PolylinePoint p) : base(obstacle, p)
{
}
// As described in the document, we currently don't create ScanSegments where a flat top/bottom boundary may have
// intervals that are embedded within overlapped segments:
// obstacle1 | |obstacle2 | obstacle3 | | obstacle4 | obstacle2| |
// | +-----------|===========|??????????|===========|----------+ | obstacle5
// ...__________| |___________| |___________| |__________...
// Here, there will be no ScanSegment created at ??? along the border of obstacle2 between obstacle3
// and obstacle4. This is not a concern because that segment is useless anyway; a path from outside
// obstacle2 will not be able to see it unless there is another obstacle in that gap, and then that
// obstacle's side-derived ScanSegments will create non-overlapped edges; and there are already edges
// from the upper/lower extreme vertices of obstacle 3 and obstacle4 to ensure a connected graph.
// If there is a routing from an obstacle outside obstacle2 to one embedded within obstacle2, the
// port visibility will create the necessary edges.
//
// We don't try to determine nesting depth and create different VisibilityEdge weights to prevent spurious
// nested-obstacle crossings; we just care about overlapped vs. not-overlapped.
// If this changes, we would have to: Find the overlap depth at the lowNborSide intersection,
// then increment/decrement according to side type as we move from low to high, then create a different
// ScanSegment at each obstacle-side crossing, making ScanSegment.IsOverlapped a depth instead of bool.
// Then pass that depth through to VisibilityEdge as an increased weight. (This would also automatically
// handle the foregoing situation of non-overlapped intervals in the middle of a flat top/bottom border,
// not that it would really gain anything).
void CreateScanSegments(Obstacle obstacle, HighObstacleSide lowNborSide, BasicObstacleSide lowOverlapSide,
BasicObstacleSide highOverlapSide, LowObstacleSide highNborSide, BasicVertexEvent vertexEvent)
{
// If we have either of the high/low OverlapSides, we'll need to see if they're inside
// another obstacle. If not, they end the overlap.
if ((null == highOverlapSide) || IntersectionAtSideIsInsideAnotherObstacle(highOverlapSide, vertexEvent))
{
highOverlapSide = highNborSide;
}
if ((null == lowOverlapSide) || IntersectionAtSideIsInsideAnotherObstacle(lowOverlapSide, vertexEvent))
{
lowOverlapSide = lowNborSide;
}
// There may be up to 3 segments; for a simple diagram, |# means low-side border of
// obstacle '#' and #| means high-side, with 'v' meaning our event vertex. Here are
// the two cases where we create a single non-overlapped ScanSegment (from the Low
// side in the diagram, but the same logic works for the High side).
// - non-overlapped: 1| v |2
// ...---+ +---...
// - non-overlapped to an "inner" highNbor on a flat border: 1| vLow |2 vHigh
// ...---+ +-----+=========...
// This may be the low side of a flat bottom or top border, so lowNbor or highNbor
// may be in the middle of the border.
Point lowNborIntersect = ScanLineIntersectSide(vertexEvent.Site, lowNborSide);
Point highNborIntersect = ScanLineIntersectSide(vertexEvent.Site, highNborSide);
bool lowNborEndpointIsOverlapped = IntersectionAtSideIsInsideAnotherObstacle(lowNborSide,
vertexEvent.Obstacle /*obstacleToIgnore*/, lowNborIntersect);
if (!lowNborEndpointIsOverlapped && (lowNborSide == lowOverlapSide))
{
// Nothing is overlapped so create one segment.
AddSegment(lowNborIntersect, highNborIntersect, obstacle, lowNborSide, highNborSide, vertexEvent,
ScanSegment.NormalWeight);
return;
}
// Here are the different interval combinations for overlapped cases.
// - non-overlapped, overlapped: 1| |2 v |3
// ...---+ +------+===...
// - non-overlapped, overlapped, non-overlapped: 1| |2 v 2| |3
// ==+ +-------+ +--...
// - overlapped: |1 2| v |3 ...1|
// ...---+====+-----+===...-+
// - overlapped, non-overlapped: |1 2| v 1| |3
// ...---+====+------+ +---...
// We will not start overlapped and then go to non-overlapped and back to overlapped,
// because we would have found the overlap-ending/beginning sides as nearer neighbors.
// Get the other intersections we'll want.
