public PointPolygonRelation GetRelationTo(Point point)
{
int count = this.Count;
int tempValue = 0;
PointVectorRelation[] relation = new PointVectorRelation[count];
for (int i = 0; i < count; i++)
{
int j = (i + 1) % count;
relation[i] = ComputationalGeometry.GetPointVectorRelation(point, Vertexes[i], Vertexes[j]);
tempValue += (int)relation[i];
if ((i > 0 && (int)relation[i] * (int)relation[i - 1] < 1))
{
return(PointPolygonRelation.Out);
}
}
if (tempValue == count || tempValue == (-1 * count))
{
return(PointPolygonRelation.In);
}
else
{
return(PointPolygonRelation.On);
}
}
private List <int> GetAffectedPolygons(VoronoiCell polygon, List <Point> newVertexes, List <int> edgeIndexes)
{
PointVectorRelation relation = ComputationalGeometry.GetPointVectorRelation(polygon.PrimaryPoint, newVertexes[0], newVertexes[1]);
if (relation == PointVectorRelation.LiesOnTheLine)
{
throw new NotImplementedException();
}
List <int> result = new List <int>();
bool condition = false;
for (int i = 0; i < polygon.Vertexes.Count; i++)
{
PointVectorRelation tempRelation = ComputationalGeometry.GetPointVectorRelation(polygon.Vertexes[i], newVertexes[0], newVertexes[1]);
if (tempRelation != relation)
{
if (tempRelation == PointVectorRelation.LiesOnTheLine)
{
if (condition)
{
int temp = i - 1 >= 0 ? i - 1 : polygon.Vertexes.Count - 1;
result.Add(polygon.Neighbours[temp]);
}
}
else
{
condition = true;
int temp = i - 1 >= 0 ? i - 1 : polygon.Vertexes.Count - 1;
result.Add(polygon.Neighbours[temp]);
}
}
}
return(result);
}
public static List <int> GetConvexHullVertexes(PointCollection points)
{
int leftBoundIndex = points.LowerBoundIndex;
IRI.Ket.Geometry.Point initialPoint = points[leftBoundIndex];
int length = points.Count;
IndexValue <double>[] list = new IndexValue <double> [length - 1];
int counter = 0;
for (int i = 0; i < length; i++)
{
if (i == leftBoundIndex)
{
continue;
}
list[counter] = new IndexValue <double>(i,
Math.Atan2(points[i].Y - initialPoint.Y,
points[i].X - initialPoint.X));
counter++;
}
list = SortAlgorithm.Heapsort <IndexValue <double> >(list, SortDirection.Descending);
List <int> result = new List <int>();
result.Add(leftBoundIndex);
counter = 0;
while (counter < list.Length)
{
IRI.Ket.Geometry.Point tempPoint = points[list[counter].Index];
if (result.Count < 2)
{
result.Add(list[counter].Index);
counter++;
continue;
}
PointVectorRelation pointSituation = GetPointVectorRelation(tempPoint,
points[result[result.Count - 2]],
points[result[result.Count - 1]]);
if (pointSituation == PointVectorRelation.LiesLeft)
{
result.Add(list[counter].Index);
counter++;
}
else if (pointSituation == PointVectorRelation.LiesRight)
{
result.RemoveAt(result.Count - 1);
}
else
{
if (list[counter].Value == list[0].Value &&
CalculateDistance(initialPoint, tempPoint) > CalculateDistance(initialPoint, points[result[result.Count - 1]]))
{
result.Add(list[counter].Index);
counter++;
}
else if (list[counter].Value == list[length - 2].Value &&
CalculateDistance(initialPoint, tempPoint) < CalculateDistance(initialPoint, points[result[result.Count - 1]]))
{
result.Add(list[counter].Index);
counter++;
}
else
{
result.RemoveAt(result.Count - 1);
}
}
}
return(result);
}
public static PointCollection CreateConvexHull(PointCollection points)
{
int leftBoundIndex = points.LowerBoundIndex;
IRI.Ket.Geometry.Point initialPoint = points[leftBoundIndex];
int length = points.Count;
IndexValue <double>[] unsortedPoints = new IndexValue <double> [length - 1];
int counter = 0;
for (int i = 0; i < length; i++)
{
if (i == leftBoundIndex)
{
continue;
}
unsortedPoints[counter] = new IndexValue <double>(i,
Math.Atan2(points[i].Y - initialPoint.Y,
points[i].X - initialPoint.X));
counter++;
}
IndexValue <double>[] sortedPoints = SortAlgorithm.Heapsort <IndexValue <double> >(unsortedPoints, SortDirection.Descending);
IRI.Ket.Geometry.PointCollection result = new IRI.Ket.Geometry.PointCollection();
result.Add(points[leftBoundIndex]);
counter = 0;
while (counter < sortedPoints.Length)
{
IRI.Ket.Geometry.Point tempPoint = points[sortedPoints[counter].Index];
if (result.Count < 2)
{
result.Add(tempPoint);
counter++;
continue;
}
PointVectorRelation pointSituation = GetPointVectorRelation(tempPoint, result[result.Count - 2], result[result.Count - 1]);
if (pointSituation == PointVectorRelation.LiesLeft)
{
result.Add(tempPoint);
counter++;
}
else if (pointSituation == PointVectorRelation.LiesRight)
{
result.RemoveAt(result.Count - 1);
}
else
{
if (sortedPoints[counter].Value == sortedPoints[0].Value)
{
if (CalculateDistance(initialPoint, tempPoint) > CalculateDistance(initialPoint, result[result.Count - 1]))
{
result.Add(tempPoint);
}
counter++;
}
else if (sortedPoints[counter].Value == sortedPoints[length - 2].Value)
{
if (CalculateDistance(initialPoint, tempPoint) < CalculateDistance(initialPoint, result[result.Count - 1]))
{
result.Add(tempPoint);
}
counter++;
}
else
{
result.RemoveAt(result.Count - 1);
}
}
}
return(result);
}
