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I'm a student and this is my first application/project that I made and finished today in C++ using OOP and I want to hear your opinions and suggestions, what I did wrong, what I did good, what should I improve, what should I exclude, about comments, anything that can help me getting better and improve my code.

To test the code you will need to copy the file tiles.in which contains the tiles for the game.

I made a UML diagram for better understanding of the code:

UML

#include "pch.h"
#include <conio.h>
#include <exception>
#include <fstream>
#include <iostream>
#include <math.h>
#include <stdlib.h>
#include <time.h>
#include <windows.h>

#define numberOfColumns 11               // number of lines and columns for the game table
#define numberOfLines 21

using namespace std;

class Drawable                          // abstract class that is used to draw different tiles from the game or coordinates
{
protected:
    static short x;
    static short y;
public:
    static int getX();
    static void hidecursor();
    static void MoveTo(short _x, short _y);     // used to move to a specific coordinate in console
    virtual void DeleteDraw() = 0;
    virtual void Draw() = 0;
};

short Drawable::x = 5;                   // represents the coordinates where the game table will be positioning in console
short Drawable::y = 25;

int Drawable::getX()
{
    return x;
}

void Drawable::hidecursor()
{
    CONSOLE_CURSOR_INFO info = { 100,FALSE };
    SetConsoleCursorInfo(GetStdHandle(STD_OUTPUT_HANDLE), &info);
}

void Drawable::MoveTo(short _x, short _y)
{
    COORD coord = { y + _y,x + _x };
    SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
}

class Coordinates: public Drawable                // class that represents one coordinate in console (x,y)
{
private:
    short x;
    short y;
    static char form;                             // the form that every piece(point) from every tile will have
public:
    Coordinates(short x = 0, short y = 0);
    Coordinates& operator =(const Coordinates &coord);
    // getter and setter
    short getX();
    short getY();
    static char getForm();
    void setX(short x);
    void setY(short y);
    //functions using coordinates(x,y)
    void moveCoordinatesInADirection(char direction);     // used to move the coordinates in a specific direction(right, left, down)
                                                          // Will be used to move every piece(point) from a tile in a direction
    void DeleteDraw() override;
    void Draw() override;
};

char Coordinates::form = '*';

Coordinates::Coordinates(short x, short y)
{
    this->x = x;
    this->y = y;
}

Coordinates& Coordinates::operator=(const Coordinates &coord)
{
    if (this != &coord)
    {
        this->x = coord.x;
        this->y = coord.y;
        this->form = coord.form;
    }
    return *this;
}

char Coordinates::getForm()
{
    return form;
}

short Coordinates::getX()
{
    return x;
}

short Coordinates::getY()
{
    return y;
}

void Coordinates::setX(short x)
{
    this->x = x;
}

void Coordinates::setY(short y)
{
    this->y = y;
}

void Coordinates::moveCoordinatesInADirection(char direction)
{
    switch (direction)
    {
    case 'a':       // move left
        y--;
        break;
    case 'd':       // move right
        y++;
        break;
    case 's':       // move down
        x++;
        break;
    default:
        break;
    }
}

void Coordinates::DeleteDraw()
{
    MoveTo(x + Drawable::x, y + Drawable::y);   // Moves to the coordinates (x,y) and deletes a piece(point) from a tile
    cout << " ";
}

void Coordinates::Draw()
{
    MoveTo(x + Drawable::x, y + Drawable::y);   // Moves to the coordinates (x,y) and draw a piece(point) from a tile
    cout << form;
}


class Tile: public Drawable                     // class that represents a tile and all its methods
{
private:
    Coordinates coordTile[4];                         // any tile is composed of 4 coordinates and a center
    short centerOfTile;
public:
    Tile& operator=(const Tile &tile);
    // getter and setter
    short getcenterOfTile(short position);
    short getcoordX(short position);
    short getcoordY(short position);
    void setcenterOfTile(short centerOfTile);
    void setcoordX(short position, int x);
    void setcoordY(short position, int y);
    //methods using a tile
    void moveTileInADirection(char direction);          // moves the tile in a specific direction(right, left, down)
    void rotateTileInADirection(char direction);       // rotates the tile in a specific direction(right, left)
    void DeleteDraw() override;                       // overrides function DeleteDraw() from Drawable() and is used to delete the tile from the game table
    void Draw() override;                            // overrides function Draw() from Drawable() and is used to draw the tile in the game table
};

