public bool CheckForSharedEdge(DTTriangle otherTriangle)
{
foreach (DTEdge e in otherTriangle.GetEdges())
{
foreach (DTEdge myEdge in edgeList)
{
if (myEdge.checkSame(e))
{
return(true);
}
}
}
return(false);
}
//Handles set up of triangulation
public void SetupTriangulation(List <DTNode> roomList)
{
//puts all verticies into the toDo list
foreach (DTNode n in roomList)
{
nodesToAddList.Add(n);
}
//creates three artificial verticies for the omega triangle
DTNode nodeA = new DTNode(0, 250, null);
DTNode nodeB = new DTNode(-250, -200, null);
DTNode nodeC = new DTNode(250, -200, null);
//creates the omega triangle
bigTriangle = new DTTriangle(new DTEdge(nodeA, nodeB), new DTEdge(nodeA, nodeC), new DTEdge(nodeB, nodeC));
//adds the omega triangle to the triangle list
triangleList.Add(bigTriangle);
}
//Adds a verticies to the triangulation
private void AddVertexToTriangulation()
{
//Find a Random verticie from the todo list
int choice = pseudoRandom.Next(0, nodesToAddList.Count);
//set next node to selected verticies
nextNode = nodesToAddList[choice];
//remove selected verticies from todo list
nodesToAddList.Remove(nextNode);
//stores triangles created during the loop to be appended to main list after loop
List <DTTriangle> tempTriList = new List <DTTriangle>();
//All edges are clean at this point. Remove any that may be left over from previous loop
edgesToCheck.Clear();
float count = -1;
foreach (DTTriangle aTri in triangleList)
{
List <DTEdge> triEdges = aTri.GetEdges();
count++;
//Find which triangle the current vertex being add is located within
if (LineIntersection.PointInTraingle(nextNode.getNodePosition(), triEdges[0].getNodeA().getNodePosition(),
triEdges[0].getNodeB().getNodePosition(), triEdges[1].getNodeB().getNodePosition()))
{
//cache the triangle we are in so we can delete it after loop
inTriangle = aTri;
//create three new triangles from each edge of the triangle vertex is in to the new vertex
foreach (DTEdge aEdge in aTri.GetEdges())
{
DTTriangle nTri1 = new DTTriangle(new DTEdge(nextNode, aEdge.getNodeA()),
new DTEdge(nextNode, aEdge.getNodeB()),
new DTEdge(aEdge.getNodeB(), aEdge.getNodeA()));
//cache created triangles so we can add to list after loop
tempTriList.Add(nTri1);
//mark the edges of the old triangle as dirty
edgesToCheck.Add(new DTEdge(aEdge.getNodeA(), aEdge.getNodeB()));
}
break;
}
}
//add the three new triangles to the triangle list
foreach (DTTriangle aTri in tempTriList)
{
triangleList.Add(aTri);
}
//delete the old triangle that the vertex was inside of
if (inTriangle != null)
{
triangleList.Remove(inTriangle);
inTriangle.StopDraw();
inTriangle = null;
}
CheckEdges(edgesToCheck);
}
private void CheckEdges(List <DTEdge> edgesList)
{
//the current dirty edge
if (edgesList.Count == 0)
{
if (nodesToAddList.Count > 0)
{
AddVertexToTriangulation();
}
return;
}
//get the next edge in the dirty list
DTEdge currentEdge = edgesList[0];
DTTriangle[] connectedTris = new DTTriangle[2];
int index = 0;
foreach (DTTriangle aTri in triangleList)
{
if (aTri.ContainsEdge(currentEdge))
{
connectedTris[index] = aTri;
index++;
}
}
//in first case (omega triangle) this will = 1 so dont flip
if (index == 2)
{
//stores the two verticies from both triangles that arnt on the shared edge
DTNode[] uniqueNodes = new DTNode[2];
int index1 = 0;
//loop through the connected triangles and there edges. Checking for a vertex that isnt in the edge
for (int i = 0; i < connectedTris.Length; i++)
{
foreach (DTEdge aEdge in connectedTris[i].GetEdges())
{
if (!currentEdge.containsNode(aEdge.getNodeA()))
{
uniqueNodes[index1] = aEdge.getNodeA();
index1++;
break;
}
if (!currentEdge.containsNode(aEdge.getNodeB()))
{
uniqueNodes[index1] = aEdge.getNodeB();
index1++;
break;
}
}
}
//find the angles of the two unique verticies
float angle0 = CalculateVertexAngle(uniqueNodes[0].getNodePosition(),
currentEdge.getNodeA().getNodePosition(),
currentEdge.getNodeB().getNodePosition());
float angle1 = CalculateVertexAngle(uniqueNodes[1].getNodePosition(),
currentEdge.getNodeA().getNodePosition(),
currentEdge.getNodeB().getNodePosition());
//Check if the target Edge needs flipping
if (angle0 + angle1 > 180)
{
//create the new edge after flipped
DTEdge flippedEdge = new DTEdge(uniqueNodes[0], uniqueNodes[1]);
//store the edges of both triangles in the Quad
DTEdge[] firstTriEdges = new DTEdge[3];
DTEdge[] secondTriEdges = new DTEdge[3];
DTNode sharedNode0;
DTNode sharedNode1;
//set the shared nodes on the shared edge
sharedNode0 = currentEdge.getNodeA();
sharedNode1 = currentEdge.getNodeB();
//construct a new triangle to update old triangle after flip
firstTriEdges[0] = new DTEdge(uniqueNodes[0], sharedNode0);
firstTriEdges[1] = new DTEdge(sharedNode0, uniqueNodes[1]);
firstTriEdges[2] = flippedEdge;
//construct a new triangle to update the other old triangle after flip
secondTriEdges[0] = new DTEdge(uniqueNodes[1], sharedNode1);
secondTriEdges[1] = new DTEdge(sharedNode1, uniqueNodes[0]);
secondTriEdges[2] = flippedEdge;
//update the edges of the triangles involved in the flip
connectedTris[0].SetEdges(firstTriEdges[0], firstTriEdges[1], firstTriEdges[2]);
connectedTris[1].SetEdges(secondTriEdges[0], secondTriEdges[1], secondTriEdges[2]);
//Adds all edges to be potentially dirty. This is bad and should only add the edges that *could* be dirty
foreach (DTEdge eEdge in connectedTris[0].GetEdges())
{
edgesList.Add(eEdge);
}
foreach (DTEdge eEdge in connectedTris[1].GetEdges())
{
edgesList.Add(eEdge);
}
//also add new edge to dirty list
edgesList.Add(flippedEdge);
}
}
//remove the current edge from the dirty list
edgesList.Remove(currentEdge);
CheckEdges(edgesList);
}
