This does a conversion to/from GBytes and is intended for writing tests.
It's really crude but it works.
And that probably means Alex will (ab)use it for broadway.
Instead of a separate allocation for any arrays in the render node
we allocate these as part of the render node itself, using C99
flexible arrays.
This leads to less allocations, which is nice, but the major reason
for this is that it allows us to change the allocation scheme further
in the future. For instance, we want to do stack-like allocation so
that all the render-nodes for an entire frame are allocated in one
(or a few) chunks.
Instead of constantly recalculating this (especially recursively for
parents!) we do it only on construction, because everything is
immutable anyway. Also, most nodes had a bounds already and can
use the new parent member instead.
We also do direct access to the node bounds rather than calling
gsk_render_node_get_bounds in various places, which means
we do less copying.
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.
gsk_render_node_get_bounds() still exists and is computed via vfunc
call:
- containers dynamically compute the bounds from their children
- surface and texture nodes get bounds passed on construction
In the brave new world of refactored render nodes, this function doesn't
really make any sense anymore. We could turn it into a vfunc, but I
don't think it's useful.
Especially because even in the brave old world, this function was
causing a vastl overallocation of nodes when the GL renderer needed render
targets.
If we ever feel, we need this function again, we can readd it later.
But nobody is using it other than for overriding opactiy. And you can
just override opacity directly if you care.
Creating render nodes is fire-and-forget, so all one should do is create
a container, append, append, append and then send it off to the
renderer. So there's no need to replace, insert between or anything
else.
This happens in regular code paths for example when trying to render the
empty text string. We don't want to store a surface on the render
node in such a case (so actual rendering isn't slowed down), but we do
want to return a working cairo context that is not in an error state
(so the cairo rendering can continue without error messages).
We want to have the coordinate system of the created cairo surface to be
identical to the coordinate system of the node's bounds. For that, we
need to translate the cairo surface by the bounds' origin.
GskRenderNode is, at its core, a write-only API; you're supposed to set
up the render nodes instead of querying them for state.
Querying render nodes is left to the GskRenderer implementation.
The renderer will always use nearest-neighbor filters because it renders
at 1:1 pixel to texel ratio.
On the other hand, render nodes may be scaled, so we need to offer a way
to control the minification and magnification filters.
