Re: [fltk.coredev] GL root Fl_Gl_Window::draw - Forums

Le vendredi 16 septembre 2022 à 10:31:56 UTC+2, Gonzalo a écrit :

> You had written in this thread on 9 sept :
> "On Linux and Windows this works, but on macOS, as Manolo said, it does not, as it does not allow
> mixing OpenGL2 and OpenGL3+ calls. "
> I interpreted that meaning you solved how to combine GL3 + GL2 under Linux and Windows.
>

Sorry. I misspoke. I was just repeating what you mentioned about GL3/2 compatibility without having tried it myself.

You had written on the 8th of September:
"Notice this restriction is macOS-specific. The other 3 platforms allow mixing."

Let's be very explicit to avoid misunderstandings on all sides.

macOS forbids in principle to use GL2 function calls in a GL3 context.

If you do such calls, the program either crashes or does not perfom the requested operation.

The other platforms allow, in principle, to combine GL3 and GL2 calls, that's called a

compatibility context in GL3 parlance. The question of how, in practice, to call these

two sets of functions in a way that makes sense to GL remains. I don't know the answer.
I just observed that the procedure followed in OpenGL3test.cxx works under Wayland,

but fails under X11. Any suggestion welcome.