/// <summary>
/// Calculate intersection point of two line.
/// </summary>
/// <param name="source"></param>
/// <param name="target"></param>
/// <returns></returns>
public static IntersectionInfo InsersectLines(Line source, Line target)
{
var points = new Point3dCollection();
source.IntersectWith(target, Intersect.ExtendBoth, points, IntPtr.Zero, IntPtr.Zero);
if (points.Count <= 0)
{
return(null);
}
// NOTE: Use Line's GetParameterAtPoint will throw exception if the intersect point is
// on the line's extension, but LineSegment3d.GetParameterOf is available, so I convert
// the Line to LineSegment3d here.
var intersectPoint = points[0];
var sourceLineSegment = new LineSegment3d(source.StartPoint, source.EndPoint);
var targetLineSegment = new LineSegment3d(target.StartPoint, target.EndPoint);
var sourceParam = sourceLineSegment.GetParameterOf(intersectPoint);
var sourceExtendType = ParamToExtendTypeForLine(sourceParam);
var targetParam = targetLineSegment.GetParameterOf(intersectPoint);
var targetExtendType = ParamToExtendTypeForLine(targetParam);
var result = new IntersectionInfo(sourceExtendType, targetExtendType, intersectPoint);
return(result);
}
private IntersectionInfo IntersectLineAndCurve(Line line, Curve curve, Point3d sorucePoint, ExtendType desireExtendType)
{
var points = new Point3dCollection();
line.IntersectWith(curve, Intersect.ExtendThis, points, IntPtr.Zero, IntPtr.Zero);
if (points.Count == 0)
{
return(null);
}
// NOTE: Use Line's GetParameterAtPoint will throw exception if the intersect point is
// on the line's extension, but LineSegment3d.GetParameterOf is available, so I convert
// the Line to LineSegment3d here.
var lineSegment = new LineSegment3d(line.StartPoint, line.EndPoint);
Point3d?nearestPoint = null;
double? nearestDist = null;
foreach (Point3d point in points)
{
var param = lineSegment.GetParameterOf(point);
var extendType = CurveIntersectUtils.ParamToExtendTypeForLine(param);
if (extendType != desireExtendType)
{
continue;
}
var dist = (point - sorucePoint).LengthSqrd;
if (nearestDist == null || dist < nearestDist.Value)
{
nearestDist = dist;
nearestPoint = point;
}
}
IntersectionInfo result = null;
if (nearestPoint != null)
{
result = new IntersectionInfo(desireExtendType, ExtendType.None, nearestPoint.Value);
}
return(result);
}
private IntersectionInfo CreateRealIntersectionInfo(BspSplitInfo info, Point2d point, ObjectId targetId, HashSet <CurveVertex> vertexIntersects)
{
var extendType = CurveIntersectUtils.ParamToExtendTypeForLine(info.SourceParam);
if (extendType != ExtendType.None)
{
return(null);
}
// Self intersection
if ((info.SourceParam.EqualsWithTolerance(0.0) || info.SourceParam.EqualsWithTolerance(1.0)) &&
info.SourceSegment.EntityId == targetId)
{
// Need to take care of a special case:
// Polyline AEB and CED intersect at E point
// A\ D
// \ |
// \|_________B
// C / E
var vertexIntersect = new CurveVertex(new Point3d(point.X, point.Y, 0.0), info.SourceSegment.EntityId);
// More than two intersects, then it's a self intersection.
