public static IEnumerable <LineSegment2> AsLineSegments(this IEnumerable <Vector2> points)
{
foreach (var pair in points.AsPairs())
{
yield return(LineSegment2.FromOriginAndDestination(pair.Item1, pair.Item2));
}
}
public Intersection(LineSegment2 line1, LineSegment2 line2)
: this()
{
Line1 = line1;
Line2 = line2;
var p = line1.End1;
var q = line2.End1;
var r = line1.ToVector2();
var s = line2.ToVector2();
var denom = r.Cross(s);
if (denom == 0)
{
// The lines are parallel and there's no intersection
HasIntersection = false;
Distance1 = double.NaN;
Distance2 = double.NaN;
return;
}
var t = (q - p).Cross(s)/denom;
var u = (q - p).Cross(r)/denom;
Point = p + r*t;
Distance1 = t;
Distance2 = u;
HasIntersection = true;
}
public void AssertThat_IntersectionWithSegment_IntersectsDiagonalSegment()
{
var r = new BoundingRectangle(new Vector2(0, 0), new Vector2(10, 10));
var l = new LineSegment2(new Vector2(-10, -10), new Vector2(20, 20));
Assert.IsTrue(r.Intersects(l).HasValue);
}
private static IEnumerable <Point2> GetPoints(LineSegment2 entity, float elementSize, bool revert)
{
var numElements = (int)Math.Ceiling(entity.Length / elementSize);
var points = new Point2[numElements];
var start = entity.Vertex1;
var end = entity.Vertex2;
if (revert)
{
for (var i = numElements; i > 0; i--)
{
points[numElements - i] = new Point2(start.X + i * (end.X - start.X) / numElements,
start.Y + i * (end.Y - start.Y) / numElements);
}
}
else
{
for (var i = 0; i < numElements; i++)
{
points[i] = new Point2(start.X + i * (end.X - start.X) / numElements,
start.Y + i * (end.Y - start.Y) / numElements);
}
}
return(points);
}
public void TestEquality(string lineAStr, string lineBStr)
{
var lineA = LineSegment2.Parse(lineAStr);
var lineB = LineSegment2.Parse(lineBStr);
Assert.AreEqual(lineA, lineB);
}
public List <OSMWay> GetWaysIntersectingLine(LatitudeLongitude point1, LatitudeLongitude point2)
{
List <OSMWay> output = new List <OSMWay>();
try
{
foreach (OSMWay way in Ways)
{
if (way.BoundingBox.IntersectsLine(point1, point2))
{
for (int i = 0; i < way.NodeReferences.Count - 1; i++)
{
OSMNode thisNode, thatNode;
if (!NodesById.TryGetValue(way.NodeReferences[i], out thisNode) || !NodesById.TryGetValue(way.NodeReferences[i + 1], out thatNode))
{
continue;
}
Point2 intersectionPoint = LineSegment2.Intersection(point1, point2, thisNode.Location, thatNode.Location);
if (intersectionPoint != null)
{
output.Add(way);
}
}
}
}
return(output);
}
catch (Exception ex)
{
LogHelper.LogException(ex, "Error getting intersecting ways", true);
}
return(output);
}
private static HalfEdge <TVertexTag, THalfEdgeTag, TFaceTag> FindHalfEdge <TVertexTag, THalfEdgeTag, TFaceTag>(Face <TVertexTag, THalfEdgeTag, TFaceTag> face, Vector2 point)
{
Contract.Requires(face != null);
Contract.Ensures(Contract.Result <HalfEdge <TVertexTag, THalfEdgeTag, TFaceTag> >() != null);
Contract.Ensures(!Contract.Result <HalfEdge <TVertexTag, THalfEdgeTag, TFaceTag> >().IsDeleted);
HalfEdge <TVertexTag, THalfEdgeTag, TFaceTag> winner = null;
var score = float.MaxValue;
foreach (var halfEdge in face.Edges)
{
var closest = new LineSegment2(halfEdge.EndVertex.Position, halfEdge.Pair.EndVertex.Position).ClosestPoint(point);
var d = Vector2.DistanceSquared(closest, point);
if (d < score)
{
winner = halfEdge;
score = d;
}
}
if (score > 0.05f)
{
throw new InvalidOperationException("Closest edge is too far");
}
return(winner);
}
protected BuildingSideInfo[] GetNeighbourInfo(Prism bounds)
{
Contract.Ensures(Contract.Result <BuildingSideInfo[]>() != null);
Contract.Ensures(Contract.Result <BuildingSideInfo[]>().Length == bounds.Footprint.Count);
var sides = new BuildingSideInfo[bounds.Footprint.Count];
for (var i = 0; i < bounds.Footprint.Count; i++)
{
//Start and end point of this segment
var a = bounds.Footprint[i];
