Question

如何从构造的VertexArray中绘制我选择的原语？在下面的例子中，我将两个顶点添加到'vertices'数组，我试图用'window.draw（vertices，2，sf :: Lines）'绘制它，但它给了我一个错误。我知道我可以使用'sf :: Vertex foo [] = {..}'创建线对象，但我希望能够将顶点附加到数组而不是一次初始化所有内容。

#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;
}

Answer 1

您可以在声明vertices.setPrimitiveType(sf::Lines);后致电sf::VertexArray vertices;，然后绘制它：window.draw(vertices);

或者您可以在构造函数中设置其基本类型以及点数，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

来自VertexArray的SFML绘图基元

1 个答案: