feat(zoom): drive the 3D tilt from cursor motion

[EtienneLescot]

Dynamic rotation: the tilted screen follows cursor motion, on all presets (parallax).

Chantier 3D, PR 1. Spec complète et branche d intégration : #682.

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Summary by CodeRabbit

• New Features
  • Added cursor-responsive parallax for 3D zoom presets, creating a more natural screen-tilt effect as the cursor moves.
  • Improved transitions between 3D zoom presets to keep tilt behavior stable and predictable.
• Improvements
  • Screen privacy masks and cursor positioning now remain aligned with tilted content.
  • Unified screen-tilt projection behavior across supported platforms.
• Tests
  • Added coverage for cursor-driven tilt, transitions, projection alignment, and rendering behavior.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: 2e262bac-e010-45c9-924c-ae543cd35d63

📥 Commits

Reviewing files that changed from the base of the PR and between 0834a66 and 2889fbb.

📒 Files selected for processing (8)

• crates/compositor/src/compositor_linux.rs
• crates/compositor/src/compositor_macos.rs
• crates/compositor/src/compositor_windows.rs
• crates/compositor/src/frame_geometry.rs
• crates/compositor/src/regions.rs
• crates/compositor/tests/tilt_parallax_render.rs
• crates/fixture/scene-tilt.json
• crates/poc-d3d/src/bench.rs

💤 Files with no reviewable changes (1)

• crates/poc-d3d/src/bench.rs

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📝 Walkthrough

Walkthrough

Changes

Dynamic tilt and parallax

Layer / File(s)	Summary
Tilt state and projection crates/compositor/src/regions.rs	ZoomState and quad projection now support dynamic rotation, transition gating, bounded cursor parallax, and expanded geometry tests.
Frame geometry propagation crates/compositor/src/frame_geometry.rs	plan_frame derives dynamic tilt from visible cursor motion. Screen, cursor, and privacy-mask projections use the shared screen_tilt method.
Backend rendering integration crates/compositor/src/compositor_linux.rs, crates/compositor/src/compositor_macos.rs, crates/compositor/src/compositor_windows.rs	All three compositor backends use shared tilt geometry. Windows passes dynamic rotation to fallback projection.
Rendered tilt validation crates/compositor/tests/tilt_parallax_render.rs, crates/fixture/scene-tilt.json	A Windows integration test measures plane movement during cursor gestures. A fixture defines 3D zoom regions and rendering settings.

Benchmark initializer cleanup

Layer / File(s)	Summary
Benchmark clip-source updates crates/poc-d3d/src/bench.rs	Two benchmark initializers no longer set hold_sec.

Priority: ➖ Normal

Estimated code review effort: 4 (Complex) | ~60 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant CursorTrack
  participant FrameGeometry
  participant Compositor
  participant Renderer
  CursorTrack->>FrameGeometry: provide cursor motion
  FrameGeometry->>FrameGeometry: compute dynamic tilt
  Compositor->>FrameGeometry: request screen_tilt(s_px)
  FrameGeometry-->>Compositor: return projected quad
  Compositor->>Renderer: draw tilted screen and aligned overlays

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Suggested reviewers: beetix

Merge Risk: ⚪ Minimal · up to 2889f

No concrete behavior or production risk remains that should block merging after normal checks.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description states the main feature and references the related work, but it omits most required template sections, including issue status, change type, release impact, desktop impact, screenshots …	Complete the template. Add the related issue status, select the change type, release impact, and desktop impact, provide screenshots or video for the visual change, and document the testing performed.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the main change: cursor-driven 3D tilt for zoom presets.
Docstring Coverage	✅ Passed	Docstring coverage is 90.57% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 53 functions across 6 files. (1 skipped: 1 …
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Description check

Explanation

The description states the main feature and references the related work, but it omits most required template sections, including issue status, change type, release impact, desktop impact, screenshots or video, and testing details.

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[EtienneLescot]

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[EtienneLescot]

Intégrée dans integration/chantier-3d (#682) avec ses corrections de revue CodeRabbit ; le chantier avance désormais dans cette seule PR.