During the implementation of custom compositor integration, the embedder gets
callbacks on the render thread to prepare render targets (framebuffers,
textures, etc) for the engine to render into, callbacks to present these render
targets along with platform managed contents, and, callbacks to collect render
targets once they can no longer be recycled by the engine in subsequent frames.
During these callbacks, the engine mandates the OpenGL state on the render
thread be preserved. This restriction has been the source of hard to isolate
issues where the embedder trampled on the OpenGL bindings state in the callback
but failed to restore state before control went back to the engine. Due to the
nature of the OpenGL API, such errors are easy to make and overlook. This patch
lifts the restriction from the embedder. Embedders may now freely work with the
OpenGL state in custom compositor callbacks and the engine will make sure to
disregard OpenGL bindings when control flows back to it.
Disregarding current OpenGL state has a certain performance penalty and the
majority of this patch handles refactoring various engine embedder components
such that this happens only once per frame. The most trivial version of this
patch would reset context bindings on every transition of control flow from the
embedder to the engine. However, that naive approach would have necessitated
more than 50 binding resets in existing unit-test cases (depending on the number
of platform view interleaving levels and render target recycling hit rates). In
this implementation, bindings will be reset only once per frame and this does
not depend on the number of platform views in the scene.
The majority of this patch is a refactoring of engine subsystems used in
`ExternalViewEmbedder::SubmitFrame` which is thoroughly documented with each
opportunity for the embedder to invalidate OpenGL state tagged.
The refactoring also enables the implementation of the following optimizations
to engine behavior which should aid in reducing the memory needed for the
creation of render targets. These optimization include:
* The engine will only ask the embedder for render targets in which it expects
to render into. This was a quirk in the way in which root and non-root render
targets were handled. The engine could require the embedder to create a render
target but then realize it didn’t have anything to render into it. In the
presentation callback, it would skip that render target. But the embedder
still had to allocate that extra render target. This will no longer be the
case and should reduce memory use.
* The engine may now skip always realizing (via the embedder render target
creation callback) and presenting the root render target. This was also a side
effect of the same quirk. Previously, the engine would always ask the embedder
to present the root render target even if it was empty. Since this is no
longer the case, few render targets should be allocated which will reduce
memory consumption.
* The engine will now ask the embedder to collect unused render targets before
it asks it to create new ones. The previous behavior was to ask the embedder
for new targets and then collect old ones. This would cause spikes in memory
use when the size of the render targets would change. These memory use spikes
should now be troughs.
* The previous render target cache also considered the platform view ID in cache
viability considerations (instead of just the size of the render target). This
was a bug which has been fixed. This should lead to better cache utilization
in some situations.
These optimizations are now codified in unit-tests and the updated test
expectations are a result of these optimizations now being in place.
* Fixes https://github.com/flutter/flutter/issues/50751
* Fixes https://github.com/flutter/flutter/issues/46911
* Fixes https://github.com/flutter/flutter/issues/43778
* Fixes b/146142979
This change creates a test only implementation of flutter::Surface backed by an
offscreen Vulkan GrContext. Much of the code in this test Surface was lifted
from flutter::VulkanWindow which I was unable to use without extricating it
from the VkSurface/VkSwapchain code which we do not want to use in offscreen
tests. I would recommend refactoring VulkanWindow to separate GrContext
creation and VkSwapchain creation in order to promote greater code reuse
between onscreen and offscreen vulkan paths.
This change is excersised thoroughly by the shell tests and was manually
tested against these tests on Fuchsia on Intel.
This shouldn't result in any logical changes. I've done a quick smoke
test by building a local Android engine and running Flutter gallery, no
compile errors or other obvious issues.
Applied by running `/ci/format.sh | patch -p0` with the altered script
added in flutter/engine#16500. I did locally modify the script slightly
further so it would run against all Java files in the repo instead of
just modified ones.
* Modifies accessibility bridge to populate new node fields in semantics API.
* Adds additional UTs and fixes logic for breaking up updates for nodes with large values.
* Chaged tests to set node flags using bitwise-or instead of addition.
* Address bug in update size arithmetic.
* Fixes issue in TruncatesLargeValue unit test causing unexpected deletes.
* Fixes expected number of updates in BatchesLargeMessages unit test to reflect expected values now that node states are populated.
A number of POSIX methods were renamed on Windows to match standards
requirements, giving deprecation warnings when calling strdup on Windows.
This adds a wrapper, to allow calling _strdup on Windows instead.
Part of #16256
Compiling with clang on Windows fails here with a warning about implicit
cast from function pointer to object pointer. Rather than disable that
warning, this makes it an explicit cast. Since this is just test output,
it's not critical that this be a completely safe operation.
Part of #16256
Targeted suppression of some deprecation warnings that are build errors under
clang:
- Ignore the deprecation of codecvt's unicode conversion until we decide on
a replacement strategy.
- Allow the deprecated posix names of functions in third_party/txt.
Part of https://github.com/flutter/flutter/issues/16256
To give more flexibility in scheduling, we change the number of frames
in flight we can have at one time to 3. We also introduce an offset from
VSync that Flutter can use to begin its work at. It is currently set at
0ms, matching previous behavior.
Clang has different warning settings, so catches different issues than
the VS compile. This fixes various minor issues caught by clang.
Part of https://github.com/flutter/flutter/issues/16256
No change in behavior expected. We have 2 frames in flight as before. By switching to Present2 and specifying a kMaxFramesInFlight however, we allow us greater flexibility to change how Flutter schedules its frames.
This change also adds tests for SessionConnection and VsyncRecorder.
Fixes a bug where deleteBackward was checking for being at the start of
the text before checking for a non-empty selection, breaking deletion
when the entire text field was selected.
Also removes an (incorrect) post-deletion position update that was
redundant with code in insertText:replacementRange:, and thus having no
effect.
Fixes https://github.com/flutter/flutter/issues/46150
This was only necessary when the Engine had to build in multiple buildroots
where the sources where checked out at different paths relative to the
buildroot. This is no longer the case and there are already cases GN rules
have been written that mix and match variable usage with the direct
specification of the path to the Flutter sources relative to the sole buildroot.
FlutterView#enableTransparentBackground has been deprecated for some
time now since it breaks a11y highlighting in most cases. When the
warning was first added there was no known workaround, but now the v2
embedding is in stable and ready to support this usecase. Update the
warning to point to the v2 embedding.
Some parts of the embedding (e.g. VsyncWaiter) may hold global references to
system services obtained through the context used during initialization.
These must not be associated with an activity or other non-application context.
Fixes https://github.com/flutter/flutter/issues/49612
This condition may arise when the embedder passes in a path to a non-existent
dylib. Instead of crashing, the embedder will now return an error response.
Fixes https://github.com/flutter/flutter/issues/49732
