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

sf::Mutex g_mutex;

void load_texture( void* arg ) {
    sf::Image image;

    image.create( 64, 64, sf::Color::Green );

    g_mutex.lock();

    sf::Texture* texture = reinterpret_cast<sf::Texture*>( arg );
    texture->loadFromImage( image );
    glFlush();

    g_mutex.unlock();
}

int main() {
    sf::RenderWindow window( sf::VideoMode( 800, 600 ), "Test" );
    sf::Texture texture;
    sf::Clock timer;
    bool loaded = false;

    {
        sf::Image image;
        image.create( 64, 64, sf::Color::Red );
        texture.loadFromImage( image );
    }

    sf::Sprite sprite( texture );

    sf::Thread thread( &load_texture, &texture );

    while( timer.getElapsedTime() < sf::seconds( 3 ) ) {
        if( !loaded && timer.getElapsedTime() > sf::seconds( 1 ) ) {
            loaded = true;
            thread.launch();
        }

        g_mutex.lock();

        window.clear();
        window.draw( sprite );
        window.display();

        g_mutex.unlock();
    }

    return 0;
}