Point highOverlapIntersect = (highOverlapSide == highNborSide) ? highNborIntersect
: ScanLineIntersectSide(vertexEvent.Site, highOverlapSide);
Point lowOverlapIntersect = (lowOverlapSide == lowNborSide) ? lowNborIntersect
: ScanLineIntersectSide(vertexEvent.Site, lowOverlapSide);
// Create the segments.
if (!lowNborEndpointIsOverlapped)
{
// First interval is non-overlapped; there is a second overlapped interval, and may be a
// third non-overlapping interval if another obstacle surrounded this vertex.
AddSegment(lowNborIntersect, lowOverlapIntersect, obstacle, lowNborSide, lowOverlapSide, vertexEvent,
ScanSegment.NormalWeight);
AddSegment(lowOverlapIntersect, highOverlapIntersect, obstacle, lowOverlapSide, highOverlapSide, vertexEvent,
ScanSegment.OverlappedWeight);
if (highOverlapSide != highNborSide)
{
AddSegment(highOverlapIntersect, highNborIntersect, obstacle, highOverlapSide, highNborSide, vertexEvent,
ScanSegment.NormalWeight);
}
}
else
{
// Starts off overlapped so ignore lowOverlapSide.
AddSegment(lowNborIntersect, highOverlapIntersect, obstacle, lowNborSide, highOverlapSide, vertexEvent,
ScanSegment.OverlappedWeight);
if (highOverlapSide != highNborSide)
{
AddSegment(highOverlapIntersect, highNborIntersect, obstacle, highOverlapSide, highNborSide, vertexEvent,
ScanSegment.NormalWeight);
}
}
}
internal static bool IsFirstObstacleEntirelyWithinSecond(Obstacle first, Obstacle second, bool touchingOk)
{
return IsFirstPolylineEntirelyWithinSecond(first.VisibilityPolyline, second.VisibilityPolyline, touchingOk);
}
protected override bool InsertParallelReflectionSegment(Point start, Point end, Obstacle eventObstacle,
BasicObstacleSide lowNborSide, BasicObstacleSide highNborSide, BasicReflectionEvent action)
{
// See notes in InsertPerpendicularReflectionSegment for comments about an existing segment.
// Here, we call AddSegment which adds the segment and continues the reflection staircase.
if (null != ParallelScanSegments.Find(start, end))
{
return(false);
}
return(AddSegment(start, end, eventObstacle, lowNborSide, highNborSide, action, ScanSegment.ReflectionWeight));
}
internal LowBendVertexEvent(Obstacle obstacle, PolylinePoint p) : base(obstacle, p) { }
internal void Insert(Obstacle obstacle)
{
groupsAndClumps.Insert(obstacle);
}
// Called by StoreLookaheadSite only.
internal BasicReflectionEvent(Obstacle initialObstacle, Obstacle reflectingObstacle, Point site) {
this.InitialObstacle = initialObstacle;
this.ReflectingObstacle = reflectingObstacle;
this.site = site;
}
private void StoreLookaheadSite(Obstacle eventObstacle, BasicObstacleSide interveningGroupSide, BasicObstacleSide neighborSide, Point siteOnSide) {
// For reflections, NeighborSides won't be set, so there won't be an intervening group. Otherwise,
// this is on an OpenVertexEvent, so we'll either reflect of the intervening group if any, or neighborSide.
if (null == interveningGroupSide) {
this.StoreLookaheadSite(eventObstacle, neighborSide, siteOnSide, wantExtreme: false);
} else {
var siteOnGroup = ScanLineIntersectSide(siteOnSide, interveningGroupSide, this.ScanDirection);
this.StoreLookaheadSite(eventObstacle, interveningGroupSide, siteOnGroup, wantExtreme: false);
}
}
internal GroupBoundaryCrossing(Obstacle group, Directions dirToInside) {
Debug.Assert(CompassVector.IsPureDirection(dirToInside), "Impure direction");
this.Group = group;
this.DirectionToInside = dirToInside;
}
// obstacleToIgnore is the event obstacle if we're looking at intersections along its boundary.
private bool IntersectionAtSideIsInsideAnotherObstacle(BasicObstacleSide side, Obstacle eventObstacle, Point intersect) {
// See if the intersection with an obstacle side is inside another obstacle (that encloses
// at least the part of side.Obstacle containing the intersection). This will only happen
// if side.Obstacle is overlapped and in the same clump (if it's not the same clump, we must
// be hitting it from the outside).
if (!side.Obstacle.IsOverlapped) {
return false;
}
if (!side.Obstacle.IsGroup && !eventObstacle.IsGroup && (side.Obstacle.Clump != eventObstacle.Clump)) {
return false;
}
return ObstacleTree.IntersectionIsInsideAnotherObstacle(side.Obstacle, eventObstacle, intersect, ScanDirection);
}
internal void RemoveObstaclePorts(Obstacle obstacle) {
foreach (var port in obstacle.Ports) {
// Since we remove the port from the visibility graph after each routing, all we
// have to do here is remove it from the dictionary.