var b = bounds.Footprint[(i + 1) % bounds.Footprint.Count];
var seg = new LineSegment2(a, b).Transform(WorldTransformation);
var line = seg.Line;
//Neighbours which are for this segment
var ns = from n in (Neighbours ?? new NeighbourInfo[0])
where (n.Segment.Line.Parallelism(line) == Parallelism.Collinear)
let result = ExtractDataFromUnknownNode(n.Neighbour)
select new BuildingSideInfo.NeighbourInfo(n.Start, n.End, result.Key, result.Value);
//Save the results
sides[i] = new BuildingSideInfo(a, b, ns.ToArray());
}
return(sides);
}
public Intersection(LineSegment2 line1, LineSegment2 line2) : this()
{
Line1 = line1;
Line2 = line2;
var p = line1.End1;
var q = line2.End1;
var r = line1.ToVector2();
var s = line2.ToVector2();
var denom = r.Cross(s);
if (denom == 0)
{
// The lines are parallel and there's no intersection
HasIntersection = false;
Distance1 = double.NaN;
Distance2 = double.NaN;
return;
}
var t = (q - p).Cross(s) / denom;
var u = (q - p).Cross(r) / denom;
Point = p + r * t;
Distance1 = t;
Distance2 = u;
HasIntersection = true;
}
[TestCase("(10,10) (10,100)", "(0,303) (0,500)", true)] // Two vert lines
public void IsParallelTo(string line1Str, string line2Str, bool expected)
{
var line1 = LineSegment2.Parse(line1Str);
var line2 = LineSegment2.Parse(line2Str);
Assert.AreEqual(expected, line1.IsParallelTo(line2));
}
private IEnumerable <NeighbourInfo> CalculateNeighbours(KeyValuePair <Parcel, ISubdivisionContext> subject, NeighbourSet <ISubdivisionContext> nodes)
{
foreach (var edge in subject.Key.Edges)
{
var query = new LineSegment2(edge.Start, edge.End);
var neighbours = nodes.Neighbours(query, MathHelper.ToRadians(5), 1);
foreach (var neighbour in neighbours)
{
//Do not add self as a neighbour!
if (neighbour.Value.Equals(subject.Value))
{
continue;
}
yield return(new NeighbourInfo(
neighbour.Value,
neighbour.Segment.Transform(WorldTransformation),
neighbour.SegmentOverlapStart,
neighbour.SegmentOverlapEnd,
query.Transform(WorldTransformation),
neighbour.QueryOverlapStart,
neighbour.QueryOverlapEnd
));
}
}
}
private Edge FindIntersectingEdge(Vector2 a, Vector2 b, out Vector2 intersectPosition)
{
var min = new Vector2(Math.Min(a.X, b.X), Math.Min(a.Y, b.Y));
var max = new Vector2(Math.Max(a.X, b.X), Math.Max(a.Y, b.Y));
//Select the all intersections (by checking all edges in octree result)
var segment = new LineSegment2(a, b);
var best = (from candidate in _edges.Intersects(new BoundingRectangle(min, max))
let intersectionMaybe = new LineSegment2(candidate.A.Position, candidate.B.Position).Intersects(segment)
where intersectionMaybe.HasValue
let intersection = intersectionMaybe.Value
select new KeyValuePair <LinesIntersection2, Edge>(intersection, candidate));
intersectPosition = Vector2.Zero;
Edge bestEdge = null;
var bestScore = float.MaxValue;
foreach (var keyValuePair in best)
{
if (keyValuePair.Key.DistanceAlongB < bestScore)
{
intersectPosition = keyValuePair.Key.Position;
bestEdge = keyValuePair.Value;
bestScore = keyValuePair.Key.DistanceAlongB;
}
}
return(bestEdge);
}
public static VisualLine Create(LineSegment2 line, Pen pen = null)
{
return(new VisualLine(line)
{
Pen = pen
});
}
public void GetHashCode_SameForEqual()
{
var a = new LineSegment2(new Vector2(1, 2), new Vector2(3, 4));
var b = new LineSegment2(new Vector2(1, 2), new Vector2(3, 4));
Assert.AreEqual(a.GetHashCode(), b.GetHashCode());
}
public void NotEquals_TrueForNotEqual()
{
var a = new LineSegment2(new Vector2(1, 2), new Vector2(3, 4));
var b = new LineSegment2(new Vector2(6, 2), new Vector2(3, 4));
Assert.IsTrue(a != b);
}
public void NotEquals_FalseForEqual()
{
var a = new LineSegment2(new Vector2(1, 2), new Vector2(3, 4));
var b = a;
Assert.IsFalse(a != b);
}
private KeyValuePair <HalfEdge, LinesIntersection2>?FindFirstIntersection(Seed seed, float length)
{
Contract.Requires(seed != null);
