在 SFML 中检测窗口边界冲突的问题

Question

我试图让我的移动矩形在与它们碰撞时从窗口边框反弹，但是矩形正在旋转。我不确定如何定义我的碰撞函数，这就是我想出的：

//left border collision
     if(rectangle.getPosition().y<0){
         rectangle.setPosition(rectangle.getPosition().x,0);
     //top border collision
     };
     if(rectangle.getPosition().x<0){
         rectangle.setPosition(0,rectangle.getPosition().y);
     };
     //right border collision
     if(rectangle.getPosition().y+rectangle.getGlobalBounds().width>WINDOW_W){
         rectangle.setPosition(rectangle.getPosition().y,WINDOW_W-rectangle.getGlobalBounds().width);
     };
     //bottom border collision
     if(rectangle.getPosition().x+rectangle.getGlobalBounds().height>WINDOW_H){
         rectangle.setPosition(WINDOW_H-rectangle.getGlobalBounds().height,rectangle.getPosition().y);
     };

代码检测到一些碰撞，但我认为它没有考虑矩形的旋转。

这是我的全部代码：

#include <SFML/Window.hpp>
#include <SFML/Graphics.hpp>
#include <iostream>

int main() {
    // create the window
    sf::RenderWindow window(sf::VideoMode(800, 600), "My window");

    // create some shapes
    sf::CircleShape circle(100.0);
    circle.setPosition(100.0, 300.0);
    circle.setFillColor(sf::Color(100, 250, 50));

    sf::RectangleShape rectangle(sf::Vector2f(120.0, 60.0));
    rectangle.setPosition(500.0, 400.0);
    rectangle.setFillColor(sf::Color(100, 50, 250));

    sf::ConvexShape triangle;
    triangle.setPointCount(3);
    triangle.setPoint(0, sf::Vector2f(0.0, 0.0));
    triangle.setPoint(1, sf::Vector2f(0.0, 100.0));
    triangle.setPoint(2, sf::Vector2f(140.0, 40.0));
    triangle.setOutlineColor(sf::Color::Red);
    triangle.setOutlineThickness(5);
    triangle.setPosition(600.0, 100.0);

    //clock function
    sf::Clock clock;

    //finding screen resolutions for collision
    int WINDOW_W = window.getSize().y;
    int WINDOW_H = window.getSize().x;

    //declaring moving speeds for the rectangle
    float rec_vel_x = 50;
    float rec_vel_y = 150;
    //delcaring speed of rotation of the rectangle
    float rec_ang_vel = 10;


    // run the program as long as the window is open
    while (window.isOpen()) {
        //Time elapsed function
         sf::Time elapsed = clock.getElapsedTime();
         // getting elapsed time as float, needed fro the float function
         float el1 = clock.restart().asSeconds();
        // check all the window's events that were triggered since the last iteration of the loop
        sf::Event event;
        while (window.pollEvent(event)) {
            // "close requested" event: we close the window
            if (event.type == sf::Event::Closed)
                window.close();
        }
        // clear the window with black color
        window.clear(sf::Color::Black);
        // moving the rectangle per each elapsed second with the preset values
        rectangle.move(el1*rec_vel_x,el1*rec_vel_y);
        //rotating the rectangle
        rectangle.rotate(el1*rec_ang_vel);


        // draw everything here...
        window.draw(circle);
        window.draw(rectangle);
        window.draw(triangle);

        // end the current frame
        window.display();
        //game updates
         std::cout<<elapsed.asSeconds()<<std::endl;
         //extracting values for the collision
         //sf::FloatRect rectangle_bounds = rectangle.getGlobalBounds();
         //left border collision
         if(rectangle.getPosition().y<0){
             rectangle.setPosition(rectangle.getPosition().x,0);
         //top border collision
         };
         if(rectangle.getPosition().x<0){
             rectangle.setPosition(0,rectangle.getPosition().y);
         };
         //right border collision
         if(rectangle.getPosition().y+rectangle.getGlobalBounds().width>WINDOW_W){
             rectangle.setPosition(rectangle.getPosition().y,WINDOW_W-rectangle.getGlobalBounds().width);
         };
         //bottom border collision
         if(rectangle.getPosition().x+rectangle.getGlobalBounds().height>WINDOW_H){
             rectangle.setPosition(WINDOW_H-rectangle.getGlobalBounds().height,rectangle.getPosition().y);
         };
    }
    sf::FloatRect rectangle_bounds = rectangle.getGlobalBounds();
    std::cout << rectangle_bounds.top << " " << rectangle_bounds.left << " " ;
    std::cout << rectangle_bounds.width << " " << rectangle_bounds.height << std::endl;
    std::cout <<"wysokosc okna to: " << WINDOW_H << std::endl;
    std::cout <<"szerokosc okna to: " << WINDOW_W << std::endl;
    return 0;
}

我还没有实现弹跳，现在我希望矩形不要超出窗口

Answer 1

您在某些地方交换了 xs 和 ys，请记住 setPosition()、getPosition() 先取 x 再取 y。

这里是固定代码：

//left border collision
if(rectangle.getPosition().x<0){
     rectangle.setPosition(0,rectangle.getPosition().y);
};

//top border collision
if(rectangle.getPosition().y<0){
     rectangle.setPosition(rectangle.getPosition().x, 0);
};

//right border collision
if(rectangle.getPosition().x+rectangle.getGlobalBounds().width>WINDOW_W){
     rectangle.setPosition(WINDOW_W-rectangle.getGlobalBounds().width, rectangle.getPosition().y);
};

//bottom border collision
if(rectangle.getPosition().y+rectangle.getGlobalBounds().height>WINDOW_H){
     rectangle.setPosition(rectangle.getPosition().x, WINDOW_H-rectangle.getGlobalBounds().height);
};

上下边框在 y 轴上停止矩形，因此当它碰到它们时我们改变 y。左右手边界的情况类似：x 坐标应设置而 y 保持不变。

显然，WINDOW_H 和 WINDOW_W 也被交换了，应该是：

//finding screen resolutions for collision
int WINDOW_W = window.getSize().x;
int WINDOW_H = window.getSize().y;

编辑：修正了语法错误并添加了一个关于 WINDOW_H 的词。