RemoveObstaclePort(port);
}
}
// As described in the document, we currently don't create ScanSegments where a flat top/bottom boundary may have
// intervals that are embedded within overlapped segments:
// obstacle1 | |obstacle2 | obstacle3 | | obstacle4 | obstacle2| |
// | +-----------|===========|??????????|===========|----------+ | obstacle5
// ...__________| |___________| |___________| |__________...
// Here, there will be no ScanSegment created at ??? along the border of obstacle2 between obstacle3
// and obstacle4. This is not a concern because that segment is useless anyway; a path from outside
// obstacle2 will not be able to see it unless there is another obstacle in that gap, and then that
// obstacle's side-derived ScanSegments will create non-overlapped edges; and there are already edges
// from the upper/lower extreme vertices of obstacle 3 and obstacle4 to ensure a connected graph.
// If there is a routing from an obstacle outside obstacle2 to one embedded within obstacle2, the
// port visibility will create the necessary edges.
//
// We don't try to determine nesting depth and create different VisibilityEdge weights to prevent spurious
// nested-obstacle crossings; we just care about overlapped vs. not-overlapped.
// If this changes, we would have to: Find the overlap depth at the lowNborSide intersection,
// then increment/decrement according to side type as we move from low to high, then create a different
// ScanSegment at each obstacle-side crossing, making ScanSegment.IsOverlapped a depth instead of bool.
// Then pass that depth through to VisibilityEdge as an increased weight. (This would also automatically
// handle the foregoing situation of non-overlapped intervals in the middle of a flat top/bottom border,
// not that it would really gain anything).
void CreateScanSegments(Obstacle obstacle, HighObstacleSide lowNborSide, BasicObstacleSide lowOverlapSide,
BasicObstacleSide highOverlapSide, LowObstacleSide highNborSide, BasicVertexEvent vertexEvent) {
// If we have either of the high/low OverlapSides, we'll need to see if they're inside
// another obstacle. If not, they end the overlap.
if ((null == highOverlapSide) || IntersectionAtSideIsInsideAnotherObstacle(highOverlapSide, vertexEvent)) {
highOverlapSide = highNborSide;
}
if ((null == lowOverlapSide) || IntersectionAtSideIsInsideAnotherObstacle(lowOverlapSide, vertexEvent)) {
lowOverlapSide = lowNborSide;
}
// There may be up to 3 segments; for a simple diagram, |# means low-side border of
// obstacle '#' and #| means high-side, with 'v' meaning our event vertex. Here are
// the two cases where we create a single non-overlapped ScanSegment (from the Low
// side in the diagram, but the same logic works for the High side).
// - non-overlapped: 1| v |2
// ...---+ +---...
// - non-overlapped to an "inner" highNbor on a flat border: 1| vLow |2 vHigh
// ...---+ +-----+=========...
// This may be the low side of a flat bottom or top border, so lowNbor or highNbor
// may be in the middle of the border.
Point lowNborIntersect = ScanLineIntersectSide(vertexEvent.Site, lowNborSide);
Point highNborIntersect = ScanLineIntersectSide(vertexEvent.Site, highNborSide);
bool lowNborEndpointIsOverlapped = IntersectionAtSideIsInsideAnotherObstacle(lowNborSide,
vertexEvent.Obstacle /*obstacleToIgnore*/, lowNborIntersect);
if (!lowNborEndpointIsOverlapped && (lowNborSide == lowOverlapSide)) {
// Nothing is overlapped so create one segment.
AddSegment(lowNborIntersect, highNborIntersect, obstacle, lowNborSide, highNborSide, vertexEvent,
ScanSegment.NormalWeight);
return;
}
// Here are the different interval combinations for overlapped cases.
// - non-overlapped, overlapped: 1| |2 v |3
// ...---+ +------+===...
// - non-overlapped, overlapped, non-overlapped: 1| |2 v 2| |3
// ==+ +-------+ +--...
