Snake game - great for beginners

closed account (zwA4jE8b)
This is the first game I have made and I learned many things.
I am posting this to give other beginners ideas and inspiration.
Enjoy.

p.s. If you find any bugs please let me know!

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//Michael Ervin - Snake game - Windows
//Inspiration and some structural design from http://www.simonhuggins.com/courses/cbasics/course_notes/snake.htm

#include <conio.h>
#include <vector>
#include <Windows.h>
#include <iostream>
#include <ctime>
#include <fstream>

#define FOREGROUND_YELLOW 6
#define FOREGROUND_WHITE 7
#define FOREGROUND_AQUA 3

struct _coordinates
{
	int _x;
	int _y;
};

HANDLE _handle;

int _level, _score, _highscore, _numfood, _numobstacle, _speed;
const int _rows = 30, _columns = 80;
char _grid[_rows + 2][_columns], _leveltype;
const char _right = 'd', _left = 'a', _up = 'w', _down = 's';
SMALL_RECT _size = {0, 0, 79, 32};
COORD _pos = {0,0};

//Fixed level arrays
COORD _l1[30] = {25,14,26,14,27,14,28,14,29,14,30,14,31,14,32,14,33,14,34,14,35,14,36,14,37,14,38,14,39,14,40,14,
				 41,14,42,14,43,14,44,14,45,14,46,14,47,14,48,14,49,14,50,14,51,14,52,14,53,14,54,14};
COORD _l2[52] = {26,7,26,8,26,9,26,10,26,11,26,12,26,13,26,14,26,15,26,16,26,17,26,18,26,19,
				 27,19,28,19,29,19,30,19,31,19,32,19,33,19,34,19,35,19,36,19,37,19,38,19,39,19,40,19,
				 41,19,42,19,43,19,44,19,45,19,46,19,47,19,48,19,49,19,50,19,51,19,52,19,53,19,
				 53,18,53,17,53,16,53,15,53,14,53,13,53,12,53,11,53,10,53,9,53,8,53,7};
COORD _l3[30] = {20,6,20,7,20,8,20,9,20,10,20,11,20,12,20,13,20,14,20,15,
				 40,17,40,18,40,19,40,20,40,21,40,22,40,23,40,24,40,25,40,26,
				 60,6,60,7,60,8,60,9,60,10,60,11,60,12,60,13,60,14,60,15};
COORD _l4[117] = {17,7,18,7,19,7,20,7,21,7,22,7,23,7,24,7,25,7,26,7,27,7,28,7,29,7,30,7,31,7,32,7,33,7,34,7,35,7,36,7,37,7,38,7,39,7,40,7,41,7,
				 41,8,41,9,41,10,41,11,41,12,41,13,41,14,41,15,
				 42,15,43,15,44,15,45,15,46,15,47,15,48,15,49,15,50,15,51,15,52,15,53,15,54,15,55,15,56,15,57,15,58,15,59,15,60,15,61,15,62,15,63,15,64,15,65,15,66,15,
				 17,11,18,11,19,11,20,11,21,11,22,11,23,11,24,11,25,11,26,11,27,11,28,11,29,11,30,11,31,11,32,11,33,11,34,11,35,11,36,11,37,11,
				 37,12,37,12,37,13,37,14,37,15,37,16,37,17,37,18,37,19,
				 38,19,39,19,40,19,41,19,42,19,43,19,44,19,45,19,46,19,47,19,48,19,49,19,50,19,51,19,52,19,53,19,54,19,55,19,56,19,57,19,58,19,59,19,60,19,61,19,62,19,63,19,64,19,65,19,66,19};
COORD _l5[76] = {2,7,3,7,4,7,5,7,6,7,7,7,8,7,9,7,10,7,11,7,12,7,13,7,14,7,15,7,16,7,17,7,18,7,19,7,20,7,21,7,22,7,23,7,24,7,25,7,26,7,27,7,28,7,29,7,30,7,31,7,32,7,33,7,34,7,35,7,36,7,37,7,38,7,39,7,
				 40,7,41,7,42,7,43,7,44,7,45,7,46,7,47,7,48,7,49,7,50,7,51,7,52,7,53,7,54,7,55,7,56,7,57,7,58,7,59,7,60,7,61,7,62,7,63,7,64,7,65,7,66,7,67,7,68,7,69,7,70,7,71,7,72,7,73,7,74,7,75,7,76,7,77,7};