if (vertexIntersects.Contains(vertexIntersect))
{
var intersection = new IntersectionInfo(info.SourceSegment.EntityId, ExtendType.None, targetId,
ExtendType.None, new Point3d(point.X, point.Y, 0.0));
return(intersection);
}
vertexIntersects.Add(vertexIntersect);
return(null);
}
else
{
var intersection = new IntersectionInfo(info.SourceSegment.EntityId, ExtendType.None, targetId,
ExtendType.None, new Point3d(point.X, point.Y, 0.0));
return(intersection);
}
}
private IntersectionInfo IntersectArcAndCurve(Arc arc, Curve curve, Point3d point, ExtendType?coerceArcExtendType)
{
var points = new Point3dCollection();
arc.IntersectWith(curve, Intersect.ExtendThis, points, IntPtr.Zero, IntPtr.Zero);
if (points.Count <= 0)
{
return(null);
}
// Get the nearest point
var nearsetPoint = points[0];
var dist = (point - nearsetPoint).LengthSqrd;
for (int i = 1; i < points.Count; i++)
{
var newDist = (points[i] - point).LengthSqrd;
if (newDist < dist)
{
nearsetPoint = points[i];
dist = newDist;
}
}
// Calculate extend type
if (coerceArcExtendType == null)
{
var circularArc = new CircularArc3d(arc.Center, arc.Normal, arc.Normal.GetPerpendicularVector(), arc.Radius,
arc.StartAngle, arc.EndAngle);
var arcParam = circularArc.GetParameterOf(nearsetPoint);
coerceArcExtendType = CurveIntersectUtils.ParamToExtendTypeForArc(circularArc, arcParam, null);
}
var result = new IntersectionInfo(coerceArcExtendType.Value, ExtendType.None, nearsetPoint);
return(result);
}
private bool CheckIntersectionInfo(IntersectionInfo info, ExtendType desiredSourceExtendType, Point3d sourcePoint,
ExtendType desiredTargetExtendType, Point3d targetPoint, double tolerance)
{
if (info.SourceExtendType != desiredSourceExtendType)
{
return(false);
}
if (info.TargetExtendType != desiredTargetExtendType)
{
return(false);
}
var dist = (sourcePoint - info.IntersectPoint).Length;
if (dist.Larger(tolerance))
{
return(false);
}
dist = (targetPoint - info.IntersectPoint).Length;
if (dist.Larger(tolerance))
{
return(false);
}
return(true);
}
private IntersectionInfo CalcApparentIntersection(CurveVertex source, CurveVertex target, Transaction transaction)
{
var sourceEntity = transaction.GetObject(source.Id, OpenMode.ForRead);
var targetEntity = transaction.GetObject(target.Id, OpenMode.ForRead);
// Source curve
var desiredSourceExtend = CurveUtils.GetExtendType((Curve)sourceEntity, source.Point);
var sourceLine = sourceEntity as Line;
var sourceArc = sourceEntity as Arc;
var sourcePolyline = sourceEntity as Autodesk.AutoCAD.DatabaseServices.Polyline;
var sourcePolyline2d = sourceEntity as Polyline2d;
if (sourcePolyline != null)
{
sourceLine = CurveUtils.CutOutLineFromPolyLine(sourcePolyline, source.Point);
}
else if (sourcePolyline2d != null)
{
sourceLine = CurveUtils.CutOutLineFromPolyline2d(sourcePolyline2d, source.Point, transaction);
}
// Target curve
var desiredTargetExtend = CurveUtils.GetExtendType((Curve)targetEntity, target.Point);
var targetLine = targetEntity as Line;
var targetArc = targetEntity as Arc;
var targetPolyline = targetEntity as Autodesk.AutoCAD.DatabaseServices.Polyline;
var targetPolyline2d = targetEntity as Polyline2d;
if (targetPolyline != null)
{
targetLine = CurveUtils.CutOutLineFromPolyLine(targetPolyline, target.Point);
}
else if (targetPolyline2d != null)
{
targetLine = CurveUtils.CutOutLineFromPolyline2d(targetPolyline2d, target.Point, transaction);
}
// Calculate intersection.
var results = new List <IntersectionInfo>();
if (sourceLine != null && targetLine != null)
{
// Line && Line
var info = CurveIntersectUtils.InsersectLines(sourceLine, targetLine);
if (info != null)
{
info.SourceId = source.Id;
info.TargetId = target.Id;
results.Add(info);
}
}
else if (sourceLine != null && targetArc != null)
{
// Line && Arc
var infos = CurveIntersectUtils.IntersectLineArc(sourceLine, targetArc, coerceArcExtendType: desiredTargetExtend);
foreach (var info in infos)
{
info.SourceId = source.Id;
info.TargetId = target.Id;
}
results.AddRange(infos);
}
else if (sourceArc != null && targetLine != null)
{
// Arc && Line
var infos = CurveIntersectUtils.IntersectLineArc(targetLine, sourceArc, coerceArcExtendType: desiredSourceExtend);
foreach (var info in infos)
{
// Exchange entend type.
