Effects that need GLSL require that OpenGL 2 is active.
It does not matter whether the GPU would support it if
OpenGL 2 is not used.
Cherry-picked from db42152
CCBUG: 299426
Creating an EffectFrame requires I/O which takes on my system
during testing between 10 and 40 msec. Also it needs a little
bit of memory.
This changes moves out the creation of EffectFrames at Effect
load till the Effect actually needs the EffectFrame. E.g. if a
user does not filter in PresentWindows there is no need to ever
create it.
BoxSwitch effect is ignored as it should be dropped for 4.9.
REVIEW: 104815
Cube effect loads 0 to 2 textures which has been
performed during configuration. This change delays
loading the textures till cube is activated for the
first time and the loading from file is moved into
a thread.
This means that for a very short time the texture
is not yet visible, but this is not a problem as
the cube animates from fully opaque starting state.
So during the loading the texture would not be
visible anyway.
REVIEW: 104807
Client::manage calls setupCompositing on the not
yet fully managed client before it wants to create
the window decoration. This means the decoration is
created twice and maybe even if not needed (noBorder
not yet set).
If the Client is not yet managed setupCompositing
will not update the decoration - it will be handled
by manage later on.
Furthermore if compositing is not active, setup
compositing does not have to perform any action.
REVIEW: 104758
By moving the query for effects into an own thread the
startup does not have to wait till all effects are loaded.
The thread moves the loading of the effects after the
Window Manager and Compositor has been fully initialized.
This is possible as EffectsHandler is fully functional even
without any effects.
The compositor ensures that at least one frame is rendered
before the started thread returns which makes the complete
startup more responsive.
REVIEW: 104583
The I/O intensive reading of the complete KWin Script
file into a QByteArray is moved into a thread.
Evaluating and setting up the script engine is still
performed in the main thread.
REVIEW: 104782
Searching for the scripts to load is performed in an own
thread including unloading of already loaded scripts which
no longer should be loaded.
To ensure that two threads are not trying to load/unload
at the same time a mutex is added to protect the list of
loaded scripts.
REVIEW: 104768
Instead of getting the information from CompositingPrefs
the running KWin instance is queried through D-Bus.
In general the running KWin should have more information
about whether Compositing will work or not.
This means the kcm no longer has to link OpenGL.
REVIEW: 104753
Detecting CompositingPrefs invokes an external program. Waiting
for this can be moved in a second thread.
Due to the introduction of the thread the initialization order
of KWin is changed: the WindowManager is initialized before the
Compositor. Interestingly this makes KWin felt more responsive
as the screen is not frozen for several seconds.
REVIEW: 104579
Whether creating the OpenGL context succeeds or not
had no influence in any decisions on the used settings
for OpenGL based compositing.
The only valid information CompositingPrefs still detects
is whether direct rendering should be used which is
performed out of process and does not require a context.
So overall the context creation is not needed and can
be removed.
REVIEW: 104778
