The use of volatile was incorrect in GLib and has been that way for
a long time. Recently however that has changed, and this makes GTK
follow suit to avoid using volatile in the type registration.
See also: https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1719
Combined with the above merge request for GLib, this fixes a large
number of compilation warnings when using Clang.
The @filename@ directive will use the full path of the file being parsed
for enumeration types; we should use @basename@, instead, as it improves
the reproducibility of the build by using only the file name.
GSK is conceptually split into two scene graphs:
* a simple rendering tree of operations
* a complex set of logical layers
The latter is built on the former, and adds convenience and high level
API for application developers.
The lower layer, though, is what gets transformed into the rendering
pipeline, as it's simple and thus can be transformed into appropriate
rendering commands with minimal state changes.
The lower layer is also suitable for reuse from more complex higher
layers, like the CSS machinery in GTK, without necessarily port those
layers to the GSK high level API.
This lower layer is based on GskRenderNode instances, which represent
the tree of rendering operations; and a GskRenderer instance, which
takes the render nodes and submits them (after potentially reordering
and transforming them to a more appropriate representation) to the
underlying graphic system.
