/* 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; }