C++和SFML游戏入门

让我们深入探讨一下如何使用C++和SFML（Simple and Fast Multimedia Library）来创建一个更为详细的游戏代码示例。我们将构建一个简单的2D游戏，其中包含一个可移动的角色、基本的碰撞检测以及简单的得分系统。

项目结构

首先，我们定义项目的文件结构：

MyGame/
├── src/
│   ├── main.cpp
│   ├── Game.hpp
│   ├── Game.cpp
│   ├── Player.hpp
│   └── Player.cpp
└── assets/
    ├── player.png
    └── obstacle.png

初始化项目

确保你已经安装了SFML库，并且你的IDE配置正确。接下来，我们开始编写代码。

`main.cpp` - 程序入口

cpp

#include "Game.hpp"

int main() {
    Game game;
    game.run();
    return 0;
}

`Game.hpp` - 游戏类声明

cpp

#ifndef GAME_HPP
#define GAME_HPP

#include <SFML/Graphics.hpp>

class Game {
public:
    Game();
    void run();

private:
    void processEvents();
    void update(sf::Time elapsedTime);
    void render();
    bool isRunning;

    sf::RenderWindow window;
    Player player;
};

#endif // GAME_HPP

`Game.cpp` - 游戏逻辑实现

cpp

#include "Game.hpp"
#include "Player.hpp"

Game::Game() : 
    isRunning(true),
    window(sf::VideoMode(800, 600), "My Simple Game"),
    player()
{
}

void Game::run() {
    sf::Clock clock;
    while (isRunning) {
        sf::Time deltaTime = clock.restart();
        processEvents();
        update(deltaTime);
        render();
    }
}

void Game::processEvents() {
    sf::Event event;
    while (window.pollEvent(event)) {
        if (event.type == sf::Event::Closed)
            isRunning = false;
        else if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape)
            isRunning = false;
        player.handleEvent(event);
    }
}

void Game::update(sf::Time elapsedTime) {
    player.update(elapsedTime);
}

void Game::render() {
    window.clear();
    window.draw(player);
    window.display();
}

`Player.hpp` - 角色类声明

cpp

#ifndef PLAYER_HPP
#define PLAYER_HPP

#include <SFML/Graphics.hpp>

class Player : public sf::Drawable {
public:
    Player();
    void handleEvent(const sf::Event& event);
    void update(sf::Time elapsedTime);

private:
    virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;

    sf::Sprite sprite;
    sf::Texture texture;
    float speed;
};

#endif // PLAYER_HPP

`Player.cpp` - 角色逻辑实现

cpp

#include "Player.hpp"

Player::Player() : 
    speed(200.f)
{
    if (!texture.loadFromFile("assets/player.png")) {
        // Handle error
    }
    sprite.setTexture(texture);
}

void Player::handleEvent(const sf::Event& event) {
    if (event.type == sf::Event::KeyPressed) {
        if (event.key.code == sf::Keyboard::W || event.key.code == sf::Keyboard::Up)
            sprite.move(0, -speed * 0.1f);
        else if (event.key.code == sf::Keyboard::S || event.key.code == sf::Keyboard::Down)
            sprite.move(0, speed * 0.1f);
        else if (event.key.code == sf::Keyboard::A || event.key.code == sf::Keyboard::Left)
            sprite.move(-speed * 0.1f, 0);
        else if (event.key.code == sf::Keyboard::D || event.key.code == sf::Keyboard::Right)
            sprite.move(speed * 0.1f, 0);
    }
}

void Player::update(sf::Time elapsedTime) {
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::W) || sf::Keyboard::isKeyPressed(sf::Keyboard::Up))
        sprite.move(0, -speed * elapsedTime.asSeconds());
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::S) || sf::Keyboard::isKeyPressed(sf::Keyboard::Down))
        sprite.move(0, speed * elapsedTime.asSeconds());
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::A) || sf::Keyboard::isKeyPressed(sf::Keyboard::Left))
        sprite.move(-speed * elapsedTime.asSeconds(), 0);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::D) || sf::Keyboard::isKeyPressed(sf::Keyboard::Right))
        sprite.move(speed * elapsedTime.asSeconds(), 0);
}

void Player::draw(sf::RenderTarget& target, sf::RenderStates states) const {
    target.draw(sprite, states);
}