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.
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.
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
* Migrate a few last places to GrDirectContext
This is a followup to #19962 to cover a few places where we
were still using GrContext. No functional impact.
* Formatting
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 fixes all of the lint errors in lib/ui, except for a few (three, I think) where it would have changed the API, converting non-const references to pointers. For those, I just did NOLINT on the particular line instead of ignoring the whole file.
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.
* Manual merge or Dart into flutter a3815b6590...24c7666def
dart-lang/sdk@24c7666def Update tests that have the current version number hardcoded
dart-lang/sdk@f88ce7aef5 Increase Dart version to 2.10
* Update language version.
* Update license.
* Hpdate language version.
* Update license.
Refactors instantiateImageCodec and decodeImageFromPixels to provide intermediate data about the image width, height, and bytes per pixel. This allows for more fine grained control from Dart, particularly when trying to reason about how or whether to maintain aspect ratio in the targetWidth/targetHeight parameters.
This leaves the existing methods functional by re-implementing them to use the new ImmutableBuffer/ImageDescriptor class.
The ImmutableBuffer class is provided so that callers can avoid copying the image data multiple times if they wish to re-recreate the image descriptor.
Related Issues
Tweak the primary flutter build rule so that fuchsia is more similar to
other platforms in how tests and the shell are built.
Only embedder_unittests and GLFW tests are disabled on Fuchsia now.
TEST: Ran unittests on host/fuchsia; workstation on fuchsia
BUG: fxb/53847, fxb/54056
This change makes it so that we track all the motion events encountered by `FlutterView` and all of its subviews in the `MotionEventTracker` class, indexed by a unique `MotionEventId`. This identifier is then passed to the Flutter framework as seen in https://github.com/flutter/flutter/pull/60930. Once the gestures take part in gesture disambiguation and are sent back to the engine, we look-up the original motion event using the `MotionEventId` and dispatch it to the platform.
Bug: https://github.com/flutter/flutter/issues/58837
Additionally create "_next" permutations for all of the test binaries
on Fuchsia, in order to test both code-paths.
Using the #define follow-up CLs can also create a flutter_runner_next
binary that does not contain any legacy integration code.
BUG: 53847
