main.cpp

#include <iostream>
#include <conio.h>
#include <time.h>
#include <process.h>
#include <cstdlib>
#include <windows.h>
using namespace std;
// dimensions
#define MAX 100
#define WIDTH 77
#define HEIGHT 22
#define INIT_SNAKE_LENGTH 4
#define FOOD 1
// direction
#define RIGHT 0
#define UP 1
#define LEFT 2
#define DOWN 3
// places off the permit
#define EXIT -1
#define WALL -2
#define SNAKE -1

#define NOTHING 0

static int dx[5] = {1, 0, -1, 0};
static int dy[5] = {0, -1, 0, 1};
// direction array ^^
//(1, 0) -> rigth cord
//(0, -1) -> up cord
//(-1, 0) -> left cord
//(0, 1) -> down cord

int input = RIGHT; // user's input
int item = NOTHING;

void gotoxy(int column, int row)
{
    HANDLE outputSt;
    COORD cord;

    outputSt = GetStdHandle(STD_OUTPUT_HANDLE);
    if (outputSt == INVALID_HANDLE_VALUE)
        return;
    cord.X = column;
    cord.Y = row;
    SetConsoleCursorPosition(outputSt, cord);
}

void clearScreen()
{
    HANDLE outputSt;
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    DWORD count;
    DWORD cellCount;
    COORD homeCoords = {0, 0};

    outputSt = GetStdHandle(STD_OUTPUT_HANDLE);
    if (outputSt == INVALID_HANDLE_VALUE)
        return;

    /* Get the number of cells and cell attributes in the current buffer */
    if (!GetConsoleScreenBufferInfo(outputSt, &csbi))
        return;
    cellCount = csbi.dwSize.X * csbi.dwSize.Y;

    /* Fill the entire buffer with spaces */
    if (!FillConsoleOutputCharacter(
            outputSt,   // handle
            (TCHAR)' ', // spaces to the buffer
            cellCount,  // number of cells
            homeCoords, // first cell
            &count      // number of characters
            ))
        return;

    /* Fill the entire buffer with the current colors and attributes */
    if (!FillConsoleOutputAttribute(
            outputSt,         // handle to console screen buffer
            csbi.wAttributes, // Character attributes to use
            cellCount,        // Number of cells to set attribute
            homeCoords,       // Coordinate of first cell
            &count            // receives the number of characters written
            ))
        return;

    /* Move the cursor home */
    SetConsoleCursorPosition(outputSt, homeCoords);
}

// check if 2 directions are opposite
int oppositeDirection(int input1, int input2)
{
    if (input1 == LEFT && input2 == RIGHT)
        return 1;
    if (input1 == RIGHT && input2 == LEFT)
        return 1;
    if (input1 == UP && input2 == DOWN)
        return 1;
    if (input1 == DOWN && input2 == UP)
        return 1;

    return 0;
}

struct Coordinate
{
    int x, y;
};

class snake
{
private:
    int length;
    Coordinate body[WIDTH * HEIGHT];
    int direction;
    int ground[MAX][MAX];
    int foodCounter;

public:
    void boardMatrix()
    {
        int i, j;
        for (i = 0; i < MAX; i++)
            for (j = 0; j < MAX; j++)
                ground[i][j] = 0;

        for (i = 0; i <= WIDTH + 1; i++)
        {
            // top bottom wall
            ground[0][i] = WALL;
            ground[HEIGHT + 1][i] = WALL;
        }
        for (i = 0; i <= HEIGHT + 1; i++)
        {
            // right left wall
            ground[i][0] = WALL;
            ground[i][WIDTH + 1] = WALL;
        }
    }

    void snakeBody()
    {
        length = INIT_SNAKE_LENGTH; // set head of snake to be at the centre
        body[0].x = WIDTH / 2;
        body[0].y = HEIGHT / 2;
        direction = input;
        foodCounter = 0;

        int i;
        for (i = 1; i < length; i++)
        {
            body[i].x = body[i - 1].x - dx[direction]; // if moving right,
            body[i].y = body[i - 1].y - dy[direction]; // body is on the left
        }
        // let the ground know the snake's position
        for (i = 0; i < length; i++)
            ground[body[i].y][body[i].x] = SNAKE;
    }