// - overlapped: |1 2| v |3 ...1|
// ...---+====+-----+===...-+
// - overlapped, non-overlapped: |1 2| v 1| |3
// ...---+====+------+ +---...
// We will not start overlapped and then go to non-overlapped and back to overlapped,
// because we would have found the overlap-ending/beginning sides as nearer neighbors.
// Get the other intersections we'll want.
Point highOverlapIntersect = (highOverlapSide == highNborSide) ? highNborIntersect
: ScanLineIntersectSide(vertexEvent.Site, highOverlapSide);
Point lowOverlapIntersect = (lowOverlapSide == lowNborSide) ? lowNborIntersect
: ScanLineIntersectSide(vertexEvent.Site, lowOverlapSide);
// Create the segments.
if (!lowNborEndpointIsOverlapped) {
// First interval is non-overlapped; there is a second overlapped interval, and may be a
// third non-overlapping interval if another obstacle surrounded this vertex.
AddSegment(lowNborIntersect, lowOverlapIntersect, obstacle, lowNborSide, lowOverlapSide, vertexEvent,
ScanSegment.NormalWeight);
AddSegment(lowOverlapIntersect, highOverlapIntersect, obstacle, lowOverlapSide, highOverlapSide, vertexEvent,
ScanSegment.OverlappedWeight);
if (highOverlapSide != highNborSide) {
AddSegment(highOverlapIntersect, highNborIntersect, obstacle, highOverlapSide, highNborSide, vertexEvent,
ScanSegment.NormalWeight);
}
}
else {
// Starts off overlapped so ignore lowOverlapSide.
AddSegment(lowNborIntersect, highOverlapIntersect, obstacle, lowNborSide, highOverlapSide, vertexEvent,
ScanSegment.OverlappedWeight);
if (highOverlapSide != highNborSide) {
AddSegment(highOverlapIntersect, highNborIntersect, obstacle, highOverlapSide, highNborSide, vertexEvent,
ScanSegment.NormalWeight);
}
}
}
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);
}
private bool AddParallelReflectionSegment(Obstacle eventObstacle, BasicObstacleSide lowNborSide
, BasicObstacleSide highNborSide, BasicReflectionEvent action) {
// If this is reflecting to a low neighbor, then that intersect is 'start' in the low-to-high
// sequence, and the event site is the end; otherwise we start at the event site and end at
// the high neighbor.
Point intersect = ScanLineIntersectSide(action.Site, lowNborSide ?? highNborSide);
Point start = (null != lowNborSide) ? intersect : action.Site;
Point end = (null != lowNborSide) ? action.Site : intersect;
// Now get the opposite neighbors so AddSegment can continue the reflection chain.
if (null == lowNborSide) {
lowNborSide = scanLine.NextLow(highNborSide).Item;
}
else {
highNborSide = scanLine.NextHigh(lowNborSide).Item;
}
return InsertParallelReflectionSegment(start, end, eventObstacle, lowNborSide, highNborSide, action);
}
private static void GrowGroupAroundLoosePolyline(Obstacle group, Polyline loosePolyline)
{
var points = group.VisibilityPolyline.Select(p => p).Concat(loosePolyline.Select(p => p));
group.SetConvexHull(new OverlapConvexHull(ConvexHull.CreateConvexHullAsClosedPolyline(points), new[] { group }));
}
protected bool ScanLineCrossesObstacle(Point eventSite, Obstacle obstacle) {
// An inner or outer neighbor's side is only an overlap start/stop candidate if its obstacle
// brackets the open/close event's Perpendicular Scan coord.
return (ScanDirection.ComparePerpCoord(eventSite, obstacle.VisibilityBoundingBox.LeftBottom) > 0)
&& (ScanDirection.ComparePerpCoord(eventSite, obstacle.VisibilityBoundingBox.RightTop) < 0);
}
public bool IsInSameClump(Obstacle other)
{
return(this.IsOverlapped && (this.Clump == other.Clump));
}
// Called by StoreLookaheadSite only.
internal BasicReflectionEvent(Obstacle initialObstacle, Obstacle reflectingObstacle, Point site)
{
this.InitialObstacle = initialObstacle;
this.ReflectingObstacle = reflectingObstacle;
this.site = site;
}
// Calculate reflections from the lines, depending on line side (Low vs. High) and slope.
