private static IEnumerable <Vertex> GetLeftChain(IList <Vertex> sortedVerts, Face face)
{
var heHandle = new int();
var endOfChain = sortedVerts.Last();
var startingAtFirstV = _geometry.GetVertexStartingHalfEdges(sortedVerts[0].Handle).ToList();
if (startingAtFirstV.Count > 1)
{
foreach (var heh in startingAtFirstV)
{
var he = heh;
if (he.IncidentFace == face.Handle)
{
heHandle = heh.Handle;
}
}
}
else
{
heHandle = sortedVerts[0].IncidentHalfEdge;
}
do
{
var halfEdge = _geometry.GetHalfEdgeByHandle(heHandle);
yield return(_geometry.GetVertexByHandle(halfEdge.OriginVertex));
heHandle = halfEdge.NextHalfEdge;
} while (_geometry.GetHalfEdgeByHandle(heHandle).OriginVertex != endOfChain.Handle);
}
private static bool IsEdgeExisting(HalfEdge halfEdge, IEnumerable <BoundaryEdge> boundaryEdges, out int existingHeHandle)
{
existingHeHandle = new int();
var newHeTargetVert = new int();
foreach (var be in boundaryEdges)
{
if (be.HalfEdge.Handle == halfEdge.NextHalfEdge)
{
newHeTargetVert = be.HalfEdge.OriginVertex;
}
}
if (newHeTargetVert == default(int))
{
throw new ArgumentException("Target vertex not found!");
}
var heStartingAtOldV = _geometry.GetVertexStartingHalfEdges(halfEdge.OriginVertex).ToList();
foreach (var heHandle in heStartingAtOldV)
{
var he = heHandle;
var oldHeTargetVert = _geometry.GetHalfEdgeByHandle(he.NextHalfEdge).OriginVertex;
if (oldHeTargetVert != newHeTargetVert)
{
continue;
}
existingHeHandle = heHandle.Handle;
return(true);
}
return(false);
}
private static Geometry ExtrudeFaceByHandle(Geometry geometry, int faceHandle, float offset, float3 extrusionVector)
{
var face = geometry.GetFaceByHandle(faceHandle);
//get HE of Face
var start = geometry.GetHalfEdgeByHandle(face.OuterHalfEdge);
var next = start;
var vertexIncHe = new Dictionary <int, List <HalfEdge> >();
var allFaceVertices = geometry.GetFaceVertices(faceHandle);
foreach (var vertex in allFaceVertices)
{
vertexIncHe.Add(vertex.Handle, geometry.GetVertexStartingHalfEdges(vertex.Handle).ToList());
}
var allH2NEdges = new List <HalfEdge>();
do
{
var nextOriginV = geometry.GetVertexByHandle(next.OriginVertex);
var newVertex = new Vertex(geometry.CreateVertHandleId(), nextOriginV.VertData.Pos);
var twinEdge = geometry.GetHalfEdgeByHandle(next.TwinHalfEdge);
var prevEdge = geometry.GetHalfEdgeByHandle(next.PrevHalfEdge);
var prevTwinEdge = geometry.GetHalfEdgeByHandle(prevEdge.TwinHalfEdge);
nextOriginV.VertData.Pos = nextOriginV.VertData.Pos + extrusionVector * offset;
var h4 = new HalfEdge(geometry.CreateHalfEdgeHandleId());
var h2n = new HalfEdge(geometry.CreateHalfEdgeHandleId());
var h1 = new HalfEdge(geometry.CreateHalfEdgeHandleId());
var currentList = vertexIncHe[nextOriginV.Handle];
foreach (var halfEdge in currentList)
{
if (halfEdge == next)
{
continue;
}
var edge = GeomEditing.UpdateHalfEdgeOrigin(halfEdge, newVertex.Handle);
geometry.ReplaceHalfEdge(edge);
}
nextOriginV.IncidentHalfEdge = next.Handle;
h4.OriginVertex = nextOriginV.Handle;
h2n.OriginVertex = newVertex.Handle;
h1.OriginVertex = newVertex.Handle;
h4.TwinHalfEdge = h2n.Handle;
h2n.TwinHalfEdge = h4.Handle;
h4.NextHalfEdge = h1.Handle;
h1.PrevHalfEdge = h4.Handle;
h1.TwinHalfEdge = next.TwinHalfEdge;
twinEdge.TwinHalfEdge = h1.Handle;
prevTwinEdge.OriginVertex = newVertex.Handle;
newVertex.IncidentHalfEdge = h2n.Handle;
geometry.ReplaceHalfEdge(twinEdge);
geometry.ReplaceHalfEdge(prevTwinEdge);
geometry.ReplaceVertex(nextOriginV);
geometry.DictVertices.Add(newVertex.Handle, newVertex);
geometry.DictHalfEdges.Add(h4.Handle, h4);
geometry.DictHalfEdges.Add(h1.Handle, h1);
geometry.DictHalfEdges.Add(h2n.Handle, h2n);
allH2NEdges.Add(h2n);
next = geometry.GetHalfEdgeByHandle(next.NextHalfEdge);
} while (start != next);
start = geometry.GetHalfEdgeByHandle(face.OuterHalfEdge);
next = start;
do
{
var newFace = new Face(geometry.CreateFaceHandleId());
var twinEdge = geometry.GetHalfEdgeByHandle(next.TwinHalfEdge);
var h1 = geometry.GetHalfEdgeByHandle(twinEdge.TwinHalfEdge);
