This change introduces a method for direct access to the paintable of
a PaintableFragment. This method is intended to replace the usage of
the layout node pointer. Currently, we are only eliminating the use
of `layout_node()` in hit testing.
Additionally, we no longer check if a fragment's layout node is a
`BlockContainer` before recursing into its children during hit testing.
This check was likely relevant when all fragments were owned by
`PaintableWithLines`, but now it should be safe to remove this check.
The paintable tree structure more closely matches the painting order
when fragments are owned by corresponding inline paintables. This
change does not affect the layout tree, as it is more convenient for
layout purposes to have all fragments owned by a block container in
one place.
Additionally, this improves performance significantly on pages with
many fragments, as we no longer have to walk the ancestor chain up
to the closest block container to determine if a fragment belongs
to an inline paintable.
Rather than resolving the text-shadow each time painting commands are
recorded, we can resolve it once during the layout commit and save the
resolved values in paintable fragments. This is also step towards
getting rid of layout node pointer in paintable fragment.
This is a part of refactoring towards making the paintable tree
independent of the layout tree. Now, instead of transferring text
fragments from the layout tree to the paintable tree during the layout
commit phase, we allocate separate PaintableFragments that contain only
the information necessary for painting. Doing this also allows us to
get rid LineBoxes, as they are used only during layout.
CSSPixels should not be wrapped into CSS::Length before being passed
to resolved() to end up resolving percentages without losing
precision.
Fixes thrashing layout when 33.3333% width is used together with
"box-sizing: border-box".
With this change, a stacking context can be established by any
paintable, including inline paintables. The stacking context traversal
is updated to remove the assumption that the stacking context root is
paintable box.
Fragments contained by the inline node should be painted in the
foreground phase for this node, instead of being painted as a part of
the containing PaintableWithLines. This change implements that by
marking all fragments contained by inline nodes so they can be skipped
while painting the content of PaintableWithLines. This is an ugly way,
and instead, we should make InlinePaintables own all fragments
contained by them.
With this change, instead of applying scroll offsets during the
recording of the painting command list, we do the following:
1. Collect all boxes with scrollable overflow into a PaintContext,
each with an id and the total amount of scrolling offset accumulated
from ancestor scrollable boxes.
2. During the recording phase assign a corresponding scroll_frame_id to
each command that paints content within a scrollable box.
3. Before executing the recorded commands, translate each command that
has a scroll_frame_id by the accumulated scroll offset.
This approach has following advantages:
- Implementing nested scrollables becomes much simpler, as the
recording phase only requires the correct assignment of the nearest
scrollable's scroll_frame_id, while the accumulated offset from
ancestors is applied subsequently.
- The recording of painting commands is not tied to a specific offset
within scrollable boxes, which means in the future, it will be
possible to update the scrolling offset and repaint without the need
to re-record painting commands.
Instead, we now pass String if we have one. In particular, this fixes an
issue where image elements with a data: URL src would copy the entire
URL string every time we painted (before the image had been decoded).
This was very noticeable on "fully downloaded" web pages where every
single image has been turned into a data: URL.
Before this change, we would only cache and reuse Gfx::ScaledFont
instances for downloaded CSS fonts.
By moving it into Gfx::VectorFont, we get caching for all vector fonts,
including local system TTFs etc.
This avoids a *lot* of style invalidations in LibWeb, since we now vend
the same Gfx::Font pointer for the same font when used repeatedly.
This commit un-deprecates DeprecatedString, and repurposes it as a byte
string.
As the null state has already been removed, there are no other
particularly hairy blockers in repurposing this type as a byte string
(what it _really_ is).
This commit is auto-generated:
$ xs=$(ack -l \bDeprecatedString\b\|deprecated_string AK Userland \
Meta Ports Ladybird Tests Kernel)
$ perl -pie 's/\bDeprecatedString\b/ByteString/g;
s/deprecated_string/byte_string/g' $xs
$ clang-format --style=file -i \
$(git diff --name-only | grep \.cpp\|\.h)
$ gn format $(git ls-files '*.gn' '*.gni')
Out-of-flow boxes (floating and absolutely-positioned elements) were
previously collected and put in the anonymous block wrapper as well, but
this actually made hit testing not able to find them, since they were
breaking expectations about tree structure that hit testing relies on.
After this change, we simply let out-of-flow boxes stay in their
original parent, preserving the author's intended box tree structure.
According to the CSS font matching algorithm specification, it is
supposed to be executed for each glyph instead of each text run, as is
currently done. This change partially implements this by having the
font matching algorithm produce a list of fonts against which each
glyph will be tested to find its suitable font.
Now, it becomes possible to have per-glyph fallback fonts: if the
needed glyph is not present in a font, we can check the subsequent
fonts in the list.
