private void CreateInitialSimplex()
{
List <int> list = FindInitialPoints();
int[] array = new int[NumOfDimensions + 1];
for (int i = 0; i < NumOfDimensions + 1; i++)
{
int[] array2 = new int[NumOfDimensions];
int j = 0;
int num = 0;
for (; j <= NumOfDimensions; j++)
{
if (i != j)
{
if (j == list.Count)
{
int num2 = 0;
num2++;
}
int num3 = list[j];
array2[num++] = num3;
}
}
ConvexFaceInternal convexFaceInternal = FacePool[ObjectManager.GetFace()];
convexFaceInternal.Vertices = array2;
Array.Sort(array2);
mathHelper.CalculateFacePlane(convexFaceInternal, Center);
array[i] = convexFaceInternal.Index;
}
for (int k = 0; k < NumOfDimensions; k++)
{
for (int l = k + 1; l < NumOfDimensions + 1; l++)
{
UpdateAdjacency(FacePool[array[k]], FacePool[array[l]]);
}
}
int[] array3 = array;
foreach (int num5 in array3)
{
ConvexFaceInternal convexFaceInternal2 = FacePool[num5];
FindBeyondVertices(convexFaceInternal2);
if (convexFaceInternal2.VerticesBeyond.Count == 0)
{
ConvexFaces.Add(convexFaceInternal2.Index);
}
else
{
UnprocessedFaces.Add(convexFaceInternal2);
}
}
foreach (int item in list)
{
VertexVisited[item] = false;
}
}
/// <summary>
/// Create the first faces from (dimension + 1) vertices.
/// </summary>
/// <returns></returns>
int[] CreateInitialHull(List <int> initialPoints)
{
var faces = new int[Dimension + 1];
for (var i = 0; i < Dimension + 1; i++)
{
var vertices = new int[Dimension];
for (int j = 0, k = 0; j <= Dimension; j++)
{
if (i != j)
{
vertices[k++] = initialPoints[j];
}
}
var newFace = FacePool[ObjectManager.GetFace()];
newFace.Vertices = vertices;
Array.Sort(vertices);
MathHelper.CalculateFacePlane(newFace, Center);
faces[i] = newFace.Index;
}
// update the adjacency (check all pairs of faces)
for (var i = 0; i < Dimension; i++)
{
for (var j = i + 1; j < Dimension + 1; j++)
{
UpdateAdjacency(FacePool[faces[i]], FacePool[faces[j]]);
}
}
return(faces);
}
/// <summary>
/// Init the hull if Vertices.Length == Dimension.
/// </summary>
void InitSingle()
{
var vertices = new int[Dimension];
for (int i = 0; i < Vertices.Length; i++)
{
vertices[i] = i;
}
var newFace = FacePool[ObjectManager.GetFace()];
newFace.Vertices = vertices;
Array.Sort(vertices);
MathHelper.CalculateFacePlane(newFace, Center);
// Make sure the normal point downwards in case this is used for triangulation
if (newFace.Normal[Dimension - 1] >= 0.0)
{
for (int i = 0; i < Dimension; i++)
{
newFace.Normal[i] *= -1.0;
}
newFace.Offset = -newFace.Offset;
newFace.IsNormalFlipped = !newFace.IsNormalFlipped;
}
ConvexFaces.Add(newFace.Index);
}
/// <summary>
/// Find the (dimension+1) initial points and create the simplexes.
/// Creates the initial simplex of n+1 vertices by using points from the bounding box.
/// Special care is taken to ensure that the vertices chosen do not result in a degenerate shape
/// where vertices are collinear (co-planar, etc). This would technically be resolved when additional
/// vertices are checked in the main loop, but: 1) a degenerate simplex would not eliminate any other
/// vertices (thus no savings there), 2) the creation of the face normal is prone to error.
/// </summary>
private void CreateInitialSimplex()
{
var initialPoints = FindInitialPoints();
#region Create the first faces from (dimension + 1) vertices.
var faces = new int[NumOfDimensions + 1];
for (var i = 0; i < NumOfDimensions + 1; i++)
{
var vertices = new int[NumOfDimensions];
for (int j = 0, k = 0; j <= NumOfDimensions; j++)
{
if (i != j)
{
vertices[k++] = initialPoints[j];
}
}
var newFace = FacePool[ObjectManager.GetFace()];
newFace.Vertices = vertices;
Array.Sort(vertices);
mathHelper.CalculateFacePlane(newFace, Center);
faces[i] = newFace.Index;
}
// update the adjacency (check all pairs of faces)
for (var i = 0; i < NumOfDimensions; i++)
{
for (var j = i + 1; j < NumOfDimensions + 1; j++)
{
UpdateAdjacency(FacePool[faces[i]], FacePool[faces[j]]);
}
}
#endregion
#region Init the vertex beyond buffers.
foreach (var faceIndex in faces)
{
var face = FacePool[faceIndex];
FindBeyondVertices(face);
if (face.VerticesBeyond.Count == 0)
{
ConvexFaces.Add(face.Index); // The face is on the hull
}
else
{
UnprocessedFaces.Add(face);
}
}
#endregion
// Set all vertices to false (unvisited).
foreach (var vertex in initialPoints)
{
VertexVisited[vertex] = false;
}
}
/// <summary>
/// Removes the faces "covered" by the current vertex and adds the newly created ones.
