/* updateNode updates the parent of a node and the gFromStartingNodeCost of a node
* Parameter: (AIDynamicWeightedSearchNode) nodeToUpdate is the node to be updated
* (AIDynamicWeightedSearchNode) 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(AIDynamicWeightedSearchNode nodeToUpdate, AIDynamicWeightedSearchNode newParentNode, float newCost)
{
AIPolygon temp = nodeToUpdate.getPolygon();
deleteNodeOfId(nodeToUpdate.getPolygon().getID());
addNode(temp, newParentNode, newCost);
}
//used for debugging
void printSolutionRecusively(AIDynamicWeightedSearchNode currentNode)
{
if (currentNode != null)
{
printSolutionRecusively(currentNode.getParentNode());
polygonFinalCount++;
}
}
/*
* swap method will swap two nodes in the heap according to the indices passed in
* Parameter: (int)first is the index of the first node to swap
* (int)second is the index of the second node to swap
* Return: none
*/
void swap(int first, int second)
{
AIDynamicWeightedSearchNode tempNode = heap [first];
heap [first] = heap [second];
indicesArray [heap [first].getPolygon().getID()] = first;
heap [second] = tempNode;
indicesArray [heap [second].getPolygon().getID()] = second;
}
int epsion = 4; // used for the weight
/* AIDynamicWeightedSearchNode method is a constructor for this class.
* Parmeters: (AIPolygon) polygonToAdd is the polygon held by this node
* (AIAgentAStarSearchNode) parentToAdd is the parent of this node
* (float) gCostToAdd is the gFromStartingNode value for this node
* (Vector3) goalPositionToAdd is the goalPosition for this instance
* (flaot)HToAdd is the H value from the starting node
* (int) nodesExpandedToAdd is how many nodes were expanded to get to this nod
*/
public AIDynamicWeightedSearchNode(AIPolygon polygonToAdd, AIDynamicWeightedSearchNode parentToAdd, float gCostToAdd, Vector3 goalPositionToAdd, float HToAdd, int nodesExpandedToAdd)
{
polygonBeingHeld = polygonToAdd;
parentNode = parentToAdd;
gFromStartingNode = gCostToAdd;
nextNode = null;
goalPosition = new Vector3(goalPositionToAdd.x, goalPositionToAdd.y, goalPositionToAdd.z);
N = HToAdd / AINavigationMeshAgent.polygonLengthMin;
nodesExpandedForThis = nodesExpandedToAdd;
calculateCost(gFromStartingNode, goalPosition);
}
/*
* addFinalsolutionPolygons 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 order
* from start until end
* Parameter: (AIAgentAStarSearchNode)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 addFinalSolutionPolygons(AIDynamicWeightedSearchNode currentNode, ref int counter)
{
if (currentNode != null)
{
addFinalSolutionPolygons(currentNode.getParentNode(), ref counter);
finalSolutionArray [counter] = currentNode.getPolygon();
if (counter != 0)
{
finalPathCost += (finalSolutionArray[counter].getCenterVector() - finalSolutionArray[counter - 1].getCenterVector()).magnitude;
}
counter++;
}
}
/*
* AStarSearch method will preform an A* algorithm for searching a space to find a goal. It does this by taking the best
* polygon for the search off the openList, adding its neighbors to the openlist, placing the node on the closed list
* then repeating until it found a polygon that has the goal gameObject inside it
* Parameters: none
* Return: none
*/
void AStarSearch()
{
maxQueueSize = 1;
AIDynamicWeightedSearchNode currentNode;
float gCost = 0f;
bool[] closedList2 = new bool[polygonArray.Length];
for (int count = 0; count < polygonArray.Length; count++)
{
closedList2 [count] = false;
}
while (openList.isEmpty() == false) //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;
}
closedList2[currentNode.getPolygon().getID()] = true;
if (currentNode.getPolygon().getHasGoal() == true) //checks to see if the currentNode has the goal inside its polygon
{
finalSolutionStart = currentNode;
return;
}
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 (closedList2[currentNode.getPolygon().getNeighborAt(count)] == false)
{
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();
}
}
}
/* addNode adds a node to this list in order according to its fTotalCost value
* Parameter: (AIPolygon) polygonToAdd is the polygon that will be held by the node
* (AIAgentAStarSearchNode) parentNodeToAdd is the parent of the node to be added
* (float) gCostToAdd is the getGFromStartingNode value to be stored in the node to be added
* Return: none
*/
public void addNode(AIPolygon polygonToAdd, AIDynamicWeightedSearchNode parentNodeToAdd, float gCostToAdd)
{
AIDynamicWeightedSearchNode newSearchNode;
if (numberOfNodesHeld == 0)
{
newSearchNode = new AIDynamicWeightedSearchNode(polygonToAdd, parentNodeToAdd, gCostToAdd, goalPosition, AIDynamicWeightedSearch.startingH, 1);
}
else
{
newSearchNode = new AIDynamicWeightedSearchNode(polygonToAdd, parentNodeToAdd, gCostToAdd, goalPosition, AIDynamicWeightedSearch.startingH, (parentNodeToAdd.getDoFN() + 1));
}
inList [polygonToAdd.getID()] = true;
indicesArray [polygonToAdd.getID()] = numberOfNodesHeld;
heap [numberOfNodesHeld] = newSearchNode;
shiftUp(numberOfNodesHeld);
numberOfNodesHeld++;
}
/* popNode removes and returns the node at the front of the list (node with lowest fToatlCost value)
* Parameter: none
* Return: (AIDynamicWeightedSearchNode)
* node that was removed from the front of this list
*/
public AIDynamicWeightedSearchNode popNode()
{
if (numberOfNodesHeld == 0)
{
return(null);
}
AIDynamicWeightedSearchNode 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);
}
/* setParentNode sets the parent node for this instance
* Parameter: (AIDynamicWeightedSearchNode) newParentNode is the node to be set as this instance's parent node
* Return: none
*/
public void setParentNode(AIDynamicWeightedSearchNode newParentNode)
{
parentNode = newParentNode;
}
/* setNextNode sets a new nextNode value for the current node
* Parameter: (AIDynamicWeightedSearchNode) newNextNode is the node to be set as this instances nextNode
* Return: none
*/
public void setNextNode(AIDynamicWeightedSearchNode newNextNode)
{
nextNode = newNextNode;
}
