/**
* Build neighbourly relations between vertices and wedges using the triangles of the model
**/
private void BuildNeighbourlyRelations(List <Wedge> wedges, Vertex[] vertices, int[] tris)
{
for (int i = 0; i != tris.Length; i += 3)
{
Vertex v0 = vertices[tris[i]];
Vertex v1 = vertices[tris[i + 1]];
Vertex v2 = vertices[tris[i + 2]];
Triangle triangle = new Triangle(v0, v1, v2);
//Set this triangle as an adjacent triangle for every vertex
v0.AddAdjacentTriangle(triangle);
v1.AddAdjacentTriangle(triangle);
v2.AddAdjacentTriangle(triangle);
Wedge w0 = GetWedgeHoldingVertex(wedges, v0);
Wedge w1 = GetWedgeHoldingVertex(wedges, v1);
Wedge w2 = GetWedgeHoldingVertex(wedges, v2);
w0.AddNeighbor(w1);
w0.AddNeighbor(w2);
w1.AddNeighbor(w0);
w1.AddNeighbor(w2);
w2.AddNeighbor(w0);
w2.AddNeighbor(w1);
}
}
/**
* Build neighbourly relations between vertices and wedges using the triangles of the model
**/
private void BuildNeighbourlyRelations(List <Wedge> wedges, Vertex[] vertices, List <int> tris)
{
for (int i = 0; i != tris.Count; i += 3)
{
Vertex v0 = vertices[tris[i]];
Vertex v1 = vertices[tris[i + 1]];
Vertex v2 = vertices[tris[i + 2]];
Triangle triangle = new Triangle(v0, v1, v2);
//m_triangles.Add(triangle);
//Set this triangle as an adjacent triangle for every vertex
//v0.AddAdjacentTriangle(triangle);
//v1.AddAdjacentTriangle(triangle);
//v2.AddAdjacentTriangle(triangle);
//for each triangle vertex, set the 2 opposite points as neighbors
//v0.AddNeighbor(v1);
//v0.AddNeighbor(v2);
//v1.AddNeighbor(v0);
//v1.AddNeighbor(v2);
//v2.AddNeighbor(v0);
//v2.AddNeighbor(v1);
Wedge w0 = GetWedgeHoldingVertex(wedges, v0);
Wedge w1 = GetWedgeHoldingVertex(wedges, v1);
Wedge w2 = GetWedgeHoldingVertex(wedges, v2);
w0.AddNeighbor(w1);
w0.AddNeighbor(w2);
w1.AddNeighbor(w0);
w1.AddNeighbor(w2);
w2.AddNeighbor(w0);
w2.AddNeighbor(w1);
WedgeTriangle wedgeTriangle = new WedgeTriangle(w0, w1, w2);
wedgeTriangle.m_mappedVertexTriangle = triangle; //map here the vertex triangle to the wedge triangle
if (wedges == m_initialWedges) //populate the m_originalTriangles using the m_initialWedges list only
{
m_originalTriangles.Add(wedgeTriangle);
}
w0.AddAdjacentTriangle(wedgeTriangle);
w1.AddAdjacentTriangle(wedgeTriangle);
w2.AddAdjacentTriangle(wedgeTriangle);
}
}
/**
* Collapse the wedge u onto the wedge v
* **/
private void Collapse(Wedge u, Wedge v)
{
//Collapse the edge uv by moving wedge u onto v
// Actually remove tris on uv, then update tris that
// have u to have v, and then remove u.
if (v == null)
{
// u is a vertex all by itself so just delete it
u.Delete();
m_wedges.Remove(u);
return;
}
// delete triangles on edge uv:
List <WedgeTriangle> uvSharedTriangles = u.GetSharedTrianglesWithWedge(v);
for (int i = 0; i != uvSharedTriangles.Count; i++)
{
uvSharedTriangles[i].Delete();
}
// update remaining triangles to have v instead of u
for (int i = 0; i != u.AdjacentTriangles.Count; i++)
{
u.AdjacentTriangles[i].ReplaceWedge(u, v);
}
//add u neighbors to v and add v as a new neighbor of u neighbors
for (int i = 0; i != u.Neighbors.Count; i++)
{
if (u.Neighbors[i] != v)
{
v.AddNeighbor(u.Neighbors[i]);
u.Neighbors[i].AddNeighbor(v);
}
}
u.Delete();
m_wedges.Remove(u);
// recompute the edge collapse costs for neighboring vertices
for (int i = 0; i < u.Neighbors.Count; i++)
{
ComputeEdgeCostAtWedge(u.Neighbors[i]);
}
}
/**
* Collapse the wedge u onto the wedge v
* **/
private void Collapse(Wedge u, Wedge v)
{
// Collapse the edge uv by moving vertex u onto v
// Actually remove tris on uv, then update tris that
// have u to have v, and then remove u.
if (v == null)
{
// u is a vertex all by itself so just delete it
u.Delete();
m_wedges.Remove(u);
return;
}
//Find vertices that will collapse or be displaced
for (int i = 0; i != u.Vertices.Count; i++)
{
Vertex vertex = u.Vertices[i];
Vertex collapseVertex = vertex.FindVertexToCollapseOn(v); //the vertex it will collapse on if it exists
if (collapseVertex != null)
{
u.m_collapsedVertices.Add(vertex.ID, collapseVertex.ID); //no exception will be thrown as unique IDs are inserted into that dictionary
//CollapsedVertex collapsedVertex = new CollapsedVertex(vertex.ID, collapseVertex.ID);
//u.m_collapsedVertices.Add(collapsedVertex);
}
else
{
DisplacedVertex displacedVertex = new DisplacedVertex();
displacedVertex.m_index = vertex.ID;
displacedVertex.m_targetPosition = v.m_position;
u.m_displacedVertices.Add(displacedVertex);
}
}
//delete triangles on edge[u - v]
List <Triangle> sharedTriangles = u.GetSharedTrianglesWithWedge(v);
for (int i = 0; i != sharedTriangles.Count; i++)
{
//delete the triangle
sharedTriangles[i].Delete();
for (int j = 0; j != sharedTriangles[i].Vertices.Length; j++)
{
Vertex vertex = sharedTriangles[i].Vertices[j];
if (!u.HasVertex(vertex) && !v.HasVertex(vertex)) //the third wedge that is not u or v holds this vertex
{
if (vertex.AdjacentTriangles.Count == 0) //vertex is isolated, remove it
{
//find the wedge and remove the vertex from its internal list
GetWedgeHoldingVertex(m_wedges, vertex).RemoveVertex(vertex);
//add the vertex ID to the list of vertices deleted during the operation of collapsing u onto v
u.m_deletedVertices.Add(vertex.ID);
}
}
}
}
//perform the actual collapse
u.CollapseOnWedge(v);
//add u neighbors to v and add v as a new neighbor of u neighbors
for (int i = 0; i != u.Neighbors.Count; i++)
{
if (u.Neighbors[i] != v)
{
v.AddNeighbor(u.Neighbors[i]);
u.Neighbors[i].AddNeighbor(v);
}
}
//neighbors of wedge u are likely to have lost one triangle through one of their vertex so invalidate them
for (int i = 0; i != u.Neighbors.Count; i++)
{
u.Neighbors[i].InvalidateAdjacentTriangles();
}
//delete the wedge and remove it from global list
u.Delete();
m_wedges.Remove(u);
// recompute the edge collapse costs for neighboring wedges
for (int i = 0; i < u.Neighbors.Count; i++)
{
ComputeEdgeCostAtWedge(u.Neighbors[i]);
}
}