//Snake object
struct snake
{
	int _length, _foodeaten;
	bool _deadsnake;
	char _direction;
	std::vector<_coordinates> snake_pos;

	snake(int _level):_length(4*_level), _direction(_right), _foodeaten(0), _deadsnake(false){init_snake();}
	void init_snake() 
	{
		for(int i = 0; i < _length; i++)
		{
			_coordinates _new;
			snake_pos.push_back(_new);
		}
	};

	void reinit_snake(int _ystart)
	{
		for(int i = 0; i < _length; i++)
		{
			snake_pos[i]._x = 40 + (_length / 2) - i;
			snake_pos[i]._y = _ystart;
		}
	};
	void next_pos()
	{
		int i;
		_old._x = snake_pos[_length - 1]._x;
		_old._y = snake_pos[_length - 1]._y;
		
		switch (_direction)
		{
		case _right:
			for(i = _length - 1; i >= 1; i--)
				snake_pos[i] = snake_pos[i - 1];
			snake_pos[0]._x += 1;
			break;
		case _left:
			for(i = _length - 1; i > 0; i--)
				snake_pos[i] = snake_pos[i - 1];
			snake_pos[0]._x -= 1;
			break;
		case _up:
			for(i = _length - 1; i > 0; i--)
				snake_pos[i] = snake_pos[i - 1];
			snake_pos[0]._y -= 1;
			break;
		case _down:
			for(i = _length - 1; i > 0; i--)
				snake_pos[i] = snake_pos[i - 1];
			snake_pos[0]._y += 1;
			break;
		}
	}

	void draw_snake()
	{
		SetConsoleTextAttribute(_handle, FOREGROUND_BLUE | FOREGROUND_INTENSITY);
		for(int i = 0; i < _length; i++)
		{
			_pos.X = snake_pos[i]._x; _pos.Y = snake_pos[i]._y;
			SetConsoleCursorPosition(_handle, _pos);
			_putch('O');
		}
	}

	void animate_snake()
	{
		if (!_deadsnake)
			SetConsoleTextAttribute(_handle, FOREGROUND_BLUE | FOREGROUND_INTENSITY);
		else
			SetConsoleTextAttribute(_handle, FOREGROUND_RED);

		for(int i = 0; i < _length; i++)
		{
			_pos.X = snake_pos[i]._x; _pos.Y = snake_pos[i]._y;
			SetConsoleCursorPosition(_handle, _pos);
			_putch('O');
		}
		_pos.X = _old._x; _pos.Y = _old._y;
		SetConsoleCursorPosition(_handle, _pos);
		_putch(' ');
	}
	void add_seg()
	{
		_coordinates _new = snake_pos.back();
		snake_pos.push_back(_new);
		_length++;
	}
private:
	_coordinates _old;
};

void init_lvl(snake&, char&);
void init_lvl_rand(_coordinates&, int);
void init_lvl_fixed(_coordinates&, int&);
void intro();
void update_info();
void collision(snake&, char&);
bool self_collision(snake&);
void dead_snake(snake&);
void end_game(char&);
void read_score();
void write_score();
void clear_grid();

int main()
{
	_handle = GetStdHandle(STD_OUTPUT_HANDLE);
	_CONSOLE_CURSOR_INFO _cinfo = {100, false};
	SetConsoleWindowInfo(_handle, true, &_size);
	SetConsoleTitleA("Snake");
	SetConsoleCursorInfo(_handle, &_cinfo);
	srand(time(0));

	char _input = '\0';
	
	do
	{
		_level = 1;
		_score = 0;
		read_score();
		snake _snake1(_level);
	
		intro();
	
		init_lvl(_snake1, _input);

