Georges Basile Stavracas Neto authored Dec 26, 2018 and Jonas Ådahl committed Aug 23, 2019

MetaWindowActor is the compositor-side representative of a
MetaWindow. Specifically it represents the geometry of the
window under Clutter scene graph. MetaWindowActors are backed
by MetaSurfaceActors, that represent the windowing system's
surfaces themselves. Naturally, these surfaces have textures
with the pixel content of the clients associated with them.
These textures are represented by MetaShapedTexture.

MetaShapedTextures are currently implemented as ClutterActor
subclasses that override the paint function to paint the
textures it holds.

Conceptually, however, Clutter has an abstraction layer for
contents of actors: ClutterContent. Which MetaShapedTexture
fits nicely, in fact.

Make MetaShapedTexture a ClutterContent implementation. This
forces a few changes in the stack:

 * MetaShapedTexture now handles buffer scale.

 * We now paint into ClutterPaintNode instead of the direct
   framebuffer.

 * Various pieces of Wayland code now use MetaSurfaceActor
   instead of MetaShapedTexture.

 * MetaSurfaceActorWayland doesn't override size negotiation
   vfuncs anymore

GNOME/mutter!409