public static bool IsInside(List <int[]> polygonEdgePoints, int[] testPoint)
{
//a imaginary ray line from point to right infinity
var rayLine = new Line()
{
x1 = testPoint[0],
y1 = testPoint[1],
x2 = double.MaxValue,
y2 = testPoint[1]
};
var intersectionCount = 0;
for (int i = 0; i < polygonEdgePoints.Count - 1; i++)
{
var edgeLine = new Line()
{
x1 = polygonEdgePoints[i][0],
y1 = polygonEdgePoints[i][1],
x2 = polygonEdgePoints[i + 1][0],
y2 = polygonEdgePoints[i + 1][1]
};
if (!LineIntersection.FindIntersection(rayLine, edgeLine).Equals(default(Point)))
{
intersectionCount++;
}
}
//should have odd intersections if point is inside the polygon
return(intersectionCount % 2 != 0);
}
public int CompareTo(object that)
{
if (Equals(that))
{
return(0);
}
var thatEvent = that as Event;
var line1 = Segment;
var line2 = thatEvent.Segment;
Point intersectionA;
if (Type == EventType.Intersection)
{
intersectionA = this as Point;
}
else
{
if (LastSweepLine == Algorithm.SweepLine)
{
intersectionA = LastIntersection;
}
else
{
intersectionA = LineIntersection.FindIntersection(line1, Algorithm.SweepLine, tolerance);
LastSweepLine = Algorithm.SweepLine;
LastIntersection = intersectionA;
}
}
Point intersectionB;
if (Type == EventType.Intersection)
{
intersectionB = thatEvent as Point;
}
else
{
if (thatEvent.LastSweepLine == thatEvent.Algorithm.SweepLine)
{
intersectionB = thatEvent.LastIntersection;
}
else
{
intersectionB = LineIntersection.FindIntersection(line2, thatEvent.Algorithm.SweepLine, tolerance);
thatEvent.LastSweepLine = thatEvent.Algorithm.SweepLine;
thatEvent.LastIntersection = intersectionB;
}
}
if (intersectionA != null && intersectionB != null)
{
int resulted = intersectionA.Y.CompareTo(intersectionB.Y);
if (resulted != 0)
{
return(resulted);
}
}
//if Y is same use slope as comparison
double slope1 = line1.Slope;
//if Y is same use slope as comparison
double slope2 = line2.Slope;
var result = slope1.CompareTo(slope2);
if (result != 0)
{
return(result);
}
//if slope is the same use diff of X co-ordinate
result = line1.Left.X.CompareTo(line2.Left.X);
if (result != 0)
{
return(result);
}
//if diff of X co-ordinate is same use diff of Y co-ordinate
result = line1.Left.Y.CompareTo(line2.Left.Y);
//at this point this is guaranteed to be not same.
//since we don't let duplicate lines with input HashSet of lines.
//see line equals override in Line class.
return(result);
}
internal static Point Intersection(this Line lineA, Line lineB, double tolerance)
{
return(LineIntersection.FindIntersection(lineA, lineB, tolerance));
}
internal static bool Intersects(this Line lineA, Line lineB, double tolerance)
{
return(LineIntersection.FindIntersection(lineA, lineB, tolerance) != null);
}
public static Point Intersection(this Line lineA, Line lineB, int precision = 5)
{
return(LineIntersection.Find(lineA, lineB, precision));
}
public static bool Intersects(this Line lineA, Line lineB, int precision = 5)
{
return(LineIntersection.Find(lineA, lineB, precision) != null);
}
public int CompareTo(Event thatEvent)
{
if (Equals(thatEvent))
{
return(0);
}
if (!Segment.HasValue || !thatEvent.Segment.HasValue)
{
throw new InvalidOperationException();
}
var line1 = Segment.Value;
var line2 = thatEvent.Segment.Value;
Point intersectionA;
if (Type == EventType.Intersection)
{
intersectionA = Point;
}
else
{
if (LastSweepLine == Algorithm.SweepLine)
{
intersectionA = LastIntersection;
}
else
{
intersectionA = LineIntersection.FindIntersection(line1, Algorithm.SweepLine, tolerance) ?? default;
LastSweepLine = Algorithm.SweepLine;
LastIntersection = intersectionA;
}
}
Point intersectionB;
if (Type == EventType.Intersection)
{
intersectionB = thatEvent.Point;
}
else
{
if (thatEvent.LastSweepLine == thatEvent.Algorithm.SweepLine)
{
intersectionB = thatEvent.LastIntersection;
}
else
{
intersectionB = LineIntersection.FindIntersection(line2, thatEvent.Algorithm.SweepLine, tolerance) ?? default;
thatEvent.LastSweepLine = thatEvent.Algorithm.SweepLine;
thatEvent.LastIntersection = intersectionB;
}
}
var result = intersectionA.Y.CompareTo(intersectionB.Y);
if (result != 0)
{
return(result);
}
//if Y is same use slope as comparison
double slope1 = line1.Slope;
//if Y is same use slope as comparison
double slope2 = line2.Slope;
result = slope1.CompareTo(slope2);
if (result != 0)
{
return(result);
}
//if slope is the same use diff of X co-ordinate
result = line1.Left.X.CompareTo(line2.Left.X);
if (result != 0)
{
return(result);
}
//if diff of X co-ordinate is same use diff of Y co-ordinate
result = line1.Left.Y.CompareTo(line2.Left.Y);
//at this point this is guaranteed to be not same.
//since we don't let duplicate lines with input HashSet of lines.
//see line equals override in Line class.
return(result);
}
