🐍 C++ Snake

SNAKE.cpp

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

#include <iostream>
#include <vector>
#include <windows.h>
#include <random>

using namespace std;

int random(int from, int to) {
	return rand() % (to - from + 1) + from;
}

struct Vector2 {
    int x;
    int y;

	Vector2 operator+(const Vector2 &other) const
	{
		return { x + other.x, y + other.y };
	}
};

enum class Tile
{
	EMPTY,
	SNAKE,
	SNAKE_HEAD,
	PELLET,
    WALL,
};

class Game
{
public:
	bool isGameOver;

	void start()
	{
		snakeSize = startingSnakeSize;
		movePellet();
	}

	void movePellet()
	{
		pelletPosition = { random(1, width - 2), random(1, height - 2) };
	}
	
	void render()
	{
		system("cls");

		for (int y = 0; y < height; y++)
		{
			for (int x = 0; x < width; x++)
			{
				cout << get_char(get_tile(x, y));
			}

			cout << "\n";
		}

		cout << "Score: " << (snakeSize - startingSnakeSize);
	}

	void moveSnake()
	{
		snakePosition = snakePosition + moveDirection;
		Tile newTile = get_tile(snakePosition.x, snakePosition.y);

		if (newTile == Tile::WALL || newTile == Tile::SNAKE || newTile == Tile::SNAKE_HEAD)
		{
			isGameOver = true;
			return;
		}

		snakePositions.push_back(snakePosition);
		
		if (snakePositions.size() > snakeSize)
		{
			snakePositions.erase(snakePositions.begin());
		}

		if (pelletPosition.x == snakePosition.x && pelletPosition.y == snakePosition.y) {
			snakeSize++;
			movePellet();
		}
	}

	void processUserInput()
	{
		int x = 0;
		int y = 0;

		if (GetAsyncKeyState(VK_UP))
		{
			y--;
		}

		if (GetAsyncKeyState(VK_DOWN))
		{
			y++;
		}

		if (GetAsyncKeyState(VK_LEFT))
		{
			x--;
		}

		if (GetAsyncKeyState(VK_RIGHT))
		{
			x++;
		}

		if (x != 0 || y != 0)
		{
			moveDirection = { x, y };
		}
	}

    void tick()
    {
		processUserInput();
		moveSnake();
		render();
    }

    Tile get_tile(int x, int y)
    {
		if ((y == 0 || y == height - 1) || (x == 0 || x == width - 1))
		{
			return Tile::WALL;
		}
		
		for (Vector2 pos : snakePositions)
		{
			if (pos.x == x && pos.y == y)
			{
				if (x == snakePosition.x && y == snakePosition.y)
				{
					return Tile::SNAKE_HEAD;
				}

				return Tile::SNAKE;
			}
		}

		if (pelletPosition.x == x && pelletPosition.y == y)
		{
			return Tile::PELLET;
		}

		return Tile::EMPTY;
    }

    char get_char(Tile tile)
    {
		switch (tile)
		{
		case Tile::EMPTY:
			return '_';
		case Tile::SNAKE:
			return 'o';
		case Tile::SNAKE_HEAD:
			return '0';
		case Tile::PELLET:
			return '*';
		case Tile::WALL:
			return '#';
		default:
			return '?';
		}
    }
private:
	const int width = 30;
	const int height = 10;
	int snakeSize = 5;
	int startingSnakeSize = 5;
	Vector2 pelletPosition;
    vector<Vector2> snakePositions;
	Vector2 moveDirection = { 1, 0 };
	Vector2 snakePosition = { 2, 2 };
};

int main()
{
	Game game;
	game.start();
		
	while (!game.isGameOver)
	{
		game.tick();
		Sleep(200);
	}

	cout << "Game Over!\n";

	return 0;
}