This makes these parameters self-documenting.
This patch does not attempt to push those enums into the data
structures that feed calls to this function.
Fixes#4158.
This adds the infrastructure necessary to support stacking contexts that
are not containing blocks for absolutely-positioned elements. Our
infrastructure did not support that before. This minor revamp actually
ended up simplifying the logic around display list building and
stacking-relative position computation for absolutely-positioned flows,
which was nice.
first-class.
This implements the scheme described here:
https://groups.google.com/forum/#!topic/mozilla.dev.servo/sZVPSfPVfkg
This commit changes Servo to generate one display list per stacking
context instead of one display list per layer. This is purely a
refactoring; there are no functional changes. Performance is essentially
the same as before. However, there should be numerous future benefits
that this is intended to allow for:
* It makes the code simpler to understand because the "new layer needed"
vs. "no new layer needed" code paths are more consolidated.
* It makes it easy to support CSS properties that did not fit into our
previous flat display list model (without unconditionally layerizing
them):
o `opacity` should be easy to support because the stacking context
provides the higher-level grouping of display items to which opacity
is to be applied.
o `transform` can be easily supported because the stacking context
provides a place to stash the transformation matrix. This has the side
benefit of nicely separating the transformation matrix from the
clipping regions.
* The `flatten` logic is now O(1) instead of O(n) and now only needs to
be invoked for pseudo-stacking contexts (right now: just floats),
instead of for every stacking context.
* Layers are now a proper tree instead of a flat list as far as layout
is concerned, bringing us closer to a production-quality
compositing/layers framework.
* This commit opens the door to incremental display list construction at
the level of stacking contexts.
Future performance improvements could come from optimizing allocation of
display list items, and, of course, incremental display list
construction.
Instead of creating a display list for the entire page, only create one
for an area that expands around the viewport. On my machine this makes
incremental layout of http://timecube.com 50% faster.
Instead of looking at the display tree, have ContentBox(es)Query consult
the flow tree. This allow optimizing away parts of the display tree
later. To do this we need to be more careful about how we send reflow
requests, only querying the flow tree when possible.
Fixes#3790.
The flow tree is currently dumped for debugging purposes early on in
the flow process, so many values are still zero. If we wait to dump it
until later, the output will more accurately reflect the real flow tree.
The flow tree is currently dumped for debugging purposes early on in
the flow process, so many values are still zero. If we wait to dump it
until later, the output will more accurately reflect the real flow tree.
This also adds some extra debugging infrastructure which I found useful tracking
this bug down. A regression in the br reftests is also uncovered by this patch,
which I'll work on fixing next.
r? @pcwalton
Now that DOM/Flow traversals have been refactored out, the `recalc_style_for_subtree`
function in `css/matching.rs` can be removed, in lieu of just running the standard
`recalc_style_for_node` and `construct_flows` traversals sequentially. Now we
no longer have the maintenance headache of duplicating selector matching logic
in two places! \o/
This passes reftests with both default arguments, and with `-y 1`.
r? @pcwalton
Now that DOM/Flow traversals have been refactored out, the `recalc_style_for_subtree`
function in `css/matching.rs` can be removed, in lieu of just running the standard
`recalc_style_for_node` and `construct_flows` traversals sequentially. Now we
no longer have the maintenance headache of duplicating selector matching logic
in two places! \o/
r? @pcwalton
This also hides the not-yet-working parts of incremental reflow behind a runtime
flag. As I get the failing reftests passing, I'll send pull requests for them one
by one.
a separate `ClipDisplayItem`.
We push down clipping areas during absolute position calculation. This
makes display items into a flat list, improving cache locality. It
dramatically simplifies the code all around.
Because we need to push down clip rects even for absolutely-positioned
children of non-absolutely-positioned flows, this patch alters the
parallel traversal to compute absolute positions for
absolutely-positioned children at the same time it computes absolute
positions for other children. This doesn't seem to break anything either
in theory (since the overall order remains correct) or in practice. It
simplifies the parallel traversal code quite a bit.
See the relevant Gecko bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=615734
stretching.
This preserves the usage of the Bloom filter throughout style recalc,
but the implementation is rewritten. Provides a 15% improvement on
Guardians of the Galaxy.
DOM traversals and Flow traversals look very similar. This patch unifies them
with the preorder/postorder pattern. Hopefully, it also opens the door for writing
the traversal code only once, instead of the duplication we have today.
This patch puts in the initial framework for incremental reflow. Nodes' styles
are no longer recalculated unless the node has changed.
I've been hacking on the general problem of incremental reflow for the past
couple weeks, and I've yet to get a full implementation that actually passes all
the reftests + wikipedia + cnn. Therefore, I'm going to try to land the different
parts of it one by one.
This patch only does incremental style recalc, without incremental flow
construction, inline-size bubbling, reflow, or display lists. Those will be coming
in that order as I finish them.
At least with this strategy, I can land a working version of incremental reflow,
even if not yet complete.
r? @pcwalton