    void updateSnake(int delay)
    {
        int i;
        Coordinate prev[WIDTH * HEIGHT];
        for (i = 0; i < length; i++)
        {
            prev[i].x = body[i].x;
            prev[i].y = body[i].y;
        }

        if (input != EXIT && !oppositeDirection(direction, input))
            direction = input;

        body[0].x = prev[0].x + dx[direction]; // head of snake
        body[0].y = prev[0].y + dy[direction]; // follows the direction

        if (ground[body[0].y][body[0].x] < NOTHING)
        {
            item = -1;
            return;
        }

        if (ground[body[0].y][body[0].x] == FOOD)
        {
            length++; // length of snake increases when it eats food
            item = FOOD;
        }
        else
        {
            ground[body[length - 1].y][body[length - 1].x] = NOTHING;
            item = NOTHING;
            gotoxy(body[length - 1].x, body[length - 1].y); // if snake does not get food,
            cout << " ";                                    // erase last part because the snake is moving
        }

        for (i = 1; i < length; i++)
        {
            body[i].x = prev[i - 1].x; // body follows the previous
            body[i].y = prev[i - 1].y; // location that it was from
        }

        gotoxy(body[1].x, body[1].y);
        cout << "+"; // change the previous head to a body
        gotoxy(body[0].x, body[0].y);
        cout << "O"; // add a head to the snake

        // let the ground know the snake's position
        for (i = 0; i < length; i++)
            ground[body[i].y][body[i].x] = SNAKE;

        Sleep(delay);

        return;
    }

    void food()
    {
        int x, y;
        do
        {
            x = rand() % WIDTH + 1;
            y = rand() % HEIGHT + 1;
        } while (ground[y][x] != NOTHING);

        ground[y][x] = FOOD;
        foodCounter++;
        gotoxy(x, y);
        cout << "\u2022"; // prints a middle dot
    }

    void go()
    {
        clearScreen();
        int i, j;
        for (i = 0; i <= HEIGHT + 1; i++)
        {
            for (j = 0; j <= WIDTH + 1; j++)
            {
                switch (ground[i][j])
                {
                case NOTHING:
                    cout << " ";
                    break;
                case WALL:
                    if ((i == 0 && j == 0) || (i == 0 && j == WIDTH + 1) || (i == HEIGHT + 1 && j == 0) || (i == HEIGHT + 1 && j == WIDTH + 1))
                        cout << "+"; // the 4 corners
                    else if (j == 0 || j == WIDTH + 1)
                        cout << "|"; // left/right wall
                    else
                        cout << "-"; // top/bottom wall
                    break;
                case SNAKE:
                    if (i == body[0].y && j == body[0].x)
                        cout << "O";
                    else
                        cout << "+";
                    break;
                default:              // food
                    cout << "\u2022"; // prints a middle dot
                }
            }
            cout << endl;
        }
    }

    int foodCount()
    {
        return foodCounter;
    }
};

void userip(void *id)
{
    do
    {
        int c = _getch();
        switch (c)
        {
        case 'W':
        case 'w':
            input = UP;
            break;
        case 'S':
        case 's':
            input = DOWN;
            break;
        case 'D':
        case 'd':
            input = RIGHT;
            break;
        case 'A':
        case 'a':
            input = LEFT;
            break;
        case 27:
            input = EXIT;
            break;
        }
    } while (input != EXIT && item >= 0);

    _endthread();
    return;
}

int main()
{
    cout<<"Welcome to the Snake Game!"<<endl;
    cout<<"Enter your name"<<endl;
    string name;
    cin>>name;
    int delay = 50;
    srand(time(NULL));
    snake S1;
    S1.boardMatrix();
    S1.snakeBody();
    S1.food();
    S1.go();
    _beginthread(userip, 0, (void *)0);

    do
    {
        S1.updateSnake(delay);
        if (item == FOOD)
            S1.food();
    } while (item >= 0 && input != EXIT);

    gotoxy(WIDTH / 2 - 5, HEIGHT / 2 - 2);
    cout << "GAME OVER!";
    gotoxy(WIDTH / 2 - 8, HEIGHT / 2 + 2);
    cout << name<<", your score is " << S1.foodCount() - 1 << "!" << endl;
    gotoxy(WIDTH / 2, HEIGHT / 2);

    _getch();
    return 0;
}