https://github.com/Crdl-Pls/Pang/blob/master/Pang.cpp

pang.cpp

#include <iostream>
#include <SFML/Graphics.hpp>
#include <string>
#include "Constants.h"
#include "Paddle.h"
#include "Ball.h"

/* This class will hold the state of the game,
 * the state will be used by initialize, render and update functions,
 * because the functions will be chaning the state of the class defined below
 * I decided to implement them as members of the class
 */
class GameState {
    public:
        GameState();

        /* This will initialize the game, if you need some configuration
         * options, like window resolution you can pass them as arguments to
         * this method. In case of larger number o arguments pass them as
         * a const reference to configuration structure */
        bool initialize(); 

        /* Handle SMFL events, returns false if game should quit, true
         * otherwise */
        bool handleEvents();

        /* Handle all game logic, that is not tied to SMFL events. */   
        void update();

        /* Draw current game state on the screen. */
        void render();

    private:
        gamePaddle paddleLeft;
        gamePaddle paddleRight;
        gameBall   ball;

        sf::RendererWindow window;
};

GameState::GameState() 
	: paddleLeft(sf::Keyboard::Key::W, sf::Keyboard::Key::S, 20);
	, paddleRight(sf::Keyboard::Key::Up, sf::Keyboard::Key::Down, (windowX-30));
	, window(sf::VideoMode(int(windowX),int(windowY)), "PANG");
    { 
}

bool GameState::initialize() {
	sf::Image icon;
	if (!icon.loadFromFile("Icon.png")) { 
        return false;
    }

	window.setIcon(128, 128, icon.getPixelsPtr());
    return true;
}

bool GameState::handleEvents() {
    bool quit = false;
    sf::Event event;
    while (window.pollEvent(event))
    {
        if (event.type == sf::Event::Closed)
        {
            window.close();
            quit = true;
        }
        else if (event.type == sf::Event::KeyPressed)
        {
            if (event.key.code == paddleLeft.getKeyUp()) paddleLeft.setMoveUp(true);
            if (event.key.code == paddleLeft.getKeyDown()) paddleLeft.setMoveDown(true);
            if (event.key.code == paddleRight.getKeyUp()) paddleRight.setMoveUp(true);
            if (event.key.code == paddleRight.getKeyDown()) paddleRight.setMoveDown(true);
            if (event.key.code == sf::Keyboard::Escape) {
                window.close();
                quit = true;
            }
        }
        else if (event.type == sf::Event::KeyReleased)
        {
            if (event.key.code == paddleLeft.getKeyUp()) paddleLeft.setMoveUp(false);
            if (event.key.code == paddleLeft.getKeyDown()) paddleLeft.setMoveDown(false);
            if (event.key.code == paddleRight.getKeyUp()) paddleRight.setMoveUp(false);
            if (event.key.code == paddleRight.getKeyDown()) paddleRight.setMoveDown(false);
        }
    }
    return quit;
}

void GameState::update() {
    paddleLeft.paddleMove();
    paddleRight.paddleMove();
    ball.ballMove();

    bool hitLeftPaddle = ball.getBoundingBox().intersects(paddleLeft.getBoundingBox());
    bool hitRightPaddle = ball.getBoundingBox().intersects(paddleRight.getBoundingBox());
    bool ballMovingLeft = ball.getVelocityX() < 0;
    bool ballMovingRight = ball.getVelocityX() > 0;

    if ((hitLeftPaddle && ballMovingLeft) || (hitRightPaddle && ballMovingRight))
        ball.hitPaddle();
}

void GameState::render() {
    window.clear(sf::Color::Black);
    window.draw(paddleLeft.getPaddle());
    window.draw(paddleRight.getPaddle());
    window.draw(ball.getBall());
    window.display();
}

static void mainLoop(GameState *state) {
    while (true) {
        const bool quit = state->handleEvents();
        if (quit == true) {
            return;
        }

        state->update();
        state->render();
    }
}

int main()
{
    GameState state;
    if (state.initialize() == false) {
        fprintf(stderr, "Initialization failed.\n");
        return 1;
    }

    mainLoop(&state);
    return 0;
}