Tetris tutorial in C++ platform independent focused in game logic for beginners

161 comments | in | about Gamedev | diciembre 14, 2008

We are going to learn how to create a Tetris clone from scratch using simple and clean C++. And this will take you less than an hour! This is the perfect tutorial for beginners. Just enjoy it and leave a comment if you want me to explain something better. I know my English sucks, so if you see some mistakes, please, tell me. Let’s go!

Updated! 03/04/2012

Download sourcecode

Here it is the complete sourcecode.

Windows platforms

The sourcecode comes with SDL includes and libs ready to compile in Visual C++ Express Edition 2008. In «Release» folder there is also an executable file just in case you want to try it directly.

Other platforms

Thanks to lmelior and to Javier Santana, there is a Linux version of this tutorial. The sourcecode is platform independent and comes with a «makefile». However, under Linux, you need libsdl-gfx1.2-dev and libsdl1.2-dev (If you are using Ubuntu you can get them this way: sudo apt-get install libsdl1.2-dev libsdl-gfx1.2-dev)

Keys

ESC Quit the game
z Rotate piece
x Drop piece
Left, Right, Down I will not offend your intelligence

Step 0: Introduction

We are going to focus on the game logic, using only rectangle primitives (SDL) for the rendering. All the game logic is isolated from the drawing, so you can expand the tutorial easily. I’m planning making a second tutorial of how to improve this Tetris clone using sprites, background, effects, etc. But right now, let’s focus on the game logic. This is how your prototype will look after you finish the tutorial:

Tetris Tutorial C++

In this tutorial you will learn:

  • How to store the pieces and board using matrices (multidimensional arrays).
  • How to solve the rotation problem in Tetris, in a really easy way, without using complex maths or anything difficult, just using an intelligent hack.
  • How to check collisions between the pieces and the board.
  • How the main loop of a Tetris game works.

What you are supposed to already know:

  • C++
  • A little bit of graphical programming if you want expand the tutorial with improved graphics. Don’t worry about that if you just want to learn the Tetris game logic.

What do you need?

  • A compiler or programming IDE. I’ve used Visual C++ Express Edition for this tutorial, that is a free C++ IDE. But you can use the one of your choice, of course.
  • Desire to learn 😀

What is the license of the sourcecode?

The sourcecode is under the «Creative Commons – Attribution 3.0 Unported». That means you can copy, distribute and transmit the work and to adapt it. But you must attribute the work (but not in any way that suggests that they endorse you or your use of the work). The manner of attribution is up to you. You can just mention me (Javier López). A backlink would be also appreciated.

Step 1: The pieces

First, we are going to create a class for storing all the pieces. There are 7 different types of pieces: square, I, L, L-mirrored, N, N-mirrored and T. But, how can we define each piece? Just check out the figure:

Tetris Tutorial C++ - Piece

As you can see, this piece is defined in a matrix of 5×5 cells. 0 means «no block», 1 means «normal block» and 2 means «pivot block». The pivot block is the rotation point: yes, the original Tetris game has a rotation point for each piece 🙂

And how can we store that using C++? Easy: using a bidimensional array of 5×5 ints (or bytes, if you are a fanatic of optimization). The previous piece is stored like that:

[c language=»++»]
{0, 0, 0, 0, 0},
{0, 0, 0, 1, 0},
{0, 0, 2, 1, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
[/c]

Now that we already now how to store each piece let’s think about rotations. We can solve the rotation problem in a lot of different ways. In other tutorials, I’ve seen them use complex rotation algebra in order to rotate the piece… but we can solve this problem easily. If we can store each piece… why don’t we just store each piece rotated too? There are four possible rotations for each piece:

Tetris Tutorial C++ - Piece and their rotations

As you can see, the longer piece is only 4 block widht. But we are using 5 blocks matrices in order to be able to store all the rotations respeting the pivot block. In a previous version of this tutorial, I was using 4-block matrices, but then it was necessary to store translations of the pivot to the origin. This way, we are using some bytes more but the sourcecode is cleaner. In total we only use 448 bytes to store all the pieces. That’s nothing 🙂

So, in order to store all this information we need a 4-dimensional array (wow!), in order to store the 4 possible rotations (matrices of 5×5) of each piece:

[c language=»++»]
// Pieces definition
char mPieces [7 /*kind */ ][4 /* rotation */ ][5 /* horizontal blocks */ ][5 /* vertical blocks */ ] =
{
// Square
{
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 0, 2, 1, 0},
{0, 0, 1, 1, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 0, 2, 1, 0},
{0, 0, 1, 1, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 0, 2, 1, 0},
{0, 0, 1, 1, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 0, 2, 1, 0},
{0, 0, 1, 1, 0},
{0, 0, 0, 0, 0}
}
},

// I
{
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 1, 2, 1, 1},
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 2, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 1, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{1, 1, 2, 1, 0},
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 1, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 2, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
}
}
,
// L
{
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 2, 0, 0},
{0, 0, 1, 1, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 1, 2, 1, 0},
{0, 1, 0, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 1, 1, 0, 0},
{0, 0, 2, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 1, 0},
{0, 1, 2, 1, 0},
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0}
}
},
// L mirrored
{
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 2, 0, 0},
{0, 1, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 1, 0, 0, 0},
{0, 1, 2, 1, 0},
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 1, 1, 0},
{0, 0, 2, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 1, 2, 1, 0},
{0, 0, 0, 1, 0},
{0, 0, 0, 0, 0}
}
},
// N
{
{
{0, 0, 0, 0, 0},
{0, 0, 0, 1, 0},
{0, 0, 2, 1, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 1, 2, 0, 0},
{0, 0, 1, 1, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 1, 2, 0, 0},
{0, 1, 0, 0, 0},
{0, 0, 0, 0, 0}
},

{
{0, 0, 0, 0, 0},
{0, 1, 1, 0, 0},
{0, 0, 2, 1, 0},
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0}
}
},
// N mirrored
{
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 2, 1, 0},
{0, 0, 0, 1, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 0, 2, 1, 0},
{0, 1, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 1, 0, 0, 0},
{0, 1, 2, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 1, 1, 0},
{0, 1, 2, 0, 0},
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0}
}
},
// T
{
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 2, 1, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0},
{0, 1, 2, 1, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 1, 2, 0, 0},
{0, 0, 1, 0, 0},
{0, 0, 0, 0, 0}
},
{
{0, 0, 0, 0, 0},
{0, 0, 1, 0, 0},
{0, 1, 2, 1, 0},
{0, 0, 0, 0, 0},
{0, 0, 0, 0, 0}
}
}
};
[/c]

Great! Now, in order to rotate a piece we just have to choose the following stored rotated piece.

There is something important that we have to take in count. Each different piece must be correctly positioned every time it is created on the top of the screen. In other words, it needs to be translated to the correct position (in order to show ONLY one row of blocks in the board and to be centered, upper blocks should be OUTSIDE the board). Like each piece is different (some are lower or smaller than others in the matrices), each one needs a different translation every time it is created. We will store these translations in another array, one translation per rotated piece. Take your time to understand this.

Tetris Tutorial C++ - Tetris pieces in good and wrong positions

The translation are two numbers (horizontal tranlastion, vertical translation) that we have to store for each piece. We will use these numbers later in «Game» class when creating the pieces each time a new piece appears, so it will be initialized in the correct position. This is the array that stores these displacements:

[c language=»++»]
// Displacement of the piece to the position where it is first drawn in the board when it is created
int mPiecesInitialPosition [7 /*kind */ ][4 /* r2otation */ ][2 /* position */] =
{
/* Square */
{
{-2, -3},
{-2, -3},
{-2, -3},
{-2, -3}
},
/* I */
{
{-2, -2},
{-2, -3},
{-2, -2},
{-2, -3}
},
/* L */
{
{-2, -3},
{-2, -3},
{-2, -3},
{-2, -2}
},
/* L mirrored */
{
{-2, -3},
{-2, -2},
{-2, -3},
{-2, -3}
},
/* N */
{
{-2, -3},
{-2, -3},
{-2, -3},
{-2, -2}
},
/* N mirrored */
{
{-2, -3},
{-2, -3},
{-2, -3},
{-2, -2}
},
/* T */
{
{-2, -3},
{-2, -3},
{-2, -3},
{-2, -2}
},
};
[/c]

And with that we have solved one of the most tricky parts of this tutorial.