		//Main game loop
		while (_input != 'x')
		{
			if (_kbhit())
			{
				_input = _getch();
				if (_input == _up || _input == _down || _input == _right || _input == _left)
					_snake1._direction = _input;
			}
		
			_snake1.next_pos();
			collision(_snake1, _input);
			_snake1.animate_snake();
			if (_snake1._foodeaten == _numfood)
			{
				_level++;
				_snake1._foodeaten = 0;
				init_lvl(_snake1, _input);
			}
			Sleep(_speed);
		}
		end_game(_input);
		clear_grid();
	}
	while(_input != 'n');
	return 0;
}
Last edited on
closed account (zwA4jE8b)
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//Display introduction and game info
void intro()
{
	SetConsoleTextAttribute(_handle, FOREGROUND_WHITE | FOREGROUND_INTENSITY);
	
	_pos.X = 36; _pos.Y = 5;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("SNAKE v1.0");

	_pos.X = 27; _pos.Y = 6;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("(Written by: Michael Ervin)");

	_pos.X = 27; _pos.Y = 9;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("w s a d - Up Down Left Right");

	_pos.X = 33; _pos.Y = 10;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("x - Exit");

	_pos.X = 33; _pos.Y = 11;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("@ - Food");

	_pos.X = 33; _pos.Y = 12;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("X - Obstacle");

	_pos.X = 30; _pos.Y = 15;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("Press 1 for random levels");
	
	_pos.X = 30; _pos.Y = 16;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("Press 2 for fixed levels");

	while(true)
	{
		Sleep(10);
		if (_kbhit())
		{
			_leveltype = _getch();
			if (_leveltype == '1' || _leveltype == '2')
				break;
		}
	}
}

void clear_grid()
{
	int i, j;
	for(i = 0; i < _rows + 2; i++)
		for(j = 0; j < _columns; j++)
			_grid[i][j] = ' ';

	for(i = 0; i < _rows + 2; i++)
		for(j = 0; j < _columns; j++)
		{
			_pos.X = j; _pos.Y = i;
			SetConsoleCursorPosition(_handle, _pos);
			_putch(_grid[i][j]);
		}
}

void init_lvl(snake& _sn0, char& _in)
{
	int i, j, _ystart = 16;
	_coordinates _stuff;
	_numfood = _level * 4;
	_numobstacle = _level * 3;

	SetConsoleTextAttribute(_handle, FOREGROUND_RED | FOREGROUND_INTENSITY);

	//Fill grid with blanks
	for(i = 0; i < _rows; i++)
		for(j = 0; j < _columns; j++)
			_grid[i][j] = ' ';
	
	//Fill grid with borders
	for(i = 1; i < _columns - 1; i++)
	{
		_grid[0][i] = '=';
		_grid[_rows-1][i] = '=';
	}
	for(i = 0; i < _rows; i++)
	{
		_grid[i][0] = '|';
		_grid[i][_columns - 1] = '|';
	}

	//Set up for either fixed or random level type
	switch (_leveltype)
	{
	case '1':
		init_lvl_rand(_stuff, _ystart);
		_speed = 200 - (15 * _level);
		break;
	case '2':
		if (_level == 6)
			_in =  'x';
		else
			init_lvl_fixed(_stuff, _ystart);
		_speed = 200 - (30 * _level);
		break;
	}

	//Draw grid
	for(i = 0; i < _rows; i++)
		for(j = 0; j < _columns; j++)
		{
			_pos.X = j; _pos.Y = i;
			SetConsoleCursorPosition(_handle, _pos);
			if (_grid[i][j] == '@')
				SetConsoleTextAttribute(_handle, FOREGROUND_AQUA| FOREGROUND_INTENSITY);
			else
				SetConsoleTextAttribute(_handle, FOREGROUND_RED | FOREGROUND_INTENSITY);
			_putch(_grid[i][j]);
		}
	
