A GskGLShader is an abstraction of a GLSL fragment shader that
can produce pixel values given inputs:
* N (currently max 4) textures
* Current arguments for the shader uniform
Uniform types are: float,(u)int,bool,vec234)
There is also a builder for the uniform arguments which are
passed around as immutable GBytes in the built form.
A GskGLShaderNode is a render node that renders a GskGLShader inside a
specified rectangular bounds. It renders its child nodes as textures
and passes those as texture arguments to the shader. You also pass it
a uniform arguments object.
The introspection scanner tries to match a type name with a get_type()
function, in order to correctly identify a type as a class.
If the function is not available, we have two choices:
- add some special case inside the introspection scanner, similar to
how GParamSpec subclasses are handled in GObject
- add a simple get_type() function
The latter is the simplest approach, and we don't need to change that
much, since we still register all render nodes at once.
Language bindings—especially ones based on introspection—cannot deal
with custom type hiearchies. Luckily for us, GType has a derivable type
with low overhead: GTypeInstance.
By turning GskRenderNode into a GTypeInstance, and creating derived
types for each class of node, we can provide an introspectable API to
our non-C API consumers, with no functional change to the C API itself.
We use a compilation symbol in our build to allow the inclusion of
specific headers while building GTK, to avoid the need to include only
the global header.
Each namespace has its own compilation symbol because we used to have
different libraries, and strict symbol visibility between libraries;
now that we have a single library, and we can use private symbols across
namespaces while building GTK, we should have a single compilation
symbol, and simplify the build rules.
Instead of only allowing for glyph indexes, allow ASCII characters as
replacements. So this glyph sequence
glyphs: 65 8, 66 8, 67 8
Can be replaced by
glyphs: "ABC"
provided that the glyph for "A", "B" and "C" are 65, 66 and 67
respectively and their advance is exactly 8.
x offset and y offset must always be 0 and every glyph must start a
cluster.
The code didn't change, it was just shuffled around to make the
with_bounds() versions of the text rendering unnecessary and instead
pass through the generic append_node() path.
They were a neat idea while they lasted. But now, it's time for
categorized transform nodes, where matrices with
GSK_MATRIX_CATEGORY_2D_TRANSLATE are the exact replacement.
Renderers have not been adapted for this purpose, so they (continue to)
run slow paths.
And of course, gsk_render_node_get_name() is gone, too.
The replacement is of course debug nodes.
As a side effect, GskRenderNode is now *really* immutable.
We pulled out the bounds calculation for performance reasons, but the
caller can't know how to properly compute them. Inside gtk+, we can do
that but it's not good enough for public API.
This is a special case of the transform node that does a 2D translation.
The implementation in the Vulkan and GL renderers is crude and just does
the same as the transform node.
Nothing uses that node yet.
An alternative GskTextNode constructor that does no text measuring. That
way, we can measure the text before and check if the node will be
outside of the current clip anyway.
Remove all the old 2.x and 3.x version annotations.
GTK+ 4 is a new start, and from the perspective of a
GTK+ 4 developer all these APIs have been around since
the beginning.
The copy of the PangoGlyphString we do here was showing up
in some profiles. To avoid it, allocate the PangoGlyphInfo array
as part of the node itself. Update all callers to deal with
the slight api change required for this.
Rename the surface getter to peek, following other render
node getters, and make the surface-based constructor private,
since it is not something we want to encourage.
Update all callers.
This commit takes several steps towards rendering text
like we want to.
The creation of the cairo surface and texture is moved
to the backend (in GskVulkanRenderer). We add a mask
shader that is used in the next text pipeline to use
the texture as a mask, like cairo_mask_surface does.
There is a separate color text pipeline that uses the
already existing blend shaders to use the texture as
a source, like cairo_paint does.
The text node api is simplified to have just a single
offset, which determines the left end of the text baseline,
like all our other text drawing APIs.
This node essentially implements the feColorMatrix SVG filter. I got the
idea yesterday after looking at the opacity implementation.
It can be used for opacity (not sure if we want to) and to implement a
bunch of the CSS filters.
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.
I had originally thought I'd use GskShadow for box-shadow, but didn't in
the end.
So now it's only used for text-shadow and icon-shadow, and those don't
have a spread.