var h2 = allH2NEdges.First(n => n.OriginVertex == twinEdge.OriginVertex);
var h3 = new HalfEdge(geometry.CreateHalfEdgeHandleId());
var h4 = geometry.GetHalfEdgeByHandle(h1.PrevHalfEdge);
//set Face
h1.IncidentFace = newFace.Handle;
h2.IncidentFace = newFace.Handle;
h3.IncidentFace = newFace.Handle;
h4.IncidentFace = newFace.Handle;
h1.NextHalfEdge = h2.Handle;
h2.NextHalfEdge = h3.Handle;
h3.NextHalfEdge = h4.Handle;
h4.NextHalfEdge = h1.Handle;
h1.PrevHalfEdge = h4.Handle;
h2.PrevHalfEdge = h1.Handle;
h3.PrevHalfEdge = h2.Handle;
h4.PrevHalfEdge = h3.Handle;
h3.TwinHalfEdge = next.Handle;
h3.OriginVertex = geometry.GetHalfEdgeByHandle(next.NextHalfEdge).OriginVertex;
next.TwinHalfEdge = h3.Handle;
newFace.OuterHalfEdge = h1.Handle;
//write all changes
geometry.ReplaceHalfEdge(h1);
geometry.ReplaceHalfEdge(h2);
geometry.ReplaceHalfEdge(h4);
geometry.ReplaceHalfEdge(next);
geometry.DictHalfEdges.Add(h3.Handle, h3);
geometry.DictFaces.Add(newFace.Handle, newFace);
newFace.FaceData.FaceNormal = GeometricOperations.CalculateFaceNormal(geometry.GetFaceVertices(newFace.Handle).ToList());
geometry.ReplaceFace(newFace);
next = geometry.GetHalfEdgeByHandle(next.NextHalfEdge);
} while (start != next);
return(geometry);
}
/// <summary>
/// Inserts a new Vertex between two given exsisting Vertices.
/// </summary>
/// <param name="geometry">The Geometry to insert a Vertex.</param>
/// <param name="p">Handle of Vertex one.</param>
/// <param name="q">Handle of Vertex two.</param>
/// <param name="pos">Position of the new Vertex</param>
/// <returns>New Vertex Handle.</returns>
public static int InsertVertex(this Geometry geometry, int p, int q, float3 pos)
{
var adjacentVertices = geometry.GetVertexAdjacentVertices(p).ToList();
for (var i = 0; i < adjacentVertices.Count; i++)
{
if (adjacentVertices[i].Handle == q)
{
break;
}
if (i == adjacentVertices.Count - 1)
{
throw new ArgumentException("Vertices with Handle q=" + q + " and p=" + p + " are not adjacent!");
}
}
var newVertex = new Vertex(geometry.CreateVertHandleId(), pos);
//add two new Half Edges
var newHalfEdge1 = new HalfEdge(geometry.CreateHalfEdgeHandleId());
var newHalfEdge2 = new HalfEdge(geometry.CreateHalfEdgeHandleId());
//set origin to new Vertex
newHalfEdge1.OriginVertex = newVertex.Handle;
newHalfEdge2.OriginVertex = newVertex.Handle;
newVertex.IncidentHalfEdge = newHalfEdge2.Handle;
var vertexP = geometry.GetVertexByHandle(p);
var vertexQ = geometry.GetVertexByHandle(q);
//Find Half Edge between p and q
var incomingEdges = geometry.GetVertexStartingHalfEdges(vertexP.Handle);
var he1 = new HalfEdge();
var he2 = new HalfEdge();
foreach (var halfEdge in incomingEdges)
{
var twinEdge = geometry.GetHalfEdgeByHandle(halfEdge.TwinHalfEdge);
if (twinEdge.OriginVertex != vertexQ.Handle)
{
continue;
}
he1 = halfEdge;
he2 = twinEdge;
}
var next1 = geometry.GetHalfEdgeByHandle(he2.NextHalfEdge);
var next2 = geometry.GetHalfEdgeByHandle(he1.NextHalfEdge);
//change Handels
he1.TwinHalfEdge = newHalfEdge1.Handle;
newHalfEdge1.TwinHalfEdge = he1.Handle;
newHalfEdge1.NextHalfEdge = he2.NextHalfEdge;
he2.NextHalfEdge = newHalfEdge1.Handle;
newHalfEdge1.PrevHalfEdge = he2.Handle;
next1.PrevHalfEdge = newHalfEdge1.Handle;
he2.TwinHalfEdge = newHalfEdge2.Handle;
newHalfEdge2.TwinHalfEdge = he2.Handle;
newHalfEdge2.NextHalfEdge = he1.NextHalfEdge;
he1.NextHalfEdge = newHalfEdge2.Handle;
newHalfEdge2.PrevHalfEdge = he1.Handle;
next2.PrevHalfEdge = newHalfEdge2.Handle;
//reconnect faces
newHalfEdge1.IncidentFace = he2.IncidentFace;
newHalfEdge2.IncidentFace = he1.IncidentFace;
//replace exsisnting Edges
geometry.ReplaceHalfEdge(he1);
geometry.ReplaceHalfEdge(he2);
geometry.ReplaceHalfEdge(next1);
geometry.ReplaceHalfEdge(next2);
//add to dict
geometry.DictVertices.Add(newVertex.Handle, newVertex);
geometry.DictHalfEdges.Add(newHalfEdge1.Handle, newHalfEdge1);
geometry.DictHalfEdges.Add(newHalfEdge2.Handle, newHalfEdge2);
return(newVertex.Handle);
}
