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Code Issues Releases Activity

Correct implementations of A* algorithm. Seemingly fixes #2496, it's also faster.

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This commit is contained in:
DjWarmonger
2016-12-15 16:29:23 +01:00
parent 63d33a1e7c
commit ee3aec55f2
1 changed files with 34 additions and 38 deletions
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64
lib/rmg/CRmgTemplateZone.cpp
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@ -847,25 +847,24 @@ bool CRmgTemplateZone::connectPath(CMapGenerator* gen, const int3& src, bool onl
//A* algorithm taken from Wiki http://en.wikipedia.org/wiki/A*_search_algorithm //A* algorithm taken from Wiki http://en.wikipedia.org/wiki/A*_search_algorithm
std::set<int3> closed; // The set of nodes already evaluated. std::set<int3> closed; // The set of nodes already evaluated.
std::set<int3> open{ src }; // The set of tentative nodes to be evaluated, initially containing the start node auto open = std::move(createPiorityQueue()); // The set of tentative nodes to be evaluated, initially containing the start node
std::map<int3, int3> cameFrom; // The map of navigated nodes. std::map<int3, int3> cameFrom; // The map of navigated nodes.
std::map<int3, float> distances; std::map<int3, float> distances;
//int3 currentNode = src; //int3 currentNode = src;
cameFrom[src] = int3(-1, -1, -1); //first node points to finish condition cameFrom[src] = int3(-1, -1, -1); //first node points to finish condition
distances[src] = 0; distances[src] = 0.f;
open.push(std::make_pair(src, 0.f));
// Cost from start along best known path. // Cost from start along best known path.
// Estimated total cost from start to goal through y. // Estimated total cost from start to goal through y.
while (open.size()) while (!open.empty())
{ {
int3 currentNode = *boost::min_element(open, [&distances](const int3 &pos1, const int3 &pos2) -> bool auto node = open.top();
{ open.pop();
return distances[pos1] < distances[pos2]; int3 currentNode = node.first;
});
vstd::erase_if_present(open, currentNode);
closed.insert(currentNode); closed.insert(currentNode);
if (gen->isFree(currentNode)) //we reached free paths, stop if (gen->isFree(currentNode)) //we reached free paths, stop
@ -883,25 +882,25 @@ bool CRmgTemplateZone::connectPath(CMapGenerator* gen, const int3& src, bool onl
{ {
auto foo = [gen, this, &open, &closed, &cameFrom, &currentNode, &distances](int3& pos) -> void auto foo = [gen, this, &open, &closed, &cameFrom, &currentNode, &distances](int3& pos) -> void
{ {
if (gen->isBlocked(pos)) //no paths through blocked or occupied tiles if (vstd::contains(closed, pos))
return;
//no paths through blocked or occupied tiles, stay within zone
if (gen->isBlocked(pos) || gen->getZoneID(pos) != id)
return; return;
int distance = distances[currentNode] + 1; int distance = distances[currentNode] + 1;
int bestDistanceSoFar = 1e6; //FIXME: boost::limits int bestDistanceSoFar = std::numeric_limits<int>::max();
auto it = distances.find(pos); auto it = distances.find(pos);
if (it != distances.end()) if (it != distances.end())
bestDistanceSoFar = it->second; bestDistanceSoFar = it->second;
if (distance < bestDistanceSoFar || !vstd::contains(closed, pos)) if (distance < bestDistanceSoFar)
{
//auto obj = gen->map->getTile(pos).topVisitableObj();
if (gen->getZoneID(pos) == id)
{ {
cameFrom[pos] = currentNode; cameFrom[pos] = currentNode;
open.insert(pos); open.push(std::make_pair(pos, distance));
distances[pos] = distance; distances[pos] = distance;
} }
}
}; };
if (onlyStraight) if (onlyStraight)
@ -913,7 +912,6 @@ bool CRmgTemplateZone::connectPath(CMapGenerator* gen, const int3& src, bool onl
} }
for (auto tile : closed) //these tiles are sealed off and can't be connected anymore for (auto tile : closed) //these tiles are sealed off and can't be connected anymore
{ {
//TODO: refactor, unify?
