Reduces errors caused by the loss of floating point precision when the
two extrema of the lerp differ significantly in magnitude. Previously,
we used the calculation:
a + (b - a) * t
When the difference in magnitude between `a` and `b` exceeds the
precision representable by double-precision floating point math, `b - a`
results in the larger-magnitude value of `a` or `b`. The error between
the value produced and the correct value is then scaled by t.
A simple example of the impact can be seen when `a` is significantly
larger in magnitude than `b`. In that case, `b - a` results in `a` and
when `t` is 1.0, the resulting value is `a - (a) * 1.0 == 0`.
The patch transforms the computation to the mathematically-equivalent
expression:
a * (1.0 - t) + b * t
By scaling each value independently, the behaviour is more accurate.
From the point of view of performance, this adds an extra
multiplication, but multiplication is relatively cheap and the behaviour
is significantly better.
This patch also adds a `precisionErrorTolerance` constant to
test_utils.dart and migrates existing tests to use `closeTo()` for
testing.
The tests themselves *do* currently use values that have an exact
floating-point representation, but we should allow for flexibility in
future implementation changes.
Previously, the behaviour of lerpDouble with respect to NaN and infinity
was relatively complex and difficult to reason about. This patch
simplifies the behaviour with respect to those conditions and adds
documentation and tests.
In general, if `a == b` or both values are null, infinite, or NaN, `a`
is returned. Otherwise we require `a` and `b` and `t` to be finite or
null and the result of the linear interpolation is returned.
This extracts a Dart test utilities library, containing
`expectAssertion` and `expectArgumentError` functions that simplify
running tests that test assertions across debug, profile, and release
configurations.
This change also restricts Dart unit tests to testing files whose
filename matches `*_test.dart` under `flutter/testing/dart`; previously
any file in that directory was run, but all files matched the above
pattern.
The behaviour of lerpDouble with respect to null inputs isn't entirely
obvious. In the case where both inputs are null, it returns null.
Otherwise, it defaults the null parameter to 0.0 and carries on.
Post non-null by default, it might be nice to strengthen the parameter
contract to require them to be non-null. While this would be a breaking
change, it seems likely that the framework either meets this guarantee
or can provide it without a framework breaking change.
https://github.com/flutter/flutter/issues/64617 tracks the above.
In the meantime, adding a test to lock in the current behaviour.
This is a Fuchsia-only shell test, confirming that when the timezone
setting is changed on the realm via Fuchsia's FIDL interface
`fuchsia.settings.Intl`, the Dart isolate running in that realm receives
the change and starts reporting the appropriate timestamp.
We already have a [similar test][tst] that verifies the timezones in the
dart VM matches the local timezone at start, but there was no test that
also verified timezone changes.
[tst]: https://github.com/flutter/engine/blob/master/shell/common/shell_unittests.cc#L1166
See issue #61284
I just made a pass on the scenario scripts so that they can be more easily run from the scenario directory, set the ANDROID_HOME correctly, and generally fixed lint errors.
Also compile_android_aot.sh didn't appear to work, and I think I fixed it (it builds now).
This converts the ci/format.sh script to a Dart script that uses process_runner and isolates to multi-process the clang-format, diffs, and grepping needed to do the formatting changes.
It also will (by default) only check the formatting of changed files.
The user can optionally check all files (--all-files) or do only some types of checks with --check. --verbose prints the versions of the tools used for Clang format and Java format.
Specifying --fix will cause any formatting errors that would have been detected to be fixed.
Reland #19396 with a fix for improper scale that was affecting internal tests
Tested: Ran all unittests, ran internal tests, and ran workstation on Fuchsia
BUG: 53062, 53063
The fuchsia code around metrics and sizing was just sending this
information through a side-channel, when the engine already had the
information available. So, delete all of it to make future CLs simpler.
Additionally, the SceneUpdateContext has many unneccesary dependencies
re: metrics and PaintTasks. Break those to make future CLs simpler.
Tested: Ran all unittests and ran workstation on Fuchsia
BUG: 53062, 53063
This is part of a larger effort to expose the difference between GrDirectContext,
which runs on the GPU thread and can directly perform operations like uploading
textures, and GrRecordingContext, which can only queue up work to be delivered
to the GrDirectContext later.