Contract.Ensures(!Contract.Result <KeyValuePair <HalfEdge, LinesIntersection2>?>().HasValue || Contract.Result <KeyValuePair <HalfEdge, LinesIntersection2>?>().Value.Key != null);
//Create the bounds of this new line (inflated slightly, just in case it's perfectly axis aligned)
var a = seed.Origin.Position;
var b = seed.Origin.Position + seed.Direction * length;
var bounds = new BoundingRectangle(Vector2.Min(a, b), Vector2.Max(a, b)).Inflate(0.2f);
var segment = new LineSegment2(a, b);
//Find all edges which intersect this bounds, then test them one by one for intersection
var results = _mesh
.FindEdges(bounds)
.Select(e => new KeyValuePair <HalfEdge, LinesIntersection2?>(e, e.Segment.Intersects(segment)))
.Where(i => i.Value.HasValue)
.Select(i => new KeyValuePair <HalfEdge, LinesIntersection2>(i.Key, i.Value.Value));
//Find the first intersection from all the results
KeyValuePair <HalfEdge, LinesIntersection2>?result = null;
foreach (var candidate in results)
{
if (result == null || candidate.Value.DistanceAlongB < result.Value.Value.DistanceAlongB)
{
result = candidate;
}
}
return(result);
}
public void Slope(string sp, string ep, double expected)
{
var spv = Vector2.Parse(sp);
var epv = Vector2.Parse(ep);
var l1 = new LineSegment2(spv, epv);
Assert.AreEqual(expected, l1.Slope);
}
public void IsVertical(string sp, string ep, bool expected)
{
var spv = Vector2.Parse(sp);
var epv = Vector2.Parse(ep);
var l1 = new LineSegment2(spv, epv);
Assert.AreEqual(expected, l1.IsVertical);
}
public static PostgisLineString ToPGis(LineSegment2 <double> geom)
{
if (geom != null)
{
return(new PostgisLineString(new Coordinate2D[] { new Coordinate2D(geom.Start.X, geom.Start.Y), new Coordinate2D(geom.End.X, geom.End.Y) }));
}
return(null);
}
internal void AddSegment(LineSegment2 <T> segment)
{
if (segment == null)
{
return;
}
this.lineSegments.Add(segment, this.masterNodes);
}
public void TesthasOverlap(string line1Str, string line2Str, bool expectedOverlap)
{
var line1 = LineSegment2.Parse(line1Str);
var line2 = LineSegment2.Parse(line2Str);
var hasOverlap = line1.HasOverlap(line2);
Assert.AreEqual(expectedOverlap, hasOverlap);
}
[TestCase("(6,56497115745559, -13,4350288425444), (20, -1,77635683940025E-15)", "(0, 0), (20, 0)", false)] // // A line touches another - no proper intersection
public void TestProperIntersection(string line1Str, string line2Str, bool expectedProperIntersection)
{
var line1 = LineSegment2.Parse(line1Str);
var line2 = LineSegment2.Parse(line2Str);
var properIntersection = line1.IsIntersectionProper(line2);
Assert.AreEqual(expectedProperIntersection, properIntersection);
}
private KeyValuePair <HalfEdge, float>?FindFirstParallelEdge(Seed seed, float length, float distance, float parallelThreshold)
{
Contract.Requires(seed != null);
var start = seed.Origin.Position;
var end = seed.Origin.Position + seed.Direction * length;
var segment = new LineSegment2(start, end);
//Calculate the expanded bounds to query. This is as wide as the parallel check distance
var p = seed.Direction.Perpendicular() * distance / 2;
var a = start + p;
var b = start - p;
var c = end + p;
var d = end - p;
var queryBounds = new BoundingRectangle(
Vector2.Min(Vector2.Min(a, b), Vector2.Min(c, d)),
Vector2.Max(Vector2.Max(a, b), Vector2.Max(c, d))
);
//now get all lines which intersect this bounds and check them for parallelism
var candidates = _mesh.FindEdges(queryBounds);
KeyValuePair <HalfEdge, float>?firstParallel = null;
foreach (var candidate in candidates)
{
var dirCandidate = candidate.Segment.Line.Direction;
var dir = segment.Line.Direction;
//Dot product directions of lines to check parallelism (compare with threshold)
var dot = Math.Abs(Vector2.Dot(dir, dirCandidate));
if (dot > parallelThreshold)
{
//Our query bounds were larger than the actual area we wanted to query (because we're limited to axis aligned bounds)
