C++ Snake Game

// Snake.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <conio.h>
#include <windows.h>
#include <queue>
#include <time.h>


using namespace std;

bool gameOver;
const int width = 50;
HANDLE hScr;
const int height = 20;
const int startx = width / 2 + 1;
const int starty = height / 2 + 1;
enum eDirecton { STOP = 0, LEFT, RIGHT, UP, DOWN };

int currentx = startx;
int currenty = starty;

queue<eDirecton> Tail;

int fruitX, fruitY, score;
int tailX, tailY;


const char WALL = '#';
const char FRUIT = 'X';
const char SNAKE = (char)219;
const char HEADLEFT = '<';
const char HEADRIGHT = '>';
const char HEADUP = '^';
const char HEADDOWN = 'v';


eDirecton dir;

// Create a coordinate for positioning the cursor in the console
COORD GetPos(int x, int y)
{
    COORD Pos = { x, y };
    return Pos;
}


// Returns the character at the specified coordiate.  This allows us to check what the snake ran into
int GetCharAt(HANDLE h, COORD Pos)
{
    const int BUFFSIZE = 1;
    char buf[BUFFSIZE + 1] = "";
    DWORD numb_read;
    ReadConsoleOutputCharacter(hScr, (LPTSTR) buf, (DWORD) BUFFSIZE, Pos, (LPDWORD) &numb_read);

    return buf[0];

}

// Resets the game
void NewGame()
{
    // Not moving
    dir = STOP;

    //Reset the tail queue (FIFI collection)
    queue <eDirecton> ResetQ;
    swap(Tail, ResetQ);
    score = 0;

    //Reset the current position
    currentx = startx;
    currenty = starty;

    // Set the tail coordinates to the same location (since it's size is 1)
    tailX = currentx;
    tailY = currenty;

    // clear the screen
    system("cls");

    // set the random seed
    srand(time(NULL));

    //Draw the walls
    for (int i = 0; i <= width + 2; i++)
        cout << WALL;

    for (int i = 1; i < height + 1; ++i)
    {
        SetConsoleCursorPosition(hScr, GetPos(0, i));
        cout << WALL;
        SetConsoleCursorPosition(hScr, GetPos(width + 2, i));
        cout << WALL;
    }

    SetConsoleCursorPosition(hScr, GetPos(0, height + 1));
    for (int i = 0; i <= width + 2; i++)
        cout << WALL;


    // Draw the star position of the snake
    SetConsoleCursorPosition(hScr, GetPos(currentx, currenty));
    cout << SNAKE;

    // Draw the first fruit
    do
    {
        fruitX = rand() % width + 1;
        fruitY = rand() % height + 1;
        SetConsoleCursorPosition(hScr, GetPos(fruitX, fruitY));


    } while (GetCharAt(hScr, GetPos(fruitX, fruitY)) != ' ');
    cout << FRUIT;
    SetConsoleCursorPosition(hScr, GetPos(0, height + 4));
    cout << "Score: " << score << "                    ";



}

bool UpdatePosition(eDirecton dir)
{
    char cHEAD;
    if (dir == STOP)
        return true;
    if (Tail.size() > 0)
    {
        SetConsoleCursorPosition(hScr, GetPos(currentx, currenty));
        cout << SNAKE;

    }

    // Push the current direction to our Tail queue (FIFO collection);
    Tail.push(dir);

    // Based on the direction, change the coordinates
    switch (dir)
    {
    case LEFT:
        --currentx;
        cHEAD = HEADLEFT;
        break;
    case RIGHT:
        ++currentx;
        cHEAD = HEADRIGHT;
        break;
    case UP:
        --currenty;
        cHEAD = HEADUP;
        break;
    case DOWN:
        ++currenty;
        cHEAD = HEADDOWN;
        break;
    }


    // Check the character at the new coordiantes so we can see if we hit the wall, tail, fruit or an empty space
    int c = GetCharAt(hScr, GetPos(currentx, currenty));

    // We hit the fruit!
    if (c == (int)FRUIT)
    {
        score += 10;

        do
        {
            fruitX = rand() % width + 1;
            fruitY = rand() % height + 1;
            SetConsoleCursorPosition(hScr, GetPos(fruitX, fruitY));
        } while(GetCharAt(hScr, GetPos(fruitX, fruitY)) != ' ');
        cout << FRUIT;
        SetConsoleCursorPosition(hScr, GetPos(0, height + 4));
        cout << "Score: " << score << "                    ";
    }
    else if (c != ' ')  // if it is not a space, we hit the wall or the tail.  We lost!!!
    {
        return false;
    }
    else // This must be a empty space.  The tail doesn't grow, so we remove the end of the tail
    {
        // Set the position to the last character in the tail and set it to blank;
        SetConsoleCursorPosition(hScr, GetPos(tailX, tailY));
        cout << ' ';

        // Find the direction we were going for the end of the tail.  This allows us to follow the tail and blank the space at the end of it
        switch (Tail.front())
        {
        case LEFT:
            tailX--;
            break;
        case RIGHT:
            tailX++;
            break;
        case UP:
            tailY--;
            break;
        case DOWN:
            tailY++;
            break;
        }
        Tail.pop();  // Remove the last item for the tail
    }
    // Now add the head character
    SetConsoleCursorPosition(hScr, GetPos(currentx, currenty));
    cout << cHEAD;

    return true;
}



void Input()
{
    if (_kbhit())
    {
        char C = _getch();
        if (C == -32)  // Extended key pressed
        {
            C = _getch();
            switch (C)
            {
            case 'H':   // Up Arrow key pressed
                dir = UP;
                break;
            case 'P':   // Down Arrow key pressed
                dir = DOWN;
                break;
            case 'M':   // Right Arrow key pressed
                dir = RIGHT;
                break;
            case 'K':   // Left Arrow key pressed
                dir = LEFT;
                break;
            }
        }
        else if (C == 'x' || C == 'X')
            gameOver = true;
    }
}



int main()

{

    hScr = GetStdHandle(STD_OUTPUT_HANDLE);

    // remove the flickering cursor
    CONSOLE_CURSOR_INFO info;
    info.dwSize = 100;
    info.bVisible = FALSE;
    SetConsoleCursorInfo(hScr, &info);

    // Start a new game
    NewGame();
    gameOver = false;

    while (!gameOver)
    {
        Input();

        // Update the position
        if (!UpdatePosition(dir))
        {
            // If UpdatePosition returns false, the game is over
            HANDLE h = GetStdHandle(STD_OUTPUT_HANDLE);
            SetConsoleCursorPosition(h, GetPos(0, height + 6));
            cout << "GAME OVER!!!  Play Again? (Y/N)";
            char x = NULL;
            while (x != 'Y' && x != 'N')
                x = toupper(_getch());

            if (x == 'Y')
            {
                NewGame();
                continue;
            }
            return 0;
        }

        Sleep(100);



    }

    CloseHandle(hScr);


    return 0;



}