var newInfo = new IntersectionInfo(source.Id, info.TargetExtendType, target.Id,
info.SourceExtendType, info.IntersectPoint);
results.Add(newInfo);
}
}
else if (sourceArc != null && targetArc != null)
{
// Arc && Arc
var infos = CurveIntersectUtils.IntersectArcs(sourceArc, desiredSourceExtend, targetArc,
desiredTargetExtend);
foreach (var info in infos)
{
info.SourceId = source.Id;
info.TargetId = target.Id;
}
results.AddRange(infos);
}
IntersectionInfo result = null;
foreach (var info in results)
{
var valid = CheckIntersectionInfo(info, desiredSourceExtend, source.Point, desiredTargetExtend, target.Point, _tolerance);
if (valid)
{
result = info;
break;
}
}
return(result);
}
private IntersectionInfo GetUnderShootIntersection(CurveVertex vertex, Transaction transaction, double tolerance)
{
var curve = transaction.GetObject(vertex.Id, OpenMode.ForRead);
var desiredExtend = CurveUtils.GetExtendType((Curve)curve, vertex.Point);
var line = curve as Line;
var arc = curve as Arc;
var polyline = curve as Polyline;
var polyline2d = curve as Polyline2d;
if (polyline != null)
{
line = CurveUtils.CutOutLineFromPolyLine(polyline, vertex.Point);
}
else if (polyline2d != null)
{
line = CurveUtils.CutOutLineFromPolyline2d(polyline2d, vertex.Point, transaction);
}
// Construct a polygon to get adjacent entities.
Point3dCollection polygon = null;
if (line != null)
{
var direction = line.EndPoint - line.StartPoint;
if (desiredExtend == ExtendType.ExtendStart)
{
direction = -1.0 * direction;
}
polygon = BuildSelectionPolygonForLine(vertex.Point, direction, tolerance);
}
else if (arc != null)
{
polygon = BuildSelectionPolygonForArc(vertex.Point, tolerance);
}
// Zoom window
var minPt = new Point3d(vertex.Point.X - tolerance, vertex.Point.Y - tolerance, 0.0);
var maxPt = new Point3d(vertex.Point.X + tolerance, vertex.Point.Y + tolerance, 0.0);
var extents = new Extents3d(minPt, maxPt);
Editor.ZoomToWin(extents, factor: 2.0);
var selectionResult = Editor.SelectCrossingPolygon(polygon, SelectionFilterUtils.OnlySelectCurve());
if (selectionResult.Status != PromptStatus.OK || selectionResult.Value == null)
{
return(null);
}
// Check each adjacent entity whether they are intersected.
var intersectionInfos = new List <IntersectionInfo>();
var adjacentIds = selectionResult.Value.GetObjectIds();
foreach (ObjectId objId in adjacentIds)
{
var targetCurve = transaction.GetObject(objId, OpenMode.ForRead) as Curve;
if (targetCurve == null)
{
continue;
}
// Calculate the intersection
IntersectionInfo info = null;
if (line != null)
{
info = IntersectLineAndCurve(line, targetCurve, vertex.Point, desiredExtend);
}
else if (arc != null)
{
info = IntersectArcAndCurve(arc, targetCurve, vertex.Point, desiredExtend);
}
if (info != null && info.SourceExtendType == desiredExtend)
{
info.SourceId = vertex.Id;
info.TargetId = objId;
intersectionInfos.Add(info);
}
}
// Get nearest point.
if (intersectionInfos.Count <= 0)
{
return(null);
}
var nearest = intersectionInfos[0];
var nearsetDist = (intersectionInfos[0].IntersectPoint - vertex.Point).Length;
for (int i = 1; i < intersectionInfos.Count; i++)
{
var dist = (intersectionInfos[i].IntersectPoint - vertex.Point).Length;
if (dist < nearsetDist)
{
nearsetDist = dist;
nearest = intersectionInfos[i];
}
}
if (nearsetDist.Larger(tolerance))
{
return(null);
}
return(nearest);
}