public static bool less(IndexedVertex a, IndexedVertex b)
{
if (a.Vertex.x - center.x >= 0 && b.Vertex.x - center.x < 0)
{
return(true);
}
if (a.Vertex.x - center.x < 0 && b.Vertex.x - center.x >= 0)
{
return(false);
}
if (a.Vertex.x - center.x == 0 && b.Vertex.x - center.x == 0)
{
if (a.Vertex.z - center.z >= 0 || b.Vertex.z - center.z >= 0)
{
return(a.Vertex.z > b.Vertex.z);
}
return(b.Vertex.z > a.Vertex.z);
}
// compute the cross product of vectors (center -> a) x (center -> b)
var det = (a.Vertex.x - center.x) * (b.Vertex.z - center.z) - (b.Vertex.x - center.x) * (a.Vertex.z - center.z);
if (det < 0)
{
return(true);
}
if (det > 0)
{
return(false);
}
// points a and b are on the same line from the center
// check which point is closer to the center
var d1 = (a.Vertex.x - center.x) * (a.Vertex.x - center.x) + (a.Vertex.z - center.z) * (a.Vertex.z - center.z);
var d2 = (b.Vertex.x - center.x) * (b.Vertex.x - center.x) + (b.Vertex.z - center.z) * (b.Vertex.z - center.z);
return(d1 > d2);
}
private List <int> TriangulateBorder(List <int> borderIndicies, List <Vector3> Points, Vector3 PlaneNormal)
{
var res = new List <int>();
var centerPoint = new Vector3();
var rotatedPoints = new List <IndexedVertex>(borderIndicies.Count);
for (int i = 0; i < borderIndicies.Count; i++)
{
centerPoint += Points[borderIndicies[i]];
rotatedPoints.Add(new IndexedVertex()
{
Index = borderIndicies[i], Vertex = Points[borderIndicies[i]]
});
}
centerPoint /= borderIndicies.Count;
Triangulator.center = centerPoint;
var rotation = Quaternion.FromToRotation(PlaneNormal, Vector3.up);
for (int i = 0; i < rotatedPoints.Count; i++)
{
var rotated = RotatePointArroundOrigin(rotatedPoints[i].Vertex, centerPoint, rotation);
rotatedPoints[i] = new IndexedVertex()
{
Index = rotatedPoints[i].Index, Vertex = rotated
};
}
rotatedPoints.Sort(new IndexedVertexComparator());
var rotatedTris = Triangulator.Triangulate(rotatedPoints);
for (int i = 0; i < rotatedPoints.Count - 2; i++)
{
res.AddRange(new int[] { rotatedPoints[0].Index, rotatedPoints[i + 1].Index, rotatedPoints[i + 2].Index });
}
return(res);
}