We can now create our Pieces class, this file is called «Pieces.h»:

[c language=»++»]
#ifndef _PIECES_
#define _PIECES_

// ——————————————————————————–
// Pieces
// ——————————————————————————–

class Pieces
{
public:

int GetBlockType (int pPiece, int pRotation, int pX, int pY);
int GetXInitialPosition (int pPiece, int pRotation);
int GetYInitialPosition (int pPiece, int pRotation);
};

#endif // _PIECES_
[/c]

The 3 methods that you can see in the header returns some information that we will need later. Their implementation is trivial:

[c language=»++»]
/*
======================================
Return the type of a block (0 = no-block, 1 = normal block, 2 = pivot block)

Parameters:

>> pPiece: Piece to draw
>> pRotation: 1 of the 4 possible rotations
>> pX: Horizontal position in blocks
>> pY: Vertical position in blocks
======================================
*/
int Pieces::GetBlockType (int pPiece, int pRotation, int pX, int pY)
{
return mPieces [pPiece][pRotation][pX][pY];
}

/*
======================================
Returns the horizontal displacement of the piece that has to be applied in order to create it in the
correct position.

Parameters:

>> pPiece: Piece to draw
>> pRotation: 1 of the 4 possible rotations
======================================
*/
int Pieces::GetXInitialPosition (int pPiece, int pRotation)
{
return mPiecesInitialPosition [pPiece][pRotation][0];
}

/*
======================================
Returns the vertical displacement of the piece that has to be applied in order to create it in the
correct position.

Parameters:

>> pPiece: Piece to draw
>> pRotation: 1 of the 4 possible rotations
======================================
*/
int Pieces::GetYInitialPosition (int pPiece, int pRotation)
{
return mPiecesInitialPosition [pPiece][pRotation][1];
}
[/c]

Step 2: The board

Now we are going to learn how to store the pieces in the board and check collisions. This class stores a bidimensional array of N x N blocks that are initialized to POS_FREE. The pieces will be stored by filling these blocks when they fall down updating the block to POS_FILLED. In this class we need to implement methods in order to store a piece, check if a movement is possible, delete lines, etc. Our board is going to be very flexible, we will be able to choose the amount of horizontal and vertical blocks and the size of each block.

This is the header of the class («Board.h»):

[c language=»++»]
#ifndef _BOARD_
#define _BOARD_

// —— Includes —–

#include "Pieces.h"

// —— Defines —–

#define BOARD_LINE_WIDTH 6 // Width of each of the two lines that delimit the board
#define BLOCK_SIZE 16 // Width and Height of each block of a piece
#define BOARD_POSITION 320 // Center position of the board from the left of the screen
#define BOARD_WIDTH 10 // Board width in blocks
#define BOARD_HEIGHT 20 // Board height in blocks
#define MIN_VERTICAL_MARGIN 20 // Minimum vertical margin for the board limit
#define MIN_HORIZONTAL_MARGIN 20 // Minimum horizontal margin for the board limit
#define PIECE_BLOCKS 5 // Number of horizontal and vertical blocks of a matrix piece

// ——————————————————————————–
// Board
// ——————————————————————————–

class Board
{
public:

Board (Pieces *pPieces, int pScreenHeight);

int GetXPosInPixels (int pPos);
int GetYPosInPixels (int pPos);
bool IsFreeBlock (int pX, int pY);
bool IsPossibleMovement (int pX, int pY, int pPiece, int pRotation);
void StorePiece (int pX, int pY, int pPiece, int pRotation);
void DeletePossibleLines ();
bool IsGameOver ();

private:

enum { POS_FREE, POS_FILLED }; // POS_FREE = free position of the board; POS_FILLED = filled position of the board
int mBoard [BOARD_WIDTH][BOARD_HEIGHT]; // Board that contains the pieces
Pieces *mPieces;
int mScreenHeight;

void InitBoard();
void DeleteLine (int pY);
};

#endif // _BOARD_
[/c]

Now, let’s see each different method.

InitBoard method is just a nested loop that initializes all the board blocks to POS_FREE.

[c language=»++»]
/*
======================================
Init the board blocks with free positions
======================================
*/
void Board::InitBoard()
{
for (int i = 0; i < BOARD_WIDTH; i++)
for (int j = 0; j < BOARD_HEIGHT; j++)
mBoard[i][j] = POS_FREE;
}
[/c]

StorePiece method, just stores a piece in the board by filling the appropriate blocks as POS_FILLED. There is a nested loop that iterates through the piece matrix and store the blocks in the board.

[c language=»++»]
/*

======================================
Store a piece in the board by filling the blocks

Parameters:

>> pX: Horizontal position in blocks
>> pY: Vertical position in blocks
>> pPiece: Piece to draw
>> pRotation: 1 of the 4 possible rotations
======================================
*/
void Board::StorePiece (int pX, int pY, int pPiece, int pRotation)
{
// Store each block of the piece into the board
for (int i1 = pX, i2 = 0; i1 < pX + PIECE_BLOCKS; i1++, i2++)
{
for (int j1 = pY, j2 = 0; j1 < pY + PIECE_BLOCKS; j1++, j2++)
{
// Store only the blocks of the piece that are not holes
if (mPieces->GetBlockType (pPiece, pRotation, j2, i2) != 0)
mBoard[i1][j1] = POS_FILLED;
}
}
}
[/c]

IsGameOver checks if there are blocks in the first row. That means the game is over.

[c language=»++»]
/*
======================================
Check if the game is over becase a piece have achived the upper position

Returns true or false
======================================
*/
bool Board::IsGameOver()
{
//If the first line has blocks, then, game over
for (int i = 0; i < BOARD_WIDTH; i++)
{
if (mBoard[i][0] == POS_FILLED) return true;
}

return false;
}
[/c]

DeleteLine is the method that erases a line and moves all the blocks of upper positions one row down. It just starts from the line that has to be removed, and then, iterating through the board in a nested loop, moves all the blocks of the upper lines one row done.

[c language=»++»]
/*
======================================
Delete a line of the board by moving all above lines down

Parameters:

>> pY: Vertical position in blocks of the line to delete
======================================
*/
void Board::DeleteLine (int pY)
{
// Moves all the upper lines one row down
for (int j = pY; j > 0; j–)
{
for (int i = 0; i < BOARD_WIDTH; i++)
{
mBoard[i][j] = mBoard[i][j-1];
}
}
}
[/c]

DeletePossibleLines is a method that removes all the lines that should be erased from the board. It works by first checking which lines should be removed (the ones that have all their horizontal blocks filled). Then, it uses the DeleteLine method in order to erase that line and move all the upper lines one row down.

[c language=»++»]
/*
======================================
Delete all the lines that should be removed
======================================
*/
void Board::DeletePossibleLines ()
{
for (int j = 0; j < BOARD_HEIGHT; j++)
{
int i = 0;
while (i < BOARD_WIDTH)
{
if (mBoard[i][j] != POS_FILLED) break;
i++;
}

if (i == BOARD_WIDTH) DeleteLine (j);
}
}
[/c]

IsFreeBlock is a trivial method that checks out if a board block is filled or not.

[c language=»++»]
/*
======================================
Returns 1 (true) if the this block of the board is empty, 0 if it is filled

Parameters:

>> pX: Horizontal position in blocks
>> pY: Vertical position in blocks
======================================
*/
bool Board::IsFreeBlock (int pX, int pY)
{
if (mBoard [pX][pY] == POS_FREE) return true; else return false;
}
[/c]

Until now we have been always talking about «blocks». But in order to draw them to the screen we need to specify the position in pixels. So, we need two methods (GetXPosInPixels and GetYPosInPixels ) in order to obtain the horizontal and vertical position in pixels of a given block.

[c language=»++»]
/*
======================================
Returns the horizontal position (in pixels) of the block given like parameter

Parameters:

>> pPos: Horizontal position of the block in the board
======================================
*/
int Board::GetXPosInPixels (int pPos)
{
return ( ( BOARD_POSITION – (BLOCK_SIZE * (BOARD_WIDTH / 2)) ) + (pPos * BLOCK_SIZE) );
}

/*
======================================
Returns the vertical position (in pixels) of the block given like parameter

Parameters:

>> pPos: Horizontal position of the block in the board
======================================
*/
int Board::GetYPosInPixels (int pPos)
{
return ( (mScreenHeight – (BLOCK_SIZE * BOARD_HEIGHT)) + (pPos * BLOCK_SIZE) );
}
[/c]

IsPossibleMovement is the last and most complex method of Board class. This method will be used later in the main loop to check if the movement of a piece is possible or not. The method compares all the blocks of a piece with the blocks already stored in the board and with the board limits. That comparison is made by iterating through the piece matrix and comparing with the appropriate 5×5 area in the board. If there is a collision that means the movement is not possible, so it returns false. If there is no collision, the movement is possible and it returns true.

