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General / Multithreading Results in Window Context Activation Fail

« on: January 07, 2014, 06:07:42 pm »

Hi,

My code is causing errors in the console window:
"Failed to activate the window's context" and sometimes something about creating the OpenGL context.
The errors are thrown repeatedly.

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

struct gameClass
{
    gameClass(): cSettings(24,8,16,4,4), window(sf::VideoMode(800, 600), "OpenGL", sf::Style::Default, cSettings) {}
    sf::ContextSettings cSettings;
    sf::Window window;
    std::atomic_bool glHasControl;
};

int drawGLScene(gameClass* gameCore)                // Here's where we draw
{
    gameCore->window.setActive(true);

    while (gameCore->glHasControl.load(std::memory_order_acquire))
        gameCore->window.display();

    gameCore->window.setActive(false);
    return 1;                    // Everything went OK
}

int main()
{
    gameClass gameCore;

    sf::ContextSettings settings = gameCore.window.getSettings();
    std::cout << "depth bits:" << settings.depthBits << std::endl;
    std::cout << "stencil bits:" << settings.stencilBits << std::endl;
    std::cout << "antialiasing level:" << settings.antialiasingLevel << std::endl;
    std::cout << "version:" << settings.majorVersion << "." << settings.minorVersion << std::endl;

    gameCore.window.setVerticalSyncEnabled(true);
    gameCore.glHasControl.store(true, std::memory_order_release);
    sf::Thread displayThread(&drawGLScene, &gameCore);
    displayThread.launch();
    while (gameCore.window.isOpen())
    {
        sf::Event event;
        while (gameCore.window.pollEvent(event))
        {
            gameCore.glHasControl.store(false, std::memory_order_release);
            displayThread.wait();
            gameCore.window.setActive(true);

            if (event.type == sf::Event::Closed)
                gameCore.window.close();
        }
    }
    return 0;
}
 

-Jared