/// </summary>
/// <returns><c>true</c> if possible, <c>false</c> otherwise.</returns>
private bool CreateCone()
{
var currentVertexIndex = CurrentVertex;
ConeFaceBuffer.Clear();
for (var fIndex = 0; fIndex < AffectedFaceBuffer.Count; fIndex++)
{
var oldFaceIndex = AffectedFaceBuffer[fIndex];
var oldFace = FacePool[oldFaceIndex];
// Find the faces that need to be updated
var updateCount = 0;
for (var i = 0; i < NumOfDimensions; i++)
{
var af = oldFace.AdjacentFaces[i];
if (!AffectedFaceFlags[af]) // Tag == false when oldFaces does not contain af
{
UpdateBuffer[updateCount] = af;
UpdateIndices[updateCount] = i;
++updateCount;
}
}
for (var i = 0; i < updateCount; i++)
{
var adjacentFace = FacePool[UpdateBuffer[i]];
var oldFaceAdjacentIndex = 0;
var adjFaceAdjacency = adjacentFace.AdjacentFaces;
for (var j = 0; j < adjFaceAdjacency.Length; j++)
{
if (oldFaceIndex == adjFaceAdjacency[j])
{
oldFaceAdjacentIndex = j;
break;
}
}
var forbidden = UpdateIndices[i]; // Index of the face that corresponds to this adjacent face
var newFaceIndex = ObjectManager.GetFace();
var newFace = FacePool[newFaceIndex];
var vertices = newFace.Vertices;
for (var j = 0; j < NumOfDimensions; j++)
{
vertices[j] = oldFace.Vertices[j];
}
var oldVertexIndex = vertices[forbidden];
int orderedPivotIndex;
// correct the ordering
if (currentVertexIndex < oldVertexIndex)
{
orderedPivotIndex = 0;
for (var j = forbidden - 1; j >= 0; j--)
{
if (vertices[j] > currentVertexIndex)
{
vertices[j + 1] = vertices[j];
}
else
{
orderedPivotIndex = j + 1;
break;
}
}
}
else
{
orderedPivotIndex = NumOfDimensions - 1;
for (var j = forbidden + 1; j < NumOfDimensions; j++)
{
if (vertices[j] < currentVertexIndex)
{
vertices[j - 1] = vertices[j];
}
else
{
orderedPivotIndex = j - 1;
break;
}
}
}
vertices[orderedPivotIndex] = CurrentVertex;
if (!mathHelper.CalculateFacePlane(newFace, InsidePoint))
{
return(false);
}
ConeFaceBuffer.Add(MakeDeferredFace(newFace, orderedPivotIndex, adjacentFace, oldFaceAdjacentIndex,
oldFace));
}
}
return(true);
}
/// <summary>
/// Removes the faces "covered" by the current vertex and adds the newly created ones.
/// </summary>
private bool CreateCone()
{
var currentVertexIndex = CurrentVertex.Index;
ConeFaceBuffer.Clear();
for (int fIndex = 0; fIndex < AffectedFaceBuffer.Count; fIndex++)
{
var oldFace = AffectedFaceBuffer[fIndex];
// Find the faces that need to be updated
int updateCount = 0;
for (int i = 0; i < Dimension; i++)
{
var af = oldFace.AdjacentFaces[i];
if (af.Tag == 0) // Tag == 0 when oldFaces does not contain af
{
UpdateBuffer[updateCount] = af;
UpdateIndices[updateCount] = i;
++updateCount;
}
}
for (int i = 0; i < updateCount; i++)
{
var adjacentFace = UpdateBuffer[i];
int oldFaceAdjacentIndex = 0;
var adjFaceAdjacency = adjacentFace.AdjacentFaces;
for (int j = 0; j < Dimension; j++)
{
if (object.ReferenceEquals(oldFace, adjFaceAdjacency[j]))
{
oldFaceAdjacentIndex = j;
break;
}
}
var forbidden = UpdateIndices[i]; // Index of the face that corresponds to this adjacent face
ConvexFaceInternal newFace;
int oldVertexIndex;
VertexWrap[] vertices;
newFace = ObjectManager.GetFace();
vertices = newFace.Vertices;
for (int j = 0; j < Dimension; j++)
{
vertices[j] = oldFace.Vertices[j];
}
oldVertexIndex = vertices[forbidden].Index;
int orderedPivotIndex;
// correct the ordering
if (currentVertexIndex < oldVertexIndex)
{
orderedPivotIndex = 0;
for (int j = forbidden - 1; j >= 0; j--)
{
if (vertices[j].Index > currentVertexIndex)
{
vertices[j + 1] = vertices[j];
}
else
{
orderedPivotIndex = j + 1;
break;
}
}
}
else
{
orderedPivotIndex = Dimension - 1;
for (int j = forbidden + 1; j < Dimension; j++)
{
if (vertices[j].Index < currentVertexIndex)
{
vertices[j - 1] = vertices[j];
}
else
{
orderedPivotIndex = j - 1;
break;
}
}
}
vertices[orderedPivotIndex] = CurrentVertex;
if (!CalculateFacePlane(newFace))
{
return(false);
}
ConeFaceBuffer.Add(MakeDeferredFace(newFace, orderedPivotIndex, adjacentFace, oldFaceAdjacentIndex, oldFace));
}
}
return(true);
}
