snake-sfml/squared.cpp

#include <SFML/Graphics.hpp>
#include <iostream>
#include <vector>

#define SCALE 20

using namespace std;
using namespace sf;

enum direction {
    STOP = 0,
    UP,
    RIGHT,
    DOWN,
    LEFT
} dir;


void generateFood(vector<vector<int>>*, int, int);
void printBoard(RenderWindow*, vector<vector<int>>*, int, int, int);

int main (int argc, char* argv[]) {    
    srand(time(0));

    const int height = 600 / SCALE;
    const int width = 800 / SCALE;
    vector<vector<int>> board = {}; // x = 1st dim; y = 2nd;
    int headX = width / 2, 
        headY = height / 2, 
        length = 1;

    for (int i = 0; i < width; i ++) {
        board.push_back({});
        for (int j = 0; j < height; j ++) {
            board[i].push_back(0);
        }
    }

    RenderWindow win(VideoMode(width * SCALE, height * SCALE), "Snake");
    dir = STOP;
    win.setFramerateLimit(10);
    win.display();
    generateFood(&board, width, height);
    while (win.isOpen()) {
        board[headX][headY] = length;

        printBoard(&win, &board, width, height, length);
        
        Event e;
        while (win.pollEvent(e)) {
            switch (e.type) {
                case Event::Closed:
                    win.close();
                break;
                case Event::KeyPressed:
                    switch (e.key.code) {
                        case Keyboard::W:
                            if(board[headX][headY - 1] <= 0)
                                dir = UP;
                        break;
                        case Keyboard::D:
                            if(board[headX + 1][headY] <= 0)
                                dir = RIGHT;
                        break;
                        case Keyboard::S:
                            if(board[headX][headY + 1] <= 0)
                                dir = DOWN;
                        break;
                        case Keyboard::A:
                            if(board[headX - 1][headY] <= 0)
                                dir = LEFT;
                        break;
                    }
                break;
            }
        }

        for (int i = 0; i < width; i ++) {
            for (int j = 0; j < height; j ++) {
                if (board[i][j] > 0) board[i][j] --;
            }
        }

        switch (dir) {
            case UP:
                headY -= 1;
            break;
            case RIGHT:
                headX += 1;
            break;
            case DOWN:
                headY += 1;
            break;
            case LEFT:
                headX -= 1;
            break;
        }

        if (headX >= width  // collide with board or itself
            || headX <= -1
            || headY <= -1
            || headY >= height
            || (board[headX][headY] > 0 && board[headX][headY] < length)) {
            printf("Game over! Score: %i\n", length);

            return 0;
        }

        if (board[headX][headY] == -1) { // collide with eat
            length ++;
            generateFood(&board, width, height);
        } 
    }
    return 0;
}

void generateFood(vector<vector<int>>* board, int width, int height) {
    int appleX = rand() % width,
        appleY = rand() % height;
    while((*board)[appleX][appleY] != 0){
        appleX = rand() % width;
        appleY = rand() % height;
    }
    (*board)[appleX][appleY] = -1;
}

void printBoard(RenderWindow* win, vector<vector<int>>* board, int width, int height, int length) {
    for (int i = 0; i < (*board).size(); i ++) {
        for (int j = 0; j < (*board)[0].size(); j ++) {
            if ((*board)[i][j] < -1 || (*board)[i][j] == 0 ) continue;
            RectangleShape* rectangle = new RectangleShape();
            rectangle->setPosition(Vector2f(i * SCALE, j * SCALE));
            rectangle->setSize(Vector2f(SCALE - 1, SCALE - 1));
            rectangle->setFillColor(Color::Red);
            if ((*board)[i][j] > 0 && (*board)[i][j] < length) {
                if((*board)[i][j] % 2 == 0) {
                    rectangle->setFillColor(Color::Green);
                } else {
                    rectangle->setFillColor(Color::Cyan);
                }
            }
            if ((*board)[i][j] == length) {
                rectangle->setFillColor(Color::Yellow);
            }
            if ((*board)[i][j] == -1) {
                rectangle->setFillColor(Color::Red);
            }
            win->draw(*rectangle);
            delete rectangle;
        }
    }
    win->display();
    win->clear(Color::Black);
}