//Check that this line enters the smaller OABB area
//We'll do this check by checking if the line segment intersects any of the four OABB segments (AB, BC, CD, DA)
if (new LineSegment2(a, b).Intersects(candidate.Segment).HasValue ||
new LineSegment2(b, c).Intersects(candidate.Segment).HasValue ||
new LineSegment2(c, d).Intersects(candidate.Segment).HasValue ||
new LineSegment2(d, a).Intersects(candidate.Segment).HasValue)
{
//check how far along this segment the parallelism starts
var startDist = segment.ClosestPointDistanceAlongSegment(candidate.StartVertex.Position);
var endDist = segment.ClosestPointDistanceAlongSegment(candidate.EndVertex.Position);
var minDist = Math.Min(startDist, endDist);
if (firstParallel == null || minDist < firstParallel.Value.Value)
{
firstParallel = new KeyValuePair <HalfEdge, float>(candidate, minDist);
}
}
}
}
return(firstParallel);
}
public void Lenght(string sp, string ep, double expected)
{
var spv = Vector2.Parse(sp);
var epv = Vector2.Parse(ep);
var l1 = new LineSegment2(spv, epv);
Assert.AreEqual(l1.Length, expected);
}
[TestCase("(10, 20),(60, 70)", "(35,30),(45,40)")] // two parallel but nonaxial non overlapping lines
public void TestNoOverlap(string line1Str, string line2Str)
{
var line1 = LineSegment2.Parse(line1Str);
var line2 = LineSegment2.Parse(line2Str);
var overlap = line1.HasOverlap(line2);
Assert.AreEqual(false, overlap);
}
public void TestLineCollisions(string line1Str, string line2Str, bool expectedCollision)
{
var line1 = LineSegment2.Parse(line1Str);
var line2 = LineSegment2.Parse(line2Str);
var collides = line1.HasCollision(line2);
Assert.AreEqual(expectedCollision, collides);
}
public LineSegment2 Reflect(LineSegment2 segment)
{
if (!this.valid)
{
return(segment);
}
return(new LineSegment2(Reflect(segment.A), Reflect(segment.B)));
}
public void Equals_FalseForNotEqual()
{
var a = new LineSegment2(new Vector2(1, 2), new Vector2(3, 4));
var b = new LineSegment2(new Vector2(5, 6), new Vector2(7, 8));
Assert.IsFalse(a.Equals(b));
Assert.IsFalse(a.Equals((object)b));
Assert.IsFalse(a == b);
}
public NeighbourResult(LineSegment2 segment, float segmentOverlapStart, float segmentOverlapEnd, T value, float queryOverlapStart, float queryOverlapEnd)
{
Segment = segment;
SegmentOverlapStart = segmentOverlapStart;
SegmentOverlapEnd = segmentOverlapEnd;
Value = value;
QueryOverlapStart = queryOverlapStart;
QueryOverlapEnd = queryOverlapEnd;
}
public Angle MaximalAngleWith(LineSegment2 line)
{
if (!this.valid)
{
return(Angle.ZERO);
}
return(this.direction.MaximalAngleWithAxis(line.VectorAB));
}
/// <summary>
/// Get 2 rays from 3 points. The Rays interception Point is the Middlepoint of the Arc
/// </summary>
/// <param name="startPoint"></param>
/// <param name="interPoint"></param>
/// <param name="endPoint"></param>
/// <returns></returns>
private static Ray[] RaysFromDescriptorPoints(Vector2 startPoint, Vector2 interPoint, Vector2 endPoint, Direction direction)
{
Ray[] rays = new Ray[2];
Vector2 vRay1 = new Vector2(startPoint, interPoint).GetOrthogonalVector(direction); //Direction doesn't matter !?
Vector2 vRay2 = new Vector2(interPoint, endPoint).GetOrthogonalVector(direction); //Direction doesn't matter !?
var ray1StartPoint = new LineSegment2(startPoint, interPoint).MiddlePoint;
var ray2StartPoint = new LineSegment2(interPoint, endPoint).MiddlePoint;
rays[0] = new Ray(vRay1, ray1StartPoint);
rays[1] = new Ray(vRay2, ray2StartPoint);
return rays;
}
/// <summary>
/// Returns the angle formed between this <see cref="LineSegment2"/> and the supplied <paramref name="lineSegment"/>.
/// </summary>
/// <param name="lineSegment"></param>
/// <returns></returns>
public double AngleTo(LineSegment2 lineSegment)
{
return ToVector2().Angle - lineSegment.ToVector2().Angle;
}