GtkGLArea: How to create GL resources outside of signal callback functions?

[felinis]

Hello.

When going through GtkGLArea examples, I noticed that all of them use the “realize” signal callback function for resource creation (vertex buffers, etc.).
However, I am programming a level editor and nothing about the level contents are known during the call to “realize”, so I cannot create any GL resources here. It would be practical to create such resources outside of that function, more specifically when the user open a level file.

So, is it possible to create GL resources outside of the GtkGLArea signal callbacks? If so, how?

I tried calling GL functions outside of the signal callback functions, but it simply does not work. Looks like it is colliding with a different internal-to-GTK4 GL context.

[jfrancis (Jason Francis)]

You must call gtk_gl_area_make_current first to use the context from that area outside the render signal.

If you’re loading a lot of data and find that it stalls the main thread, there are some other ways to create GL resources from other threads using context sharing but I don’t have a good example of this at the moment.

[felinis]

It is working properly now, thank you!