Tetris Tutorial C++ - Collisions with the stored blocks and board limits

[c language=»++»]
/*
======================================
Check if the piece can be stored at this position without any collision
Returns true if the movement is possible, false if it not possible

Parameters:

>> pX: Horizontal position in blocks
>> pY: Vertical position in blocks
>> pPiece: Piece to draw
>> pRotation: 1 of the 4 possible rotations
======================================
*/
bool Board::IsPossibleMovement (int pX, int pY, int pPiece, int pRotation)
{
// Checks collision with pieces already stored in the board or the board limits
// This is just to check the 5×5 blocks of a piece with the appropriate area in the board
for (int i1 = pX, i2 = 0; i1 < pX + PIECE_BLOCKS; i1++, i2++)
{
for (int j1 = pY, j2 = 0; j1 < pY + PIECE_BLOCKS; j1++, j2++)
{
// Check if the piece is outside the limits of the board
if ( i1 < 0 ||
i1 > BOARD_WIDTH – 1 ||
j1 > BOARD_HEIGHT – 1)
{
if (mPieces->GetBlockType (pPiece, pRotation, j2, i2) != 0)
return 0;
}

// Check if the piece have collisioned with a block already stored in the map
if (j1 >= 0)
{
if ((mPieces->GetBlockType (pPiece, pRotation, j2, i2) != 0) &&
(!IsFreeBlock (i1, j1)) )
return false;
}
}
}

// No collision
return true;
}
[/c]

Step 3: The game

Now we are going to implement a general class, called «Game», that itializes the game, draws the board and pieces by drawing each block as a rectangle (using another class that we will see later called «IO» that uses SDL) and creates new random pieces.

This is the header, «Game.h»:

[c language=»++»]
#ifndef _GAME_
#define _GAME_

// —— Includes —–

#include "Board.h"
#include "Pieces.h"
#include "IO.h"
#include <time.h>

// —— Defines —–

#define WAIT_TIME 700 // Number of milliseconds that the piece remains before going 1 block down */

// ——————————————————————————–
// Game
// ——————————————————————————–

class Game
{
public:

Game (Board *pBoard, Pieces *pPieces, IO *pIO, int pScreenHeight);

void DrawScene ();
void CreateNewPiece ();

int mPosX, mPosY; // Position of the piece that is falling down
int mPiece, mRotation; // Kind and rotation the piece that is falling down

private:

int mScreenHeight; // Screen height in pixels
int mNextPosX, mNextPosY; // Position of the next piece
int mNextPiece, mNextRotation; // Kind and rotation of the next piece

Board *mBoard;
Pieces *mPieces;
IO *mIO;

int GetRand (int pA, int pB);
void InitGame();
void DrawPiece (int pX, int pY, int pPiece, int pRotation);
void DrawBoard ();
};

#endif // _GAME_
[/c]

As you can see, the current piece is defined using 4 variables: mPosX, mPosY (the position of the piece in blocks), mPiece (the type of the piece), mRotation (the current matrix that defines the piece, as we have seen, each piece has four matrices, one for each rotation).

Let’s see the implementation of the methods.

GetRand is a trivial method that returns a random number between two boundaries.

[c language=»++»]
/*
======================================
Get a random int between to integers

Parameters:
>> pA: First number
>> pB: Second number
======================================
*/
int Game::GetRand (int pA, int pB)
{
return rand () % (pB – pA + 1) + pA;
}
[/c]

InitGame, takes care of the initialization of the game by selecting the first and next piece randomly. The next piece is shown so the player can see which piece will appear next. This method also sets the position in blocks of that pieces. We use two methods that we have seen before in «Pieces» class: GetXInitialPosition and GetYInitialPosition in order to initialize the piece in the correct position.

[c language=»++»]
/*
======================================
Initial parameters of the game
======================================
*/
void Game::InitGame()
{
// Init random numbers
srand ((unsigned int) time(NULL));

// First piece
mPiece = GetRand (0, 6);
mRotation = GetRand (0, 3);
mPosX = (BOARD_WIDTH / 2) + mPieces->GetXInitialPosition (mPiece, mRotation);
mPosY = mPieces->GetYInitialPosition (mPiece, mRotation);

// Next piece
mNextPiece = GetRand (0, 6);
mNextRotation = GetRand (0, 3);
mNextPosX = BOARD_WIDTH + 5;
mNextPosY = 5;
}
[/c]

CreateNewPiece method sets the «next piece» as the current one and resets its position, then selects a new «next piece».

[c language=»++»]
/*
======================================
Create a random piece
======================================
*/
void Game::CreateNewPiece()
{
// The new piece
mPiece = mNextPiece;
mRotation = mNextRotation;
mPosX = (BOARD_WIDTH / 2) + mPieces->GetXInitialPosition (mPiece, mRotation);
mPosY = mPieces->GetYInitialPosition (mPiece, mRotation);

// Random next piece
mNextPiece = GetRand (0, 6);
mNextRotation = GetRand (0, 3);
}
[/c]

DrawPiece is a really easy method that iterates through the piece matrix and draws each block of the piece. It uses green for the normal blocks and blue for the pivot block. For drawing the rectangles it calls to DrawRectangle method of the class «IO» that we will see later.

[c language=»++»]
/*
======================================
Draw piece

Parameters:

>> pX: Horizontal position in blocks
>> pY: Vertical position in blocks
>> pPiece: Piece to draw
>> pRotation: 1 of the 4 possible rotations
======================================
*/
void Game::DrawPiece (int pX, int pY, int pPiece, int pRotation)
{
color mColor; // Color of the block

// Obtain the position in pixel in the screen of the block we want to draw
int mPixelsX = mBoard->GetXPosInPixels (pX);
int mPixelsY = mBoard->GetYPosInPixels (pY);

// Travel the matrix of blocks of the piece and draw the blocks that are filled
for (int i = 0; i < PIECE_BLOCKS; i++)
{
for (int j = 0; j < PIECE_BLOCKS; j++)
{
// Get the type of the block and draw it with the correct color
switch (mPieces->GetBlockType (pPiece, pRotation, j, i))
{
case 1: mColor = GREEN; break; // For each block of the piece except the pivot
case 2: mColor = BLUE; break; // For the pivot
}

if (mPieces->GetBlockType (pPiece, pRotation, j, i) != 0)
mIO->DrawRectangle (mPixelsX + i * BLOCK_SIZE,
mPixelsY + j * BLOCK_SIZE,
(mPixelsX + i * BLOCK_SIZE) + BLOCK_SIZE – 1,
(mPixelsY + j * BLOCK_SIZE) + BLOCK_SIZE – 1,
mColor);
}
}
}
[/c]

DrawBoard is similiar to the previous method. It draws two blue columns that are used as the limits of the boards. Then draws the board blocks that are flagged as POS_FILLED in a nested loop.

[c language=»++»]
/*
======================================
Draw board

Draw the two lines that delimit the board
======================================
*/
void Game::DrawBoard ()
{

// Calculate the limits of the board in pixels
int mX1 = BOARD_POSITION – (BLOCK_SIZE * (BOARD_WIDTH / 2)) – 1;
int mX2 = BOARD_POSITION + (BLOCK_SIZE * (BOARD_WIDTH / 2));
int mY = mScreenHeight – (BLOCK_SIZE * BOARD_HEIGHT);

// Check that the vertical margin is not to small
//assert (mY > MIN_VERTICAL_MARGIN);

// Rectangles that delimits the board
mIO->DrawRectangle (mX1 – BOARD_LINE_WIDTH, mY, mX1, mScreenHeight – 1, BLUE);

mIO->DrawRectangle (mX2, mY, mX2 + BOARD_LINE_WIDTH, mScreenHeight – 1, BLUE);

// Check that the horizontal margin is not to small
//assert (mX1 > MIN_HORIZONTAL_MARGIN);

// Drawing the blocks that are already stored in the board
mX1 += 1;
for (int i = 0; i < BOARD_WIDTH; i++)
{
for (int j = 0; j < BOARD_HEIGHT; j++)
{
// Check if the block is filled, if so, draw it
if (!mBoard->IsFreeBlock(i, j))
mIO->DrawRectangle ( mX1 + i * BLOCK_SIZE,
mY + j * BLOCK_SIZE,
(mX1 + i * BLOCK_SIZE) + BLOCK_SIZE – 1,
(mY + j * BLOCK_SIZE) + BLOCK_SIZE – 1,
RED);
}
}
}
[/c]

DrawScene, just calls the previous methods in order to draw everything.

[c language=»++»]
/*
======================================
Draw scene

Draw all the objects of the scene
======================================
*/
void Game::DrawScene ()
{
DrawBoard (); // Draw the delimitation lines and blocks stored in the board
DrawPiece (mPosX, mPosY, mPiece, mRotation); // Draw the playing piece
DrawPiece (mNextPosX, mNextPosY, mNextPiece, mNextRotation); // Draw the next piece
}
[/c]

Step 4: Easy drawing, window management and keyboard input using SDL, isolated from the game logic

«IO.cpp» and «IO.h» are the files that implement the «IO» class. It uses SDL in order to create the window, clear it, update the screen and take care of the keyboard input. You can check out «IO.cpp» and «IO.h» files in order to see its implementation. I’m not going to explain the methods that are SDL related. You can change this class in order to use a different renderer (like IndieLib, Allegro, OpenGL, Direct3d, etc).

