/// <summary>
/// Compares two <see cref="Coordinate" />s for their relative position along a segment
/// lying in the specified <see cref="Octant" />.
/// </summary>
/// <param name="octant"></param>
/// <param name="p0"></param>
/// <param name="p1"></param>
/// <returns>
/// -1 if node0 occurs first, or
/// 0 if the two nodes are equal, or
/// 1 if node1 occurs first.
/// </returns>
public static int Compare(Octants octant, Coordinate p0, Coordinate p1)
{
// nodes can only be equal if their coordinates are equal
if (p0.Equals2D(p1))
return 0;
int xSign = RelativeSign(p0.X, p1.X);
int ySign = RelativeSign(p0.Y, p1.Y);
switch (octant)
{
case Octants.Zero:
return CompareValue(xSign, ySign);
case Octants.One:
return CompareValue(ySign, xSign);
case Octants.Two:
return CompareValue(ySign, -xSign);
case Octants.Three:
return CompareValue(-xSign, ySign);
case Octants.Four:
return CompareValue(-xSign, -ySign);
case Octants.Five:
return CompareValue(-ySign, -xSign);
case Octants.Six:
return CompareValue(-ySign, xSign);
case Octants.Seven:
return CompareValue(xSign, -ySign);
}
Assert.ShouldNeverReachHere("invalid octant value: " + octant);
return 0;
}
/// <summary>
/// Compares two <see cref="Coordinate" />s for their relative position along a segment
/// lying in the specified <see cref="Octant" />.
/// </summary>
/// <param name="octant"></param>
/// <param name="p0"></param>
/// <param name="p1"></param>
/// <returns>
/// -1 if node0 occurs first, or
/// 0 if the two nodes are equal, or
/// 1 if node1 occurs first.
/// </returns>
public static int Compare(Octants octant, ICoordinate p0, ICoordinate p1)
{
// nodes can only be equal if their coordinates are equal
if (p0.Equals2D(p1))
return 0;
int xSign = RelativeSign(p0.X, p1.X);
int ySign = RelativeSign(p0.Y, p1.Y);
switch (octant)
{
case Octants.Zero:
return CompareValue(xSign, ySign);
case Octants.One:
return CompareValue(ySign, xSign);
case Octants.Two:
return CompareValue(ySign, -xSign);
case Octants.Three:
return CompareValue(-xSign, ySign);
case Octants.Four:
return CompareValue(-xSign, -ySign);
case Octants.Five:
return CompareValue(-ySign, -xSign);
case Octants.Six:
return CompareValue(-ySign, xSign);
case Octants.Seven:
return CompareValue(xSign, -ySign);
}
Assert.ShouldNeverReachHere("invalid octant value: " + octant);
return 0;
}
public void CreateMapToOctant1()
{
Action <int, Vector> testMapping =
(octant, toMap) =>
{
var mapper = Octants.CreateMapToOctant1(octant);
Assert.AreEqual(Vector.Create(2, 1), mapper(toMap));
};
// End is expected to map to 2, 1 in Octant 1
// Octant 1
testMapping(1, Vector.Create(2, 1));
// Octant 2
testMapping(2, Vector.Create(2, -1));
// Octant 3
testMapping(3, Vector.Create(1, -2));
// Octant 4
testMapping(4, Vector.Create(-1, -2));
// Octant 5
testMapping(5, Vector.Create(-2, -1));
// Octant 6
testMapping(6, Vector.Create(-2, 1));
// Octant 7
testMapping(7, Vector.Create(-1, 2));
// Octant 8
testMapping(8, Vector.Create(1, 2));
}
/// <summary>
/// Initializes a new instance of the <see cref="SegmentNode"/> class.
/// </summary>
/// <param name="segString"></param>
/// <param name="coord"></param>
/// <param name="segmentIndex"></param>
/// <param name="segmentOctant"></param>
public SegmentNode(SegmentString segString, ICoordinate coord, int segmentIndex, Octants segmentOctant)
{
this.segString = segString;
this.Coordinate = new Coordinate(coord);
this.SegmentIndex = segmentIndex;
this.segmentOctant = segmentOctant;
isInterior = !coord.Equals2D(segString.GetCoordinate(segmentIndex));
}
private void CheckNodePosition(LineSegment seg, Coordinate p0, Coordinate p1, int expectedPositionValue)
{
Octants octant = Octant.GetOctant(seg.P0, seg.P1);
int posValue = SegmentPointComparator.Compare(octant, p0, p1);
Console.WriteLine(octant + " " + p0 + " " + p1 + " " + posValue);
Assert.IsTrue(posValue == expectedPositionValue);
}
/// <summary>
/// Initializes a new instance of the <see cref="SegmentNode"/> class.
