来自 VertexArray 的 SFML 绘图原语

SFML drawing primitives from VertexArray

如何从构造的 VertexArray 中绘制我选择的图元?在下面的示例中,我向 'vertices' 数组添加了两个顶点,我试图用 'window.draw(vertices, 2, sf::Lines)' 绘制它,但它给了我一个错误。我知道我可以用 'sf::Vertex foo[] = {..}' 创建线对象,但我希望能够继续将顶点附加到数组而不是一次初始化所有顶点。

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

int main()
{
    // Create the main window
    sf::RenderWindow window(sf::VideoMode(640, 480), "SFML");
    sf::Clock clock;

    sf::VertexArray vertices;
    sf::Vertex vertex;

    vertex.position = sf::Vector2f(0, 0);
    vertex.color = sf::Color(100, 0, 200);
    vertices.append(vertex);
    vertex.position = sf::Vector2f(100, 100);
    vertex.color = sf::Color(100, 0, 200);
    vertices.append(vertex);

    // Start the game loop
    bool running = true;
    while (running)
    {
        // Process events
        sf::Event event;
        while (window.pollEvent(event))
        {
            // Close window: exit
            if (event.type == sf::Event::Closed)
                running = false;
        }

        window.clear(sf::Color::Black);
        window.draw(vertices,2 ,sf::Lines);

        window.display();
    }

    return 0;
}

声明sf::VertexArray vertices;后可以调用vertices.setPrimitiveType(sf::Lines);,然后绘制:window.draw(vertices);

或者您可以在构造函数中设置它的原始类型以及点数,然后您可以使用 operator[]:

访问这些点
sf::VertexArray line(sf::Lines, 2); //or sf::LineStrip
line[0].position = sf::Vector2f(0, 0);
line[0].color = sf::Color(100, 0, 200);
line[1].position = sf::Vector2f(100, 100);
line[1].color = sf::Color(100, 0, 200);
...
window.draw(line);

参考:enum sf::PrimitiveType, sf::VertexArray, VertexArray tutorial