gen->setOccupied (tile, ETileType::BLOCKED); gen->setOccupied (tile, ETileType::BLOCKED);
vstd::erase_if_present(possibleTiles, tile); vstd::erase_if_present(possibleTiles, tile);
} }
@ -926,25 +924,21 @@ bool CRmgTemplateZone::connectWithCenter(CMapGenerator* gen, const int3& src, bo
//A* algorithm taken from Wiki http://en.wikipedia.org/wiki/A*_search_algorithm //A* algorithm taken from Wiki http://en.wikipedia.org/wiki/A*_search_algorithm
std::set<int3> closed; // The set of nodes already evaluated. std::set<int3> closed; // The set of nodes already evaluated.
std::set<int3> open{ src }; // The set of tentative nodes to be evaluated, initially containing the start node auto open = std::move(createPiorityQueue()); // The set of tentative nodes to be evaluated, initially containing the start node
std::map<int3, int3> cameFrom; // The map of navigated nodes. std::map<int3, int3> cameFrom; // The map of navigated nodes.
std::map<int3, float> distances; std::map<int3, float> distances;
//int3 currentNode = src;
cameFrom[src] = int3(-1, -1, -1); //first node points to finish condition cameFrom[src] = int3(-1, -1, -1); //first node points to finish condition
distances[src] = 0; distances[src] = 0;
open.push(std::make_pair(src, 0.f));
// Cost from start along best known path. // Cost from start along best known path.
// Estimated total cost from start to goal through y.
while (open.size()) while (!open.empty())
{ {
int3 currentNode = *boost::min_element(open, [&distances](const int3 &pos1, const int3 &pos2) -> bool auto node = open.top();
{ open.pop();
return distances[pos1] < distances[pos2]; int3 currentNode = node.first;
});
vstd::erase_if_present(open, currentNode);
closed.insert(currentNode); closed.insert(currentNode);
if (currentNode == pos) //we reached center of the zone, stop if (currentNode == pos) //we reached center of the zone, stop
@ -962,6 +956,12 @@ bool CRmgTemplateZone::connectWithCenter(CMapGenerator* gen, const int3& src, bo
{ {
auto foo = [gen, this, &open, &closed, &cameFrom, &currentNode, &distances](int3& pos) -> void auto foo = [gen, this, &open, &closed, &cameFrom, &currentNode, &distances](int3& pos) -> void
{ {
if (vstd::contains(closed, pos))
return;
if (gen->getZoneID(pos) != id)
return;
float movementCost = 0; float movementCost = 0;
if (gen->isFree(pos)) if (gen->isFree(pos))
movementCost = 1; movementCost = 1;
@ -971,21 +971,17 @@ bool CRmgTemplateZone::connectWithCenter(CMapGenerator* gen, const int3& src, bo
return; return;
float distance = distances[currentNode] + movementCost; //we prefer to use already free paths float distance = distances[currentNode] + movementCost; //we prefer to use already free paths
int bestDistanceSoFar = 1e6; //FIXME: boost::limits int bestDistanceSoFar = std::numeric_limits<int>::max(); //FIXME: boost::limits
auto it = distances.find(pos); auto it = distances.find(pos);
if (it != distances.end()) if (it != distances.end())
bestDistanceSoFar = it->second; bestDistanceSoFar = it->second;
if (distance < bestDistanceSoFar || !vstd::contains(closed, pos)) if (distance < bestDistanceSoFar)
{
//auto obj = gen->map->getTile(pos).topVisitableObj();
if (gen->getZoneID(pos) == id)
{ {
cameFrom[pos] = currentNode; cameFrom[pos] = currentNode;
open.insert(pos); open.push(std::make_pair(pos, distance));
distances[pos] = distance; distances[pos] = distance;
} }
}
}; };
if (onlyStraight) if (onlyStraight)