Tile& Tile::operator=(const Tile &tile)
{
    if (this != &tile)
    {
        for (short i = 0; i < 4; i++)
        {
            this->coordTile[i] = tile.coordTile[i];
        }
    }
    return *this;
}

short Tile::getcoordX(short position)
{
    return coordTile[position].getX();
}

short Tile::getcoordY(short position)
{
    return coordTile[position].getY();
}

short Tile::getcenterOfTile(short position)
{
    return centerOfTile;
}

void Tile::setcoordX(short position, int x)
{
    coordTile[position].setX(x);
}

void Tile::setcoordY(short position, int y)
{
    coordTile[position].setY(y);
}

void Tile::setcenterOfTile(short centerOfTile)
{
    this->centerOfTile = centerOfTile;
}

void Tile::moveTileInADirection(char direction)
{
    for (short i = 0; i < 4; i++)
    {
        coordTile[i].moveCoordinatesInADirection(direction);
    }
}

void Tile::rotateTileInADirection(char direction)
{
    short dir = 0;

    switch (direction)
    {
    case 'e':           // to rotate the tile to the right we need +90* check formula down
        dir = 1;
        break;
    case 'q':           // to rotate the tile to the left we need -90* check formula down
        dir = -1;
        break;
    default:
        return;
    }

    if (centerOfTile != -1) // If the tile can be rotated
    {
        float centerOfTileX = coordTile[centerOfTile].getX();
        float centerOfTileY = coordTile[centerOfTile].getY();

        float tileX;
        float tileY;

        for (short i = 0; i < 4; i++)  // we rotate every piece(point) from the tile with 90*(to right) or -90*(to left) depends on dir
        {
            tileX = coordTile[i].getX();
            tileY = coordTile[i].getY();
            coordTile[i].setX(round((tileX - centerOfTileX)*cos((90 * 3.14*dir) / 180) + (tileY - centerOfTileY)*sin((90 * 3.14*dir) / 180) + centerOfTileX));
            coordTile[i].setY(round((centerOfTileX - tileX)*sin((90 * 3.14*dir) / 180) + (tileY - centerOfTileY)*cos((90 * 3.14*dir) / 180) + centerOfTileY));
        }
    }
}

void Tile::DeleteDraw()
{
    for (short i = 0; i < 4; i++)
    {
        coordTile[i].DeleteDraw();      // Deleting the tile by deleting every piece(point) of it
    }
}


void Tile::Draw()
{
    for (short i = 0; i < 4; i++)
    {
        coordTile[i].Draw();             // Drawing the tile by drawing every piece(point) of it
    }
}

class Tiles                       // class that represents the number of tiles the game has and all tiles
{
private:
    short numberOfTiles;
    Tile *figuri;
public:
    Tiles();
    Tile getTile(short number);
    short getNumberOfTiles();
    ~Tiles();
};

Tiles::Tiles()
{
    ifstream input("tiles.in");               // reading from a file the number of tiles and than the coordinates of each tile and setting the center for every tile
    input >> numberOfTiles;

    figuri = new Tile[numberOfTiles];
    short auxiliaryVar = 0;
    short counter = 0;

    for (short i = 0; i < numberOfTiles; i++)
    {
        counter = 0;
        for (short j = 0; j < 4; j++)
        {
            for (short k = 0; k < 4; k++)
            {
                input >> auxiliaryVar;
                if (auxiliaryVar != 0)
                {
                    figuri[i].setcoordX(counter, j);
                    figuri[i].setcoordY(counter, k);
                    counter++;
                    if ((j == 1) && (k == 2))
                    {
                        figuri[i].setcenterOfTile(counter - 1);
                    }
                }
            }
        }
    }

    figuri[0].setcenterOfTile(2);
    figuri[3].setcenterOfTile(-1);
    input.close();
}

