C++_detect_buildings_path_in_map.cpp

#include <iostream>
#include <vector>
#include <queue>

#include "Image.h"

using namespace std;

enum Direction {
    UP,
    RIGHT,
    DOWN,
    LEFT
};

struct Point {
    int x;
    int y;

    Point(){}
    Point(int _x, int _y) : x(_x), y(_y) {}

    bool operator==(const Point& point){
        return point.x == x && point.y == y;
    }
    bool operator!=(const Point& point){
        return !operator==(point);
    }
};

ostream& operator<<(ostream& os, const Point& point){
    return os << "(" << point.x << ", " << point.y << ")";
}

bool isBuilding(const Image& image, Point position){
    return position.x >= 0 && position.y >= 0
        && position.x < image.getX() && position.y < image.getY()
        && image.get(position.x, position.y) == sf::Color::White;
}

vector<Point> getPath(const Image& image, Point initialPosition, Direction initialDirection){
    vector<Point> path;

    path.push_back(initialPosition);

    Direction currentDirection = initialDirection;
    Point currentPosition = initialPosition;

    do{
        switch(currentDirection){
        case UP:
            if(isBuilding(image, Point{currentPosition.x, currentPosition.y - 1})){
                currentPosition.y -= 1;
                currentDirection = LEFT;
            }else{
                currentDirection = RIGHT;
            }
            break;
        case RIGHT:
            if(isBuilding(image, Point{currentPosition.x + 1, currentPosition.y})){
                currentPosition.x += 1;
                currentDirection = UP;
            }else{
                currentDirection = DOWN;
            }
            break;
        case DOWN:
            if(isBuilding(image, Point{currentPosition.x, currentPosition.y + 1})){
                currentPosition.y += 1;
                currentDirection = RIGHT;
            }else{
                currentDirection = LEFT;
            }
            break;
        case LEFT:
            if(isBuilding(image, Point{currentPosition.x - 1, currentPosition.y})){
                currentPosition.x -= 1;
                currentDirection = DOWN;
            }else{
                currentDirection = UP;
            }
            break;
        }

        if(path.back() != currentPosition){
            path.push_back(currentPosition);
        }
    }while(currentPosition != initialPosition || currentDirection != initialDirection);

    if(path.size() > 1){
        path.pop_back();
    }

    return path;
}

void clearBuilding(Image& image, Point position){
    queue<Point> toProcess;

    toProcess.push(position);

    do{
        Point point = toProcess.front();
        toProcess.pop();

        if(isBuilding(image, point)){
            image.set(point.x, point.y, sf::Color::Red);

            toProcess.push(Point{point.x+1, point.y});
            toProcess.push(Point{point.x-1, point.y});
            toProcess.push(Point{point.x, point.y+1});
            toProcess.push(Point{point.x, point.y-1});
        }
    }while(toProcess.size() > 0);
}

vector<Point> getBuilding(Image& image, Point position, Direction direction){
    vector<Point> path = getPath(image, position, direction);

    clearBuilding(image, position);

    return path;
}

int main(int argc, char** argv){
    if(argc != 2){
        cout << "First argument: file path" << endl;

        return -1;
    }

    Image image;

    cout << "Loading file: " << argv[1] << endl;
    image.loadFromBMP(argv[1]);

    if(!image.isValid()){
        cout << "ERROR: Couldn't load image" << endl;

        return 1;
    }

    cout << "Processing buildings..." << endl;
    for(int i=0; i<image.getX(); i++){
        for(int j=0; j<image.getY(); j++){
            if(image.get(i,j) == sf::Color::White){
                vector<Point> building = getBuilding(image, Point{i, j}, UP);

                cout << "BUILDING FOUND:" << endl;
                for(Point point : building){
                    cout << point << endl;
                }
                cout << endl;
            }
        }
    }
}