	SetConsoleTextAttribute(_handle, FOREGROUND_AQUA| FOREGROUND_INTENSITY);
	_pos.X = 3; _pos.Y = 31;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("Level: ");

	_pos.X = 20; _pos.Y = 31;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("Score: ");

	_pos.X = 40; _pos.Y = 31;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("High Score: ");

	_sn0.reinit_snake(_ystart);
	_sn0.draw_snake();
	update_info();

	while(!_kbhit()){Sleep(10);}
}

void init_lvl_rand(_coordinates& _stuff, int _ystart)
{
	int i;
	//Fill grid with food and obstacles
	for(i = 0; i < _numfood; i++)
	{
		_stuff._y = (rand()%(_rows - 2)) + 1;
		if (_stuff._y == _ystart)
			i--;
		_stuff._x = (rand()%(_columns - 2)) + 1;
		_grid[_stuff._y][_stuff._x] = '@';
	}

	for(i = 0; i < _numobstacle; i++)
	{
		_stuff._y = (rand()%(_rows - 2)) + 1;
		_stuff._x = (rand()%(_columns - 2)) + 1;
		if (_grid[_stuff._y][_stuff._x] != ' ' || _stuff._y == _ystart)
			i--;
		else
			_grid[_stuff._y][_stuff._x] = 'X';
	}
}
void init_lvl_fixed(_coordinates& _stuff, int& _ystart)
{
	int i;
	switch (_level)
	{
	case 1:
		for(i = 0; i < 30; i++)
		{
			_stuff._y = _l1[i].Y;
			_stuff._x = _l1[i].X;
			_grid[_stuff._y][_stuff._x] = 'X';
		}
		break;
	case 2:
		for(i = 0; i < 52; i++)
		{
			_stuff._y = _l2[i].Y;
			_stuff._x = _l2[i].X;
			_grid[_stuff._y][_stuff._x] = 'X';
		}
		_ystart = 21;
		break;
	case 3:
		for(i = 0; i < 30; i++)
		{
			_stuff._y = _l3[i].Y;
			_stuff._x = _l3[i].X;
			_grid[_stuff._y][_stuff._x] = 'X';
		}
		_ystart = 14;
		break;
	case 4:
		for(i = 0; i < 117; i++)
		{
			_stuff._y = _l4[i].Y;
			_stuff._x = _l4[i].X;
			_grid[_stuff._y][_stuff._x] = 'X';
		}
		_ystart = 6;
		break;
	case 5:
		for(i = 1; i < 4; i++)
		{
			for(int j = 0; j < 76; j++)
			{
			_stuff._y = _l5[j].Y * i;
			_stuff._x = _l5[j].X;
			_grid[_stuff._y][_stuff._x] = 'X';
			}
		}
		_ystart = 6;
		break;
	}

	for(i = 0; i < _numfood; i++)
	{
		_stuff._y = (rand()%(_rows - 2)) + 1;
		_stuff._x = (rand()%(_columns - 2)) + 1;
		if (_grid[_stuff._y][_stuff._x] != ' ' || _stuff._y == _ystart)
			i--;
		else
			_grid[_stuff._y][_stuff._x] = '@';
	}
}

void update_info()
{
	SetConsoleTextAttribute(_handle, FOREGROUND_YELLOW | FOREGROUND_INTENSITY);
	//Show level
	_pos.X = 10; _pos.Y = 31;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("%d", _level);

	//Show score
	_pos.X = 27; _pos.Y = 31;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("%d", _score);

	//Show highscore
	_pos.X = 52; _pos.Y = 31;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("%d", _highscore);
}

void collision(snake& _sn1, char& _in)
{
	_coordinates _check = _sn1.snake_pos[0];
	
