QGLWidget doesn't hide

[Uwe]

As far as the official line goes, QWS simply doesn't support OpenGL. If you're indeed using QWS then don't use OpenGL. If you need OpenGL, don't use QWS. Best if you just switch to Qt5 with wayland as the compositor. If your hardware supports OpenGLES, it should handle wayland as well.

I'm not sure if this is really the official line - it's more like the current generation of Qt developers doesn't know QWS themself anymore. When I had to deal with these issues ( 4.6, 4.7 days ) the official line was, that QPA is the new thing and QWS won't be touched anymore. But QPA 4.8. was declared as "not worth to be documented yet" - so the situation is quite unsatisfying at the moment. Guess the strategy today is simply waiting for Wayland.

But in fact QWS/OpenGL is not so far from being usable if someone would be interested in fixing it. F.e the wrong stacking order of the subsurfaces is an easy patch. More difficult is the logic that tries to restore parts of the screen from the backing store, that doesn't exits for OpenGL surfaces.

So when you are not willing to patch Qt I would completely agree with Witold: QWS means raster only.

Uwe

As far as the official line goes, QWS simply doesn't support OpenGL. If you're indeed using QWS then don't use OpenGL. If you need OpenGL, don't use QWS. Best if you just switch to Qt5 with wayland as the compositor. If your hardware supports OpenGLES, it should handle wayland as well.

I'm not sure if this is really the official line - it's more like the current generation of Qt developers doesn't know QWS themself anymore. When I had to deal with these issues ( 4.6, 4.7 days ) the official line was, that QPA is the new thing and QWS won't be touched anymore. But QPA 4.8. was declared as "not worth to be documented yet" - so the situation is quite unsatisfying at the moment. Guess the strategy today is simply waiting for Wayland.

But in fact QWS/OpenGL is not so far from being usable if someone would be interested in fixing it. F.e the wrong stacking order of the subsurfaces is an easy patch. More difficult is the logic that tries to restore parts of the screen from the backing store, that doesn't exits for OpenGL surfaces.

So when you are not willing to patch Qt I would completely agree with Witold: QWS means raster only.

Uwe

As far as the official line goes, QWS simply doesn't support OpenGL. If you're indeed using QWS then don't use OpenGL. If you need OpenGL, don't use QWS. Best if you just switch to Qt5 with wayland as the compositor. If your hardware supports OpenGLES, it should handle wayland as well.

I'm not sure if this is really the official line - it's more like the current generation of Qt developers doesn't know QWS themself anymore. When I had to deal with these issues ( 4.6, 4.7 days ) the official line was, that QPA is the new thing and QWS won't be touched anymore. But QPA 4.8. was declared as "not worth to be documented yet" - so the situation is quite unsatisfying at the moment. Guess the strategy today is simply waiting for Wayland.

But in fact QWS/OpenGL is not so far from being usable if someone would be interested in fixing it. F.e the wrong stacking order of the subsurfaces is an easy patch. More difficult is the logic that tries to restore parts of the screen from the backing store, that doesn't exits for OpenGL surfaces.

So when you are not willing to patch Qt I would completely agree with Witold: QWS means raster only.

Actually QGLWidget is also used to display some overlay data through QPainter, which can't be achieved through V4L (i think).

Copying a camera image through QPainter/OpenGL is a complete waste of CPU. This could be done much better by hardware - if it supports stuff like different layers. I strongly recommend to read the specs of your GPU !

Uwe

[wysota]

I'm not sure if this is really the official line - it's more like the current generation of Qt developers doesn't know QWS themself anymore. When I had to deal with these issues ( 4.6, 4.7 days ) the official line was, that QPA is the new thing and QWS won't be touched anymore. But QPA 4.8. was declared as "not worth to be documented yet" - so the situation is quite unsatisfying at the moment. Guess the strategy today is simply waiting for Wayland.

One of the videos from last DevDays, the one on QPA in Qt5 contains a quote from the developer (AFAIR even with a slide to support that) that QWS doesn't support OpenGL. He also says it is technically possible to combine the two after a lot of struggle but it depends on the hardware and QWS simply isn't prepared for it.