Tile Tiles::getTile(short number)
{
    return figuri[number];
}

short Tiles::getNumberOfTiles()
{
    return numberOfTiles;
}

Tiles::~Tiles()
{
    delete[] figuri;
}


class Table: public Drawable           // class that represents the game table 
{
private:
    short **table;            // the game table= a matrix with 0 if there is nothing draw in that point and 1 if there is something draw 
    long score;
    Tile actualTile;         // the tile that moves in the game table(the actual tile)
    Tiles allTiles;         // the actual tile will be chosen random from all the tiles possible

public:
    Table();
    long getScore();
    void informationAboutGame();
    void generateRandomTile();
    void deleteLineFromTable(short line);        // after a line from the table is completated, it will be deleted from the game table and the score will rise
    void moveTileDownAutomatically();
    void moveTileInADirection(char direction);
    void possibleMoves(short &time);          // possible moves of a player (right, left, down)
    void positioningTileInTableAfterRotation();
    void rotateTileInADirection(char direction);
    void start();
    void DeleteDraw();
    void Draw();
    bool belongsToActualTile(short x, short y);
    bool checkIfCanMoveInADirection(char direction);
    bool checkIfPlayerLost();
    ~Table();
};

Table::Table()
{
    // creating the game table and initialize the table

    time_t t;
    srand((unsigned)(time(&t)));

    score = 0;

    table = new short*[numberOfLines];
    for (short i = 0; i < numberOfLines; i++)
    {
        table[i] = new short[numberOfColumns];
    }

    for (short i = 0; i < numberOfLines; i++)
    {
        for (short j = 0; j < numberOfColumns; j++)
        {
            table[i][j] = 0;
        }
    }
}

long Table::getScore()
{
    return score;
}

void Table::informationAboutGame()
{
    cout << "\n\n\n\t This is a tetris game.The controls for the game are:\n";
    cout << "\n\t a - move the tile left";
    cout << "\n\t d - move the tile right";
    cout << "\n\t s - move the tile down";
    cout << "\n\t e - rotate the tile right";
    cout << "\n\t q - rotate the tile left";
    cout << "\n\n\t When you are ready, press any key to start the game. Good luck ! ";
    _getch();
}

void Table::generateRandomTile()
{
    // generating a random tile from all the tiles possible and setting its coordinates for the game table

    short randomTile;
    randomTile = rand() % allTiles.getNumberOfTiles();

    actualTile = allTiles.getTile(randomTile);
    actualTile.setcenterOfTile(allTiles.getTile(randomTile).getcenterOfTile(randomTile));

    for (short i = 0; i < 4; i++)
    {
        actualTile.setcoordY(i, numberOfColumns / 2 - actualTile.getcoordY(i) + 2);
    }
}

void Table::deleteLineFromTable(short line) 
{
    // Deleting the line which is completed
    // This is done by replacing every line starting that line by the previous one
    for (short i = line; i > 0; i--)
    {
        for (short j = 0; j < numberOfColumns; j++)
        {
            Drawable::MoveTo(i + Drawable::x, j + Drawable::y);
            if (table[i - 1][j] == 0)
            {
                cout << " ";
            }
            else {
                cout << Coordinates::getForm();
            }

            table[i][j] = table[i - 1][j];
        }
    }

    for (short i = 0; i < numberOfColumns; i++)
    {
        Drawable::MoveTo(0 + Drawable::x, i + Drawable::y);
        cout << " ";
        table[0][i] = 0;
    }
}

void Table::moveTileDownAutomatically()
{
    //Moving the actual tile down every 0.5s and checking if the player wants to make a move(right, left, down) or rotate(right, left) the tile
    actualTile.Draw();

    do {
        short time = 1;

        while (time < 500)
        {
            if (_kbhit())             // if the player presses a key on keyboard
            {
                possibleMoves(time);
            }

            Sleep(1);
            time = time + 1;
        }

        if (checkIfCanMoveInADirection('s'))
        {
            actualTile.DeleteDraw();
            moveTileInADirection('s');
            actualTile.Draw();
        }
        else {
            break;
        }
    } while (true); 
}

void Table::moveTileInADirection(char direction)
{
    // To move the tile in a direction we need to :
    // - delete the previous tile from the game table by putting 0
    // - move the tile to the new coordinates
    // - actualizate the game table by putting 1 on its coordinates 
    for (short i = 0; i < 4; i++)
    {
        table[actualTile.getcoordX(i)][actualTile.getcoordY(i)] = 0;
    }

