Files
MultilevelAStarExt/src/MultilevelAStarEx.cpp
2024-06-06 00:02:18 +02:00

401 lines
8.6 KiB
C++

#include "MultilevelAStarEx.h"
#include <godot_cpp/core/class_db.hpp>
#include <godot_cpp/core/error_macros.hpp>
#include <godot_cpp/variant/utility_functions.hpp>
#include <set>
#define TERRAIN(x, y) (_terrain[(x) + (y) * _width])
#define UNITS(x, y) (_units[(x) + (y) * _width])
#define NODES(x, y) (_nodes[(x) + (y) * _width])
using namespace godot;
static const int STRAIGHT_DISTANCE = 10;
static const int DIAGONAL_DISTANCE = 14;
Node::Node()
{
this->openPass = 0;
this->closedPass = 0;
}
Node::Node(int x, int y) : Node()
{
this->x = x;
this->y = y;
}
void Node::open(int pass, Node *parent, int distanceFromStart, const Vector2i &end)
{
DEV_ASSERT(this->openPass != pass);
this->openPass = pass;
this->parent = parent;
this->distanceFromStart = distanceFromStart;
int dx = abs(x - end.x);
int dy = abs(y - end.y);
int max, min;
if (dx > dy)
{
max = dx;
min = dy;
}
else
{
max = dy;
min = dx;
}
this->distanceToEnd = min * 14 + (max - min) * 10;
if ((dx == 0 || dx == 1) && (dy == 0 || dy == 1))
{
this->distanceToEndForClosest = STRAIGHT_DISTANCE;
}
else
{
this->distanceToEndForClosest = this->distanceToEnd;
}
}
void Node::close(int pass)
{
DEV_ASSERT(openPass == pass && closedPass != pass);
closedPass = pass;
}
Node::NodeState Node::state(int pass) const
{
if (closedPass == pass)
{
return CLOSED;
}
else if (openPass == pass)
{
return OPEN;
}
else
{
return UNUSED;
}
}
int Node::total_cost() const
{
return distanceFromStart + distanceToEnd;
}
bool Node::compare_nodes(const Node *left, const Node *right) {
if (left->total_cost() < right->total_cost())
{
return true;
}
else if (left->total_cost() > right->total_cost())
{
return false;
}
else // if (left->total_cost() == right->total_cost())
{
if (left->distanceToEnd < right->distanceToEnd)
{
return true;
}
else if (left->distanceToEnd > right->distanceToEnd)
{
return false;
}
else // if (left->distanceToEnd == right->distanceToEnd)
{
// make sure no two nodes are the same
return left < right;
}
}
}
void MultilevelAStarEx::_bind_methods()
{
ClassDB::bind_method(D_METHOD("init", "region"), &MultilevelAStarEx::init);
ClassDB::bind_method(D_METHOD("get_region"), &MultilevelAStarEx::get_region);
ClassDB::bind_method(D_METHOD("set_terrain", "cell", "type"), &MultilevelAStarEx::set_terrain);
ClassDB::bind_method(D_METHOD("get_terrain", "cell"), &MultilevelAStarEx::get_terrain);
ClassDB::bind_method(D_METHOD("set_unit", "cell", "blocked"), &MultilevelAStarEx::set_unit);
ClassDB::bind_method(D_METHOD("get_unit", "cell"), &MultilevelAStarEx::get_unit);
ClassDB::bind_method(D_METHOD("find_path", "from", "to", "return_closest"), &MultilevelAStarEx::find_path);
BIND_ENUM_CONSTANT(STAIRS);
BIND_ENUM_CONSTANT(BLOCKED);
BIND_ENUM_CONSTANT(GROUND);
}
MultilevelAStarEx::MultilevelAStarEx()
{
//UtilityFunctions::print("Constructor.");
_init = false;
_pass = 0;
}
MultilevelAStarEx::~MultilevelAStarEx() { }
void MultilevelAStarEx::init(const Rect2i &region)
{
DEV_ASSERT(!_init);
DEV_ASSERT(region.get_area() >= 0);
_region = region;
_width = region.get_size().width;
_height = region.get_size().height;
_trans = region.get_position();
_terrain.resize(_width * _height, BLOCKED);
_units.resize(_width * _height, false);
_nodes.resize(_width * _height);
std::vector<Node>::iterator iter = _nodes.begin();
for (int y = 0; y < _height; y++)
{
for (int x = 0; x < _width; x++)
{
*iter++ = Node(x, y);
}
}
_init = true;
}
Rect2i MultilevelAStarEx::get_region() const
{
DEV_ASSERT(_init);
return _region;
}
void MultilevelAStarEx::set_terrain(const Vector2i &cell, TerrainType type)
{
DEV_ASSERT(_init);
DEV_ASSERT(_region.has_point(cell));
Vector2i cell2 = cell - _trans;
TERRAIN(cell2.x, cell2.y) = type;
}
MultilevelAStarEx::TerrainType MultilevelAStarEx::get_terrain(const Vector2i &cell) const
{
DEV_ASSERT(_init);
DEV_ASSERT(_region.has_point(cell));
Vector2i cell2 = cell - _trans;
return TERRAIN(cell2.x, cell2.y);
}
void MultilevelAStarEx::set_unit(const Vector2i &cell, bool blocked)
{
DEV_ASSERT(_init);
DEV_ASSERT(_region.has_point(cell));
Vector2i cell2 = cell - _trans;
UNITS(cell2.x, cell2.y) = blocked;
}
