[vector_graphics_compiler] Set the m4_10 (Z scale) value to 1 when constructing an AffineMatrix from an SVG matrix #9813
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…nstructing an AffineMatrix from an SVG matrix The 4x4 matrix produced by the SVG matrix() function should have its 10th element set to 1. (see https://developer.mozilla.org/en-US/docs/Web/CSS/transform-function/matrix) The SVG matrix parser constructs an AffineMatrix from the SVG input. The AffineMatrix is then converted into a list that is given to Flutter engine APIs. Before flutter/engine@62cb2c9, the Flutter engine was implicitly overriding the 10th element of the matrix with a 1 value. After that commit, the engine uses the matrix contents as is and does not override any values. This PR changes the SVG matrix parser to explicitly set the AffineMatrix m4_10 parameter to 1. This reflects the SVG spec and produces output that matches the original engine behavior. See flutter/flutter#171854
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This pull request corrects the SVG matrix() transform parsing by explicitly setting the Z-scale component of the AffineMatrix to 1.0, aligning it with the SVG specification. Previously, it incorrectly defaulted to the X-scale value. The tests are updated to reflect this fix. Since this issue originated from the AffineMatrix constructor's default behavior, it may be beneficial to review other transform parsers in the same file for similar issues.
flar
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Aug 14, 2025
Your understanding of this is better than mine. Can you file an issue in https://github.com/flutter/flutter/issues and tag it with |
jtmcdole
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Aug 14, 2025
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… 1 when constructing an AffineMatrix from an SVG matrix (flutter/packages#9813)
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flutter/packages@09533b7...5c52c55 2025-08-15 stuartmorgan@google.com [video_player] Move Android buffer updates to Dart (flutter/packages#9771) 2025-08-15 sfprhythnn@gmail.com [webview_flutter] Add support for payment requests on Android (flutter/packages#9679) 2025-08-15 jason-simmons@users.noreply.github.com [vector_graphics_compiler] Set the m4_10 (Z scale) value to 1 when constructing an AffineMatrix from an SVG matrix (flutter/packages#9813) 2025-08-15 magder@google.com [url_launcher_ios] Fix test button text to work on iOS 26 (flutter/packages#9766) 2025-08-15 stuartmorgan@google.com [video_player] Simplify native iOS code (flutter/packages#9800) 2025-08-14 stuartmorgan@google.com [image_picker] Add the ability to pick multiple videos - platform_interface (flutter/packages#9804) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages-flutter-autoroll Please CC flutter-ecosystem@google.com on the revert to ensure that a human is aware of the problem. To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
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* main: (24 commits) Roll Flutter from 0a2906b81d5e to b3fb4c786d80 (5 revisions) (flutter#9840) Update repo for 3.35 stable release (flutter#9816) Roll Flutter from 52af7a504025 to 0a2906b81d5e (16 revisions) (flutter#9836) [image_picker] Updates min SDK to 3.29 (flutter#9830) [image_picker] Add the ability to pick multiple videos (flutter#9775) [image_picker] Add the ability to pick multiple videos - platform implementations (flutter#9818) [various] Updates min SDK for third_party/packages to 3.29 (flutter#9819) [vector_graphics] Updates min SDK to 3.29 (flutter#9820) [google_maps_flutter] Updates min SDK to 3.29 (flutter#9821) [video_player] Updates min SDK to 3.29 (flutter#9826) [shared_preferences] Updates min SDK to 3.29 (flutter#9829) [image_picker_ios] Add photo to simulator Photos library during test (flutter#9759) [interactive_media_ads] Updates `README` with information about enabling desugaring on Android (flutter#9790) [in_app_purchase] Updates min SDK to 3.29 (flutter#9825) Roll Flutter from f4334d27934b to 52af7a504025 (29 revisions) (flutter#9832) [go_router] Update generated output format (flutter#9817) [video_player] Move Android buffer updates to Dart (flutter#9771) [webview_flutter] Add support for payment requests on Android (flutter#9679) [vector_graphics_compiler] Set the m4_10 (Z scale) value to 1 when constructing an AffineMatrix from an SVG matrix (flutter#9813) [url_launcher_ios] Fix test button text to work on iOS 26 (flutter#9766) ... # Conflicts: # packages/go_router_builder/CHANGELOG.md # packages/go_router_builder/example/lib/all_types.g.dart # packages/go_router_builder/example/lib/main.g.dart # packages/go_router_builder/example/lib/shell_route_with_keys_example.g.dart # packages/go_router_builder/example/lib/shell_route_with_observers_example.g.dart
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The 4x4 matrix produced by the SVG matrix() function should have its 10th element set to 1. (see https://developer.mozilla.org/en-US/docs/Web/CSS/transform-function/matrix)
The SVG matrix parser constructs an AffineMatrix from the SVG input. The AffineMatrix is then converted into a list that is given to Flutter engine APIs.
Before flutter/engine@62cb2c9, the Flutter engine was implicitly overriding the 10th element of the matrix with a 1 value. After that commit, the engine uses the matrix contents as is and does not override any values.
This PR changes the SVG matrix parser to explicitly set the AffineMatrix m4_10 parameter to 1. This reflects the SVG spec and produces output that matches the original engine behavior.
See flutter/flutter#171854