test(fixtures): end-to-end mixed-feature fixture

[danko-nobre]

Spec 035 (project health), follow-up PR: the end-to-end mixed-feature fixture - the sixth now-item, split out from the toolchain/shipping PR (#112) as agreed.

What

One fixture that stacks every Blender-to-Godot feature in a single document, so the golden catches interactions a single-feature fixture cannot:

• Skinned body - a 2-face polygon weighted across root / spine, exporting per-bone weights plus the per-face polygons index arrays.
• sprite_frame mouth - a 4-frame Sprite2D bone-parented to head.
• Drive-from-Bone - a scripted driver on mouth.proscenio.frame reading jaw ROT_Y; the animation bakes into a bone_transform track plus the driven sprite_frame track.
• Slot with mixed attachments - face.slot holds face_neutral (mesh / Polygon2D) and face_glow (sprite / Sprite2D), default face_neutral.
• Packed atlas - every element shares one atlas.png: meshes derive their region from UV bounds, the two sprite strips carry a manual region. One image keeps the top-level atlas field deterministic.
• One animation mixed_anim.

Layout

Lands in the blender_to_godot/ bucket - new fixtures go there per its README; the flat legacy fixtures move later. Builder scripts under packages/fixtures/mixed_feature/ (Pillow draw_layers.py + bpy build_blend.py), golden + .blend + atlas.png + Godot wrapper under examples/generated/blender_to_godot/mixed_feature/.

Wiring + verification

• test-blender: the golden is auto-discovered by run_tests.py; the local re-export is byte-clean (8/8 fixtures, baked on Blender 5.1.1 to match CI).
• test-godot: a tests/fixtures/mixed_feature.proscenio copy plus a _run_mixed_checks() block in test_importer.gd walking the whole stack (skinned Polygon2D with 2 bones + 2 faces, 4-frame Sprite2D mouth, mixed slot attachments, the mixed_anim tracks, and the saved-scene no-script guard). Local run: 82 assertions, exit 0.
• Both .proscenio validate against proscenio.schema.json (the validate-schema job).
• sync_fixtures.py picks the fixture up (gitignored dev-project output).

🤖 Generated with Claude Code

Summary by CodeRabbit

• Fixtures

  • Added a new mixed-feature visual fixture demonstrating combined skinned mesh + sprite attachments, slots, and animation.

• Tests

  • Extended importer tests to validate the mixed-feature scene, structure, attachments, and animation tracks.

• Tools

  • Added asset-generation tooling to produce the fixture atlas and Blender-based fixture builder for reproducible fixtures.

• Documentation

  • Marked the mixed-feature fixture task as completed in project TODOs.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 64ef773f-7c1e-4f92-b6a3-d984d064a50d

📥 Commits

Reviewing files that changed from the base of the PR and between 28a6755 and 4d55146.

📒 Files selected for processing (1)

• packages/fixtures/mixed_feature/build_blend.py

🚧 Files skipped from review as they are similar to previous changes (1)

• packages/fixtures/mixed_feature/build_blend.py

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📝 Walkthrough

Walkthrough

End-to-end mixed_feature fixture: Proscenio scene (skeleton, skinned body, sprite attachments, slots, animation), a generated atlas, a Blender builder that creates the .blend with drivers/animation, and extended Godot importer tests validating the built scene.

Changes

Mixed Feature Fixture Implementation

Layer / File(s)	Summary
Fixture specification: skeleton, elements, slots, animation apps/godot/tests/fixtures/mixed_feature.proscenio	Proscenio config defining a four-bone skeleton (root, spine, head, jaw), a textured two-face polygonal body with per-face vertex weights, sprite-based face attachments (face_neutral, face_glow) and a frame-based mouth, a face.slot with default attachment, atlas reference, and mixed_anim with bone_transform and sprite_frame tracks.
Atlas texture generation packages/fixtures/mixed_feature/draw_layers.py	Standalone script generating a 128×128 atlas (four 64×64 quadrants: 4-frame mouth strip, 2-frame glow strip, body block, face disc) and saving examples/generated/blender_to_godot/mixed_feature/atlas.png.
Blender fixture builder: armature, components, drivers, animation packages/fixtures/mixed_feature/build_blend.py	Blender orchestration that validates atlas existence, wipes session, builds a four-bone armature, creates skinned two-face body and mouth quad, assembles face.slot with mixed attachments, installs a scripted driver mapping jaw ROT_Y to mouth.proscenio.frame (expression var * 2 + 2), creates mixed_anim keyframes, saves .blend, and rewrites image paths to relative.
Godot importer test: fixture validation apps/godot/tests/test_importer.gd	Adds MIXED_FIXTURE constant and _run_mixed_checks() to build the fixture scene and assert skeleton structure, polygonal skinned body weights and faces, mouth sprite frame count, slot mixed attachments and default visibility, presence of mixed_anim with expected tracks, and no addon scripts in the saved scene.
Project status: end-to-end fixture delivered specs/035-project-health/TODO.md	Marks the end-to-end mixed-feature fixture as delivered and checks off authoring, baking, and wiring checklist items.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• firebound/proscenio#112: Adds saved-scene and addon-script detection helpers reused by the mixed-feature test stage.
• firebound/proscenio#26: Implements slot/slot_attachment behavior that the mixed-feature fixture exercises.
• firebound/proscenio#39: Related to bone-driven driver behavior (drive from bone) similar to the scripted driver installed by the Blender fixture.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 60.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding an end-to-end mixed-feature fixture that combines multiple Blender-to-Godot features. It is specific, concise, and clearly conveys the primary change.
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.