bool MultilevelAStarEx::get_unit(const Vector2i &cell) const
{
DEV_ASSERT(_init);
DEV_ASSERT(_region.has_point(cell));
Vector2i cell2 = cell - _trans;
return UNITS(cell2.x, cell2.y);
}
bool MultilevelAStarEx::can_move(const Node *current, int x, int y) const
{
if (UNITS(x, y)) return false;
TerrainType tc = TERRAIN(current->x, current->y);
TerrainType td = TERRAIN(x, y);
if (td == BLOCKED)
{
return false;
}
else if (td == tc)
{
return true;
}
else if (td < 0 && tc > 0) // td is stairs
{
if (-td == tc || -td == tc - 1) return true;
}
else if (td > 0 && tc < 0) // tc is stairs
{
if (-tc == td || -tc == td - 1) return true;
}
else if (td < 0 && tc < 0) // both are stairs
{
return abs(td - tc) < 2;
}
return false;
}
TypedArray<Vector2i> MultilevelAStarEx::generate_path(const Node *current) const
{
// count the number of nodes in the path
int cnt = 0;
for (const Node *n = current; n != nullptr; n = n->parent) cnt++;
TypedArray<Vector2i> arr;
arr.resize(cnt);
int i = cnt;
while (current != nullptr)
{
arr[--cnt] = Vector2i(current->x, current->y) + _trans;
current = current->parent;
}
return arr;
}
TypedArray<Vector2i> MultilevelAStarEx::find_path(const Vector2i &from, const Vector2i &to, bool return_closest)
{
DEV_ASSERT(_init);
DEV_ASSERT(_region.has_point(from));
DEV_ASSERT(_region.has_point(to));
_pass++;
Vector2i from2 = from - _trans;
Vector2i to2 = to - _trans;
std::set<Node *, decltype(Node::compare_nodes)*> open(&Node::compare_nodes);
Node *closest = &NODES(from2.x, from2.y);
closest->open(_pass, nullptr, 0, to2);
open.insert(closest);
auto process = [this, &open, &to2, &closest](Node *current, int x, int y, int distance) {
Node *node = &NODES(x, y);
if (node->state(_pass) == Node::CLOSED)
{
return;
}
else if (node->state(_pass) == Node::UNUSED)
{
node->open(_pass, current, current->distanceFromStart + distance, to2);
open.insert(node);
}
else if (current->distanceFromStart + distance < node->distanceFromStart)
{
auto nodeIter = open.find(node);
DEV_ASSERT(nodeIter != open.end());
open.erase(nodeIter);
node->parent = current;
node->distanceFromStart = current->distanceFromStart + distance;
open.insert(node);
}
// find the closest cell
if (node->distanceToEndForClosest < closest->distanceToEndForClosest)
{
closest = node;
}
else if (node->distanceToEndForClosest == closest->distanceToEndForClosest)
{
if (node->distanceFromStart < closest->distanceFromStart)
{
closest = node;
}
}
};
while (!open.empty())
{
Node *current = *open.begin();
if (current->distanceToEnd == 0)
{
// found the path
return generate_path(current);
}
// close it
open.erase(open.begin());
current->close(_pass);
// expand it
if (current->x - 1 >= 0) // left
{
if (can_move(current, current->x - 1, current->y))
{
process(current, current->x - 1, current->y, STRAIGHT_DISTANCE);
}
}
if (current->x + 1 < _width) // right
{
if (can_move(current, current->x + 1, current->y))
{
process(current, current->x + 1, current->y, STRAIGHT_DISTANCE);
}
}
if (current->y - 1 >= 0) // up
{
if (can_move(current, current->x, current->y - 1))
{
process(current, current->x, current->y - 1, STRAIGHT_DISTANCE);
}
}
if (current->y + 1 < _height) // down
{
if (can_move(current, current->x, current->y + 1))
{
process(current, current->x, current->y + 1, STRAIGHT_DISTANCE);
}
}
if ((current->x - 1 >= 0) && (current->y - 1 >= 0)) // top left
{
if (can_move(current, current->x - 1, current->y - 1))
{
process(current, current->x - 1, current->y - 1, DIAGONAL_DISTANCE);
}
}
if ((current->x + 1 < _width) && (current->y - 1 >= 0)) // top right
{
if (can_move(current, current->x + 1, current->y - 1))
{
process(current, current->x + 1, current->y - 1, DIAGONAL_DISTANCE);
}
}
if ((current->x - 1 >= 0) && (current->y + 1 < _height)) // bottom left
{
if (can_move(current, current->x - 1, current->y + 1))
{
process(current, current->x - 1, current->y + 1, DIAGONAL_DISTANCE);
}
}
if ((current->x + 1 < _width) && (current->y + 1 < _height)) // bottom right
{
if (can_move(current, current->x + 1, current->y + 1))
{
process(current, current->x + 1, current->y + 1, DIAGONAL_DISTANCE);
}
}
}
if (return_closest)
{
// return path to closest
return generate_path(closest);
}
return TypedArray<Vector2i>();
}