Awl + SFML Demo

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

sf::Texture tex1;
sf::Texture tex2;
sf::Texture tex3;
bool loaded[3] = {false};

int main()
{
    sf::RenderWindow win(sf::VideoMode(640, 480), "Image Loader");
    tex1.Create(1000, 700);
    tex2.Create(1000, 700);
    tex3.Create(1000, 700);
    sf::Sprite sp1(tex1);
    sf::Sprite sp2(tex2);
    sf::Sprite sp3(tex3);

    sp1.SetPosition(10, 10);
    sp2.SetPosition(50, 50);
    sp3.SetPosition(100, 100);

    // Execute this block in an asynchronous way
    AwlAsyncBlock
    {
        tex1.LoadFromFile("big_image1.png");
        glFlush(); // Make sure the texture is updated in the main thread's GL context

        // We don't want to care about concurrent access issues, so execute this
        // on the main thread ;
        // We could also protect our actions with a mutex, that's your choice
        AwlMainThreadBlock
        {
            // Suppose this is a non-atomic operation and suppose that doing
            // this in a concurrent way would cause issues
            loaded[0] = true;
        }
        AwlCloseMainThreadBlock;

        // Repeat with second texture
        tex2.LoadFromFile("big_image2.png");
        glFlush();

        AwlMainThreadBlock {
            loaded[1] = true;
        } AwlCloseMainThreadBlock;

        // Repeat with third texture
        tex3.LoadFromFile("big_image3.png");
        glFlush();

        AwlMainThreadBlock {
            loaded[2] = true;
        } AwlCloseMainThreadBlock;
    }
    AwlCloseAsyncBlock;


    while (win.IsOpened() && aw::WorkLoop::Default().Run())
    {
        sf::Event ev;
        // Here we run the WorkLoop to process the tasks we wanted to perform
        // on the main thread
        while (win.PollEvent(ev))
        {
            if (ev.Type == sf::Event::Closed)
                win.Close();

            if (ev.Type == sf::Event::KeyPressed && ev.Key.Code == sf::Keyboard::Escape)
                win.Close();
        }

        win.Clear();
        // Show how loading progresses (we may not see any difference with 3 images but.. whatever)
        if (loaded[0]) win.Draw(sp1);
        if (loaded[1]) win.Draw(sp2);
        if (loaded[2]) win.Draw(sp3);

        win.Display();
    }
}