The ClutterRootNode paint node is theoretically the
top-most node of a paint nodes tree, except that we
are not in the point of having full rendering trees
in Clutter (all rendering performed by paint nodes
is still local and immediate).
When controlling the rendering tree, MetaShapedTexture
may need to paint into an offscreen framebuffer under
some circumstations.
Expose ClutterRootNode so that MetaShapedTexture can
use it to render to offscreen framebuffers.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/405
When painting to an offscreen framebuffer, MetaShapedTexture will
need to have full control of the painting routines of paint nodes.
As such, expose clutter_paint_node_paint() to allow forcing a
paint nodes paint from MetaShapedTexture.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/405
The multitexture API is not a shortcut for multiple calls
to the single texture API. It is meant to wrap calls to
cogl_framebuffer_draw_multitexture_rectangle(), which
uses the passed texture coordinates at different layers of
the pipeline.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/405
