/// <summary>
/// Create a new triangle with 3 new edge
/// </summary>
/// <param name="vert1"></param>
/// <param name="vert2"></param>
/// <param name="vert3"></param>
/// <param name="he1"></param>
/// <param name="he2"></param>
/// <param name="he3"></param>
public static void CreateTriangle( IVertex<float> vert1, IVertex<float> vert2, IVertex<float> vert3,
out Half_Edge he1, out Half_Edge he2, out Half_Edge he3 )
{
// create the new triangle
he1 = new Half_Edge();
he2 = new Half_Edge();
he3 = new Half_Edge();
// CCW test
if ( ( ( vert2.X - vert1.X ) * ( vert3.Y - vert1.Y ) - ( vert3.X - vert1.X ) * ( vert2.Y - vert1.Y ) ) > 0 ) {
he1.NextEdge = he2;
he2.NextEdge = he3;
he3.NextEdge = he1;
} else {
he1.NextEdge = he3;
he3.NextEdge = he2;
he2.NextEdge = he1;
}
// set the vertex
he1.StartVertex = vert1;
he2.StartVertex = vert2;
he3.StartVertex = vert3;
// set null the twin edge
he1.TwinEdge = null;
he2.TwinEdge = null;
he3.TwinEdge = null;
}
/// <summary>
/// Create a new node
/// </summary>
/// <param name="item"></param>
/// <param name="before"></param>
/// <param name="after"></param>
public BoundaryNode( Half_Edge item, Boolean IsTheRoot = false )
{
// set the current item
this.currentEdge = item;
// set if this node is the root
this.IsTheRoot = IsTheRoot;
}
public Face( Half_Edge HalfEnd )
{
// set the internal pointers
this.HalfEnd = HalfEnd;
// link this face to the edge
HalfEnd.Face = this;
HalfEnd.NextEdge.Face = this;
HalfEnd.NextEdge.NextEdge.Face = this;
// update the internal state
this.Update();
}
/// <summary>
/// Create a new triangle with 1 old edge and 2 new edge
/// </summary>
/// <param name="he1">The old edge</param>
/// <param name="vert2"></param>
/// <param name="vert3"></param>
/// <param name="he2"></param>
/// <param name="he3"></param>
public static void CreateTriangle( Half_Edge he1, IVertex<float> vert2, IVertex<float> vert3,
out Half_Edge he2, out Half_Edge he3 )
{
// create the new triangle
he2 = new Half_Edge();
he3 = new Half_Edge();
// link the triangle
he1.NextEdge = he2;
he2.NextEdge = he3;
he3.NextEdge = he1;
// set the vertex
he2.StartVertex = vert2;
he3.StartVertex = vert3;
}
/// <summary>
/// Link the half edges
/// </summary>
/// <param name="half_Edge"></param>
public void LinkEdge(Half_Edge half_Edge)
{
// link the twin edges :P
this.TwinEdge = half_Edge;
half_Edge.TwinEdge = this;
}
/// <summary>
/// Recursive correction of triangles
/// the common edge is the edge of the other triangle
/// </summary>
/// <param name="CommonEdge"></param>
/// <param name="faceTree"></param>
public void DelaunayCorrection( Half_Edge CommonEdge, IFaceTree faceTree )
{
if (CommonEdge != null && this.InCircle(CommonEdge.NextEdge.NextEdge.StartVertex))
{
// remove the faces from the tree before to change them
faceTree.Remove(CommonEdge.Face);
faceTree.Remove(CommonEdge.TwinEdge.Face);
// swap the common edge
CommonEdge.Swap();
// add the face again with the new parameters
faceTree.Add(CommonEdge.Face);
faceTree.Add(CommonEdge.TwinEdge.Face);
// run correction for the next 2 triangles
if(CommonEdge.StartVertex == this.StartVertex){
CommonEdge.DelaunayCorrection(CommonEdge.NextEdge.TwinEdge, faceTree);
CommonEdge.TwinEdge.NextEdge.DelaunayCorrection(CommonEdge.TwinEdge.NextEdge.NextEdge.TwinEdge, faceTree);
}else{
CommonEdge.NextEdge.DelaunayCorrection(CommonEdge.NextEdge.NextEdge.TwinEdge, faceTree);
CommonEdge.TwinEdge.DelaunayCorrection(CommonEdge.TwinEdge.NextEdge.TwinEdge, faceTree);
}
}
}
/// <summary>
/// Update the internal half edge and the min/max
/// </summary>
/// <param name="newHE"></param>
public void Update(Half_Edge newHE)
{
// set the internal half edge
HalfEnd = newHE;
HalfEnd.Face = this;
HalfEnd.NextEdge.Face = this;
HalfEnd.NextEdge.NextEdge.Face = this;
// update the min/max
this.Update();
}
/// <summary>
/// find the min Dist of the vert from all the edges.
/// Return the edge that have the min dist
/// </summary>
/// <param name="vert"></param>
/// <param name="minEdge"></param>
/// <returns></returns>
public double minDistEdge(IVertex<float> vert, out Half_Edge minEdge)
{
double dist1, dist2, dist3;
// get the 3 dist from the edge
dist1 = HalfEnd.Dist(vert);
dist2 = HalfEnd.NextEdge.Dist(vert);
dist3 = HalfEnd.NextEdge.NextEdge.Dist(vert);
// find the minimum
if (dist1 < dist2)
if (dist1 < dist3)
{
minEdge = this.HalfEnd;
return dist1;
}
else
{
minEdge = this.HalfEnd.NextEdge.NextEdge;
return dist3;
}
else if (dist2 < dist3)
{
minEdge = this.HalfEnd.NextEdge;
return dist2;
}
else
{
minEdge = this.HalfEnd.NextEdge.NextEdge;
return dist3;
}
}