    actualTile.moveTileInADirection(direction);

    for (short i = 0; i < 4; i++)
    {
        table[actualTile.getcoordX(i)][actualTile.getcoordY(i)] = 1;
    }
}

void Table::possibleMoves(short &time)
{
    //Possible moves that can be effectuated on a tile ( move and rotate )
    char direction = _getch();

    if (checkIfCanMoveInADirection(direction))
    {
        actualTile.DeleteDraw();                  // delete old tile
        moveTileInADirection(direction);          // move the tile in the direction the player wanted
        actualTile.Draw();                        // draw the new tile
        if (direction == 's')
        {
            time = 1;
        }
    }
    // check if the player wanted to rotate the tile (right, left)
    if ((direction == 'e') || (direction == 'q'))
    {
        actualTile.DeleteDraw();
        rotateTileInADirection(direction);
        actualTile.Draw();
    }
}

void Table::positioningTileInTableAfterRotation()
{
    // This method is used to check and correct a tile if it goes out of boundaries of the game table after a rotation
    short index = 0;
    short ok = 1;

    while (index < 4)
    {
        if (actualTile.getcoordY(index) < 0)
        {
            // passed left boundary of the game table
            for (short j = 0; j < 4; j++)
            {
                actualTile.setcoordY(j, actualTile.getcoordY(j) + 1);
            }
            ok = 0;
        }

        if (actualTile.getcoordY(index) > numberOfColumns - 1)
        {
            // passed right boundary of the game table
            for (short j = 0; j < 4; j++)
            {
                actualTile.setcoordY(j, actualTile.getcoordY(j) - 1);
            }
            ok = 0;
        }

        if (actualTile.getcoordX(index) < 0)
        {
            // passed top boundary of the game table and there are cases where the player loses
            for (short j = 0; j < 4; j++)
            {
                actualTile.setcoordX(j, actualTile.getcoordX(j) + 1);
            }

            for (short j = 0; j < 4; j++)
            {
                if ((actualTile.getcoordX(j) > 0) && (table[actualTile.getcoordX(j)][actualTile.getcoordY(j)] == 1))
                {
                    throw 0;
                }
            }
            ok = 0;
        }

        if ((actualTile.getcoordX(index) > numberOfLines - 1) ||
            (table[actualTile.getcoordX(index)][actualTile.getcoordY(index)] == 1))
        {
            // passed the down boundary or reached a possition that is occupied
            for (short j = 0; j < 4; j++)
            {
                actualTile.setcoordX(j, actualTile.getcoordX(j) - 1);
            }
            ok = 0;
        }

        if (ok == 0)
        {
            index = 0;
            ok = 1;
        }
        else {
            index++;
        }
    }
}

void Table::rotateTileInADirection(char direction)
{
    // To rotate the tile in a direction we need to :
    // - delete the previous tile from the game table by putting 0
    // - move the tile to the new coordinates and adjust it so it doesnt pass the boundaries of the game table
    // - actualizate the game table by putting 1 on its coordinates
    for (short i = 0; i < 4; i++)
    {
        table[actualTile.getcoordX(i)][actualTile.getcoordY(i)] = 0;
    }

    actualTile.rotateTileInADirection(direction);
    positioningTileInTableAfterRotation();

    for (short i = 0; i < 4; i++)
    {
        table[actualTile.getcoordX(i)][actualTile.getcoordY(i)] = 1;
    }
}

void Table::start()
{
    Drawable::hidecursor();
    informationAboutGame();

    DeleteDraw();
    Draw();

    short ok = 1;

    while (true)
    {
        // This while will end when the player will lose and the program will end
        // checking if there is any line completed and needs to be deleted
        for (short i = 0; i < numberOfLines; i++)
        {
            ok = 1;

            for (short j = 0; j < numberOfColumns; j++)
            {
                if (table[i][j] == 0)
                {
                    ok = 0;
                    break;
                }
            }
            if (ok)
            {
                deleteLineFromTable(i);
                score++;
            }
        }

        generateRandomTile();

        if (checkIfPlayerLost() == 1)
        {
            moveTileDownAutomatically();
        }
        else {
            Drawable::MoveTo(numberOfLines + 1 + Drawable::x, 0);
            cout << "\n" << "Good job, you made " << score * 1000 << " points.\n";
            break;
        }
    }
}

