[edwin-hollen]

Adds a new _paintBlurTag command (writePaintBlur / onPaintBlur) to vector_graphics_codec (1.2.0) to support encoding and decoding Gaussian blur image filters (sigmaX, sigmaY) alongside paint records.

This is split out from #11909 so the codec changes can land and be published first.

Part of flutter/flutter#158592

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter.
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or I have commented below to indicate which version change exemption this PR falls under[^1].
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style, or I have commented below to indicate which CHANGELOG exemption this PR falls under[^1].
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or I have commented below to indicate which test exemption this PR falls under[^1].
• All existing and new tests are passing.

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[gemini-code-assist]

Code Review

This pull request introduces support for encoding and decoding paint blur commands (writePaintBlur and onPaintBlur) in the vector_graphics_codec package, including corresponding unit tests. The review feedback suggests adding assertions to validate paintId and ensure sigmaX and sigmaY are non-negative, and updating the unit test to assert the exact sequence of decoded commands rather than using a partial match.

[gemini-code-assist]

Add assertions to validate that paintId is within the valid range (0 to kMaxId) and that the Gaussian blur standard deviations (sigmaX and sigmaY) are non-negative. Negative standard deviations are mathematically invalid for Gaussian blurs and will cause rendering errors.

  void writePaintBlur(VectorGraphicsBuffer buffer, int paintId, double sigmaX, double sigmaY) {
    assert(paintId >= 0 && paintId < kMaxId);
    assert(sigmaX >= 0.0);
    assert(sigmaY >= 0.0);
    buffer._checkPhase(_CurrentSection.paints);
    buffer._putUint8(_paintBlurTag);
    buffer._putUint16(paintId);
    buffer._putFloat32(sigmaX);
    buffer._putFloat32(sigmaY);
  }

[gemini-code-assist]

Instead of using contains to only check for the presence of OnPaintBlur, verify the exact list of decoded commands. This ensures that the commands are decoded in the correct order and that no extra or malformed commands are generated, matching the style of other tests in this file.

  test('Can encode and decode paint blur', () {
    final buffer = VectorGraphicsBuffer();
    final listener = TestListener();
    final int paintId = codec.writeFill(buffer, 23, 0);
    codec.writePaintBlur(buffer, paintId, 2.5, 3.5);
    final int pathId = codec.writePath(
      buffer,
      Uint8List.fromList(<int>[ControlPointTypes.moveTo, ControlPointTypes.close]),
      Float32List.fromList(<double>[1, 2]),
      0,
    );
    codec.writeDrawPath(buffer, pathId, paintId, null);

    codec.decode(buffer.done(), listener);

    expect(listener.commands, <Object>[
      OnPaintObject(
        color: 23,
        strokeCap: null,
        strokeJoin: null,
        blendMode: 0,
        strokeMiterLimit: null,
        strokeWidth: null,
        paintStyle: 0,
        id: paintId,
        shaderId: null,
      ),
      OnPaintBlur(paintId, 2.5, 3.5),
      OnPathStart(pathId, 0),
      const OnPathMoveTo(1, 2),
      const OnPathClose(),
      const OnPathFinished(),
      OnDrawPath(pathId, paintId, null),
    ]);
  });

[edwin-hollen]

@walley892 for visibility

[auto-submit]

autosubmit label was removed for flutter/packages/13148, because This PR has not met approval requirements for merging. The PR author is not a member of flutter-hackers and needs 1 more review(s) in order to merge this PR.

• Merge guidelines: A PR needs at least one approved review if the author is already part of flutter-hackers or two member reviews if the author is not a member of flutter-hackers before re-applying the autosubmit label. Reviewers: If you left a comment approving, please use the "approve" review action instead.

[gaaclarke]

lgtm! thanks

[edwin-hollen]

@gaaclarke The post-submit release run for this PR failed at "Wait for test check-in" (https://github.com/flutter/packages/actions/runs/38633635933), so vector_graphics_codec 1.2.0 hasn't been published to pub.dev yet (blocking #11909). Could you re-run that release job when you get a chance?