This is the header («IO.h»):

[c language=»++»]
#ifndef _IO_
#define _IO_

// —— Includes —–

#ifndef LINUX
#include "SDL/include/SDL.h"
#include "SDL/SDL_GfxPrimitives/SDL_gfxPrimitives.h"
#else
#include <SDL/SDL.h>
#include "SDL/SDL_GfxPrimitives/sdl_gfxprimitives.h"
#endif
#pragma comment (lib, "SDL/lib/SDL.lib")
#pragma comment (lib, "SDL/SDL_GfxPrimitives/SDL_GfxPrimitives_Static.lib")

// —— Enums —–

enum color {BLACK, RED, GREEN, BLUE, CYAN, MAGENTA, YELLOW, WHITE, COLOR_MAX}; // Colors

// ——————————————————————————–
// IO
// ——————————————————————————–

class IO
{
public:

IO ();

void DrawRectangle (int pX1, int pY1, int pX2, int pY2, enum color pC);
void ClearScreen ();
int GetScreenHeight ();
int InitGraph ();
int Pollkey ();
int Getkey ();
int IsKeyDown (int pKey);
void UpdateScreen ();

};

#endif // _IO_
[/c]

Step 5: The main loop

The main loop is quite simple. In each frame we draw everything. Later, we use keyboard input in order to move the piece. Before each movement, we first check out if it is possible. We also measure the time in order to move the piece down every n milliseconds. When the piece fall down one block, we check out if that movement is possible, if not, we store the piece in the board. We also check out if there are blocks in the upper row, if so, the game is over.

Let’s see «Main.cpp» step by step:

First, we initialize all the classes. Then, we get the actual milliseconds, which will be used to determine when the piece should move down.

[c language=»++»]
#include "Game.h"
#ifndef LINUX
#include <windows.h>
#endif

/*
==================
Main
==================
*/
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
// —– Vars —–

// Class for drawing staff, it uses SDL for the rendering. Change the methods of this class
// in order to use a different renderer
IO mIO;
int mScreenHeight = mIO.GetScreenHeight();

// Pieces
Pieces mPieces;

// Board
Board mBoard (&mPieces, mScreenHeight);

// Game
Game mGame (&mBoard, &mPieces, &mIO, mScreenHeight);

// Get the actual clock milliseconds (SDL)
unsigned long mTime1 = SDL_GetTicks();
[/c]

This is the main loop. We can exit by pressing ESC. In each frame we clear and update the screen and draw everything.

[c language=»++»]
// —– Main Loop —–

while (!mIO.IsKeyDown (SDLK_ESCAPE))
{
// —– Draw —–

mIO.ClearScreen (); // Clear screen
mGame.DrawScene (); // Draw staff
mIO.UpdateScreen (); // Put the graphic context in the screen
[/c]

We start with the input. If we press left, down or right we try to move the piece in that directions. We only move the piece if the movement is possible.

[c language=»++»]
// —– Input —–

int mKey = mIO.Pollkey();

switch (mKey)
{
case (SDLK_RIGHT):
{
if (mBoard.IsPossibleMovement (mGame.mPosX + 1, mGame.mPosY, mGame.mPiece, mGame.mRotation))
mGame.mPosX++;
break;
}

case (SDLK_LEFT):
{
if (mBoard.IsPossibleMovement (mGame.mPosX – 1, mGame.mPosY, mGame.mPiece, mGame.mRotation))
mGame.mPosX–;
break;
}

case (SDLK_DOWN):
{
if (mBoard.IsPossibleMovement (mGame.mPosX, mGame.mPosY + 1, mGame.mPiece, mGame.mRotation))
mGame.mPosY++;
break;
}
[/c]

By pressing «x», the piece will fall down directly to the ground. This is really easy to implement by trying to move the piece down until the movement is not possible. Then we store the piece, delete possible lines and check out if the game is over, if not, we create a new piece.

[c language=»++»]
case (SDLK_x):
{
// Check collision from up to down
while (mBoard.IsPossibleMovement(mGame.mPosX, mGame.mPosY, mGame.mPiece, mGame.mRotation)) { mGame.mPosY++; }

mBoard.StorePiece (mGame.mPosX, mGame.mPosY – 1, mGame.mPiece, mGame.mRotation);

mBoard.DeletePossibleLines ();

if (mBoard.IsGameOver())
{
mIO.Getkey();
exit(0);
}

mGame.CreateNewPiece();

break;
}
[/c]

By pressing «z» we rotate the piece. With the methods that we have already implement this is an easy task. The rotation is in fact to change to the next rotated stored piece. We first should check that the rotated piece will be drawn without colliding, if so, we sets this rotation as the current one.

[c language=»++»]
case (SDLK_z):
{
if (mBoard.IsPossibleMovement (mGame.mPosX, mGame.mPosY, mGame.mPiece, (mGame.mRotation + 1) % 4))
mGame.mRotation = (mGame.mRotation + 1) % 4;

break;
}
}
[/c]

If WAIT_TIME passed, the piece should fall down one block. We have to check out if the movement is possible, if not, the piece should be stored and we have to check if we can delete lines. We also see if the game is over, if not, we create a new piece.

[c language=»++»]
// —– Vertical movement —–

unsigned long mTime2 = SDL_GetTicks();

if ((mTime2 – mTime1) > WAIT_TIME)
{
if (mBoard.IsPossibleMovement (mGame.mPosX, mGame.mPosY + 1, mGame.mPiece, mGame.mRotation))
{
mGame.mPosY++;
}
else
{
mBoard.StorePiece (mGame.mPosX, mGame.mPosY, mGame.mPiece, mGame.mRotation);

mBoard.DeletePossibleLines ();

if (mBoard.IsGameOver())
{
mIO.Getkey();
exit(0);
}

mGame.CreateNewPiece();
}

mTime1 = SDL_GetTicks();
}
}

return 0;
}
[/c]

And that’s all! Please leave a comment if you see some mistakes, language errors or if you have any doubts… or just to say thanks! 🙂

Credits

  • Javier López
  • Special thanks: Imelior, who fixed English mistakes and compiled the tutorial under Linux.
  • Special thanks: Javier Santana, who added #ifndef sentences and pointed that was necessary to use libsdl-gfx1.2-dev and libsdl1.2-dev under Linux.

Bonus

Don’t forget to play with the «defines». Crazy example:

[c language=»++»]
#define BLOCK_SIZE 5 // Width and Height of each block of a
#define BOARD_WIDTH 90 // Board width in blocks
#define BOARD_HEIGHT 90 // Board height in blocks
[/c]

Tetris Tutorial C++

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Comentarios (161)

  • Muy bueno el tutorial! La verdad es que estos tutoriales son una currada tremenda, pero también ayudan a mucha gente… ¡Espero que tengas ánimo para seguir con ello!

    14 de diciembre de 2008
  • Nice tut thanks!

    15 de diciembre de 2008
  • I like your solution to having the output be scalable. I also find your rotation solution interesting. I wouldn’t have taken that approach. 16 lines of data per piece! Draws the code out, which is fine in most cases. But personally I prefer one piece declaration and procedurally rotate it. It makes the code a bit harder to read, tho, but that’s the way I did Alleytris.
    (Hope you don’t mind the plug *insert smiley*)

    15 de diciembre de 2008
  • Javier López

    Thank you taking a look to the tutorial, Joe. I usually prefer to have everything precalculated. It is usually easier to understand and faster. But a procedurally rotation is also interesting. Alleytris is a great example of a good tetris clones. Good work!

    15 de diciembre de 2008
  • Good job!
    +1

    15 de diciembre de 2008
  • Nice tutorial, it reminds me of all the love and effort I put into my first C++ programm that was… Tetris !!! I had just learned what templates and subclasses were and used all that without knowing about pointers etc… But it was fun ! Anyway, as it was my 1st programm, it was in no way as clean as your solution, but what fun ! Thanks for reminding me this good ol’ time 😉

    15 de diciembre de 2008
  • Javier López

    Francois, Tetris also make me remember the first games I tried to develope 15 years ago using Basic in my old MSX. Snif! Snif!

    15 de diciembre de 2008
  • Javier López

    Thank you for the appreciative comments, Adrián and Miguel 🙂

    16 de diciembre de 2008
  • Javier López

    Thanks, nihed.

    16 de diciembre de 2008
  • Really is a great tutorial! I’m hoping to create my first game! 🙂

    16 de diciembre de 2008
  • Javier López

    @Ivan, thank you! Don’t forget to post your game.

    16 de diciembre de 2008
  • Emeka

    This is great, I have been thinking of how to great this for something now, and I have always being intimidated. Now, you have done the hard job for me. But, I feel like asking some stupid questions. Could you support me get started in game programming? Or will you be there to answer my questions?

    22 de diciembre de 2008
  • Javier López

    Welcome Emeka,

    If you want to get started in game programming, I think this is the correct place. Feel free to ask whatever questions you have! I’ll try to help you, of course!

    I think a good start is also visiting IndieLib.com. IndieLib is a 2d game engine I developed for rapid game prototyping under c++. I think is a good engine in order to start learning game programming.

