Currently when we move the mouse the one render loop triggers a repaint.
When the cursor layer needs a new update we end up in the compositor
repainting the main content.
Even though painting should mostly no-op it still goes through all
existing items and effects to collect damage, still potentially making
the GL context current which could stall. A waste when we know we
haven't got anything to do. It's enough to cause noticable mouse lag on
some hardware.
Co-authored-by: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
This change ports the drm backend to the GraphicsBuffer and
GraphicsBufferAllocator.
The main motivation is to unify graphics buffer abstractions across
various backends and to prepare it for output layers, which could be
nicer if we could have direct control over the buffers.
This makes it possible to ensure type safety for enums, as each drm property
object can have its own type now, and it reduces the amount of typing needed
to access properties
