Make the FrameLayerBuilder remember for what region it has calculated
display item visibility, then recompute the visibility whenever the
dirty region it is passed to DrawPaintedLayer changes.
This means that the caller does not have to know the entire dirty region
that will be drawn for the transaction, but we can still optimise cases
where it knows some of the dirty region in advance.
This fixes a regression where MultiTiledContentClient's low-res display
port would not be painted if a smaller region of its high-res buffer had
already been painted that transaction, since the FrameLayerBuilder
had decided that most of the larger low-res region was invisible.
Bug 1176077 introduced the parameter aDirtyRegion to
DrawPaintedLayerCallback, which allows the callback to recompute the
visibility of all items to be painted in that transaction in a single
go. However, this parameter can not always be determined correctly
when using RotatedBuffer, and using an incorrect value was causing
graphical glitches.
Make the parameter optional, and on null values do not perform the
optimisation. Pass null from ClientPaintedLayer, which uses
RotatedBuffer and was causing problems, but continue to pass the
correct value from other Layer implementations. This optimisation was
most important for tiled layers using progressive paint, so this is
okay.
FrameLayerManager::RecomputeItemsVisibility() was being called on every
call to FrameLayerBuilder::DrawPaintedLayer(), each time for the region
to be painted by that paint call. This is inefficient when progressive
paint is enabled. Change it so that we compute the visibility of all the
layer's items within the total region to be painted, but only on the
first paint after the display list has been modified.
Get rid of EnumerateEntries by inlining those enumerate functions. Also
move gPaintedDisplayItemLayerUserData, gColorLayerUserData, etc. to the
front of the file since LayerManagerData::Dump() references to one of
them.
The bulk of this commit was generated by running:
run-clang-tidy.py \
-checks='-*,llvm-namespace-comment' \
-header-filter=^/.../mozilla-central/.* \
-fix
This adds support for class="reftest-opaque-layer" and for
reftest-assigned-layer="some-layer-name" to the reftest harness.
From reftest/README.txt:
Opaque Layer Tests: class="reftest-opaque-layer"
================================================
If an element should be assigned to a PaintedLayer that's opaque, set the class
"reftest-opaque-layer" on it. This checks whether the layer is opaque during
the last paint of the test, and it works whether your test is an invalidation
test or not. In order to pass the test, the element has to have a primary
frame, and that frame's display items must all be assigned to a single painted
layer and no other layers, so it can't be used on elements that create stacking
contexts (active or inactive).
Layerization Tests: reftest-assigned-layer="layer-name"
=======================================================
If two elements should be assigned to the same PaintedLayer, choose any string
value as the layer name and set the attribute reftest-assigned-layer="yourname"
on both elements. Reftest will check whether all elements with the same
reftest-assigned-layer value share the same layer. It will also test whether
elements with different reftest-assigned-layer values are assigned to different
layers.
The same restrictions as with class="reftest-opaque-layer" apply: All elements
must have a primary frame, and that frame's display items must all be assigned
to the same PaintedLayer and no other layers. If these requirements are not
met, the test will fail.