    See you there and here!

    Soon… more tutorials!

    23 de diciembre de 2008
  • Emeka

    Javier,
    Thanks so much, I checked out IndieLib game engine tutorial and I liked what I found. However, the tutorial is based on only visual C++ 2008 Express Edition. I have different compiler. Hope IndieLib would work in a environment.

    Emeka

    24 de diciembre de 2008
  • Javier López

    Don’t worry, post your doubts on IndieLib forums. I’m sure we will be able to help you.

    24 de diciembre de 2008
  • Santiago

    Muy bueno el tutorial!
    Una pregunta, estoy usando la librería IO que hiciste para hacer mi versión del tetris, pero me sale un error de «undefined reference to _boxColor» cuando compilo con el CodeBlocks.
    Te agradezco si me podés ayudar.
    saludos!

    28 de diciembre de 2008
  • Javier López

    Bienvenido, Santiago!

    El error posiblemente se deba a que no se ha linkado correctamente SDL_GfxPrimitives_Static.lib. La tienes en tetris_tutorial_sdlSDLSDL_GfxPrimitives.

    Yo usé vc2008 Express Edition y para linkarla usé la directiva «pragma». Es decir, puse:

    #pragma comment (lib, «SDL/lib/SDL.lib»)
    #pragma comment (lib, «SDL/SDL_GfxPrimitives/SDL_GfxPrimitives_Static.lib»)

    Puede que en Code Blocks los linkados se hagan de manera distinta. No te lo sé decir porque no lo uso. Busca o pregunta cómo se linka una .lib en un proyecto de Code Blocks y supuestamente resolverás el problema.

    Mantenme al tanto, espero que lo puedas solucionar 🙂

    Si decides pasarte a vc20008 express edition, te recuerdo sólo que es gratis.

    ¡Un saludo y suerte!

    28 de diciembre de 2008
  • Santiago

    Me anduvo con el vc++2008 usando el mismo proyecto del tutorial pero con mis archivos, muchas gracias!

    1 de enero de 2009
  • Callum

    Thanks for the well commented tutorial! I was wanting to create tetris but was unsure how i could implement the blocks and i certainly like your method 🙂

    Just a quick question, how does the maths behind the GetXPosInPixels work? i just cant seem to figure out how you manage to convert block size into pixels and would love to find out how it actually does.

    Thanks 🙂

    8 de enero de 2009
  • Javier López

    You are welcome! 🙂

    So, for getting the X coordinate in pixeles we have:

    return ( ( BOARD_POSITION – (BLOCK_SIZE * (BOARD_WIDTH / 2)) ) + (pPos * BLOCK_SIZE) );

    Maybe this line seems a bit tricky, so maybe you could try to use pen and paper in order to change the variables by real numbers.

    Let’s say:
    BOARD_POSITION = 320 (in pixels)
    BLOCK_SIZE = 16 (in pixels)
    BOARD_WIDTH = 10 (in blocks)
    pPos = 2 (Horizontal position of the block (in blocks)

    So, having that, we now we want to get the x coordinate in pixels of a block that is in a third column (it is in pPos 2 and we have to start counting by 0).

    So, with this line:

    ( ( BOARD_POSITION – (BLOCK_SIZE * (BOARD_WIDTH / 2)) )

    We just one to calculate the x coordinate in pixels of the left corner of the board. Remember that BOARD_POSITION is the center of the board, in pixels. So we have to substract to that value the amount in pixels of the half of the blocks that fill in a board.

    After that we add to this value this line:

    (pPos * BLOCK_SIZE)

    This is just for getting the width of 2 blocks, that is the same as getting the x coordinate in order to draw a block in position 3.

    I hope this was explanatory enough.

    9 de enero de 2009
  • This is brilliant! Thank you so much! Really, really helpful.

    15 de enero de 2009
  • Johan

    Great tutorial, there is only one thing that’s unclear for me and that is that in step 1 I’m not sure in what header file I should put the information of the blocks.

    17 de enero de 2009
  • Javier López

    In fact I put the information not in the header but in the .cpp (check out the sourcecode you can download). But it could be in the header if you wish.

    17 de enero de 2009
  • Alexess

    very good!! thanks you.

    20 de enero de 2009
  • Javier López

    Thank to all you for the appreciative comments 🙂

    20 de enero de 2009
  • hey Javier Lopez I am studying game and simulation programming at devry and I got many years to get to programm a game engine. I am just curious what books you read or what helped you learn c++ to make a game engine by yourself. Wow that is amazing what you have done.. I love your work.

    23 de enero de 2009
  • Emeka

    I have not been able to get my head around this method mPiecesInitialPosition , please explain it further.

    24 de enero de 2009
  • … I’ve written a Java Tetris years ago – it’s an applet and should run in your browser (if Java’s installed).

    The game does not use matrices or anything – the positions are hard-coded too, but in an even simpler way 🙂

    25 de enero de 2009
  • Javier López

    @Emeka, mPiecesInitialPosition is just an array that has the displacement that each piece (the 4 possible rotations) has to suffer in order to be positioned when it is created. Just check out the two images that shows that in the tutorial:
    http://gametuto.com/images/wrong_and_good_tetris_positions.png
    http://gametuto.com/images/wrong_and_good_tetris_positions.png

    In the first image, we has drawn the piece without applying the translation, so it is not correctly positioned when created. On the second image, we have applied the translation to the piece, so it is correcly positioned when created.

    I hope this will clarify your doubt.

    25 de enero de 2009
  • @arbi, thank you very much for the appreciative words. It took me lot of years to in order to arrive to the 1.0 release. I think I spent more or less 5 years, but only working in spare time and with breaks of several months.

    I’m quite autodidact, I learnt c++ by myself, and before that Pascal, and Basic. I also work using Java and php. And I’m starting to enjoy c#. I’ve been programming since I was 9 years old and I’m currently 27 years old.

    I don’t know any book I can tell you to take a look. Anything I needed was is on Google, specially reading source code from other open source engines and talking in forums. I used to write a lot on stratos-ad.com forums (spanish). Now, I usually write on IndieLib forums: http://www.indielib.com/forum

    It would be great if you come to IndieLib forum and join our community. People like you, motivated and well prepared, will give the community a lot of value. Furthermore, if you are interested on engine programming, maybe you want to join the IndieLib development team, what do you think?

    See you!

    25 de enero de 2009
  • Javier López

    @Bob, that seems cool. What about explaining it a bit more? I’m interested!

    25 de enero de 2009
  • Very nice tutorial (simple, easy to understand and detailed). Backlinked to my blog.
    Keep up the good work.

    26 de enero de 2009
  • Javier López

    @Victor Almeida, thank you very much neighbour (iberic) 🙂

    26 de enero de 2009
  • Javier,
    Thank you for your reply sorry I am replying so late. Been busy programming. Taking 2 courses now. I am not so much a self learner but I am starting to be. Anyways the book that I use right now are C++ primer plus, Problem solving with C++, game programming with C++, and i look online for http://www.cplusplus.com/tutorial. It will take me some time just like you to really get a grasp of this language. One question I had did you first truely understand one language before you jumped into another or did you learn two at the same time. I am studying c++ but I know Java is easier since it has a garbage collector. Also C++ is ideal for game development but java is still used.

    I will for sure joing your forum. Thank you again for the reply. Sorry for the late reply

    6 de febrero de 2009
  • Javier López

    @arbi

    Hello again! That books you are talking about seems really interesting.

    Answering your question, sometimes, like right now, I have to deal with learning different languages at the same time. For example, currently I’m learning Php, because I need it for my day work. But I’m still learning C++… because you know: you never knows everything about nothing 🙂

    The best way to go is to have a good knowledge of POO programming and the different programming metodologies. Then is just a matter of getting some new concepts and keywords when learning a new language.

    8 de febrero de 2009
  • Veiko

    Hi Javier.

    This is really good tutorial. Its clean, its simple and it explains really good whats going on. The big bonus is pictures. I have searched such Tetris tutorial for a long time.

    I have bookmarked your site and this tutorial.

    Thanks alot Javier.

    10 de febrero de 2009
  • Javier López

    @Veiko, thanks alot to you for reading! 🙂

    10 de febrero de 2009
  • BERNARD

    This is good man. Do some of these code lines change when using borland c++. I am a beginner in c++ programming.

    15 de febrero de 2009
  • vkson

    Thanks Javier López.
    Tutor is detail. Easy to understand. But Could you add rotation solution into project is very good 🙂
    Thanks

    15 de febrero de 2009
  • Niko

    Javier thank you so much for very good tutorial/lesson. Keep up good work!

    16 de febrero de 2009
  • Dave

    Thanks that was a really great tutorial!

    I want to get into programming games and have found this really useful. Please write more soon!