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✨ Finishing Touches

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• Commit on current branch

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• Create PR with unit tests
• Commit unit tests in branch feat/spec-035-mixed-feature-fixture

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• Commit simplified code in branch feat/spec-035-mixed-feature-fixture

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

apps/godot/tests/fixtures/mixed_feature.proscenio (1)

6-63: mixed_feature flat bone hierarchy: likely supported; document the intent
In apps/godot/tests/fixtures/mixed_feature.proscenio (lines 6–63), root, spine, head, and jaw all have "parent": null (flat hierarchy). Other fixtures in the same folder (e.g., slots_demo.proscenio, skinned_dummy.proscenio) also contain bones with "parent": null, so this pattern appears supported/used elsewhere—if it’s intentional for the test, adding a short comment explaining the rationale would prevent it from looking like accidental/integrity-broken data.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@apps/godot/tests/fixtures/mixed_feature.proscenio` around lines 6 - 63, Add a
short inline comment above the "bones" array in the mixed_feature.proscenio
fixture stating that bones "root", "spine", "head", and "jaw" intentionally use
a flat hierarchy with "parent": null (this mirrors other fixtures like
slots_demo and skinned_dummy) so readers know this is deliberate, not corrupted
data; update the fixture header or the bones block comment accordingly.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/fixtures/mixed_feature/build_blend.py`:
- Around line 283-315: The driver expression "var * 2 + 2" in
_install_mouth_driver maps jaw ROT_Y (radians) to invalid frame indices; change
the expression to normalize var from the jaw rotation range [-π/2, +π/2] into
integer frame indices [0, 3] by first adding π/2, dividing by π, then scaling by
3 (i.e., (var + π/2) / π * 3) and assign the same corrected expression to
mouth_obj.proscenio.driver_expression; keep the TRANSFORMS variable setup (var,
target.id=armature_obj, target.bone_target="jaw", target.transform_type="ROT_Y")
and ensure transform_space/rotation_mode remain as-is.

---

Nitpick comments:
In `@apps/godot/tests/fixtures/mixed_feature.proscenio`:
- Around line 6-63: Add a short inline comment above the "bones" array in the
mixed_feature.proscenio fixture stating that bones "root", "spine", "head", and
"jaw" intentionally use a flat hierarchy with "parent": null (this mirrors other
fixtures like slots_demo and skinned_dummy) so readers know this is deliberate,
not corrupted data; update the fixture header or the bones block comment
accordingly.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: ac0a3364-2150-411e-a9e2-61143ca21027

📥 Commits

Reviewing files that changed from the base of the PR and between 34aec4a and 28a6755.

⛔ Files ignored due to path filters (5)

• examples/generated/blender_to_godot/mixed_feature/atlas.png is excluded by !**/*.png, !**/generated/**
• examples/generated/blender_to_godot/mixed_feature/godot/MixedFeature.gd is excluded by !**/generated/**
• examples/generated/blender_to_godot/mixed_feature/godot/MixedFeature.tscn is excluded by !**/generated/**
• examples/generated/blender_to_godot/mixed_feature/mixed_feature.blend is excluded by !**/generated/**, !**/*.blend
• examples/generated/blender_to_godot/mixed_feature/mixed_feature.expected.proscenio is excluded by !**/generated/**

📒 Files selected for processing (5)

• apps/godot/tests/fixtures/mixed_feature.proscenio
• apps/godot/tests/test_importer.gd
• packages/fixtures/mixed_feature/build_blend.py
• packages/fixtures/mixed_feature/draw_layers.py
• specs/035-project-health/TODO.md

📜 Review details

🧰 Additional context used

📓 Path-based instructions (1)

apps/godot/**/*.{gd,gdc,gdns,gdst,tscn,scn}

📄 CodeRabbit inference engine (AGENTS.md)

The Godot plugin runs only at editor import time. Generated scenes must use only built-in nodes (Skeleton2D, Bone2D, Polygon2D, Sprite2D, Node2D, AnimationPlayer, AnimationLibrary). No GDExtension or native runtime

Files:

• apps/godot/tests/test_importer.gd

🔇 Additional comments (8)

specs/035-project-health/TODO.md (1)

37-42: LGTM!

apps/godot/tests/fixtures/mixed_feature.proscenio (2)

167-181: LGTM!

Also applies to: 182-228

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256-322: LGTM!

packages/fixtures/mixed_feature/draw_layers.py (2)

49-71: LGTM!

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62-64: No issue: border() supports (canvas, color[, thickness]).
packages/fixtures/_shared/_draw.py defines border(canvas: Canvas, color: RGBA, thickness: int = 1), so the call border(canvas, (0.20, 0.40, 0.25, 1.0)) is consistent (uses default thickness).

packages/fixtures/mixed_feature/build_blend.py (1)

53-71: LGTM!

apps/godot/tests/test_importer.gd (2)

253-318: LGTM!

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33-33: LGTM!

Also applies to: 44-44