/// <summary>
/// Testing whether 2 line segments overlapped
/// </summary>
/// <param name="lineSegment1">First line segment</param>
/// <param name="lineSegment2">Second line segment</param>
/// <param name="overlappedSegment">The resulting overlapped line segment</param>
/// <param name="mode">The enumeration of the result</param>
/// <returns></returns>
public static bool overlap(LineSegment3D lineSegment1, LineSegment3D lineSegment2, out LineSegment3D overlappedSegment, out LineSegmentOverlapEnum mode)
{
mode = LineSegmentOverlapEnum.Undefined;
overlappedSegment = lineSegment1;
// First check whether they have the same lineDirection (absolute: -v = +v for overlap test)
if (!Line3D.parallel(lineSegment1.baseLine, lineSegment2.baseLine))
{
return(false);
}
// The lines are parallel, now check whether there is at least one point falls in the segment
// Test points in line 2 on line 1
LineSegmentOnSegmentEnum p1l1_s, p2l1_s;
LineSegmentOnSegmentEnum p1l2_s, p2l2_s;
bool p1l1 = isInSegment(lineSegment1, lineSegment2.startPoint, out p1l1_s);
bool p2l1 = isInSegment(lineSegment1, lineSegment2.endPoint, out p2l1_s);
if (p1l1 && p2l1)
{
if ((p1l1_s == p2l1_s && p2l1_s == LineSegmentOnSegmentEnum.InsideSegment) ||
(p1l1_s == LineSegmentOnSegmentEnum.CoincideEndSegment && p2l1_s == LineSegmentOnSegmentEnum.InsideSegment) ||
(p1l1_s == LineSegmentOnSegmentEnum.InsideSegment && p2l1_s == LineSegmentOnSegmentEnum.CoincideEndSegment))
{
mode = LineSegmentOverlapEnum.SubSegment;
}
if (p1l1_s == p2l1_s && p1l1_s == LineSegmentOnSegmentEnum.CoincideEndSegment)
{
mode = LineSegmentOverlapEnum.ExactlyOverlap;
}
overlappedSegment = lineSegment2;
return(true);
}
else if (p1l1 || p2l1)
{
if (p1l1_s == LineSegmentOnSegmentEnum.CoincideEndSegment || p2l1_s == LineSegmentOnSegmentEnum.CoincideEndSegment)
{
mode = LineSegmentOverlapEnum.Touch;
// Zero lenth line segments = a point, a valid data
if (p1l1)
{
overlappedSegment = new LineSegment3D(lineSegment2.startPoint, lineSegment2.startPoint);
}
if (p2l1)
{
overlappedSegment = new LineSegment3D(lineSegment2.endPoint, lineSegment2.endPoint);
}
}
if (p1l1_s == LineSegmentOnSegmentEnum.InsideSegment || p2l1_s == LineSegmentOnSegmentEnum.InsideSegment)
{
bool p1l2 = isInSegment(lineSegment2, lineSegment1.startPoint, out p1l2_s);
bool p2l2 = isInSegment(lineSegment2, lineSegment1.endPoint, out p2l2_s);
if (p1l1_s == LineSegmentOnSegmentEnum.InsideSegment && p1l2_s == LineSegmentOnSegmentEnum.InsideSegment)
{
overlappedSegment = new LineSegment3D(lineSegment2.startPoint, lineSegment1.startPoint);
}
if (p2l1_s == LineSegmentOnSegmentEnum.InsideSegment && p1l2_s == LineSegmentOnSegmentEnum.InsideSegment)
{
overlappedSegment = new LineSegment3D(lineSegment2.endPoint, lineSegment1.startPoint);
}
if (p1l1_s == LineSegmentOnSegmentEnum.InsideSegment && p2l2_s == LineSegmentOnSegmentEnum.InsideSegment)
{
overlappedSegment = new LineSegment3D(lineSegment2.startPoint, lineSegment1.endPoint);
}
if (p2l1_s == LineSegmentOnSegmentEnum.InsideSegment && p2l2_s == LineSegmentOnSegmentEnum.InsideSegment)
{
overlappedSegment = new LineSegment3D(lineSegment2.endPoint, lineSegment1.endPoint);
}
mode = LineSegmentOverlapEnum.PartiallyOverlap;
}
return(true);
}
else
{
// if both p1l1 and p2l1 are false, there is probability that the l1 are inside the l2 instead. Only this case needs to be checked since other
// cases should be covered by the previous conditional checks
bool p1l2 = isInSegment(lineSegment2, lineSegment1.startPoint, out p1l2_s);
bool p2l2 = isInSegment(lineSegment2, lineSegment1.endPoint, out p2l2_s);
if ((p1l2 && p2l2) &&
(p1l2_s == p2l2_s && p1l2_s == LineSegmentOnSegmentEnum.InsideSegment))
{
mode = LineSegmentOverlapEnum.SuperSegment;
overlappedSegment = lineSegment1;
return(true);
}
}
return(false);
}
/// <summary>
/// Calculating intersection beween 2 Faces. The outcome of the intersection should be a LineSegment
/// </summary>
/// <param name="F1">First Face</param>
/// <param name="F2">Second Face</param>
/// <param name="intersectionLine">The resulting intersection line. Zero if no intersection</param>
/// <param name="mode">The mode of the intersection: No intersection/parallel, partially intersect, no actual intersection/undefined</param>
/// <returns></returns>
public static bool intersect(Face3D F1, Face3D F2, out LineSegment3D intersectionLine, out FaceIntersectEnum mode)
{
intersectionLine = new LineSegment3D(new Point3D(0, 0, 0), new Point3D(0, 0, 0));
mode = FaceIntersectEnum.Undefined;
if (F1._basePlane.normalVector == F2._basePlane.normalVector)
{
// test points inside another face
for (int i = 0; i < F2._vertices.Count; i++)
{
if (!Face3D.inside(F1, F2._vertices[i]))
{
continue;
}
mode = FaceIntersectEnum.Overlap;
return(true);
}
mode = FaceIntersectEnum.NoIntersectionParallel;
return(false);
}
LineSegment3D ls1;
LineSegment3D ls2;
bool res1 = Plane3D.PPintersect(F1._basePlane, F2, out ls1);
bool res2 = Plane3D.PPintersect(F2._basePlane, F1, out ls2);
if (!res1 || !res2)
{
return(false); // the faces do not intersect
}
// Special case if the intersection occurs only at a single point
if (ls1.startPoint == ls1.endPoint && ls2.startPoint == ls2.endPoint)
{
if (ls1.startPoint.Equals(ls2.startPoint))
{
mode = FaceIntersectEnum.IntersectPartial;
return(true);
}
return(false);
}
else if (ls1.startPoint.Equals(ls1.endPoint))
{
// a single point intersection: ls1 is 0 length linesegnment = point
if (LineSegment3D.isInSegment(ls2, ls1.startPoint))
{
mode = FaceIntersectEnum.IntersectPartial;
return(true);
}
return(false);
}
else if (ls2.startPoint.Equals(ls2.endPoint))
{
// a single point intersection: ls1 is 0 length linesegnment = point
if (LineSegment3D.isInSegment(ls1, ls2.startPoint))
{
mode = FaceIntersectEnum.IntersectPartial;
return(true);
}
return(false);
}
LineSegment3D ovSegment;
LineSegmentOverlapEnum ovstat = LineSegmentOverlapEnum.Undefined;
bool lint = LineSegment3D.overlap(ls1, ls2, out ovSegment, out ovstat);
if (lint)
{
intersectionLine = ovSegment;
mode = FaceIntersectEnum.IntersectPartial;
return(true);
}
return(false);
}