    I was motivated to build tetris by this great lecture about an academic course that looks inspiring.
    http://video.google.com/videoplay?docid=7654043762021156507

    http://www1.idc.ac.il/tecs/

    Thought you might enjoy these fun tetris vids:

    http://www.youtube.com/watch?v=SYRLTF71Sow&feature=related

    http://www.notsonoisy.com/tetris/index.html

    20 de febrero de 2009
  • Bobic

    Very Good!
    Thanks.

    24 de febrero de 2009
  • Nick

    Thanks for writing a good tutorial. I’ve found it to be in-depth and very easy to understand.

    Just one question – why the use of WinMain and windows.h in main.cpp? From what I have done in the past using SDL on Windows, you can just use the normal int main(int argc, char** argv) entry point.

    2 de marzo de 2009
  • chris

    Thank you so much for this tuitorial. I have some questions, How can i execute this game? Right now i’m figuring it out but failed to execute it. Do i need to debug it in C++? and what file? or how can i make an exe DOS file out of it, to make it work?

    15 de marzo de 2009
  • mya

    nice ,awesome !!!!!!!!
    i expect more such ideas in upcoming game

    18 de abril de 2009
  • Roque Terrani

    Muchísimas gracias por el código y el tutorial, me ayudo bastante a terminar de darme la idea de como afrontar la mecánica del juego. Te comento que yo lo estoy programando en C para *PIC (microcontrolador de la empresa Microchip) y ya tenia bastante pensado los diagramas de la lógica del juego pero tu código me ayuda en la cuestión técnica de la programación. Obviamente ni bien lo tenga terminado paso a dejar fotos del bicho funcionando asi todos nos sentimos orgullosos.

    pd: Para los amantes de la electrónica dejo una breve explicación de lo que estoy haciendo. Pic 16f877a, 4 registros de desplazamiento para las filas, 6 matrices de 7×5 leds(2,5 cm x 5,3 cm en total), 3 display de 7 segmentos para las lineas y 4 pulsadores que hacen de teclas (Luego serán remplazados con una interfaz a teclado ps/2)

    19 de abril de 2009
  • Wai Kam

    Love it, and thx!!!

    5 de mayo de 2009
  • Battie

    Thank you very much for this wonderfull tutorial… However i want to implement something that it computes what the highest point of the POS_FILLED is.

    The time to drop a block should always be 6 no matter how much there POS_FILLED there are.

    in addition to that there should be 4 seconds inbetween a block is dropped and a new block appears in the air.

    Is this possible or not?

    18 de mayo de 2009
  • Soo

    Nice tutorial, thanks you a lot for that.
    I just have one question, i got 1 error when i tried to compile this project. It is about an undefined reference to ‘boxColor’.
    Can anyone help me with this plz ?

    29 de mayo de 2009
  • Sam L.

    Hi Javier, I translate your tutorial to Brazilian Portuguese.
    Download:
    http://www.4shared.com/file/95111285/e93a8160/Tetris_tutorial_para_iniciantes.html

    vlw!

    13 de junio de 2009
  • sshow

    Great tutorial!

    I’m using this to write my first game in C#.
    Planning on implementing multi-player features like in TetriNET.

    Great introduction for me, even though I’ve never used C++.
    The logic was basically what I was looking for, and you are explaining things _well_!

    Thanks!

    16 de junio de 2009
  • Alekh

    Hi a really nice tutorial. But I want to add some animations to this like the line complete animation. How do i implement such animations? Pls help me on this.. I really need help..

    17 de junio de 2009
  • Tom

    Hey – thanks alot for this tutorial – it’s very enlightening.

    However, I am having trouble understanding the StorePiece method in the Board class. I just can’t seem to follow it. Could you explain in more detail what this is doing? Also, why are you adding the PIECE_BLOCKS constant to pX and pY?

    Thanks

    23 de junio de 2009
  • Emeka

    Hello,
    I can’t find where this field » mScreenHeight» was assigned value?

    Emeka

    23 de junio de 2009
  • jimmy

    Had a lot of fun going through this great tutorial, but I run into the craziest problem when I try to alter the values of the #define’s… the compiler still keeps the original #define values!

    I’ve tried changing the #define’s to const int’s, and I’ve even completely commented out the #define’s… and the compiler still doesn’t mind.

    How does this happen??

    29 de junio de 2009
  • Wow amazing! What a clear, nice code!
    Though I’m wondering, in Board::StorePiece() you make a call to mPieces->GetBlockType(pPiece, pRotation, j2, i2) .. should this be: mPieces->GetBlockType(pPiece, pRotation, i2, j2)
    .. for clearity sake?

    15 de julio de 2009
  • Heather

    You know, you can very easily, without complex code, rotate the tetris pieces and cut down on your piece array.

    In a nested loop where the array is 5 wide by 5 wide:

    No rotation: newarray[j][i] = oldarray[j][i]
    1 step counterclockwise: newarray[4 – i][j] = oldarray[j][i]
    2 step counterclockwise: newarray[4 – j][4 – i] = oldarray[j][i]
    3 step counterclockwise: newarray[i][4-j] = oldarray[j][i]

    19 de julio de 2009
  • ~MoZzY~

    Very good tutorial…2 thumbs up…

    28 de julio de 2009
  • FFUUU

    Not another Tetris clone!

    31 de julio de 2009
  • Joe

    Greetings,

    Has anyone managed to run this in MacOSX? I managed to build it but when I tried to run it I got the following error message: Terminating app due to uncaught exception ‘NSInternalInconsistencyException’, reason: ‘Error (1002) creating CGSWindow’

    23 de agosto de 2009
  • Skaruts

    Just a minor detail I noticed: I remember in the original tetris that the pieces rotations only cycled through 2 positions.

    Taking the I shape example figures, figures 3 and 4 wouldn’t exist. They would only cycle through 1 and 2.

    Despite that, very nice and neat tut.
    Thanks.

    16 de septiembre de 2009
  • adnoctum

    Thx man, i will help from this because i will make a tetris in VB, thanx again

    11 de noviembre de 2009
  • feng

    vr nice n well explained tutorial
    reli appreciate it!
    but i was stuck in here :

    bool Board::IsGameOver()
    {
    //If the first line has blocks, then, game over
    for (int i = 0; i < BOARD_WIDTH; i++)
    {
    if (mBoard[i][0] == POS_FILLED) return true;
    }

    return false;
    }

    xxxxxxxxxx
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    1111111111

    this function is it checking the xxxxxx row?
    then i tot suppose the if statement sud look like this
    «if (mBoard[i][0] == POS_FILLED) return true;»

    anyone pls correct me if im wrong

    13 de noviembre de 2009
  • feng

    (sorry the upper comment is wrong, pls refer to this)

    vr nice n well explained tutorial
    reli appreciate it!
    but i was stuck in here :

    bool Board::IsGameOver()
    {
    //If the first line has blocks, then, game over
    for (int i = 0; i < BOARD_WIDTH; i++)
    {
    if (mBoard[i][0] == POS_FILLED) return true;
    }

    return false;
    }

    xxxxxxxxxx
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    0 0
    1111111111

    this function is it checking the xxxxxx row?
    then i tot suppose the if statement sud look like this
    “if (mBoard[0][i] == POS_FILLED) return true;”

    anyone pls correct me if im wrong

    13 de noviembre de 2009
  • feng

    oohh.. i understand d
    mBoard[x(width)][y(height)]

    13 de noviembre de 2009
  • supreme aryal

    Thank you for the tutorial. I implemented it in C. The code looks much the same, but it is in one large file. You can see it in action at:

    http://www.youtube.com/watch?v=WD52EoZHNJA

    14 de noviembre de 2009
  • great tut,

    just one difficulty i’m having with it.
    forgive me if it’s obvious, i’m new to game programming!!!

    I created a new piece ( a cross) and i’m not sure how to make the random piece function thingy include it in it’s selections…

    if someone could post and say all the places i would have to change, it would be greatly appreciated

    28 de noviembre de 2009
  • thanks javier.you’re my hero

    30 de noviembre de 2009
  • feng

    very nice, neat and easy understanding tetris tutorial!
    appreciate this so much !

    3 de diciembre de 2009
  • Pilot Boy

    Nice tut! Just what I needed!

    22 de diciembre de 2009
  • amir yazdanbakhsh

    Dear López,
    Thx for your brilliant game and tutorial.
    I’m going to write a simple game that are somehow similar with Tetris. I want capture mouse clicks. If player click on the one of these blocks, that blocks disapper, and if the blocks reach bottom of the board the user get a negative point.
    I’d appreciate if you could help me.

    Best Regards

    26 de diciembre de 2009
  • I was looking for a good tutorial making TETRIS!
    so here I am 🙂

    I’m not good in english but I’d like to say «thank you very much»

    from south korea 🙂

    13 de enero de 2010
  • heLLo!!

    ammhpp…anyone cud help me how to make a bingo chess game in Turbo C????

    pLz……

    8 de febrero de 2010
  • Mahi

    Hi,

    I went through the whole code and i really really appriciate it, though i am a rookie in programming. So can anyone help me getting this code with direct3d please? i will really appreciate it 🙂

    Thnx,

    Mahi

    15 de marzo de 2010
  • Eko

    Hello going through your code, but stopped at

    int Pieces::GetXInitialPosition (int pPiece, int pRotation)
    {
    return mPiecesInitialPosition [pPiece [pRotation][0];
    }

    the method only have 2 parameter, but return 3? What is the third doing «[0]» ? And why doesnt it say anything about it in description above? Ty for help.

