Hey guys, I had a look at this with a debug build of the NVIDIA driver which might help. I tried Michael's suggestion of adding a glFinish() before glX/eglMakeCurrent but that didn't have an effect. For the record I'm using the GTK4 app "newsflash", which includes a WebKit view, and currently that area is completely blank.
What seems to be the issue is that the alpha channel of the pixmap that the WebKit process renders to is zero, but the GUI process interprets it as ARGB data. If I hack cairo to always interpret the data as XRGB instead it fixes the problem for me.
I'm still not sure whether it's a driver bug or an issue in WebKit, but at least this narrows it down somewhat. The pixmap *is* depth-32 so it's a bit strange that no alpha data is getting written.
Hey guys, I had a look at this with a debug build of the NVIDIA driver which might help. I tried Michael's suggestion of adding a glFinish() before glX/eglMakeCurrent but that didn't have an effect. For the record I'm using the GTK4 app "newsflash", which includes a WebKit view, and currently that area is completely blank.
What seems to be the issue is that the alpha channel of the pixmap that the WebKit process renders to is zero, but the GUI process interprets it as ARGB data. If I hack cairo to always interpret the data as XRGB instead it fixes the problem for me.
I'm still not sure whether it's a driver bug or an issue in WebKit, but at least this narrows it down somewhat. The pixmap *is* depth-32 so it's a bit strange that no alpha data is getting written.