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

Le vendredi 16 septembre 2022 à 00:04:43 UTC+2, Gonzalo a écrit :

> El 15 sep. 2022, a las 13:45, Manolo escribió:
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> Le mercredi 14 septembre 2022 à 21:41:51 UTC+2, Gonzalo a écrit :
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> > El 13 sep. 2022, a las 06:28, Manolo escribió:
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> > @Gonzalo: I realize now my proposal was wrong.
> > The good solution is not to use a transparent GL2 window but a transparent normal window,
> > see attached example program which builds upon OpenGL3test.cxx :
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> That *almost* works. What is missing is giving the button a transparent or semi-transparent color, like in the cube.cxx demo. I would need that, or a FL_STENCIL on the window, so I can implement drawing in the window (with erasing with the stencil).
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> I attach a new attempt to allow transparent colors. It uses the recent changes to FLTK 1.4 committed to git.
> Unfortunately it works only partially under macOS because transparency starts correctly but then disappears, for a reason that remains unclear to me.

I tried it on macOS and could not make it fail. It was always semi transparent. What triggers the disappearance of the transparency?

What I see is:

- run the program, the button's background is colored red blended to the underlying blue color; that's good;

- hide the program (cmd-H) , show it again: the button is colored pure red; that's bad.

I run here macOS Ventura 13.0 public beta. It might be a Ventura bug?

> The code is meant to be cross platform with a macOS version and a version for other platforms.
> It works well under the wayland platform.
> But the transition between GL3-style and GL2-style drawing that works under Wayland fails under X11.

That’s too bad.

> Did you succeed in doing that? If yes, can you, please, share your procedure?
>

No. I am currently working on macOS and will try the other platforms later.

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.