Repository: flutter
Issue: Unable to scroll diagonally with a trackpad in a TwoDimensionalScrollView
Labels: framework,f: scrolling,platform-web,a: desktop,P2,team-framework,triaged-framework

### Steps to reproduce

1. Build the example application from the ["2D scrolling - Flutter Build Show"](https://www.youtube.com/watch?v=ppEdTo-VGcg).
2. Try scrolling diagonally using a trackpad.

### Expected results

I would expect the viewport to change offset in both axes simultaneously.

### Actual results

The viewport changes its offset in a single axis only.

### Code sample

<details open><summary>Code sample</summary>

[DartPad - Two Dimensional Grid in Flutter](https://dartpad.dev/?id=4424936c57ed13093eb389123383e894)

You can additionaly wrap the scroll view in a [Listener](https://api.flutter.dev/flutter/widgets/Listener-class.html) to make sure the scroll events have offset in both axes.

```dart
...
body: Listener(
  onPointerSignal: (PointerSignalEvent signal) {
    if (signal is PointerScrollEvent) {
      print(signal.scrollDelta);
    }
  },
  child: TwoDimensionalGridView(
...
```

Output sample:

```console
flutter: Offset(-7.8, -14.4)
flutter: Offset(-6.1, -14.4)
flutter: Offset(-7.0, -14.4)
flutter: Offset(-6.1, -14.4)
```

</details>


### Screenshots or Video

<details open>
<summary>Screenshots / Video demonstration</summary>

Diagonal drag scrolling works as expected:

![Scrolling a 2D scroll view diagonally using drag gestures](https://github.com/user-attachments/assets/69e0c7dd-2916-414d-bdfe-c61edd37bad1)

Diagonal pointer scrolls are not applied on both axes at the same time:

![Scrolling a 2D scroll view diagonally using a trackpad](https://github.com/user-attachments/assets/8bca8ceb-ce69-41e2-bcbb-c71be5dfd320)

</details>


### Logs

_No response_

### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[✓] Flutter (Channel stable, 3.24.5, on Fedora Linux 41 (Workstation Edition) 6.11.7-300.fc41.x86_64, locale
    en_US.UTF-8)
    • Flutter version 3.24.5 on channel stable at /home/kamil/.local/apps/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision dec2ee5c1f (7 days ago), 2024-11-13 11:13:06 -0800
    • Engine revision a18df97ca5
    • Dart version 3.5.4
    • DevTools version 2.37.3

[✗] Android toolchain - develop for Android devices
    ✗ Unable to locate Android SDK.
      Install Android Studio from: https://developer.android.com/studio/index.html
      On first launch it will assist you in installing the Android SDK components.
      (or visit https://flutter.dev/to/linux-android-setup for detailed instructions).
      If the Android SDK has been installed to a custom location, please use
      `flutter config --android-sdk` to update to that location.


[✓] Chrome - develop for the web
    • CHROME_EXECUTABLE = /usr/bin/brave-browser-stable

[✓] Linux toolchain - develop for Linux desktop
    • clang version 19.1.0 (Fedora 19.1.0-1.fc41)
    • cmake version 3.30.5
    • ninja version 1.12.1
    • pkg-config version 2.3.0

[!] Android Studio (not installed)
    • Android Studio not found; download from https://developer.android.com/studio/index.html
      (or visit https://flutter.dev/to/linux-android-setup for detailed instructions).

[✓] VS Code (version 1.95.3)
    • VS Code at /usr/share/code
    • Flutter extension version 3.100.0

[✓] Connected device (2 available)
    • Linux (desktop) • linux  • linux-x64      • Fedora Linux 41 (Workstation Edition) 6.11.7-300.fc41.x86_64
    • Chrome (web)    • chrome • web-javascript • Brave Browser 131.1.73.89

[✓] Network resources
    • All expected network resources are available.

! Doctor found issues in 2 categories.
```

</details>