Cannot get window from its handle

[EntityinArray]

When i try to get existing window by handle, application crashes returning code -1073740771 (0xC000041D)

#include <SFML/Graphics.hpp>
#include <SFML/System.hpp>
#include <math.h>
#include <gui.h>

void shutdown(){
    exit(0);
}

void render(sf::WindowHandle windowhandle){

    printf("Starting render thread for window %u...",(unsigned int)windowhandle);

    sf::RenderWindow window(windowhandle); //crash

    /*
    while(window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event)){
            if (event.type == sf::Event::Closed)
                shutdown();
        }

        ...

        window.display();

    }
    */

}

int main(){

    sf::RenderWindow window(sf::VideoMode(800,600),"cool thinge",sf::Style::Close);
    window.setVerticalSyncEnabled(true);

    sf::Thread thrender(&render,window.getSystemHandle());
    thrender.launch();

    return 0;
}
 

[eXpl0it3r]

This is not a supported use-case of window handles. The reason that one can create a window based on an existing handle is, so you can have some other code handle the creation of the window, while SFML just "attaches" to that window.

What you're trying to do is have an existing render window get the handle and create another render window on top. That doesn't work.

Also, you should use a debugger to get better information like a call stack on application crashes.

[EntityinArray]

Thanks!

May i ask how do i get the window from it's handle to manipulate it from another separate thread?

[eXpl0it3r]

The question is rather, why would you want to do that?
Or, what exactly are you trying to achieve here?

[EntityinArray]

I want to render a game from a separate thread because rendering from main will block everything else

[eXpl0it3r]

And by "block everything" what exactly are you thinking of with everything?

[EntityinArray]

Maybe physics and networking between client and server, i'm not sure yet. I'm very new to C, i was programming on Lua and JavaScript before.

[Rosme]

You should learn more about C++ (and not C) with a good book before going into SFML. The tutorials also explain(briefly how to have everything in a single loop and not blocking everything through a game loop. You don't want to do multithreading for this. Even less when you clearly lack some knowledge of the language.