This change fixes a problem that we should not call `to_px()` to
resolve any length or percentage values during paintables traversal
because that is supposed to happen while performing layout.
Also it improves performance because before we were resolving border
radii during each painting phase but now it happens only once during
layout.
BorderRadiusCornerClipper usage to clip border radius is specific to
CPU painter so it should not be stored in painting commands.
Also with this change bitmaps for corner sampling are allocated during
painting commands replaying instead of commands recording.
Previously, we determined the positions of glyphs for each text run at
the time of painting, which constituted a significant portion of the
painting process according to profiles. However, since we already go
through each glyph to figure out the width of each fragment during
layout, we can simultaneously gather data about the position of each
glyph in the layout phase and utilize this information in the painting
phase.
I had to update expectations for a couple of reference tests. These
updates are due to the fact that we now measure glyph positions during
layout using a 1x font, and then linearly scale each glyph's position
to device pixels during painting. This approach should be acceptable,
considering we measure a fragment's width and height with an unscaled
font during layout.
Currently, in CPU painter, border painting is implemented by building
a Gfx::Path that is filled by Gfx::AntiAliasingPainter. In the GPU
painter, we will likely want to do something different, and with a
special command, it becomes possible.
Also, by making this change, the CPU executor also benefits because now
we can skip building paths for borders that are out of the viewport.
By consistently accepting only device pixel values instead of a mix of
CSSPixels and DevicePixels values, we can simplify the implementation
of paint_border() and paint_all_borders().
Reduction of bug:
```html
<!DOCTYPE html><style>
html {
overflow-x: hidden;
overflow-y: scroll;
}
div {
background: orange;
height: 1000px;
width: 500px;
}
</style><body><div>
```
Fixes https://github.com/SerenityOS/serenity/issues/21690 and painting
on many other websites (null.com, servo.org).
By storing painting command coordinates relative to the nearest
stacking context we can get rid of the Translate command.
Additionally, this allows us to easily check if the bounding
rectangles of the commands cover or intersect within a stacking
context. This should be useful if we decide to optimize by avoiding
the execution of commands that will be overpainted by the results of
subsequent commands.
With the recording painter the actual painting operations are delayed,
so now if multiple corner clippers are constructed, and they use a
shared bitmap they can interfere with each other. The use of this shared
bitmap was somewhat questionable anyway, so this is not much of a loss.
This fixes the border-radius.html test page.
This modification introduces a new layer to the painting process. The
stacking context traversal no longer immediately calls the
Gfx::Painter methods. Instead, it writes serialized painting commands
into newly introduced RecordingPainter. Created list of commands is
executed later to produce resulting bitmap.
Producing painting command list will make it easier to add new
optimizations:
- It's simpler to check if the painting result is not visible in the
viewport at the command level rather than during stacking context
traversal.
- Run painting in a separate thread. The painting thread can process
serialized painting commands, while the main thread can work on the
next paintable tree and safely invalidate the previous one.
- As we consider GPU-accelerated painting support, it would be easier
to back each painting command rather than constructing an alternative
for the entire Gfx::Painter API.
Instead of resolving lengths used in the backdrop-filter during
painting, we can do that earlier in apply_style().
This change moves us a bit closer to the point when the stacking
context tree will be completely separated from the layout tree :)
This fixes an issue where the value would be out of sync with reality
in anonymous wrapper block boxes, since we forgot to compute m_visible
after assigning the computed values to them.
Fixes#21106
d06d4eb made the `clip` property apply to children of an absolute-
positioned element, but caused it not to be applied to the element the
property was applied to directly.
To fix this, apply the clip in new `before_paint()` and `after_paint()`
functions. Doing so keeps painter state from leaking from `paint()`,
but still allows subclasses of `PaintableBox` clip their contents
correctly without repeating the application of the clip rectangle.
This is intended to annotate conversions from unknown floating-point
values to CSSPixels, and make it more obvious the fp value will be
rounded to the nearest fixed-point value.
In general it is not safe to convert any arbitrary floating-point value
to CSSPixels. CSSPixels has a resolution of 0.015625, which for small
values (e.g. scale factors between 0 and 1), can produce bad results
if converted to CSSPixels then scaled back up. In the worst case values
can underflow to zero and produce incorrect results.
Fixes bug when "clip" property does not affect abspos children.
This change makes "clip" property to be applied together with
"overflow: hidden" in `apply_clip_overflow_rect()` that already
handles abspos children correctly.
Instead of applying relative offsets (like position:relative insets)
during painting and hit testing, we now do a pass at the end of layout
and assign the final resolved offsets to paintables.
This makes painting and hit testing easier since they don't have to
think about relative offsets, and it also fixes a bug where offsets were
not applied to text fragments inside inline-flow elements that were
themselves position:relative.