	//Check for border collisions
	//Check self collisions
	//Check food collisions
	//Check obstacle collisions
	if (_grid[_check._y][_check._x] == '=' || _grid[_check._y][_check._x] == '|' || _grid[_check._y][_check._x] == 'X' || self_collision(_sn1))
	{
		_sn1._deadsnake = true;
		update_info();
		_in =  'x';
	}
	else if (_grid[_check._y][_check._x] == '@')
	{
		_sn1.add_seg();
		_sn1._foodeaten++;
		_score += (5 * _level);
		update_info();
	}
}

bool self_collision(snake& _sn2)
{
	bool _temp = false;
	for(int i = 1; i < _sn2._length - 1; i++)
		if (_sn2.snake_pos[0]._x == _sn2.snake_pos[i]._x && _sn2.snake_pos[0]._y == _sn2.snake_pos[i]._y)
			_temp = true;
	return _temp;
}

//End of game procedure - check if highscore
void end_game(char& _in)
{
	_pos.X = (_columns / 2) - 4; _pos.Y = (_rows / 2) - 4;
	SetConsoleTextAttribute(_handle, FOREGROUND_GREEN);
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("GAME OVER");

	if (_score > _highscore)
	{
		write_score();
		_pos.X = (_columns / 2) - 8; _pos.Y = (_rows / 2) + 2;
		SetConsoleTextAttribute(_handle, FOREGROUND_GREEN);
		SetConsoleCursorPosition(_handle, _pos);
		_cprintf("New High Score: %d", _score);
	}

	SetConsoleTextAttribute(_handle, FOREGROUND_GREEN);
	_pos.X = (_columns / 2) - 17; _pos.Y = 25;
	SetConsoleCursorPosition(_handle, _pos);
	_cprintf("Do you want to play again? (y / n)");
	while(true)
	{
		Sleep(10);
		if (_kbhit())
		{
			_in = _getch();
			break;
		}
	}
}

//Write highscore to file
void write_score()
{
	std::ofstream _outf("highscore.sco");
	_outf << _score;
	_outf.close();
}

//Read in highscore
void read_score()
{
	std::ifstream _inf("highscore.sco");
	if (_inf.is_open())
		_inf >> _highscore;
	else
		_highscore = 0;
	_inf.close();
}
Last edited on
closed account (zwA4jE8b)
The program flow is as such.

In main there is a game loop.
1) get input.
2) position snake in direction of input. (_snake1.next_pos())
3) check for collisions. (collisions(snake&))
4) draw snake. (_snake1.animate_snake())
5) check if the level needs to be advanced. (eaten the number of foods on the board)
Last edited on
ne555 (10692)
std::vector<_coordinates*> snake_pos; ¿why pointers instead of objects? You are having memory leaks as you don't have a single delete in your code. (and the assignment operator and copy constructor will be wrong)

You could also use a queue<coordinates> snake_pos;
the movement will be simply a snake_pos.push( new_position ); instead of moving all the cells one place

Don't know about that windows specific stuff xP
Disch (13742)
¿why pointers instead of objects?


+1 @ This. No need for pointers/dynamically created objects here. You're just making it harder on yourself and introducing bugs/leaks.
closed account (zwA4jE8b)
I do not have a delete because the snake only grows.

But I kind of understand what you mean about the pointers.
closed account (zwA4jE8b)
Thanks for the advice though.

I Edited the code (also in the original posts).

Works great w/o pointers.

At the time it just seemed like the right thing to do.

I didn't plan any of this out. Just sort of made it up as I went along.
Last edited on
closed account (zwA4jE8b)
The only problem I really see so far is that sometimes the level advances when there is one food left and sometimes it doesn't.
closed account (zwA4jE8b)
Newest version posted.

Are my loops and keyboard input methods efficient?

I moved update_info() from the main loop into the collision function so it is only ran if there is a change, instead of constantly.

I use Sleep(10) in the waiting loops to keep the processor usage at or near 0 while waiting for user.

I passed by reference because for some reason I think that is more efficient, although I am not sure where I got that idea.
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