public void LineAlgorithmsIsParallelTest()
{
// parallel lines
Coordinate firstLineStart = new Coordinate(1, 1);
Coordinate firstLineEnd = new Coordinate(4, 1);
Coordinate secondLineStart = new Coordinate(2, 2);
Coordinate secondLineEnd = new Coordinate(4, 2);
Assert.IsTrue(LineAlgorithms.IsParallel(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
Assert.IsFalse(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1.2, 1.2);
firstLineEnd = new Coordinate(1.2, 7.2);
secondLineStart = new Coordinate(2.2, 8.2);
secondLineEnd = new Coordinate(2.2, 15.2);
Assert.IsTrue(LineAlgorithms.IsParallel(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
Assert.IsFalse(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1, 1);
firstLineEnd = new Coordinate(1, 7);
secondLineStart = new Coordinate(1, 1);
secondLineEnd = new Coordinate(1, 7);
Assert.IsTrue(LineAlgorithms.IsParallel(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// non parallel lines
firstLineStart = new Coordinate(1, 1);
firstLineEnd = new Coordinate(1, 7);
secondLineStart = new Coordinate(2, 1);
secondLineEnd = new Coordinate(2.2, 8);
Assert.IsFalse(LineAlgorithms.IsParallel(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1, 1);
firstLineEnd = new Coordinate(1, 7);
secondLineStart = new Coordinate(0, 2);
secondLineEnd = new Coordinate(10, 2);
Assert.IsFalse(LineAlgorithms.IsParallel(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// parallel infinite lines
firstLineStart = new Coordinate(1, 1);
CoordinateVector firstVector = new CoordinateVector(0, 1);
secondLineStart = new Coordinate(2, 2);
CoordinateVector secondVector = new CoordinateVector(0, 1);
Assert.IsTrue(LineAlgorithms.IsParallel(firstLineStart, firstVector, secondLineStart, secondVector));
firstLineStart = new Coordinate(2, 5);
firstVector = new CoordinateVector(0, 1);
secondLineStart = new Coordinate(2, 4);
secondVector = new CoordinateVector(0, 4);
Assert.IsTrue(LineAlgorithms.Coincides(firstLineStart, firstVector, secondLineStart, secondVector));
Assert.IsTrue(LineAlgorithms.IsParallel(firstLineStart, firstVector, secondLineStart, secondVector));
firstLineStart = new Coordinate(2, 4);
firstVector = new CoordinateVector(-3, 1);
secondLineStart = new Coordinate(5, 3);
secondVector = new CoordinateVector(-3, 1);
Assert.IsTrue(LineAlgorithms.IsParallel(firstLineStart, firstVector, secondLineStart, secondVector));
// non parallel infinite lines
firstLineStart = new Coordinate(1, 1);
firstVector = new CoordinateVector(0, 1);
secondLineStart = new Coordinate(1, 1);
secondVector = new CoordinateVector(1, 0);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstVector, secondLineStart, secondVector));
Assert.IsFalse(LineAlgorithms.IsParallel(firstLineStart, firstVector, secondLineStart, secondVector));
firstLineStart = new Coordinate(2, 5);
firstVector = new CoordinateVector(0, 1);
secondLineStart = new Coordinate(2, 4);
secondVector = new CoordinateVector(4, 0);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstVector, secondLineStart, secondVector));
Assert.IsFalse(LineAlgorithms.IsParallel(firstLineStart, firstVector, secondLineStart, secondVector));
}
public void LineAlgorithmsIntersectsTest()
{
// coinciding lines
Coordinate firstLineStart = new Coordinate(1, 1);
Coordinate firstLineEnd = new Coordinate(4, 1);
Coordinate secondLineStart = new Coordinate(1, 1);
Coordinate secondLineEnd = new Coordinate(4, 1);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// parallel lines
firstLineStart = new Coordinate(1.3, 1.3);
firstLineEnd = new Coordinate(1.3, 4.3);
secondLineStart = new Coordinate(2.3, 1.3);
secondLineEnd = new Coordinate(2.3, 4.3);
Assert.IsFalse(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// intersecting lines
firstLineStart = new Coordinate(1, 1);
firstLineEnd = new Coordinate(1, 4);
secondLineStart = new Coordinate(4, 2);
secondLineEnd = new Coordinate(0, 2);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1, 1);
firstLineEnd = new Coordinate(4, 4);
