Qt pacman

A pacman game made with Qt Creator.

Play with w, a, s, d keys.

Other Contributors

Tuhin Saha
Arijoy Majumdar
Tanmoy Roy

Qt spec

This is developed on Qt 6.2.1. If you want to develop under Qt 6, you may need to uncomment some lines in Qt-pac-man.pro file.

Name: Qt 6.2.1 GCC 64bit
ABI: x86-linux-generic-elf-64bit
Source: /opt/Qt/6.2.1/gcc_64
mkspec: linux-g++

How to call pacman game API

You can take reference from mainwindow.cpp and mainwindow.h for detailed code. Assume that the following steps are implemented in a QMainWindow.

Step 1: declare objects and functions

• Add a QGraphicsView named graphicsView for displaying game. (In the source code, graphicsView is defined in mainwindow.ui.)
• Add a QLabel named score for displaying score.
• Add two QLabels named win_label and lose_label for displaying when game is over.
• Add a QTimer named score_timer for updating current score.
• Declare keyPressEvent override function.
• Declare update_score slot function.
• Include game.h.

#include <QMainWindow>
#include <QLabel>
#include <QKeyEvent>
#include <QTimer>
#include "game.h"

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
    void keyPressEvent(QKeyEvent*) override;

private slots:
    void update_score();

private:
    Ui::MainWindow *ui;
    QLabel *score, *win_label, *lose_label;
    QTimer *score_timer;
    Game *game;
};

Step 2: initialize objects

Setup graphicsView in the constructor of MainWindow.

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->graphicsView->setStyleSheet("QGraphicsView {border: none;}");
    ui->graphicsView->setBackgroundBrush(Qt::black);
    ui->graphicsView->setFocusPolicy(Qt::NoFocus);

Set the geometry of graphicsView and game. Read game map from map.txt.

    int map_height = 20, map_width = 29;            // 20x29 game map
    int x = 50, y = 50;                             // coordinate in mainwindow
    int w = (map_width * GameObject::Width);        // width pixel
    int h = (map_height * GameObject::Width);       // height pixel
    ui->graphicsView->setGeometry(x, y, w, h);
    game = new Game(x, y, map_width, map_height, ":/game_objects/map_objects/map.txt");
    ui->graphicsView->setScene(game);

Initialize labels and the timer.

    score = new QLabel(this);
    win_label = new QLabel(this);
    lose_label = new QLabel(this);
    score_timer = new QTimer(this);
    // setup labels' properties here...

Start timer and game.

    score_timer->start(25);
    connect(score_timer, SIGNAL(timeout()), this , SLOT(update_score()));
    game->start();
}

Step 3: Implement update_score and keyPressEvent

Update score when score_timer ticks. If the pacman eats all points, game->stat will change to Game::Win. If a ghost catches the pacman, game->stat will change to Game::Lose. Stop timer and show win_label or lose_label when game is over.

void MainWindow::update_score()
{
    score->setText(QString::number(game->get_score()));
    if (game->stat == Game::Win) {
        win_label->show();
        score_timer->stop();
    } else if (game->stat == Game::Lose) {
        lose_label->show();
        score_timer->stop();
    }
}

Detect key press events from w, a, s, d keys and make pacman move.

void MainWindow::keyPressEvent(QKeyEvent *e)
{
    switch (e->key()) {
    case Qt::Key_W:
        game->pacman_next_direction(GameObject::Up);
        break;
    case Qt::Key_A:
        game->pacman_next_direction(GameObject::Left);
        break;
    case Qt::Key_S:
        game->pacman_next_direction(GameObject::Down);
        break;
    case Qt::Key_D:
        game->pacman_next_direction(GameObject::Right);
        break;
    }
}

Changeable game parameters

Here are some changeable macro in game.h.

#define BALL_SCORE       10     // score of balls
#define POWERBALL_SCORE  30     // score of powerballs
#define GHOST_SCORE      50     // score of ghosts
#define INTERVAL         10     // move interval of pacman
#define NORMAL_INTERVAL  10     // move interval of normal ghosts
#define PANNIC_INTERVAL  15     // move interval of pannic ghosts
#define RUNNING_INTERVAL 5      // move interval of running ghosts
#define PANNIC_TIME      1000   // interval number of pannic ghosts
#define FLASH_INTERVAL   200    // flash interval of powerballs

Here's a changeable array in game.cpp.

// interval number before ghosts going out the cage
int GHOST_RELEASE_TIME[] = {0, 200, 400, 600};