This makes our QPlatformOpenGLContext private subclass simpler.
As a slightly unrelated change, this patch also fixes a bug where our
platform opengl context may return a wrong surface format if surfaceless
contexts are unsupported.
The main advantage of SPDX license identifiers over the traditional
license headers is that it's more difficult to overlook inappropriate
licenses for kwin, for example GPL 3. We also don't have to copy a
lot of boilerplate text.
In order to create this change, I ran licensedigger -r -c from the
toplevel source directory.
Summary:
Depending on whether the underlying platform supports offscreen surfaces,
QOffscreenSurface may create an invisible QWindow. In our case that's the
case, for each offscreen surface a native window is created. This may
lead to some funky results related to window decorations, see bug 407612.
There are several ways to implement offscreen surfaces - either use pbuffers
or utilize a surfaceless context extension. For the sake of simplicity
this change sticks with pbuffers, but it's a good idea to support both
methods.
CCBUG: 407612
Reviewers: #kwin, romangg
Reviewed By: #kwin, romangg
Subscribers: romangg, alexeymin, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D22150
