This is in preparation for accepting the image type paintable.
It's a bit incovenient because we need more code to track width/height
ourselves (as the paintable no longer does it for us), but it's not too
hard.
GtkIconHelper does not track invalidations on the paintable.
The Vulkan renderer creates a fallback surface for each shadow
node, even if we end up not rendering anything to it. Avoiding
this is a nice optimization.
This showed up in profiles in certain scenarios, so export a
_get_n_shadows getter instead and let callers provide a sufficiently
large allocated array of GskShadows, which we can use with
g_alloc/g_newa.
gtk_snapshot_pop() => removed
gtk_snapshot_pop_and_append() => gtk_snapshot_pop()
So now there is no way to get a rendernode out of the snapshotting API
until you gtk_snapshot_finish().
... and make the icon rendering code use it.
This requires moving even more shadow renering code into GSK, but so be
it. At least the "shadows not implemented" warning is now gone!
It is now possible to call push() subfunctions for simple container
nodes with just a single child. So you can for example
gtk_snapshot_push_clip() a clip region that all the nodes that get
appended later will then obey.
gtk_snapshot_pop() will then not return a container node, but a clip
node containing the container node (and similar for the transform
example).
This is implemented internally by providing a "collect function" when
pushing that is called when popping to collects all the accumulated
nodes and combine them into the single node that gets returned.
To simplify things even more, gtk_snapshot_pop_and_append() has been
added, which pops the currently pushed node and appends it to the
parent.
The icon rendering code has been converted to this approach.
Instead of appending a container node and adding the nodes to it as they
come in, we now collect the nodes until gtk_snapshot_pop() is called and
then hand them out in a container node.
The caller of gtk_snapshot_push() is then responsible for doing whatever
he wants with the created node.
Another addigion is the keep_coordinates flag to gtk_snapshot_push()
which allows callers to keep the current offset and clip region or
discard it. Discarding is useful when doing transforms, keeping it is
useful when inserting effect nodes (like the ones I'm about to add).
Instead of having a setter for the transform, have a GskTransformNode.
Most of the oprations that GTK does do not require a transform, so it
doesn't make sense to have it as a primary attribute.
Also, changing the transform requires updating the uniforms of the GL
renderer, so we're happy if we can avoid that.
The equivalent to cairo_matrix_multiply (a, b, c) is
graphene_matrix_multiply (c, b, a).
graphene_matrix_multiply (a, b, c) may not be called with b and c being
the same matrix.
Yes, I like playing around. To enjoy, add this CSS to your application
of choice (preferrably glade or something with lots of images):
GtkImage { animation: spin 2s linear infinite; }
You can thank me later.