secondLineStart = new Coordinate(1, 4);
secondLineEnd = new Coordinate(4, 1);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(2, 2);
firstLineEnd = new Coordinate(2, 8);
secondLineStart = new Coordinate(2, 5);
secondLineEnd = new Coordinate(2, 10);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(2, 2);
firstLineEnd = new Coordinate(2, 8);
secondLineStart = new Coordinate(2, 1);
secondLineEnd = new Coordinate(2, 8);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(7, 7);
firstLineEnd = new Coordinate(7, 7);
secondLineStart = new Coordinate(7, 7);
secondLineEnd = new Coordinate(7, 7);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// not intersecting lines
firstLineStart = new Coordinate(2, 2);
firstLineEnd = new Coordinate(2, 8);
secondLineStart = new Coordinate(2.1, 1);
secondLineEnd = new Coordinate(10, 8);
Assert.IsFalse(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(2, 2);
firstLineEnd = new Coordinate(2, 8);
secondLineStart = new Coordinate(1, 8.001);
secondLineEnd = new Coordinate(10, 8.001);
Assert.IsFalse(LineAlgorithms.Intersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// internally intersecting lines
firstLineStart = new Coordinate(1, 4);
firstLineEnd = new Coordinate(4, 1);
secondLineStart = new Coordinate(3, 2);
secondLineEnd = new Coordinate(2, 3);
Assert.IsTrue(LineAlgorithms.InternalIntersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1, 4);
firstLineEnd = new Coordinate(4, 1);
secondLineStart = new Coordinate(3, 2);
secondLineEnd = new Coordinate(3, 2);
Assert.IsTrue(LineAlgorithms.InternalIntersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1, 4);
firstLineEnd = new Coordinate(4, 1);
secondLineStart = new Coordinate(1, 2);
secondLineEnd = new Coordinate(200, 3);
Assert.IsTrue(LineAlgorithms.InternalIntersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1, 4);
firstLineEnd = new Coordinate(4, 1);
secondLineStart = new Coordinate(1, 2);
secondLineEnd = new Coordinate(200, 3);
Assert.IsTrue(LineAlgorithms.InternalIntersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// not internally intersecting lines
firstLineStart = new Coordinate(0, 0);
firstLineEnd = new Coordinate(0, 1000.33);
secondLineStart = new Coordinate(1000.33, 200);
secondLineEnd = new Coordinate(0, 0);
Assert.IsFalse(LineAlgorithms.InternalIntersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
firstLineStart = new Coordinate(1, 1);
firstLineEnd = new Coordinate(100, 1);
secondLineStart = new Coordinate(1, 4);
secondLineEnd = new Coordinate(1, 1);
Assert.IsFalse(LineAlgorithms.InternalIntersects(firstLineStart, firstLineEnd, secondLineStart, secondLineEnd));
// intersecting infinite lines
firstLineStart = new Coordinate(2, 5);
CoordinateVector firstVector = new CoordinateVector(0, 1);
secondLineStart = new Coordinate(2, 4);
CoordinateVector secondVector = new CoordinateVector(4, 0);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstVector, secondLineStart, secondVector));
firstLineStart = new Coordinate(2, 4);
firstVector = new CoordinateVector(-3, 1);
secondLineStart = new Coordinate(5, 3);
secondVector = new CoordinateVector(-3, 1);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstVector, secondLineStart, secondVector));
firstLineStart = new Coordinate(1, 1);
firstVector = new CoordinateVector(0, 1);
secondLineStart = new Coordinate(1, 1);
secondVector = new CoordinateVector(1, 0);
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstVector, secondLineStart, secondVector));
firstLineStart = new Coordinate(1, 1);
firstVector = new CoordinateVector(0, 1);
secondLineStart = new Coordinate(2, 2);
secondVector = new CoordinateVector(0, 1);
Assert.IsTrue(LineAlgorithms.IsParallel(firstLineStart, firstVector, secondLineStart, secondVector));
Assert.IsTrue(LineAlgorithms.Intersects(firstLineStart, firstVector, secondLineStart, secondVector));
}
/// <summary>
/// Computes whether one or more line strings specified by coordinates intersects with each other.
