While we will cover the entire surface with our textured quads, the clear
is still necessary in order to make top-levels with TranslucentBackground
render correctly: We don't want to blend transparent areas with undefined
content that is in the surface's framebuffer.
Blending is problematic for alpha values. We now prevent the blended alpha
from being written out. This ensures that in examples like qquickviewcomparison,
where the backingstore image contains an alpha of 0.5 while the QQuickWidget
texture 1.0, the result is still an alpha value of 1.0 in the final image.
Writing out an alpha of 0.5 would break on systems where windows get an alpha
buffer by default.
hellogl2 can now take a --transparent parameter which makes the QOpenGLWidget
being cleared to transparent in order to verify it works in combination
with Qt::WA_TranslucentBackground.
The swapped red and blue problem is also corrected. RGBA8888 does not need
swizzling. The only format that needs this is RGB32.
Task-number: QTBUG-40716
Change-Id: I54a9fd3a91a1b59575b38cdb908835315514e40f
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>
Change them to use QOpenGLWidget and QOpenGLTexture.
Advocate also the usage of VBOs.
Hopeless examples, that rely on the fixed pipeline and will
not compile or work in ES and dynamic builds, are moved to
a "legacy" directory. The documentation pages for these are
removed. This long due change avoids the confusion newcomers
experience when trying to get started with Qt 5 and OpenGL.
hellowindow's behavior is changed to open a single window only
by default. The old default behavior, that opened three windows
on platforms that supported both MultipleWindows & ThreadedOpenGL,
can be requested by passing --multiple. --single is removed since it
is the default now. This plays much nicer with drivers that have
issues with threading.
In addition, say hello to hellogl2.
This is the old hellogl example updated to use QOpenGLWidget and
OpenGL 2. It also has a mainwindow with multiple (un)dockable widgets
containing the OpenGL widgets. This helps testing the behavior when
the top-level of the QOpenGLWidget changes and provides a very
important example of how to do proper resource management in this case.
(must use aboutToBeDestroyed() of the context, since the context goes
away and is replaced by a new one on every dock/undock)
As a bonus, the logo is now real 3D, no more orthographic nonsense.
Launch with --multisample to request 4x MSAA.
Launch with --coreprofile to request 3.2 Core. In this particular example
the shaders are present in both versions and there is a VAO so the application
is functional with core profile contexts.
Change-Id: Id780a80cb0708ef164cc172450ed74050f065596
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>
