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#include "astar.hpp"
#include <cmath>
#include <iostream>
AStar::AStar(int *graph_in, const unsigned int& width, const unsigned int height) : graph(graph_in), graph_width(width), graph_height(height), graph_size(width * height), path_length(PATHLENGTH) {
closed_set = new Node[graph_size];
Node tmp;
for(unsigned int i = 0; i < graph_size; ++i)
closed_set[i] = tmp;
find_start_end();
open_set.clear();
}
AStar::AStar(const AStar& other) : open_set(other.open_set), closed_set(other.closed_set), graph(other.graph), graph_width(other.graph_width), graph_height(other.graph_height), graph_size(other.graph_size), path_length(PATHLENGTH), start_node(other.start_node), end_node(other.end_node) {
}
AStar::~AStar() {
delete[] closed_set;
}
AStar& AStar::operator=(const AStar& other) {
open_set = other.open_set;
closed_set = other.closed_set;
graph = other.graph;
graph_width = other.graph_width;
graph_height = other.graph_height;
graph_size = other.graph_size;
path_length = PATHLENGTH;
start_node = other.start_node;
end_node = other.end_node;
return *this;
}
bool AStar::start_algorithm(int *curr_graph, const unsigned int& width, const unsigned int& height) {
graph_width = width;
graph_height = height;
graph_size = width * height;
graph = curr_graph;
if(find_start_end())
return start_algorithm();
return false;
}
bool AStar::start_algorithm() {
open_set.clear();
if(!find_start_end()) {
throw "Couldn't find start or end";
return false;
}
reset_closed_set();
open_set.push(start_node);
while(open_set.first() != end_node) {
Node current = open_set.pop();
closed_set[current.index] = current;
for(unsigned int i = 0; i < NEIGHBOUR_NUM; ++i) {
Node n = get_neighbour(current, i);
if(n.index != -1 && graph[n.index] != 1) {
graph[n.index] = 9;
int cost = current.g_score + path_length;
if(open_set.check_item(n))
if(cost < open_set[open_set.get_index(n)].g_score)
open_set.remove_item(n);
if(closed_set[n.index] == n) {
if(cost < closed_set[n.index].g_score) {
Node tmp;
closed_set[n.index] = tmp;
}
}
if(!open_set.check_item(n) && (closed_set[n.index] != n)) {
n.g_score = cost;
calc_heuristic(n);
n.f_score = n.g_score + n.h_score;
n.prev_index = current.index;
open_set.push(n);
}
}
}
}
recreate_path(open_set.first());
return true;
}
void AStar::recreate_path(Node n) {
while(n != start_node) {
graph[n.index] = 8;
n = closed_set[n.prev_index];
}
}
bool AStar::find_start_end() {
for(unsigned int i = 0; i < graph_size; ++i)
if(graph[i] == 3) {
start_node.index = i;
start_node.g_score = 0;
calc_heuristic(start_node);
start_node.f_score = start_node.g_score + start_node.h_score;
start_node.prev_index = -1;
} else if(graph[i] == 2) {
end_node.index = i;
}
Node n;
return !(start_node == n || end_node == n);
}
Node AStar::get_neighbour(Node& n_in, const int& neighbour_num) {
Node n;
if(neighbour_num == 0 && n_in.index / graph_width > 0) {
n.index = n_in.index - graph_width;
path_length = PATHLENGTH;
} else if(neighbour_num == 1 && n_in.index % graph_width < graph_width - 1) {
n.index = n_in.index + 1;
path_length = PATHLENGTH;
} else if(neighbour_num == 2 && n_in.index / graph_width < graph_height - 1) {
n.index = n_in.index + graph_width;
path_length = PATHLENGTH;
} else if(neighbour_num == 3 && n_in.index % graph_width > 0) {
n.index = n_in.index - 1;
path_length = PATHLENGTH;
} else if(neighbour_num == 4 && n_in.index / graph_width > 0 && n_in.index % graph_width < graph_height - 1) {
n.index = n_in.index - graph_width + 1;
path_length = DIAGLENGTH;
} else if(neighbour_num == 5 && n_in.index / graph_width < graph_height - 1 && n_in.index % graph_width < graph_width - 1) {
n.index = n_in.index + graph_width + 1;
path_length = DIAGLENGTH;
} else if(neighbour_num == 6 && n_in.index / graph_width < graph_height - 1 && n_in.index % graph_width > 0) {
n.index = n_in.index - graph_width - 1;
path_length = DIAGLENGTH;
} else if(neighbour_num == 7 && n_in.index / graph_width > 0 && n_in.index % graph_width > 0) {
n.index = n_in.index + graph_width - 1;
path_length = DIAGLENGTH;
}
return n;
}
void AStar::reset_closed_set() {
delete[] closed_set;
closed_set = new Node[graph_size];
Node tmp;
for(unsigned int i = 0; i < graph_size; ++i)
closed_set[i] = tmp;
}
void AStar::calc_heuristic(Node& n) {
n.h_score = PATHLENGTH * sqrt(((end_node.index % graph_width - n.index % graph_width) * (end_node.index % graph_width - n.index % graph_width) + (end_node.index / graph_width - n.index / graph_width) * (end_node.index / graph_width - n.index / graph_width)));
}
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