public void no_intersection_perpendicular()
{
var a = new Segment2(new Point2(0, 1), new Point2(1, 0));
var b = new Segment2(new Point2(2, 2), new Point2(1, 1));
var res = SegmentIntersectionOperation.IntersectionDetails(a, b);
Assert.Null(res.Geometry);
res = SegmentIntersectionOperation.IntersectionDetails(b, a);
Assert.Null(res.Geometry);
}
public void intersection_overlap()
{
var a = new Segment2(new Point2(0, 0), new Point2(1, 1));
var b = new Segment2(new Point2(.5, .5), new Point2(2, 2));
var exp = new Segment2(new Point2(.5, .5), new Point2(1, 1));
var res = SegmentIntersectionOperation.IntersectionDetails(a, b) as SegmentIntersectionOperation.SegmentResult;
Assert.Equal(exp, res.S);
Assert.Equal(new Vector2(.5, 0), res.A.Ratios);
Assert.Equal(new Vector2(1, 1 / 3.0), res.B.Ratios);
res = SegmentIntersectionOperation.IntersectionDetails(b, a) as SegmentIntersectionOperation.SegmentResult;
Assert.Equal(exp, res.S);
Assert.Equal(new Vector2(0, .5), res.A.Ratios);
Assert.Equal(new Vector2(1 / 3.0, 1), res.B.Ratios);
}
public void intersection_cross_ends()
{
var a = new Segment2(new Point2(0, 0), new Point2(1, 1));
var b = new Segment2(new Point2(0.5, 1.5), new Point2(1, 1));
var res = (SegmentIntersectionOperation.PointResult)SegmentIntersectionOperation.IntersectionDetails(a, b);
Assert.Equal(new Point2(1, 1), res.P);
Assert.Equal(new Vector2(1, 1), res.Ratios);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Head, res.TypeA);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Head, res.TypeB);
res = (SegmentIntersectionOperation.PointResult)SegmentIntersectionOperation.IntersectionDetails(b, a);
Assert.Equal(new Point2(1, 1), res.P);
Assert.Equal(new Vector2(1, 1), res.Ratios);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Head, res.TypeA);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Head, res.TypeB);
}
public void intersection_within()
{
var a = new Segment2(new Point2(0, 0), new Point2(1, 1));
var b = new Segment2(new Point2(-.5, -.5), new Point2(2, 2));
var res = SegmentIntersectionOperation.IntersectionDetails(a, b) as SegmentIntersectionOperation.SegmentResult;
Assert.Equal(a, res.S);
Assert.Equal(new Vector2(0, .2), res.A.Ratios);
Assert.Equal(1, res.B.S);
Assert.Equal(.6, res.B.T, 10);
res = SegmentIntersectionOperation.IntersectionDetails(b, a) as SegmentIntersectionOperation.SegmentResult;
Assert.Equal(a, res.S);
Assert.Equal(new Vector2(.2, 0), res.A.Ratios);
Assert.Equal(.6, res.B.S, 10);
Assert.Equal(1, res.B.T);
}
public void intersection_same()
{
var a = new Segment2(new Point2(0, 0), new Point2(1, 1));
var b = new Segment2(new Point2(1, 1), new Point2(0, 0));
var res = SegmentIntersectionOperation.IntersectionDetails(a, a) as SegmentIntersectionOperation.SegmentResult;
AreSpatiallyEqual(a, res.S);
AreSpatiallyEqual(b, res.S);
Assert.Equal(a.A, res.S.A);
Assert.Equal(a.B, res.S.B);
Assert.Equal(new Vector2(0, 0), res.A.Ratios);
Assert.Equal(new Vector2(1, 1), res.B.Ratios);
res = SegmentIntersectionOperation.IntersectionDetails(b, b) as SegmentIntersectionOperation.SegmentResult;
AreSpatiallyEqual(a, res.S);
AreSpatiallyEqual(b, res.S);
Assert.Equal(b.A, res.S.A);
Assert.Equal(b.B, res.S.B);
Assert.Equal(new Vector2(0, 0), res.A.Ratios);
Assert.Equal(new Vector2(1, 1), res.B.Ratios);
res = SegmentIntersectionOperation.IntersectionDetails(a, b) as SegmentIntersectionOperation.SegmentResult;
AreSpatiallyEqual(a, res.S);
AreSpatiallyEqual(b, res.S);
Assert.Equal(a.A, res.S.A);
Assert.Equal(a.B, res.S.B);
Assert.Equal(new Vector2(0, 1), res.A.Ratios);
Assert.Equal(new Vector2(1, 0), res.B.Ratios);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Butt, res.A.TypeA);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Head, res.A.TypeB);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Head, res.B.TypeA);
Assert.Equal(SegmentIntersectionOperation.SegmentIntersectionType.Butt, res.B.TypeB);
res = SegmentIntersectionOperation.IntersectionDetails(b, a) as SegmentIntersectionOperation.SegmentResult;
AreSpatiallyEqual(a, res.S);
AreSpatiallyEqual(b, res.S);
Assert.Equal(b.A, res.S.A);
Assert.Equal(b.B, res.S.B);
Assert.Equal(new Vector2(0, 1), res.A.Ratios);
Assert.Equal(new Vector2(1, 0), res.B.Ratios);
}
private static void AddPointCrossings(List <PolygonCrossing> results, Segment2Data segmentDataA, Segment2Data segmentDataB)
{
Contract.Requires(results != null);
Contract.Ensures(results.Count >= Contract.OldValue(results).Count);
Contract.Assume(null != segmentDataA.Segment);
Contract.Assume(null != segmentDataB.Segment);
var intersectionDetails = SegmentIntersectionOperation.IntersectionDetails(segmentDataA.Segment, segmentDataB.Segment);
if (intersectionDetails is SegmentIntersectionOperation.PointResult)
{
var pointResult = (SegmentIntersectionOperation.PointResult)intersectionDetails;
if (IsNotHead(pointResult))
{
results.Add(CreatePolygonCrossing(pointResult, segmentDataA, segmentDataB));
}
}
else if (intersectionDetails is SegmentIntersectionOperation.SegmentResult)
{
var segmentResult = intersectionDetails as SegmentIntersectionOperation.SegmentResult;
var bIsNotHead = IsNotHead(segmentResult.B);
if (IsNotHead(segmentResult.A))
{
var resultA = CreatePolygonCrossing(segmentResult.A, segmentDataA, segmentDataB);
if (bIsNotHead)
{
results.AddRange(new[] { resultA, CreatePolygonCrossing(segmentResult.B, segmentDataA, segmentDataB) });
}
else
{
results.Add(resultA);
}
}
else if (bIsNotHead)
{
results.Add(CreatePolygonCrossing(segmentResult.B, segmentDataA, segmentDataB));
}
}
}
/// <summary>
/// Calculates the geometry resulting from the intersection of two segments.
/// </summary>
/// <param name="a">An end point on the first segment.</param>
/// <param name="b">Another end point on the first segment.</param>
/// <param name="c">An end point on the second segment.</param>
/// <param name="d">Another end point on the second segment.</param>
/// <returns>The resulting intersection geometry.</returns>
public static IPlanarGeometry Intersection(Point2 a, Point2 b, Point2 c, Point2 d)
{
Point2.SegmentOrder(ref a, ref b, ref c, ref d);
return(SegmentIntersectionOperation.Intersection(a, b, c, d));
}
