/* updateNode updates the parent of a node and the gFromStartingNodeCost of a node
* Parameter: (AIDynBiDirOpNode) nodeToUpdate is the node to be updated
* (AIDynBiDirOpNode) newParentNode is the new parent of the node to be updated
* (float) newCost is the new gFromStartingNodeCost of the node to be updated
* Return: none
*/
public void updateNode(AIDynBiDirOpNode nodeToUpdate, AIDynBiDirOpNode newParentNode, float newCost)
{
AIPolygon temp = nodeToUpdate.getPolygon();
deleteNodeOfId(nodeToUpdate.getPolygon().getID());
addNode(temp, newParentNode, newCost);
}
/*
* addFinalsolutionPolygonsPreOrder method is a recusive method that will look at the parent of each node passed in until
* the node passed in is null, then it will add each Node's polygon to the finalSolutionArray in pre order
* from start until end
* Parameter: (AIDynBiDirOpNode)currentNode is the node that needs to be checked and then have its parent passed
* (ref int)counter is the current count of polygons in the FinalSolution array used to access the next index
* Return: none
*/
void addFinalSolutionPolygonsPreOrder(AIDynBiDirOpNode currentNode, ref int counter)
{
if (currentNode != null)
{
finalSolutionArray [counter] = currentNode.getPolygon();
counter++;
addFinalSolutionPolygonsPreOrder(currentNode.getParentNode(), ref counter);
}
}
/* popNode removes and returns the node at the front of the list (node with lowest fToatlCost value)
* Parameter: none
* Return: (AIDynBiDirOpNod)
* node that was removed from the front of this list
*/
public AIDynBiDirOpNode popNode()
{
if (numberOfNodesHeld == 0)
{
return(null);
}
AIDynBiDirOpNode tempNode = heap [0];
indicesArray [tempNode.getPolygon().getID()] = -1;
numberOfNodesHeld--;
heap [0] = heap [numberOfNodesHeld];
indicesArray [heap [0].getPolygon().getID()] = 0;
if (numberOfNodesHeld > 0)
{
shiftDown(0);
}
return(tempNode);
}
/*
* doSearch method will run the A* search till a goal is found, or a node is in another agent closed list, or the
* nodes expanded is equal to the nodesToExpand variable
* Parameter: (int)nodesToExpand is the number of nodes that the search can expand
* (AIDynBiDirOpNode[]) secondSearchClosedList is the closed list from the other agent
* Return: (int)
* 0 if nothing was found
* 1 if the goal for this search agent was found
* 2 if a node on the second agent's closed list was found
*/
public int doSearch(int nodesToExpand, AIDynBiDirOpNode[] secondSearchClosedList)
{
int nodesExpandedCount = 0;
while (openList.isEmpty() == false && nodesExpandedCount < nodesToExpand) //goes until nothing is left on the open list meaning a path could not be found
{
currentNode = openList.popNode(); //take the first(Best) polygon off the openList
nodesVisited++;
if (currentNode == null)
{
return(0);
}
closedList[currentNode.getPolygon().getID()] = currentNode;
if (isBackwards == true)
{
if (currentNode.getPolygon().getHasAgent() == true)
{
finalSolutionStart = currentNode;
return(1);
}
}
else
{
if (currentNode.getPolygon().getHasGoal() == true) //checks to see if the currentNode has the goal inside its polygon
{
finalSolutionStart = currentNode;
return(1);
}
}
if (secondSearchClosedList[currentNode.getPolygon().getID()] != null)
{
finalSolutionStart = currentNode;
return(2);
}
for (int count = 0; count < currentNode.getPolygon().getNeighborsHeld(); count++) //adds all the neighbors that are not on the closed list to the open list
{
if (closedList[currentNode.getPolygon().getNeighborAt(count)] == null)
{
gCost = (currentNode.getPolygon().getCenterVector() - polygonArray[currentNode.getPolygon().getNeighborAt(count)].getCenterVector()).magnitude + currentNode.getGFromStartingNode();
if (openList.isNodeOnList(polygonArray[currentNode.getPolygon().getNeighborAt(count)]) == false)
{
openList.addNode(polygonArray[currentNode.getPolygon().getNeighborAt(count)], currentNode, gCost);
}
else if (openList.getNodeOnList(polygonArray[currentNode.getPolygon().getNeighborAt(count)]).compareToG(gCost) > 0f) //updates the a Nodes information if the new GCost (cost from start to node) is less then what was previously in it
{
openList.updateNode(openList.getNodeOnList(polygonArray[currentNode.getPolygon().getNeighborAt(count)]), currentNode, gCost);
}
}
}
if (openList.getSize() > maxQueueSize)
{
maxQueueSize = openList.getSize();
}
nodesExpandedCount++;
}
return(0);
}
/*
* getFinalPathStart method will return the starting polygon of the final solution
* Parameter: none
* Return: (AIPolygon)
* the starting polygon of the final solution
*/
public AIPolygon getFinalPathStart()
{
return(finalSolutionStart.getPolygon());
}
/*
* deletingNode method will place a node on the closed list essectially deleting it
* Parameter: (AIDynBiDirOpNode)tempNode is the node that needs to be placed on the closed list
* Return: none
*/
public void deletingNode(AIDynBiDirOpNode tempNode)
{
closedList[tempNode.getPolygon().getID()] = tempNode;
}
