[Interest] What's up with Qt's graphic stack (6.2.1) (and WebEngine)?

[Allan Sandfeld Jensen]

On Dienstag, 23. November 2021 14:53:30 CET Nils Jeisecke via Interest wrote:
> Hi list,
> 
> while checking out the status of Qt's graphics stack with very basic
> QtQuick based applications I've made the following observations:
> 
> 1. Windows 10 in VMWare Fusion: No window content is rendered for a
> trivial QtQuick Hello World application. Running with
> QT_D3D_ADAPTER_INDEX=1 helps, but this seems to activate the WARP
> software renderer (QTBUG-78648).
> 
> 2. Any QtQuick application using WebEngineView (QtWebEngineQuick) will
> automatically select OpenGLRhi backend
> (678076faeabd7e827abe31f72f4220af8d8f95ac):
> QtWebEngineQuick::initialize does
> QQuickWindow::setGraphicsApi(QSGRendererInterface::OpenGLRhi);
> 
> I've not found this restriction to be documented. OpenGL is not
> available by default on Windows and drivers are notoriously bad.
> RHI/D3D11 was supposed to be the solution for this, wasn't it?
> 
> Software Rendering is no longer an option since Chromium dropped the
> old composer codepath (QTBUG-88695), at least if video rendering is
> required.
> 
> So is it possible at all to build a QtQuick application that is
> * running out-of-the-box in VMWare (Fusion) without relying on the
> hack to select WARP?
> * using hardware accelerated Chromium on Windows without OpenGL?
> 
We only support two backends in WebEngine currently, either WGL OpenGL or the 
software backend. The software backend should work just fine though. If you 
have any other QSG backend than OpenGL, it should automatically be used, but 
you can also force it by selecting the software QSG backend or using the 
chromium flag --disable-gpu.

Best regards
Allan