/// </summary>
public void Compute()
{
// source: http://geomalgorithms.com/a09-_intersect-3.html
EndPointEvent e = _eventQueue.Next();
SweepLineSegment segment;
while (e != null)
{
switch (e.Type)
{
case EventType.Left:
segment = _sweepLine.Add(e);
if (segment.Above != null && _sweepLine.IsAdjacent(segment.Edge, segment.Above.Edge) && segment.LeftCoordinate == segment.Above.LeftCoordinate)
{
_sweepLine.Intersect(segment, segment.Above);
}
else if (segment.Below != null && _sweepLine.IsAdjacent(segment.Edge, segment.Below.Edge) && segment.LeftCoordinate == segment.Below.LeftCoordinate)
{
_sweepLine.Intersect(segment, segment.Below);
}
if (segment.Above != null && !_sweepLine.IsAdjacent(segment.Edge, segment.Above.Edge) &&
LineAlgorithms.Intersects(segment.LeftCoordinate, segment.RightCoordinate,
segment.Above.LeftCoordinate, segment.Above.RightCoordinate,
PrecisionModel))
{
_hasResult = true;
_result = true;
return;
}
if (segment.Below != null && !_sweepLine.IsAdjacent(segment.Edge, segment.Below.Edge) &&
LineAlgorithms.Intersects(segment.LeftCoordinate, segment.RightCoordinate,
segment.Below.LeftCoordinate, segment.Below.RightCoordinate,
PrecisionModel))
{
_hasResult = true;
_result = true;
return;
}
break;
case EventType.Right:
segment = _sweepLine.Search(e);
if (segment != null)
{
if (segment.Above != null && segment.Below != null && !_sweepLine.IsAdjacent(segment.Below.Edge, segment.Above.Edge) &&
LineAlgorithms.Intersects(segment.Above.LeftCoordinate, segment.Above.RightCoordinate,
segment.Below.LeftCoordinate, segment.Below.RightCoordinate,
PrecisionModel))
{
_hasResult = true;
_result = true;
return;
}
_sweepLine.Remove(segment);
}
break;
}
e = _eventQueue.Next();
}
_hasResult = true;
_result = false;
}
/// <summary>
/// Computes the result of the algorithm.
/// </summary>
public void Compute()
{
Double minDistance = Double.MaxValue;
Coordinate firstPrevious = null, secondPrevious = null;
foreach (Coordinate first in this.First)
{
if (first == null)
{
continue;
}
foreach (Coordinate second in this.Second)
{
if (second == null)
{
continue;
}
// distance between a vertex of first, and a vertex of second
Double distance = Coordinate.Distance(first, second);
if (distance < minDistance)
{
minDistance = distance;
}
// distance between a vertex of first, and a segment of second
if (secondPrevious != null)
{
distance = DistanceFromLine(first, secondPrevious, second);
if (distance < minDistance)
{
minDistance = distance;
}
}
// distance between a vertex of second, and a segment of first
if (firstPrevious != null)
{
distance = DistanceFromLine(second, firstPrevious, first);
if (distance < minDistance)
{
minDistance = distance;
}
}
if (firstPrevious != null && secondPrevious != null && LineAlgorithms.Intersects(firstPrevious, first, secondPrevious, second))
{
this.result = 0;
this.hasResult = true;
return;
}
secondPrevious = second;
}
firstPrevious = first;
}
this.result = this.precisionModel.MakePrecise(minDistance);
this.hasResult = true;
}
/// <summary>
/// Computes whether one or more line strings specified by coordinates intersects with each other.
/// </summary>
public void Compute()
{
EndPointEvent e = this.eventQueue.Next();
SweepLineSegment segment;
while (e != null)
{
switch (e.Type)
{
case EventType.Left:
segment = this.sweepLine.Add(e);
if (segment.Above != null && this.sweepLine.IsAdjacent(segment.Edge, segment.Above.Edge) && segment.LeftCoordinate == segment.Above.LeftCoordinate)
{
this.sweepLine.Intersect(segment, segment.Above);
}
else if (segment.Below != null && this.sweepLine.IsAdjacent(segment.Edge, segment.Below.Edge) && segment.LeftCoordinate == segment.Below.LeftCoordinate)
{
this.sweepLine.Intersect(segment, segment.Below);
}
if (segment.Above != null && !this.sweepLine.IsAdjacent(segment.Edge, segment.Above.Edge) &&
LineAlgorithms.Intersects(segment.LeftCoordinate, segment.RightCoordinate,
segment.Above.LeftCoordinate, segment.Above.RightCoordinate,
this.PrecisionModel))
{
this.hasResult = true;
this.result = true;
return;
}
if (segment.Below != null && !this.sweepLine.IsAdjacent(segment.Edge, segment.Below.Edge) &&
LineAlgorithms.Intersects(segment.LeftCoordinate, segment.RightCoordinate,
segment.Below.LeftCoordinate, segment.Below.RightCoordinate,
this.PrecisionModel))
{
this.hasResult = true;
this.result = true;
return;
}
break;
case EventType.Right:
segment = this.sweepLine.Search(e);
if (segment != null)
{
if (segment.Above != null && segment.Below != null && !this.sweepLine.IsAdjacent(segment.Below.Edge, segment.Above.Edge) &&
LineAlgorithms.Intersects(segment.Above.LeftCoordinate, segment.Above.RightCoordinate,
segment.Below.LeftCoordinate, segment.Below.RightCoordinate,
this.PrecisionModel))
{
this.hasResult = true;
this.result = true;
return;
}
this.sweepLine.Remove(segment);
}
break;
}
e = this.eventQueue.Next();
}
this.hasResult = true;
this.result = false;
}