| commit | cf927ae715c5d72c83b904addecd27231593acfb | [log] [tgz] |
|---|---|---|
| author | Brandon DeRosier <bdero@google.com> | Wed Mar 27 17:42:48 2024 -0700 |
| committer | dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com> | Wed Mar 27 18:27:53 2024 -0700 |
| tree | aa77b24d21d1715d12559d6e743ae73bd67e9d50 | |
| parent | 1dd3c166d070f2da533e6ddc877edde6d801a9a0 [diff] |
[Impeller] Reland: Use the scissor to limit all draws by clip coverage. (#51731) Reland https://github.com/flutter/engine/pull/51698. This reverts commit https://github.com/flutter/engine/commit/73c145c9ac3a3d7ea7b644e696b0ea4306ec849f. Attempts to improve https://github.com/flutter/flutter/issues/145274. Our new clipping technique paints walls on the depth buffer "in front" of the Entities that will be affected by said clips. So when an intersect clip is drawn (the common case), the clip will cover the whole framebuffer. Depth is divvied up such that deeper clips get drawn _behind_ shallower clips, and so many clips actually don't end up drawing depth across the whole framebuffer. However, if the app does a lot of transitioning from a huge clips to a small clips, a lot of unnecessary depth churn occurs (very common in Flutter -- this happens with both the app bar and floating action button in the counter template, for example). Since progressively deeper layers in the clip coverage stack always subset their parent layers, we can reduce waste for small intersect clips by setting the scissor to the clip coverage rect instead of drawing the clip to the whole screen. Note that this change _does not_ help much with huge/fullscreen clips. Also, we could potentially improve this further by computing much stricter bounds. Rather than just using clip coverage for the scissor, we could intersect it with the union of all draws affected by the clip at the cost of a bit more CPU churn per draw. I don't think that's enough juice for the squeeze though. Before (`Play/AiksTest.CanRenderNestedClips/Metal`): https://github.com/flutter/engine/assets/919017/7858400f-793a-4f7b-a0e4-fa3581198beb After (`Play/AiksTest.CanRenderNestedClips/Metal`): https://github.com/flutter/engine/assets/919017/b2f7c96d-a820-454d-91df-f5fae4976e91 https://dart.googlesource.com/external/github.com/flutter/engine/+/918bf19cd85bc55449203df3444ac8d0a21c40ae
Monorepo is:
With depot_tools installed and on your path, create a directory for your monorepo checkout and run these commands to create a gclient solution in that directory:
mkdir monorepo cd monorepo gclient config --unmanaged https://dart.googlesource.com/monorepo gclient sync -D
This gives you a checkout in the monorepo directory that contains:
monorepo/ DEPS - the DEPS used for this gclient checkout commits.json - the pinned commits for Dart, flutter/engine, and flutter/flutter tools/ - scripts used to create monorepo DEPS engine/src/ - the flutter/buildroot repo flutter/ - the flutter/engine repo out/ - the build directory, where Flutter engine builds are created third_party/ - Flutter dependencies checked out by DEPS dart/ - the Dart SDK checkout. third_party - Dart dependencies, also used by Flutter flutter/ - the flutter/flutter repo
Flutter's instructions for building the engine are at Compiling the engine
They can be followed closely, with a few changes:
goma_ctl ensure_start is sufficient.Example build commands that work on linux:
MONOREPO_PATH=$PWD if [[ ! $PATH =~ (^|:)$MONOREPO_PATH/flutter/bin(:|$) ]]; then PATH=$MONOREPO_PATH/flutter/bin:$PATH fi export GOMA_DIR=$(dirname $(command -v gclient))/.cipd_bin goma_ctl ensure_start pushd engine/src flutter/tools/gn --goma --no-prebuilt-dart-sdk --unoptimized --full-dart-sdk autoninja -C out/host_debug_unopt popd
The Flutter commands used to build and run apps will use the locally built Flutter engine and Dart SDK, instead of the one downloaded by the Flutter tool, if the --local-engine option is provided.
For example, to build and run the Flutter spinning square sample on the web platform,
MONOREPO_PATH=$PWD cd flutter/examples/layers flutter --local-engine=host_debug_unopt \ -d chrome run widgets/spinning_square.dart cd $MONOREPO_PATH
To build for desktop, specify the desktop platform device in flutter run as -d macos or -d linux or -d windows. You may also need to run the command
flutter create --platforms=windows,macos,linux
on existing apps, such as sample apps. New apps created with flutter create already include these support files. Details of desktop support are at Desktop Support for Flutter
Tests in the Flutter source tree can be run with the flutter test command, run in the directory of a package containing tests. For example:
MONOREPO_PATH=$PWD cd flutter/packages/flutter flutter test --local-engine=host_debug_unopt cd $MONOREPO_PATH
Please file an issue or email the dart-engprod team with any problems with or questions about using monorepo.
We will update this documentation to address them.
flutter commands may download the engine and Dart SDK files for the configured channel, even though they will be using the local engine and its SDK.gclient sync needs to be run in an administrator session, because some installed dependencies create symlinks.