// Because the low neighbor intersection is on a high side of its obstacle
// and vice-versa, then the "side" of a lowNbor is a highSide, and vice versa.
protected void StoreLookaheadSite(Obstacle initialObstacle, BasicObstacleSide reflectingSide, Point reflectionSite, bool wantExtreme) {
if (!this.wantReflections) {
return;
}
// If the line is perpendicular, we won't generate reflections (they'd be redundant).
if (!IsPerpendicular(reflectingSide)) {
// If this is hitting an extreme vertex in the forward direction, we will (or already did) create a normal
// ScanSegment in the perpendicular direction.
if (!wantExtreme && !StaticGraphUtility.PointIsInRectangleInterior(reflectionSite, reflectingSide.Obstacle.VisibilityBoundingBox)) {
return;
}
// We can only do upward reflections, which fortunately is all we need.
if (SideReflectsUpward(reflectingSide)) {
// We defer actually creating the perpendicular line until we've processed
// the reflection event we're about to enqueue, so we may legitimately encounter
// two (or more) reflections at the same point along the parallel-to-scanline
// coordinate, if we have a side that is nearly but not quite perpendicular to
// the scanline. For example:
// \
// \----------------------------- line2
// \---------------------------- line1
// Assume the vertical side is very close to perpendicular; then as we process
// the horizontal lines in the upward direction, we may generate two lookahead
// reflections at coordinates that are sufficiently far apart in the vertical
// coordinate (in this example, Y) that the lines are not subsumed, but are
// sufficiently close in the horizontal coordinate (in this example, X) that
// the perpendicular lines would be subsumed. In that case, we look here to see
// if there is an active lookahead scan for the reflecting site's parallel coordinate;
// if so, then because we know that the side reflects upward, we also know that
// the perpendicular line from the lowest segment's reflection site will intersect
// the higher segments here, providing the VisibilityVertices we need, so we can
// safely ignore the duplicate lookahead.
// Don't worry about enqueueing a reflection at the extreme scanline-parallel
// vertex because we'll MergeSegments to handle that.
if (null == lookaheadScan.Find(reflectionSite)) {
lookaheadScan.Add(new BasicReflectionEvent(initialObstacle, reflectingSide.Obstacle, reflectionSite));
DevTraceInfoVgGen(1, "Storing reflection lookahead site {0}", reflectionSite);
}
else {
DevTraceInfoVgGen(1, "Reflection lookahead site {0} already exists", reflectionSite);
}
}
}
} // end StoreLookaheadSite()
// Called by LowReflectionEvent or HighReflectionEvent ctors, which are called out of
// AddReflectionEvent, which in turn is called by LoadLookaheadIntersections.
// In this case we know the eventObstacle and initialObstacle are the same obstacle (the
// one that the reflected ray bounced off of, to generate the Left/HighReflectionEvent).
internal BasicReflectionEvent(BasicReflectionEvent previousSite, Obstacle reflectingObstacle, Point site) {
this.InitialObstacle = previousSite.ReflectingObstacle;
this.ReflectingObstacle = reflectingObstacle;
this.site = site;
this.PreviousSite = previousSite;
}
protected abstract bool InsertParallelReflectionSegment(Point start, Point end, Obstacle eventObstacle,
BasicObstacleSide lowNborSide, BasicObstacleSide highNborSide, BasicReflectionEvent action);
// Return value is whether or not we added a new segment.
bool AddSegment(Point start, Point end, Obstacle eventObstacle
, BasicObstacleSide lowNborSide, BasicObstacleSide highNborSide
, SweepEvent action, double weight) {
DevTraceInfoVgGen(1, "Adding Segment [{0} -> {1} {2}] weight {3}", start, end, weight);
DevTraceInfoVgGen(2, " side {0}", lowNborSide);
DevTraceInfoVgGen(2, " -> side {0}", highNborSide);
if (PointComparer.Equal(start, end)) {
return false;
}
// See if the new segment subsumes or can be subsumed by the last one. gbcList may be null.
PointAndCrossingsList gbcList = CurrentGroupBoundaryCrossingMap.GetOrderedListBetween(start, end);
bool extendStart, extendEnd;
bool wasSubsumed = ScanSegment.Subsume(ref hintScanSegment, start, end, weight, gbcList, ScanDirection
, ParallelScanSegments, out extendStart, out extendEnd);
if (!wasSubsumed) {
Debug.Assert((weight != ScanSegment.ReflectionWeight) || (ParallelScanSegments.Find(start, end) == null),
"Reflection segments already in the ScanSegmentTree should should have been detected before calling AddSegment");
hintScanSegment = ParallelScanSegments.InsertUnique(new ScanSegment(start, end, weight, gbcList)).Item;
} else if (weight == ScanSegment.ReflectionWeight) {
// Do not continue this; it is probably a situation where a side is at a tiny angle from the axis,
// resulting in an initial reflection segment that is parallel and very close to the extreme-vertex-derived
// segment, so as the staircase progresses they eventually converge due to floating-point rounding.
