The idea is to use QtQuick for the EffectFrames. They should be rendered into a texture without using a QQuickWindow for them just like Aurorae is rendered.
That way we can use the rendered texture either as image for QPainter and XRender compositors or directly in the OpenGL compositor.
This should allow to remove lots of the custom rendering code and have one shared solution.
FWIW: WIP at davidedmundson/effectquickview
but waiting till Qt 5.12 for a patch that makes QQuickRenderControl behave nicer.
Also I've tried to keep it generic so that rendering a frame + text is just one implementation of a more generic way for effects to render arbitrary QML.
Nice. Maybe, it would be worth to port some effects to it, e.g. Track Mouse, Mouse Click Animation, Mouse Mark, etc.
That was exactly what I had in mind :)
Just to update:
There was a decision that Plasma 5.15 would still be Qt 5.11, then Plasma 5.16 will be Qt5.12
I'll prioritise other stuff for now, and then hopefully have this ready to land right at the start of the 5.16 cycle.