public void AddFace(Vector3[] positions)
{
int length = positions.Length;
HE_Vertex[] vertices = new HE_Vertex[length];
HE_Edge[] edges = new HE_Edge[length];
HE_Face face = new HE_Face();
for (int i = 0; i < length; ++i)
{
vertices[i] = new HE_Vertex();
edges[i] = new HE_Edge();
}
for (int i = 0; i < length; ++i)
{
vertices[i].pos_ = positions[i];
vertices[i].edge_ = edges[i];
edges[i].vert_ = vertices[i];
edges[i].next_ = edges[(i + 1) % length];
edges[i].prev_ = edges[(i + length - 1) % length];
edges[i].face_ = face;
}
face.edge_ = edges[0];
faces.Add(face);
}
public void GetNeighboringVertices(out List <HE_Vertex> outVertices)
{
outVertices = new List <HE_Vertex>();
HE_Edge edge = edge_;
bool bCircular = true;
do
{
outVertices.Add(edge.next_.vert_);
if (edge.pair_ == null)
{
bCircular = false;
break;
}
edge = edge.pair_.next_;
} while (edge != edge_);
if (bCircular)
{
return;
}
edge = edge_.prev_;
do
{
outVertices.Add(edge.vert_);
if (edge.pair_ == null)
{
break;
}
edge = edge.pair_.prev_;
} while (edge != edge_);
return;
}
public int GetVertexCount()
{
int count = 0;
HE_Edge edge = edge_;
do
{
edge = edge.next_;
++count;
}while (edge != edge_);
return(count);
}
public int FillVertices(int offset, Vector3[] outVertices)
{
int idx = 0;
HE_Edge edge = edge_;
do
{
outVertices[offset + (idx++)] = edge.vert_.pos_;
edge = edge.next_;
} while (edge != edge_);
return(offset + idx);
}
public HE_Edge FindEdge(Vector3 v0, Vector3 v1)
{
HE_Edge edge = edge_;
do
{
if (v0 == edge.vert_.pos_ && v1 == edge.next_.vert_.pos_)
{
return(edge);
}
edge = edge.next_;
} while (edge != edge_);
return(null);
}
void SolvePair(HE_Face face)
{
HE_Edge edge = face.edge_;
do
{
foreach (HE_Face f in faces)
{
if (f == face)
{
continue;
}
HE_Edge pair = f.FindEdge(edge.next_.vert_.pos_, edge.vert_.pos_);
if (pair != null)
{
edge.pair_ = pair;
pair.pair_ = edge;
break;
}
}
edge = edge.next_;
} while (edge != face.edge_);
}
public static HalfEdgeMesh Subdivide(HalfEdgeMesh mesh)
{
HalfEdgeMesh nextLevelMesh = new HalfEdgeMesh();
foreach (HE_Face face in mesh.faces)
{
Vector3[] next_edge_positions = new Vector3[3];
Vector3[] next_vert_positions = new Vector3[3];
{
int count = 0;
HE_Edge edge = face.edge_;
do
{
if (edge.pair_ != null)
{
next_edge_positions[count] =
edge.vert_.pos_ * 0.375f +
edge.next_.vert_.pos_ * 0.375f +
edge.prev_.vert_.pos_ * 0.125f +
edge.pair_.prev_.vert_.pos_ * 0.125f;
}
else
{
next_edge_positions[count] =
edge.vert_.pos_ * 0.5f +
edge.next_.vert_.pos_ * 0.5f;
}
{
List <HE_Vertex> neighbors;
edge.vert_.GetNeighboringVertices(out neighbors);
int n = neighbors.Count;
float beta = n > 3 ? 3.0f / (8.0f * n) : 3.0f / 16.0f;
next_vert_positions[count] = (1 - n * beta) * edge.vert_.pos_;
for (int k = 0; k < n; ++k)
{
next_vert_positions[count] += neighbors[k].pos_ * beta;
}
}
++count;
edge = edge.next_;
} while (!edge.Equals(face.edge_) && count < 3);
}
{
for (int k = 0; k < 3; ++k)
{
int prev_k = (k + 2) % 3;
Vector3[] next_face =
{
next_vert_positions[k],
next_edge_positions[k],
next_edge_positions[prev_k]
};
nextLevelMesh.AddFace(next_face);
}
Vector3[] next_face_second = { next_edge_positions[0], next_edge_positions[1], next_edge_positions[2] };
nextLevelMesh.AddFace(next_face_second);
}
}
nextLevelMesh.SolveAllPairs();
return(nextLevelMesh);
}