void Table::DeleteDraw()
{
    // Method used to delete the table
    system("cls");
}

void Table::Draw()
{
    // Method used to draw the table 
    for (short i = -1; i <= numberOfLines; i++)
    {
        MoveTo(i + Drawable::x, -1 + Drawable::y);
        cout << char(219);
        MoveTo(i + Drawable::x, numberOfColumns + Drawable::y);
        cout << char(219);
    }
    for (short i = -1; i <= numberOfColumns; i++)
    {
        Drawable::MoveTo(-1 + Drawable::x, i + Drawable::y);
        cout << char(219);
        Drawable::MoveTo(numberOfLines + Drawable::x, i + Drawable::y);
        cout << char(219);
    }
}

bool Table::belongsToActualTile(short x, short y)
{
    //Checking if a piece(point) of a tile belonds to the actual tile
    for (short i = 0; i < 4; i++)
    {
        if ((actualTile.getcoordX(i) == x) && (actualTile.getcoordY(i) == y))
        {
            return 0;
        }
    }

    return 1;
}

bool Table::checkIfCanMoveInADirection(char direction)
{
    for (short i = 0; i < 4; i++)
    {
        switch (direction)
        {
            // Check if the player can move left
        case'a':
            if ((actualTile.getcoordY(i) - 1 < 0) ||
                ((belongsToActualTile(actualTile.getcoordX(i), actualTile.getcoordY(i) - 1)) &&
                (table[actualTile.getcoordX(i)][actualTile.getcoordY(i) - 1] == 1)))
            {
                return 0;
            }
            break;
            // Check if the player can move right
        case'd':
            if ((actualTile.getcoordY(i) + 1 > numberOfColumns - 1) ||
                ((belongsToActualTile(actualTile.getcoordX(i), actualTile.getcoordY(i) + 1)) &&
                (table[actualTile.getcoordX(i)][actualTile.getcoordY(i) + 1] == 1)))
            {
                return 0;
            }
            break;
            // Check if the player can move down
        case's':
            if ((actualTile.getcoordX(i) + 1 > numberOfLines - 1) ||
                ((belongsToActualTile(actualTile.getcoordX(i) + 1, actualTile.getcoordY(i))) &&
                (table[actualTile.getcoordX(i) + 1][actualTile.getcoordY(i)] == 1)))
            {
                return 0;
            }
            break;
        default:
            break;
        }
    }
    return 1;
}

bool Table::checkIfPlayerLost()
{
    for (short i = 0; i < 4; i++)
    {
        if (table[actualTile.getcoordX(i)][actualTile.getcoordY(i)] == 1)
        {
            return 0;
        }
    }

    return 1;
}

Table::~Table() 
{
    for (short i = 0; i < numberOfLines; i++)
    {
        delete[] table[i];
    }
    delete[] table;
}

int main() 
{
    Table a;
    try {
        a.start();
    }
    catch (...) {
        Drawable::MoveTo(numberOfLines + 1 + Drawable::getX(), 0);
        cout << "\n" << "Good job, you made " << a.getScore() * 1000 << " points.\n";
    }

    return 0;
}

Edit: I managed to do some changes to the code based on your suggestions @Sandro4912, I hope this changes are good and are making the code more readable and understandable. Made one class per file with separate declaration and implementation, corrected the boolean methods, renamed the define with static contexpr, removed the global variables, used double and int, made comments only on the part that needed, omitted return 0 in main, used better random engine and some other changes. I still used using namespace std; and didn't used namespace only because i though this will make the code less readable, and I stayed with some members as private only because I though not all classes should have access to all other classes. Besides this 2 things I think I managed to modify the code as you suggested and also added some new methods, new members, new classes. This is the link to the code: Github tetris game. Sorry it took so long.
Edit 2: Made a new question with the improved code the link to the new question is: Tetris game for Windows improved version

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I don't have the time to analyse all the code. I suggest fixing these issues mentioned here and then reposte the improved version. Then we could take a look at your logic.

