MAP-21: Fix interia after two finger zoom

[maerki]

This fixes the 2d inertia after two finger move completed.

Summary by CodeRabbit

• New Features
  • Enhanced the map’s multi-touch interaction by adding inertia to camera movements. Users will experience smoother and more natural dragging, with improved responsiveness during two-finger gestures.

[coderabbitai]

Walkthrough

The changes modify the MapCamera2d class to improve how drag velocity is handled during two-finger movements. The logic in the onTwoFingerMove method now initializes or updates the drag timestamp and velocity based on movement deltas and elapsed time. In the corresponding onTwoFingerMoveComplete method, the setupInertia method is invoked when the camera is not frozen, enabling inertia-driven movement. No public API changes were made.

Changes

File	Change Summary
shared/.../MapCamera2d.cpp	Enhanced drag velocity calculation in onTwoFingerMove using time deltas and movement differences; added conditional inertia setup in onTwoFingerMoveComplete.

Sequence Diagram(s)

sequenceDiagram
    participant User
    participant MapCamera2d
    User->>MapCamera2d: Start two-finger motion
    MapCamera2d->>MapCamera2d: Check currentDragTimestamp
    alt First movement
        MapCamera2d-->>MapCamera2d: Initialize timestamp and velocity
    else Subsequent movement
        MapCamera2d-->>MapCamera2d: Calculate delta time & update velocity
    end
    User->>MapCamera2d: End two-finger motion
    MapCamera2d->>MapCamera2d: Call onTwoFingerMoveComplete
    alt Camera not frozen
        MapCamera2d->>MapCamera2d: Invoke setupInertia
    end

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Suggested reviewers

• maurhofer-ubique
• zimmermannubique

Poem

I'm a rabbit coding swift and light,
Enhancing drags with a velocity flight.
With two-finger moves, the magic begins,
Inertia now flows as the camera spins.
Hopping in code, my joy's set alight! 🐇✨

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📥 Commits

Reviewing files that changed from the base of the PR and between 5f1dd95 and 6c3b13c.

📒 Files selected for processing (1)

• shared/src/map/camera/MapCamera2d.cpp (2 hunks)

⏰ Context from checks skipped due to timeout of 90000ms (2)

• GitHub Check: build
• GitHub Check: build

🔇 Additional comments (3)

shared/src/map/camera/MapCamera2d.cpp (3)

783-794: Nice addition of drag velocity calculation for two-finger movements.

This implementation properly handles velocity calculations during two-finger gestures by tracking timestamps and calculating a weighted average velocity. It matches the approach used in the single-finger move handler and ensures consistent inertia behavior across different interaction modes.

---

860-860: Good addition of inertia for north-snap rotation case.

Adding setupInertia() here ensures that momentum continues even when the rotation snap-to-north animation is triggered.

---

865-867: Good conditional handling of inertia.

This properly ensures that inertia is only set up when the camera isn't frozen, matching the condition checks used elsewhere in the code.

✨ Finishing Touches

• 📝 Generate Docstrings

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