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.
Now that the autotools build folded the GDK/GSK bits into the main GTK+
DLL, there are some updates that need to be done for this. We need to:
-Fold the DllMain() of GDK-Win32 into the main GTK+ DllMain(), as we need
the HINSTANCE to register the window. We can't have two DllMain()'s in a
single DLL.
-Remove the GDK rc(.in) files, as that is not used anymore. Make the GTK+
.rc(.in) file load the gtk.ico GTK+ logo file instead so that we still
get the GTK+ logo for the application icon by default. Update the
autotools build files as well.
-Revert commit b9f9980 as LRN pointed out in comment 25 in bug 773299, as
GTK+ is now a monolithic DLL, and we ought not to export this private
function.
https://bugzilla.gnome.org/show_bug.cgi?id=773299
gtk/inspector/rendernodeview.c calls this private function from GSK, so we
need to ensure that this function is exported so that GTK+ can link
properly on compilers that do not support automatic exporting.
https://bugzilla.gnome.org/show_bug.cgi?id=773299
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.
If we already have a GL texture we definitely don't want to use
gdk_cairo_draw_from_gl() to draw on a Cairo context if we're going
to take the Cairo surface to which we draw and put it into an OpenGL
texture.
The child-transform is useful only if we also provide clipping to the
parent nodes, otherwise children will just be drawn outside of the
parent's bounds.
We'll introduce child transforms either at a higher layer, or once we
add clipping support to GskRenderNode.
The naming is consistent with other scene graph libraries, as it
represents an additional translation transformation applied on top of
the provided transformation matrices.
We can also simplify the implementation by applying the translation when
we compute the world matrix.
Render nodes need access to rendering information like scaling factors.
If we keep render nodes separate from renderers until we submit a nodes
tree for rendering we're going to have to duplicate all that information
in a way that makes the API more complicated and fuzzier on its
semantics.
By having GskRenderer create GskRenderNode instances we can tie nodes
and renderers together; since higher layers will also have access to
the renderer instance, this does not add any burden to callers.
Additionally, if memory measurements indicate that we are spending too
much time in the allocation of new render nodes, we can now easily
implement a free-list or a renderer-specific allocator without breaking
the API.
Using GObject as the base type for a transient tree may prove to be too
intensive, especially when creating a lot of node instances. Since we
don't need properties or signals, and we don't need complex destruction
semantics, we can use GTypeInstance directly as the base type for
GskRenderNode.
This commit changes the way GskRenderer and GskRenderNode interact and
are meant to be used.
GskRenderNode should represent a transient tree of rendering nodes,
which are submitted to the GskRenderer at render time; this allows the
renderer to take ownership of the render tree. Once the toolkit and
application code have finished assembling it, the render tree ownership
is transferred to the renderer.
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.