    26 de marzo de 2010
  • fina

    tahnk u so much for your knowledge…:)

    3 de abril de 2010
  • hordi

    This tutorial shows Tetris logic very nicely. I started to make a Tetris game with C# and this really helps.

    One thing though, I fail to see the point of the pivot points since they’re not even used to rotate the piece.

    8 de abril de 2010
  • Mariano

    ¿Que compilador o programa usas?(Compiler or what program do you use?)

    21 de abril de 2010
  • Douglas

    estou começando agora a programar jogos, você tem algum tutorial de como fazer engine pra principiantes ou algum livro para me recomendar

    21 de abril de 2010
  • lyzen

    i want a program c++ games or ATM
    before thanks,,,

    21 de mayo de 2010
  • mnlgarbe

    Muchas Gracias sinceras, un gran trabajo que ayuda a muchisima gente que como yo, empezamos en esto

    3 de junio de 2010
  • AbduRahman

    thanks for this amazing tutorial ,this what i was looking for ,logic explanation,not just code ready to run that you have no idea what is it about .but for a beginner like me , it taught me great things about games programming ,specially dealing with arrays .i wrote the game using c#.

    i hope you make similar tutorials 🙂 .

    4 de junio de 2010
  • Chris Cansler

    Janvier, excellent tutorial! On Board.cpp, the comment for GetYPosInPixels() indicates that parameter pPos is the «Horizontal position of the block in the board.» I think it should be «Vertical position of the block in the board» instead.

    14 de julio de 2010
  • Excelent tuto dude, helps to solve some issue on my game

    23 de julio de 2010
  • Hello! This tetrix tuto is really illustrative! I need it because I was requested to develop a Puyo Puyo console application, should be easier but I can’t find anything on the net.
    Very good Tuto!

    6 de agosto de 2010
  • M Salazar

    Thanks a ton! This is an awesome tutorail, I really appreicaite it! 😛

    17 de agosto de 2010
  • Andrey

    Thanks for the tutorial. Can someone help me, please? I want to add the text before the game board starts. Can you help me? Please?

    6 de septiembre de 2010
  • jayden

    hi, recently i managed to rebuild spaceinvaders and also pacman with java on a mac osx, compiled it with unix javac. some difficulties at the beginning, but managed to compile the games and had them working.

    but actually i want to learn c++ rather then java. and now i have some problems compiling c++ with unix, tried some sources, but didnt work out till now. can you give me some advice, on how i get your tetris-clone compiled?

    muchas gracias, jayden

    17 de septiembre de 2010
  • jayden

    «can you give me some advice, on how i get your tetris-clone compiled?»

    compiled on unix, i meant.

    thanks…

    17 de septiembre de 2010
  • forkon

    Thanks a lot!It’s very usful for me!

    27 de octubre de 2010
  • Craya

    I am not clear of the mPiecesInitialPosition[7][4][2]array,such as the initial of square,why is it [-2][-3]? how did you definite the number -2 and -3?

    21 de noviembre de 2010
  • Craya

    In the IO.cc, you didn’t give the implementation of the boxColor(), I could figure out it, could you add it?Thanks a lot!

    23 de noviembre de 2010
  • heaven

    JAVIER, can you translate sdl to directx for me??
    i learn directx,and i don’t understand about sdl?

    24 de noviembre de 2010
  • hi
    tnx a lot for this…
    good luck javier

    2 de enero de 2011
  • kpc

    Oh-my-god!

    Man, you just saved my life with tomorrows assignment!

    Cheers!

    19 de enero de 2011
  • bharat C. Soni

    Thank you sir,
    Tetris tutorial in c++ is really good.
    i am going to develop my own demo game based on this tutorials. thank you again and keep doing this.

    28 de enero de 2011
  • Cynth

    Is there no easier way to explain how to make this tetris game?
    The pieces created, in what file is it saved to, is it to the main.cpp or the pieces.h file?
    I’m a lil confused here
    :-s

    8 de febrero de 2011
  • it’s so nice tutorial. i can learn much about game programing from this. arigato gozaimasu…

    2 de marzo de 2011
  • Ahmed Ahsan Khan

    hey man… dude i went through your tutorial several times. i have decided to make a tetris game for my OOP project. dude i didnt find the function definitions of the IO.h header file. are the functions predefined or what? would you give us the definitions of that header file functions too?. thanks..

    2 de mayo de 2011
  • Srinivas

    Thank you very much. This tutorial and game source code will help me for my project in my college, as I am doing «Game Programming» course. Thank you once again!!

    29 de mayo de 2011
  • Camilo Muñoz

    Gracias por el tutorial. Me ha servido mucho para entrarme en este mundo de programación de videojuegos. Excelente lógica, excelentes soluciones. De nuevo gracias

    7 de junio de 2011
  • Tony

    hello!

    tell me please, what type of project should i create?
    i am using visual c++ 2008 express edition.

    but when i am trying to compile i get a lot of «error LNK2019».
    all of them seems like that:

    «error LNK2019: unresolved external symbol «public: void __thiscall Game::CreateNewPiece(void)» (?CreateNewPiece@Game@@QAEXXZ) referenced in function _WinMain@16″.

    help me please. big thanx!!!

    19 de junio de 2011
  • Timothy

    I don’t understand the function of
    int mPiecesInitialPosition [7 /*kind */ ][4 /* rotation */ ][2 /* position */]

    How does it work?
    What is the initial position of the block?

    27 de julio de 2011
  • Timothy

    The Wrong Initial Position is on the left upper corner of the board? So we have to shift two to three boxes to get the correct initial position?

    Can the wrong initial position on the right corner?
    Why it is located at the upper left?

    27 de julio de 2011
  • Timothy

    And the second question is out of the 5×5 cells

    There are nothing?(except the filled position)
    nothing means we don’t have to assign any memory location to those black background

    27 de julio de 2011
  • Timothy

    I think i have solved the first question

    27 de julio de 2011
  • Hi! I’ve been reading this tutorial since I was a game development trainee. Thanks a lot for this! 😀 I’ll give you a link for this.

    3 de agosto de 2011
  • MICRO_

    I SEE ERROR :»Program cant start because SDL.dll is missing from your computer
    Try reinstalling the program to fix probleM»
    PLEASE HELP ME TO FIX IT

    16 de agosto de 2011
  • Rafael

    Hola, tenía el motor del libro «Teach yourself game programmint in 24 hours» de Michael Morrison. Implementé la máquina virtual de Lua y reprogramé éste tutorial de Tetris en Lua. Después de algunos quebraderos de cabeza con la forma de trabajar con tablas, valores de true y false, bucles, etc (no conocía el lenguaje y ha sido una buena forma de aprender), por fin terminé.

    Muchas gracias por el tutorial.

    4 de septiembre de 2011
  • Owais

    Great Work Sir! I really need this tutorial

    8 de septiembre de 2011
  • Mau Jabur

    Hi!

    Great tutorial!

    I’m working on porting your code to Processing.

    I’ll give you the credits, so, would you please tell me how you want the comment on the top of the file?

    Thank you

    9 de septiembre de 2011
  • thanks to you because it help me.. so much

    26 de septiembre de 2011
  • Thank you very much! The tutorial is very good.

    7 de octubre de 2011
  • Ximena

    Is there any way to stay in touch with you? I’d like to ask you some things… 😀 thanks!

    9 de noviembre de 2011
  • zalook

    Thanks

    2 de abril de 2012
  • YongYe

    Hi,Javier López:
    I have already developed a very powerful Tetris Game based on a Shell Script(bash) which i had made it a open soure project at https://github.com/yongye/shell all by myself , you can see the screenshot and the matrix equation for the core algorithm at http://bbs.chinaunix.net/thread-3614425-1-1.html. In my way, all the movements of the pieces are performed by mathematics calculation which is the key to make the game so flexible and powerful that you can perform you own customizations for any kinds of the shapes of the pieces dynamically!
    I’m self-learning C++ now, i’d love to port my Shell-based Tetris to a c++ one, i’ll take some time to learn your tutorial although we perform the task in such a different way!

    24 de abril de 2012
  • samie

    Hi, I got a copy of your the program in form environment in visual studio c++, then i clicked on the debug the program error events associated with Wayne did not compile: error C1083: Cannot open include file: ‘Pieces.h’: No such file or directo.what program have this program?

