Add a function that tracks whether a render node's content is
in a wide gamut color state (in practice, that means non-sRGB).
This will be used in render_texture to determine the color
state to use when creating a texture.
This adds the following:
- ccs argument to GskRenderNode::draw
This is the compositing color state to use when drawing.
- make implementations use the CCS argument
FIXME: Some implementations are missing
- gsk_render_node_draw_with_color_state()
Draws a node with any color state, by switching to its compositing
color state, drawing in that color state and then converting to the
desired color state.
This does draw the result OVER the previous contents in the passed in
color state, so this function should be called with the target being
empty.
- gsk_render_node_draw_ccs()
This needs to be passed a css and then draws with that ccs.
The main use for this is chaining up in rendernode draw()
implementations.
- split out shared Cairo functions into gdkcairoprivate.h
gskrendernode.c and gskrendernodeimpl.c need the same functions.
Plus, there's various code in GDK that wants to use it, so put it in
gdk/ not in gsk/
gsk_render_node_draw() now calls gsk_render_node_draw_with_color_state()
with GDK_COLOR_STATE_SRGB.
That's basically the "undefined" value. We need that when drawing
nothing, which so far only happens with empty container nodes.
But empty container nodes can be children of other nodes, and that makes
things propagate. So instead of catching them, force the whole rest of
the code to deal with an undefined depth.
We also can't just set a random depth, because that will cause merging
to fail.
This is an experiment for now, but it seems that encoding srgb inside
the depth makes sense, as we not just use depth to decide on the
GL fbconfigs/Vulkan formats to pick, depth also encodes how the [0...1]
color values are quantized when stored.
Let's see where this goes.
Due to the way the intermediate offscreen gets drawn, we might end up
with seams at the edges.
And I don't think it's worth spending more time on than saying "not
opaque".
Fixes the compare-render testsuite
New testcase included.
We want to operate with opacities, so it makes sense to have this radily
available.
And we're doing a walk over all children on creation anyway, so why not
just capture the rect there.
We want to be able to express opaque grids. This means that the app
provides either a row of columns of opaque nodes or a column of rows,
and then the containers will magically figure it out.
The main use case for this is terminals, which are uilt using cells. And
when there's a transparent background configured but the contents are
opaque, it'd be nice if we could figure that out.
Also remove the 80% requirement. It is rather arbitrary and while it
helps for some cases, the aforementioned grid would suffer.
We find the first child that covers >80% of the container and return
that.
This is a nice speedup for the common case of a GtkWindow being covered
by a large opaque background.
It will fall apart for fancy themes that play with transparency or for
small windows because the shadow region gets too large.
But then we just scan the whole node tree.
We could think about adapting the 80% number, because that wasn't chosen
with any real scientific data behind it.
This takes both the vertical and horizontal rectangle that isn't
covering the rounded corners and intersects both with the child's opaque
rect.
And then it returns the larger of the two.
This means the small slices of a window near the left/right (or
top/bottom) will never be covered, but if we wanted that, we'd need to
use something else than a rectangle - either a region or actually a
rounded rect.
But that is a lot more expensive to implement.
The new renderers don't support them due to the required complexity of
integrating them with Vulkan and the assumptions those nodes make about
the renderer (the GL renderer exports its internal APIs into the
GLShader).
There haven't been any complaints that I'm aware of since 4.14 was
released where the default renderer does not support the nodes, so usage
in public seems to be close to nonexistant.
The 2 uses I know of were workarounds about missing features in GTK that
have stopped since GTK now supports them:
1. GStreamer used in to do premultiplication when the old GL renderer
did not do so in hardware but on the CPU.
2. Adwaita used it for masking before the mask node wa added in 4.10.
Fill and stroke nodes were not reporting proper offscreen-for-opacity
and preferred depth.
This was unlikely to have been noticed as their child is usually a solid
color.
Switch symbolc icon drawing from color-matrix to mask nodes
make the performance of the iconscroll demo crater (from 60fps
to 10fps).
Apply the same optimization we already have for color-matrix
nodes when drawing mask nodes. This gets us back to 60fps.
Fixes: #6700
This works better for cff fonts, where hinting is not as local as
what the autohinter does for ttf fonts, and it does not seem to
have negative effects.
Fixes: #6577Fixes: #6568
When we get an unhinted font for text node extents, don't change
the antialiasing setting. It doesn't affect the extents we get
here, but if we later need an unhinted font for rendering, the
one we create this way will be the right one, so it will already
exist.
We need precise bounds. And while hinting might shift the rendering
around from these bounds by a fraction of a pixel, we account for
this in the places where it matters: when determining diff regions,
when sizing offscreens, and when determining the size of atlas
regions for glyphs.
We lost this when a bunch of rect code was inlined in
commit 36314f28e2, and as it turns out, that broke some
applications. So, bring it back.
Fixes: #6435
We can just check if the subsurfaces contain content - and if they do,
they will be offloading and we can ignore the diff.
This essentially reverts 48740de71a
Instead of relying on diffing subsurface nodes, we track damage
generated by offloaded contents inside GskOffload.
There are 3 stages a subsurface node can be in:
1. not offloaded
Drawing is done by the renderer
2. offloaded above
The renderer draws nothing
3. offloaded below
The renderer needs to punch a hole.
Whenever the stage changes, we need to repaint.
And that can happen without the subsurface's contents changing, like
when a widget is put above the subsurface and it needs to to go from
offloaded above to below.
So we now recruit GskOffload for tracking these changes, instead of
relying on the subsurface diffing.
But we still need the subsurface diffing code to work for the
non-offloaded case, because then the offloading code is not used.
So we keep using it whenever that happens.
Not that when a subsurface transitions between being offloaded and not
being offloaded, we may diff it twice - once in the offload code and
once in the node diffing - but that shouldn't matter.
When a subsurface goes from not offloaded to offloaded (or vice versa),
we need to add the whole node to the diff region, because we switch from
whatever contents were drawn to a punched hole.
A PangoFont keeps a weak reference to its fontmap. In addition,
keep a strong reference in GskTextNode, so we can be sure that
custom font maps won't go away before the node is finalized.
These are not usable outside of GTK, so lets not burden bindings
with them.
I'll keep the get_child() function exposed, since it is needed to
iterate over node trees containing subsurface nodes.