  1. Don't use using namespace std It is considered bad practice. See: https://stackoverflow.com/questions/1452721/why-is-using-namespace-std-considered-bad-practice

  2. Use a namespace. You should wrap your functions and classes in a namespace to prevent name clashes if you use other libraries. Like this:

    namespace tetris {
        // youre classes and functions
    }
    
  3. One class per File: You currently put everything into one file. This way your separation of functions and classes doesn't help at all. It's recommended to put one class per file.
  4. Separate declarations and implementations. Separate your code in header and implementation files. In the header only declare and include the minimum required. To speed up compilation use forward declaration.
  5. Return as boolean: This:

    bool Table::checkIfPlayerLost()
    {
        for (short i = 0; i < 4; i++)
        {
            if (table[actualTile.getcoordX(i)][actualTile.getcoordY(i)] == 1)
            {
                return 0;
            }
        }
    
        return 1;
    }
    

    Should be this:

    bool Table::checkIfPlayerLost()
    {
        for (short i = 0; i < 4; i++)
        {
            if (table[actualTile.getcoordX(i)][actualTile.getcoordY(i)] == 1)
            {
                return false;
            }
        }
    
        return true;
    }
    
  6. Use constexpr for constants. This:

    #define numberOfColumns 11 
    

    Should be this (we are not in C anymore):

    static constexpr auto numberOfColumns{11}
    
  7. Don't use global variables. They are considered a maintenance hazard. Try to encapsulate them into a class;
  8. Don't use float or short. by default you should use double and int. Heres a bit about it: https://stackoverflow.com/questions/24371077/when-to-use-short-over-int
  9. Don't comment whats clear. For example this:

    #define numberOfColumns 11               // number of lines and columns for the game table
    #define numberOfLines 21
    

    Do you see any benefit in this comment? I don't.

  10. public before private. In C++ it's usually common to put the public members before the private ones.
  11. Omit return 0 in main. Unlike in old C in C++ return 0 is automatically generated by the compiler at the end of main.
  12. Use C++ container. This:

     class Table : public Drawable           // class that represents the game table 
     {
     private:
        short **table;
        ....
     }
    
     Table::Table()
     {
        ...
            table[i] = new short[numberOfColumns];
        ...
     }
    
     Table::~Table()
     {
        for (short i = 0; i < numberOfLines; i++)
        {
            delete[] table[i];
        }
        delete[] table;
     }
    

    That is so so C. First of all why allocate dynamic arrays here? You want a fixed array. So you could just declare a two dimensional C array. Since we are in c++ it would be more wise to use std::array or std::vector to use as the table representation. If you really need to allocate dynamically (here you don't) then use smart pointer like std::unique_ptr or std::shared_pointer not naked new/delete. They release the memory safely for you

  13. Use a better random engine. Since C++11 you should not use this:

         srand((unsigned)(time(&t)));
    

    Instead use the better random generator from <random> Why? https://channel9.msdn.com/Events/GoingNative/2013/rand-Considered-Harmful

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  • 3
    \$\begingroup\$ Thanks @Sandro4912 for your response. I will look into all the issues you pointed out for my code and I will learn so I don't do them anymore and modify and improve the code. I'm in middle of the exams right now so as soon as I can I'm gonna do the improvements and repost the improved code. \$\endgroup\$ – Ovidiu Firescu Jun 3 at 12:19
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    \$\begingroup\$ take youre time. this website is not going any where. If you have additional questions let me know. \$\endgroup\$ – Sandro4912 Jun 3 at 16:05
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    \$\begingroup\$ managed to change the code based on your suggestion and also made some modifications myself to the code. Sorry it took so long I really had a busy month, I can't wait to see your impression and suggestions after you see the improved code. I think it's way better than the original code I posted 1 month ago. Thanks again \$\endgroup\$ – Ovidiu Firescu Jul 9 at 17:11
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    \$\begingroup\$ i think is best to post the improved code into a new question and put a link in the top of this question here so both questions are linked together here and anyone can review it. unfortunately now im low on time. but i will take a look when theres time again. probaly someone else will already check it \$\endgroup\$ – Sandro4912 Jul 9 at 20:14
  • \$\begingroup\$ I understand I will do so, also I will let a link in this question to the new question. Let me know your thoughts on the code when you get a chance to see it, I think I implemented good the things you pointed out \$\endgroup\$ – Ovidiu Firescu Jul 9 at 20:52

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