There are currently five places that scroll offsets are stored:
- DOM: A set of scroll offsets used for script.
- Layout: An array of scroll offsets that is used for tracking
layout-side scroll offsets.
- Layout: The scroll offsets stored in the `ScrollTree`. These are
currently unset and unused.
- Compositor: The scroll offsets stored in the `ScrollTree` mirrored
from layout.
- WebRender: The scrolled offsets stored in the WebRender spatial tree.
This change is the first step in combining the first three into the
layout `ScrollTree`. It eliminates the extra array of scroll offsets
stored in layout in favor of the storing them in the `ScrollTree`. A
followup change will eliminate the ones stored in the DOM.
- In addition the `ScrollState` data structure is eliminated as these
are
now stored in a `HashMap` everywhere when passing them via IPC.
- The offsests stored in layout can now never scroll past the boundaries
of the scrolled content.
Testing: This should not change behavior and is thus covered by existing
WPT tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: stevennovaryo <steven.novaryo@gmail.com>
The compositor was accepting scroll offsets from the ScriptThread
without checking their boundaries. In some cases this could cause a
temporary discrepancy with the rendered scroll offset. This change makes
it so that all offset updates for scroll ayers in the compositor do not
scroll past the scroll boundaries of the node.
Testing: Two new tests pass with this change:
- `/css/css-position/sticky/position-sticky-left-003.html`
- `/css/css-position/sticky/position-sticky-top-003.html`
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Previously, after a layout was finished (or skipped in the case of
repaint-only layout), both the stacking context tree and display list
were built. In the case of repaint-only layout, we should be able to
skip the reconstruction of the stacking context tree and only do display
list building.
This change does that, also generally cleaning and up and clarifying the
data structure used during this phase of layout. This opens up the
possibility of a new kind of incremental layout that does both repaint
and a rebuild of the stacking context tree.
On the blaster.html test case[^1], this reduces tightly-measured layout
time from ~45-50 milliseconds to ~25-30 milliseconds on my M3.
[^1]: https://gist.github.com/mrobinson/44ec87d028c0198917a7715a06dd98a0
Testing: There are currently no performance tests for layout. :( This
should
not modify the results of WPT tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Add memory reporter integration for the fragment and box trees that are
persisted in the layout thread.
Testing: Looked at the numbers for https://servo.org and
https://html.spec.whatwg.org/. The former was very small, but the latter
was 700mb.
---------
Signed-off-by: Josh Matthews <josh@joshmatthews.net>
These two traits both exposed different parts of the compositing API,
but now that the compositor doesn't depend directly on `script` any
longer and the `script_traits` crate has been split into the
`constellation_traits` crate, this can be finally be cleaned up without
causing circular dependencies. In addition, some unit tests for the
`IOPCompositor`'s scroll node tree are also moved into
`compositing_traits` as well.
Testing: This just combines two crates, so no new tests are necessary.
Fixes: #35984.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
2025-04-06 17:34:18 +00:00
Renamed from components/shared/webrender/display_list.rs (Browse further)