/// </summary>
/// <param name="segString"></param>
/// <param name="coord"></param>
/// <param name="segmentIndex"></param>
/// <param name="segmentOctant"></param>
public SegmentNode(SegmentString segString, ICoordinate coord, int segmentIndex, Octants segmentOctant)
{
this.segString = segString;
this.Coordinate = new Coordinate(coord);
this.SegmentIndex = segmentIndex;
this.segmentOctant = segmentOctant;
isInterior = !coord.Equals2D(segString.GetCoordinate(segmentIndex));
}
/// <summary>
/// Initializes a new instance of the <see cref="SegmentNode"/> class.
/// </summary>
/// <param name="segString"></param>
/// <param name="coord"></param>
/// <param name="segmentIndex"></param>
/// <param name="segmentOctant"></param>
public SegmentNode(INodableSegmentString segString, Coordinate coord, int segmentIndex, Octants segmentOctant)
{
Coord = null;
_segString = segString;
Coord = new Coordinate(coord.X, coord.Y, coord.Z);
SegmentIndex = segmentIndex;
_segmentOctant = segmentOctant;
_isInterior = !coord.Equals2D(segString.Coordinates[segmentIndex]);
}
/// <summary>
/// Initializes a new instance of the <see cref="SegmentNode"/> class.
/// </summary>
/// <param name="segString"></param>
/// <param name="coord"></param>
/// <param name="segmentIndex"></param>
/// <param name="segmentOctant"></param>
public SegmentNode(INodableSegmentString segString, Coordinate coord, int segmentIndex, Octants segmentOctant)
{
Coord = null;
_segString = segString;
Coord = new Coordinate(coord.X, coord.Y, coord.Z);
SegmentIndex = segmentIndex;
_segmentOctant = segmentOctant;
_isInterior = !coord.Equals2D(segString.Coordinates[segmentIndex]);
}
private void checkNodePosition(Octants octant,
double x0, double y0,
double x1, double y1,
int expectedPositionValue
)
{
int posValue = SegmentPointComparator.Compare(octant,
new Coordinate(x0, y0),
new Coordinate(x1, y1)
);
Assert.IsTrue(posValue == expectedPositionValue);
}
private void checkNodePosition(Octants octant,
double x0, double y0,
double x1, double y1,
int expectedPositionValue
)
{
int posValue = SegmentPointComparator.Compare(octant,
new Coordinate(x0, y0),
new Coordinate(x1, y1)
);
Assert.IsTrue(posValue == expectedPositionValue);
}
public void BuildCoordinateMapper()
{
// End is expected to map to 2, 1 in Octant 1
var start = Vector.Create(0, 0);
// Octant 1
Assert.AreEqual(
1,
Octants.DetermineOctant(start, Vector.Create(2, 1)));
// Octant 2
Assert.AreEqual(
2,
Octants.DetermineOctant(start, Vector.Create(2, -1)));
// Octant 3
Assert.AreEqual(
3,
Octants.DetermineOctant(start, Vector.Create(1, -2)));
// Octant 4
Assert.AreEqual(
4,
Octants.DetermineOctant(start, Vector.Create(-1, -2)));
// Octant 5
Assert.AreEqual(
5,
Octants.DetermineOctant(start, Vector.Create(-2, -1)));
// Octant 6
Assert.AreEqual(
6,
Octants.DetermineOctant(start, Vector.Create(-2, 1)));
// Octant 7
Assert.AreEqual(
7,
Octants.DetermineOctant(start, Vector.Create(-1, 2)));
// Octant 8
Assert.AreEqual(
8,
Octants.DetermineOctant(start, Vector.Create(1, 2)));
// Using offset coordinates
Assert.AreEqual(
8,
Octants.DetermineOctant(
start + Directions.SouthWest,
Vector.Create(1, 2) + Directions.SouthWest));
}
