Fix incorrect rendering from drawImageNine when running on impeller with opengles#182179
Merged
auto-submit[bot] merged 3 commits intoflutter:masterfrom Feb 11, 2026
Merged
Conversation
… in texture_contents.cc
|
It looks like this pull request may not have tests. Please make sure to add tests or get an explicit test exemption before merging. If you are not sure if you need tests, consider this rule of thumb: the purpose of a test is to make sure someone doesn't accidentally revert the fix. Ask yourself, is there anything in your PR that you feel it is important we not accidentally revert back to how it was before your fix? Reviewers: Read the Tree Hygiene page and make sure this patch meets those guidelines before LGTMing. If you believe this PR qualifies for a test exemption, contact "@test-exemption-reviewer" in the #hackers channel in Discord (don't just cc them here, they won't see it!). The test exemption team is a small volunteer group, so all reviewers should feel empowered to ask for tests, without delegating that responsibility entirely to the test exemption group. |
github-actions
bot
added
engine
b-luk
changed the title
![gemini-code-assist[bot]](proxy.php?url=https://avatars.githubusercontent.com/in/956858?s=60&v=4){kind=small}
Contributor
There was a problem hiding this comment.
Code Review
This pull request corrects an issue with texture coordinate clamping when using an inverted Y-axis, which is common with the OpenGL ES backend. The change adjusts the source_rect for the fragment shader to account for the inverted Y-coordinates, preventing vertical smearing artifacts. My review includes a minor suggestion to use 1.0f for float literals to align with the project's style guide and ensure type consistency.
engine/src/flutter/impeller/entity/contents/texture_contents.cc
Outdated
Show resolved
Hide resolved
Contributor
Author
|
I expect golden changes that update the opengles canvas_test_blurred_rendering_ tests discussed in #181933 (comment) |
Contributor
Author
|
https://flutter-gold.skia.org/search?crs=github&issue=182179&patchsets=2 does show the expected fixed golden |
gaaclarke
approved these changes
Feb 11, 2026
| FSStrict::FragInfo frag_info; | ||
| frag_info.source_rect = Vector4(strict_texture_coords.GetLTRB()); | ||
| if (texture_->GetYCoordScale() < 0.0) { | ||
| frag_info.source_rect = Vector4(strict_texture_coords.GetLeft(), |
Member
There was a problem hiding this comment.
Let's FML_DCHECK that it is -1 since you aren't actually using the value.
Member
|
Nice find! |
Contributor
|
autosubmit label was removed for flutter/flutter/182179, because - The status or check suite Linux linux_host_engine_test has failed. Please fix the issues identified (or deflake) before re-applying this label. |
auto-submit
bot
removed
the
autosubmit
gaaclarke
added
the
autosubmit
flutter-dashboard
bot
removed
the
autosubmit
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 12, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 12, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 12, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 13, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 13, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 13, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 14, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 14, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 14, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 14, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 15, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 15, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 15, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 16, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 16, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 16, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 17, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 17, 2026
…impeller with opengles (flutter/flutter#182179)
engine-flutter-autoroll
added a commit
to engine-flutter-autoroll/packages
that referenced
this pull request
Feb 17, 2026
…impeller with opengles (flutter/flutter#182179)
rickhohler
pushed a commit
to rickhohler/flutter
that referenced
this pull request
Feb 19, 2026
…ith opengles (flutter#182179) The `frag_info.source_rect` passed into https://github.com/flutter/flutter/blob/98977409b2ac8209be9e918abb0bbb9c37a23d0f/engine/src/flutter/impeller/entity/shaders/texture_fill_strict_src.frag from [texture_contents.cc](https://github.com/flutter/flutter/blob/98977409b2ac8209be9e918abb0bbb9c37a23d0f/engine/src/flutter/impeller/entity/contents/texture_contents.cc#L187) did not account for an inverted y scale (used with an opengles impeller backend). This ends up causing the coordinates used to sample the texture in the fragment shader to be incorrectly clamped. A lot of the y coordinates end up incorrectly being considered outside of the source_rect, so we end up with lots of incorrect y values and vertical smearing caused by the clamping. The texture_fill_strict_src.frag shader is used primarily by calls to drawImageNIne. NinePatchConverter calls DrawImageRect with SourceRectConstraint::kStrict, which uses texture_fill_strict_src.frag. flutter#182101 shows a repro case for this. The golden test issue discussed in flutter#181933 (comment) is also caused by this. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed. <!-- Links --> [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The
frag_info.source_rectpassed into https://github.com/flutter/flutter/blob/98977409b2ac8209be9e918abb0bbb9c37a23d0f/engine/src/flutter/impeller/entity/shaders/texture_fill_strict_src.frag from texture_contents.cc did not account for an inverted y scale (used with an opengles impeller backend).This ends up causing the coordinates used to sample the texture in the fragment shader to be incorrectly clamped. A lot of the y coordinates end up incorrectly being considered outside of the source_rect, so we end up with lots of incorrect y values and vertical smearing caused by the clamping.
The texture_fill_strict_src.frag shader is used primarily by calls to drawImageNIne. NinePatchConverter calls DrawImageRect with SourceRectConstraint::kStrict, which uses texture_fill_strict_src.frag.
#182101 shows a repro case for this. The golden test issue discussed in #181933 (comment) is also caused by this.
Pre-launch Checklist
///).If you need help, consider asking for advice on the #hackers-new channel on Discord.
Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the
gemini-code-assistbot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.