    21 de junio de 2012
  • Mark

    Hi, Javier López:
    I am making this tetris game using only the ASCII characters because I am still not knowledgeable about graphics..
    but I did it in a not noticeable way that it is an ASCII chars. I put up all those char to make a square of block and put it up again to make a tetris piece.
    the drawing is done but I am having a hard time to make this collision detection,
    I googled about the collision detection and landed in here.
    I found your code in collision detection very confusing for a newbie like me, and I don’t really understand how you put the pieces in the board…
    anyway, just to finish my tetris game, I copied your code and put in mine. I based by collision detection and storing of pieces on your code and the drawing stuffs is mine. and poof! it is done..I am glad that I did it with the help of you. Thank you sir!

    24 de junio de 2012
  • Joshua

    Great tutorial.

    Quick point: for people with fedora, you should be able to install sdl libraries necessary using

    sudo yum install SDL*

    6 de agosto de 2012
  • nintendo games

    Nice blog here! Also your site a lot up fast! What web host are you the usage of? Can I get your associate hyperlink to your host? I wish my web site loaded up as fast as yours lol

    29 de agosto de 2012
  • Andy

    In IsPossibleMovement :
    if ( i1 BOARD_WIDTH – 1 || j1 > BOARD_HEIGHT – 1)
    {
    ..
    }

    Shouldn’t be i1 < BOARD_WIDTH – 1 * BLOCK_SIZE ?? If i1 == BOARD_WIDTH – 2, it still can be a problem can't it ?

    Extra tutorial, thanks a lot !

    1 de octubre de 2012
  • rtt

    Hi,
    I am using vs2008 and try to build the debug version. The compile is ok. When running, I got the error:
    Runtime Error!
    R6034
    An application has made an attempt to load the C runtime libraty incorrectly.
    Please contact teh application’s support team for more information.

    Any help will be appreciated!

    16 de noviembre de 2012
  • Protegon

    No pude ejecutarlo en QT 🙁

    18 de diciembre de 2012
  • orly

    i really appreciate it.. 😀
    i am a first year college IT student and our prof. told us to make a tetris game in tc++ but the pieces.h don’t work.
    // —— Includes —–

    #include «Pieces.h»

    // —— Defines —–
    why??? pls help me.. 🙁

    20 de diciembre de 2012
  • Wedge

    ¿Dónde está el tutorial en español? 🙁

    19 de marzo de 2013
  • Ste

    Thank you, Javier López! I want to know how to imply a Teris game, and this is just what I’m looking for! I really like the data structure you used to store the pieces and the methods with which you check the collision. Great job!

    25 de marzo de 2013
  • Ste

    And here is a tutorial on its implementation. [http://stewannahavefun.blogspot.com/]

    8 de abril de 2013
  • Jose De Jesus

    Hi, i have a question, how did i print the pieces, can you help me wih that ?
    Thanks, EXCELLENT tutorial

    16 de abril de 2013
  • aakash

    anybody have Sudoku source code using turbo c.

    18 de abril de 2013
  • Alexey

    ooo! thanks, this is what I need. chic tutorial

    25 de abril de 2013
  • Alagaola

    Thanks ! ^_^

    27 de abril de 2013
  • Wendy

    Thank you very much for the tutorial.
    However, I couldn’t have it run. My system is Ubuntu 12.04.
    After tying to complie, it gives me the follwoing error message:
    main.cpp: (.text+0X8d):undefiend reference to ‘SDL_GetTicks’
    main.cpp: (.text+0X389):undefiend reference to ‘SDL_GetTicks’
    main.cpp: (.text+0X484):undefiend reference to ‘SDL_GetTicks’
    IO.o: In function ‘IO::UpdateScreen();:
    IO.cpp:(.text+0xd5):undefined reference to ‘SDL_Flip’
    IO.o: In function ‘IO::Pollkey();:
    IO.cpp:(.text+0xd5):undefined reference to ‘SDL_PollEvent’
    ..
    ..
    ..
    (etc, a lot of similar messages)
    collect2: ld returned 1 exit status
    make:*** [tetris] Error 1

    Any idea? I tried everything that comes to my mind…
    Thank you in advance!

    12 de mayo de 2013
  • Wendy

    Well, I found the error.
    I’m running g++ on Linux, and the makefile is not compatible with my setting.
    So instead of directly using the make file, just run it directly:
    g++ Main.cpp Game.cpp Board.cpp Pieces.cpp IO.cpp -o tetris -lSDL -lSDL_gfx

    14 de mayo de 2013
  • Jason

    Hello,

    I’m having some problem with compiling. I’m using Code::Blocks on Windows 7. It compiles with 2 warnings and my Build Log says this:

    «Warning: .drectve ‘-defaultlib:MSVCRT ‘ unrecognized»
    «Warning: .drectve ‘-defaultlib:OLDNAMES ‘ unrecognized»
    «Cannot export _aacircleColor: symbol not found»
    «Cannot export _aacircleRGBA: symbol not found»

    Has anyone else run into this? Any success in fixing?

    29 de julio de 2013
  • toby

    undefined reference to boxColor ? Can anyone help ?

    15 de agosto de 2013
  • kt

    can we use structure(struct) in the game if yes then please help

    7 de enero de 2014
  • Scott Weldon

    @Javier and @Wendy:

    The reason for this is an error in the makefile. According to [1], the libraries (the variable LDFLAGS) *must* come after the object files. I made that simple change to the makefile and it worked. (I have made no other changes besides installing the required packages. Running Linux Mint 16.)

    [1] http://stackoverflow.com/questions/8640642/gcc-link-order-changed/8640681

    19 de marzo de 2014
  • Javilop

    Thank you Scott!

    20 de marzo de 2014
  • user

    can you help me with tetris project in borland c++ builder.

    14 de abril de 2014
  • Logayn

    Thank you very much, but I have two concern,
    1) I did not get that part:
    int mPiecesInitialPosition [7 /*kind */ ][4 /* r2otation */ ][2 /* position */] =
    2) I got somehow lost by the variable names
    #define BOARD_LINE_WIDTH 6
    #define BLOCK_SIZE 16
    #define BOARD_POSITION 320
    #define BOARD_WIDTH 10
    #define BOARD_HEIGHT 20
    #define MIN_VERTICAL_MARGIN 20
    #define MIN_HORIZONTAL_MARGIN 20
    #define PIECE_BLOCKS 5
    the comments beside did not clarify 100% what those names mean.
    Again this was very helpful.
    thank you in advance

    2 de julio de 2014
  • Sanunu

    Nice stuff. Thanks a lot!

    10 de agosto de 2014
  • Bee

    Really Thanks to you!! A Lot!!!

    5 de noviembre de 2014
  • FidelFiestas

    sabes como puedo ejecutar el main.cpp desde una terminal de mac?

    19 de noviembre de 2014
  • HauDo

    Hi @Javilop !
    You can make a second tutorial of how to improve this Tetris clone using sprites, background, effects, please ?

    10 de diciembre de 2014
  • Dave

    Thank You very much for this Mr. Javier. Would you be kind enough to let us know if we can change the title from «SDL_app» to anything else. Thank You.

    16 de diciembre de 2014
  • diego dm

    i never thought about programming a tetris.. interesting!

    30 de diciembre de 2014
  • abdallah

    Please guys what i need to learn to be able to write this code.

    11 de abril de 2015
  • sharon

    in linux SDL.H is missing ? IO.h:30:30: fatal error: SDL/SDL.h: No such file or directory
    #include

    17 de noviembre de 2015
  • Adam

    How would you code a ghost piece?

    29 de marzo de 2016
  • CT

    Hi @Javilop!

    Thanks a lot for your tutorial. It’s so good.

    Can you help me : how to print a text into game board? i can’t use printf in video mode of SDL :(.

    4 de mayo de 2016
  • Danial

    Hello.
    thank you for your explanation.
    Does this code works on «Dev C++»?
    If not, could you explain where should I make changes?

    18 de julio de 2016
  • JHB

    here’s the missing function:

    void boxColor(SDL_Surface *screen, int x1, int y1, int x2, int y2, Uint32 color)
    {
    SDL_Rect rect{ x1, y1, x2-x1, y2-y1 };
    SDL_FillRect(screen, &rect, color);
    }

    19 de noviembre de 2016
  • Yash Shingadiya

    Perfect code with not a single error and the best explanation ever seen.

    8 de octubre de 2017
  • js

    thank you Javier!! it’s amazing!!

    5 de diciembre de 2017
  • TX

    Can someone explain the use of variables pX and pY

    15 de marzo de 2018
  • Damian

    Very nice and clean code and examples, muchas gracias!!

    30 de abril de 2018
  • Suprio Biswas

    The code is damn good and very nicely explained…

    6 de julio de 2018
  • Wallace Mielniczki

    Não estou conseguindo compilar no g++ do linux. ele da o seguinte erro:
    Main.cpp:21:10: fatal error: windows.h: Arquivo ou diretório inexistente
    #include
    ^~~~~~~~~~~
    compilation terminated.

    29 de marzo de 2019

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