[Qtwebengine] armv7, eglfs, qtwebenginewidgets, fancybrowser result in blank screen, and how to enable logging.

[Jocelyn Turcotte]

Hello Rob,

On Tue, Apr 29, 2014 at 09:36:08PM -0700, Rob Vogelaar wrote:
> I completed an armv7 eglfs qtwebenegine build against the recent repo.
> Below are my patches and notes. I am getting a blank screen (with a
> functional mouse, and it did create a few files in /.local/, and an strace
> indicates an attempt to http:get  'www.google.com' ). apitrace does not
> indicate any gles2 from the chromium gpu command buffer, only gles2 I see
> is from Qt (mouse cursor).
> 
> - Do you have any debug suggestions based on the below output from running
> fancybrowser?

According to your output I would try to look at any call to
QtShareGLContext::GetHandle and make sure that a valid GL context handle
is handed to Chromium to setup context sharing.

I never tried the new GL rendering for QWebEngineView with eglfs, you
might get better result trying running the QtQuick version first.

> - How do I enable logging?  --enable-logging --v=1  does not seem to enable
> logging.

I never used --enable-logging, but --enable-gpu-service-logging was
useful for me to print Chromium's GPU thread GL calls on stdout.

> 
> thanks!
> Rob
> 
> 1) Qt-5.3.0-beta (+qglcontext patch from stable)
... 
> QSGContext::initialize: depth buffer support missing, expect rendering
> errors
> QSGContext::initialize: stencil buffer support missing, expect rendering
> errors

If you get this error then you probably don't have all the necessary
patches that were merged into stable for widget GL rendering. Have a look at
https://codereview.qt-project.org/#q,status:merged+owner:jocelyn.turcotte%2540digia.com+project:qt/qtbase,n,z

Cheers,
Jocelyn