Messages

1

System / Re: multi-threaded drawing

« on: June 03, 2014, 06:38:10 pm »

Looks dangerous. No synchronization between the threads.

Why do you even need/want threads?
Unless you have a very good use-case/strong need for threads (and experience with them and C++) then they are very likely to cause you far more trouble than gain.

See also:
 http://en.sfml-dev.org/forums/index.php?topic=15018.msg106017#msg106017
 http://en.sfml-dev.org/forums/index.php?topic=14113.msg100559#msg100559

I probably need to read more about threads.. I thought that they are much easier.

The reason why I want threads is that I can simplify my code and more importantly to speed up the game because I have to do CPU-intensive stuff like path finding.

2

System / multi-threaded drawing

« on: June 03, 2014, 06:10:51 pm »

Why isn't the code below working correctly? By not working I mean that it isn't fluent like if I would manage everything in the main thread. I just want to seperate the game logic and the rendering. I am very new to SFML and threads in general. Could somebody help me here? Thanks!

Code: [Select]

#include <SFML/Graphics.hpp>

void renderingThread(sf::RenderWindow* window, sf::Shape* shape)
{
    while (window->isOpen())
    {
        window->clear();
        window->draw(*shape);
        window->display();
    }
}

int main()
{
    // create the window (remember: it's safer to create it in the main thread due to OS limitations)
    sf::RenderWindow window(sf::VideoMode(800, 600), "OpenGL");

    sf::CircleShape shape(100.f);
    shape.setFillColor(sf::Color::Green);

    // deactivate its OpenGL context
    window.setActive(false);

    // launch the rendering thread
    sf::Thread thread(std::bind(&renderingThread, &window, &shape));
    thread.launch();

    while (window.isOpen())
    {
            shape.move(0.000001f,0.f);
    }

    return 0;
}
(code is taken from http://www.sfml-dev.org/tutorials/2.1/graphics-draw.php#drawing-from-threads and http://www.sfml-dev.org/tutorials/2.1/start-linux.php#compiling-a-sfml-program)