SFML community forums

Help => Graphics => Topic started by: StrawberrySwing2008 on January 19, 2019, 11:47:48 pm

Title: std::vector<sf::Vertex> vs std::vector<sf::Vertex*>
Post by: StrawberrySwing2008 on January 19, 2019, 11:47:48 pm

Hi, I'm new here ..

why when I use std::vector<sf::Vertex*> my lines do not appear correctly ?

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

int main()
{
    sf::RenderWindow window(sf::VideoMode(400, 400), "Brasil");

    std::vector<sf::Vertex*> points;

    sf::Vector2i mousePosition;

    window.setFramerateLimit(60);

    while (window.isOpen())
    {
        sf::Event event;

        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        window.clear(sf::Color(100, 100, 100));

        if (sf::Mouse::isButtonPressed(sf::Mouse::Left))
        {
            mousePosition = sf::Mouse::getPosition(window);

            points.push_back(new sf::Vertex(sf::Vector2f(mousePosition.x, mousePosition.y)));
        }

        for (std::size_t i = 0; i < points.size(); ++i)
        {
            window.draw(points[i], 2, sf::Lines);
        }

        window.display();
    }

    return 0;
}

 

unlike the code above, it works:

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

int main()
{
    sf::RenderWindow window(sf::VideoMode(400, 400), "Brasil");

    std::vector<sf::Vertex> points;

    sf::Vector2i mousePosition;

    window.setFramerateLimit(60);

    while (window.isOpen())
    {
        sf::Event event;

        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        window.clear(sf::Color(100, 100, 100));

        if (sf::Mouse::isButtonPressed(sf::Mouse::Left))
        {
            mousePosition = sf::Mouse::getPosition(window);

            points.push_back(sf::Vertex(sf::Vector2f(mousePosition.x, mousePosition.y)));
        }

        for (std::size_t i = 0; i < points.size(); ++i)
        {
            window.draw(&points[i], 2, sf::Lines);
        }

        window.display();
    }

    return 0;
}

 

I think it may be something related to continuous memory, but I'm not sure.

Title: Re: std::vector&lt;sf::Vertex&gt; vs std::vector&lt;sf::Vertex*&gt;
Post by: eXpl0it3r on January 20, 2019, 08:06:06 am

As I already pointed out on Discord, SFML's draw function doesn't take an array of pointers, but it takes an array of sf::Vertex options, or more specifically it takes a pointer to the first element in an array.