bool AStarPlanner::computePath(std::vector<Util::Point>& agent_path, Util::Point start, Util::Point goal, SteerLib::GridDatabase2D * _gSpatialDatabase, bool append_to_path)
{
gSpatialDatabase = _gSpatialDatabase;
int startIndex = gSpatialDatabase->getCellIndexFromLocation(start);
SearchNodePtr startNode(new SearchNode(startIndex, 0, 0));
int goalIndex = gSpatialDatabase->getCellIndexFromLocation(goal);
std::vector<SearchNodePtr> open;
std::vector<SearchNodePtr> closed;
SearchNodePtr goalNode(nullptr);
open.push_back(startNode);
while (!open.empty()) {
// Get the node with the minimum f, breaking ties on g.
std::vector<SearchNodePtr>::iterator minIter = std::min_element(open.begin(), open.end());
SearchNodePtr minNode = *minIter;
open.erase(minIter);
// If we're visiting the goal, we're finished.
if (minNode->index() == goalIndex) {
goalNode = minNode;
break;
}
// Expand this node.
std::vector<SearchNodePtr> expandedList = _expand(minNode, goal);
for (SearchNodePtr& expandedNode : expandedList) {
// If this cell is already in the open set, check if this is a cheaper path.
std::vector<SearchNodePtr>::iterator iter = std::find(open.begin(), open.end(), expandedNode);
if (iter != open.end()) {
if (expandedNode->g() < (*iter)->g()) {
(*iter)->g(expandedNode->g());
(*iter)->prev(minNode);
}
} else {
if (std::find(closed.begin(), closed.end(), expandedNode) == closed.end()) {
expandedNode->prev(minNode);
open.push_back(expandedNode);
}
}
}
closed.push_back(minNode);
}
// Check if a path to the goal was not found.
if (goalNode == nullptr) {
return false;
}
// Go back from goal node to start.
SearchNodePtr ptr = goalNode;
float totalPathCost = 0;
while (ptr != nullptr) {
Util::Point point;
gSpatialDatabase->getLocationFromIndex(ptr->index(), point);
agent_path.insert(agent_path.begin(), point);
SearchNodePtr prev = ptr->prev();
if (prev == nullptr) break;
Util::Point prevPoint;
gSpatialDatabase->getLocationFromIndex(prev->index(), prevPoint);
totalPathCost += distanceBetween(point, prevPoint);
ptr = prev;
}
std::cout << "\nTotal path cost is " << totalPathCost << std::endl;
std::cout << "\nThe number of expanded nodes is " << numExpanded << std::endl;
return true;
}
PathPlanner::PathPlanner(int startX, int startY, int goalX, int goalY, Map* map) {
_aStarAlgorithm = new AStarSearch<MapSearchNode>(MAX_NODES_COUNT);
MapSearchNode startNode(startX, startY, map);
MapSearchNode goalNode(goalX, goalY, map);
_aStarAlgorithm->SetStartAndGoalStates(startNode, goalNode);
}