// See RectilinearFilesTest.ReflectionStaircasesConverge.
return false;
}
// Do reflections only if the new segment is not overlapped.
if (ScanSegment.OverlappedWeight != weight) {
// If these fire, it's probably an indication that isOverlapped is not correctly set
// and one of the neighbors is an OverlapSide from CreateScanSegments.
Debug.Assert(lowNborSide is HighObstacleSide, "lowNbor is not HighObstacleSide");
Debug.Assert(highNborSide is LowObstacleSide, "highNbor is not LowObstacleSide");
// If we are closing the obstacle then the initial Obstacles of the reflections (the ones it
// will bounce between) are the opposite neighbors. Otherwise, the OpenVertexEvent obstacle
// is the ReflectionEvent initial obstacle.
if (action is CloseVertexEvent) {
// If both neighbor sides reflect upward, they can't intersect, so we don't need
// to store a lookahead site (if neither reflect upward, StoreLookaheadSite no-ops).
if (!SideReflectsUpward(lowNborSide) || !SideReflectsUpward(highNborSide)) {
// Try to store both; only one will "take" (for the upward-reflecting side).
// The initial Obstacle is the opposite neighbor.
if (extendStart) {
this.StoreLookaheadSite(highNborSide.Obstacle, lowNborSide, start, wantExtreme:false);
}
if (extendEnd) {
this.StoreLookaheadSite(lowNborSide.Obstacle, highNborSide, end, wantExtreme: false);
}
}
}
else {
if (extendStart) {
StoreLookaheadSite(eventObstacle, LowNeighborSides.GroupSideInterveningBeforeLowNeighbor, lowNborSide, start);
}
if (extendEnd) {
StoreLookaheadSite(eventObstacle, HighNeighborSides.GroupSideInterveningBeforeHighNeighbor, highNborSide, end);
}
}
}
DevTraceInfoVgGen(2, "HintScanSegment {0}{1}", hintScanSegment, wasSubsumed ? " (subsumed)" : "");
DevTrace_DumpScanSegmentsDuringAdd(3);
return true;
}
internal GroupBoundaryCrossing(Obstacle group, Directions dirToInside)
{
Debug.Assert(CompassVector.IsPureDirection(dirToInside), "Impure direction");
this.Group = group;
this.DirectionToInside = dirToInside;
}
internal OpenVertexEvent(Obstacle obstacle, PolylinePoint p) : base(obstacle, p) { }
// If true, we have a staircase situation.
internal bool IsStaircaseStep(Obstacle reflectionTarget)
{
return(this.InitialObstacle == reflectionTarget);
}
private void AddGroupIntersectionsToRestrictedRay(Obstacle obstacle, IList<IntersectionInfo> intersections) {
// We'll let the lines punch through any intersections with groups, but track the location so we can enable/disable crossing.
foreach (var intersectionInfo in intersections) {
var intersect = SpliceUtility.RawIntersection(intersectionInfo, currentRestrictedRay.Start);
// Skip intersections that are past the end of the restricted segment (though there may still be some
// there if we shorten it later, but we'll skip them later).
var distSquared = (intersect - currentRestrictedRay.Start).LengthSquared;
if (distSquared > restrictedRayLengthSquared) {
continue;
}
var dirTowardIntersect = PointComparer.GetPureDirection(currentRestrictedRay.Start, currentRestrictedRay.End);
var polyline = (Polyline)intersectionInfo.Segment1; // this is the second arg to GetAllIntersections
var dirsOfSide = CompassVector.VectorDirection(polyline.Derivative(intersectionInfo.Par1));
// The derivative is always clockwise, so if the side contains the rightward rotation of the
// direction from the ray origin, then we're hitting it from the inside; otherwise from the outside.
var dirToInsideOfGroup = dirTowardIntersect;
if (0 != (dirsOfSide & CompassVector.RotateRight(dirTowardIntersect))) {
dirToInsideOfGroup = CompassVector.OppositeDir(dirToInsideOfGroup);
}
CurrentGroupBoundaryCrossingMap.AddIntersection(intersect, obstacle, dirToInsideOfGroup);
}
}
