public HalfEdge CreateHalfEdgeRaw()
{
var halfEdge = new HalfEdge(this);
HalfEdges.Add(halfEdge);
return(halfEdge);
}
public HalfEdge CreateEdge(Node aNode, Node bNode, bool isDirected = false)
{
// if (aNode.Edge != null && bNode.Edge != null)
// throw new Exception();
var edgeAB = new HalfEdge(this);
var edgeBA = new HalfEdge(this);
var edge = new Edge(this);
var edgePolygon = CreatePolygon(edgeAB);
edgeAB.SetOrigin(aNode);
edgeBA.SetOrigin(bNode);
edgeAB.SetNext(edgeBA);
edgeAB.SetPrevious(edgeBA);
edgeAB.SetTwin(edgeBA);
edgeAB.SetPolygon(edgePolygon);
edgeBA.SetPolygon(edgePolygon);
if (isDirected)
{
edgeBA.SetActive(false);
}
edge.SetPair(edgeAB);
Edges.Add(edge);
HalfEdges.Add(edgeAB);
HalfEdges.Add(edgeBA);
return(edgeAB);
}
/// <summary>
/// Create a subdivision from a single segment (u, v).
/// </summary>
public DCEL_Subdivision(VecRat2 u, VecRat2 v)
: this()
{
if (u == v)
{
throw new Exception("Tried to create a DCELSubdivision with a segment of length 0.");
}
DCEL_Vertex vertex_u = new DCEL_Vertex(u);
DCEL_Vertex vertex_v = new DCEL_Vertex(v);
DCEL_HalfEdge halfedge_uv = new DCEL_HalfEdge();
DCEL_HalfEdge halfedge_vu = new DCEL_HalfEdge();
DCEL_Face face = new DCEL_Face();
vertex_u.IncidentEdge = halfedge_uv;
vertex_v.IncidentEdge = halfedge_vu;
halfedge_uv.Origin = vertex_u;
halfedge_uv.Twin = halfedge_vu;
halfedge_uv.IncidentFace = face;
halfedge_uv.Prev = halfedge_vu;
halfedge_uv.Next = halfedge_vu;
halfedge_vu.Origin = vertex_v;
halfedge_vu.Twin = halfedge_uv;
halfedge_vu.IncidentFace = face;
halfedge_vu.Prev = halfedge_uv;
halfedge_vu.Next = halfedge_uv;
face.InnerComponents.AddLast(halfedge_uv);
Vertices.Add(new RBTreeSetNode <DCEL_Vertex>(vertex_u));
Vertices.Add(new RBTreeSetNode <DCEL_Vertex>(vertex_u));
HalfEdges.Add(new RBTreeSetNode <DCEL_HalfEdge>(halfedge_uv));
HalfEdges.Add(new RBTreeSetNode <DCEL_HalfEdge>(halfedge_vu));
Faces.Add(new RBTreeSetNode <DCEL_Face>(face));
UnboundedFace = face;
}
// Takes a List containing another List per face with the vertex indexes belonging to that face
private bool CreateFaces(List <List <int> > faceIndexes)
{
Dictionary <string, int> edgeCount = new Dictionary <string, int>();
Dictionary <string, MeshHalfEdge> existingHalfEdges = new Dictionary <string, MeshHalfEdge>();
Dictionary <MeshHalfEdge, bool> hasTwinHalfEdge = new Dictionary <MeshHalfEdge, bool>();
// Create the faces, edges and half-edges, non-boundary loops and link references when possible;
foreach (List <int> indexes in faceIndexes)
{
MeshFace f = new MeshFace();
Faces.Add(f);
List <MeshHalfEdge> tempHEdges = new List <MeshHalfEdge>(indexes.Count);
// Create empty half-edges
for (int i = 0; i < indexes.Count; i++)
{
MeshHalfEdge h = new MeshHalfEdge();
tempHEdges.Add(h);
}
// Fill out each half edge
for (int i = 0; i < indexes.Count; i++)
{
// Edge goes from v0 to v1
int v0 = indexes[i];
int v1 = indexes[(i + 1) % indexes.Count];
MeshHalfEdge h = tempHEdges[i];
// Set previous and next
h.Next = tempHEdges[(i + 1) % indexes.Count];
h.Prev = tempHEdges[(i + indexes.Count - 1) % indexes.Count];
h.OnBoundary = false;
hasTwinHalfEdge.Add(h, false);
// Set half-edge & vertex mutually
h.Vertex = Vertices[v0];
Vertices[v0].HalfEdge = h;
// Set half-edge face & vice versa
h.Face = f;
f.HalfEdge = h;
// Reverse v0 and v1 if v0 > v1
if (v0 > v1)
{
int temp = v0;
v0 = v1;
v1 = temp;
}
string key = v0 + " " + v1;
if (existingHalfEdges.ContainsKey(key))
{
// If this half-edge key already exists, it is the twin of this current half-edge
MeshHalfEdge twin = existingHalfEdges[key];
h.Twin = twin;
twin.Twin = h;
h.Edge = twin.Edge;
hasTwinHalfEdge[h] = true;
hasTwinHalfEdge[twin] = true;
edgeCount[key]++;
}
else
{
// Create an edge and set its half-edge
MeshEdge e = new MeshEdge();
Edges.Add(e);
h.Edge = e;
e.HalfEdge = h;
// Record the newly created half-edge
existingHalfEdges.Add(key, h);
edgeCount.Add(key, 1);
}
}
HalfEdges.AddRange(tempHEdges);
}
// Create boundary edges
for (int i = 0; i < HalfEdges.Count; i++)
{
MeshHalfEdge h = HalfEdges[i];
if (!hasTwinHalfEdge[h])
{
MeshFace f = new MeshFace();
Boundaries.Add(f);
List <MeshHalfEdge> boundaryCycle = new List <MeshHalfEdge>();
MeshHalfEdge hE = h;
do
{
MeshHalfEdge bH = new MeshHalfEdge();
HalfEdges.Add(bH);
boundaryCycle.Add(bH);
MeshHalfEdge nextHE = hE.Next;
while (hasTwinHalfEdge[nextHE])
{
nextHE = nextHE.Twin.Next;
}
bH.Vertex = nextHE.Vertex;
bH.Edge = hE.Edge;
bH.OnBoundary = true;
bH.Face = f;
f.HalfEdge = bH;
bH.Twin = hE;
hE.Twin = bH;
hE = nextHE;
}while (hE != h);
int n = boundaryCycle.Count;
for (int j = 0; j < n; j++)
{
boundaryCycle[j].Next = boundaryCycle[(j + n - 1) % n];
boundaryCycle[j].Prev = boundaryCycle[(j + 1) % n];
hasTwinHalfEdge[boundaryCycle[j]] = true;
hasTwinHalfEdge[boundaryCycle[j].Twin] = true;
}
}
if (!h.OnBoundary)
{
MeshCorner corner = new MeshCorner
{
HalfEdge = h,
};
h.Corner = corner;
Corners.Add(corner);
}
}
// Check mesh for common errors
if (HasIsolatedFaces() || HasIsolatedVertices() || HasNonManifoldEdges())
{
return(false);
}
// Index elements
IndexElements();
return(true);
}
