Lesson 228: FMOD WebGL Snapshot Fest Demo Receipt (2026)

Direct answer: Before you paste the January 2027 itch HTML5 fest link into a public thread, require a GREEN Lesson 203 fmod_webgl_snapshot_receipt_v1.json, pass gesture + registration smoke on a cold browser tab, then file fmod_webgl_fest_snapshot_receipt_v1.json so BUILD_RECEIPT fmod_webgl_fest_snapshot promotes only when exploration (not combat) auditions in the first 90 seconds on itch_public.

Why this matters now (January 2027 itch HTML5 fest demos)

January 2027 teams finish Windows Wwise rows and press-key scope then promote the same build_label to itch. Facilitators open the demo in Chrome guest mode—combat music is loud because snapshots never registered after gesture, or the menu loop still runs the Combat snapshot from a debug session. Lesson 203 proves boot order; this lesson proves fest-session behavior on the storefront players actually click.

The FMOD 2.03 WebGL snapshot playbook and WebGL silent first scene help fix integration regressions; gesture parity preflight, bank-load preflight, and summer playtest desktop vs WebGL spot preflight are the ninety-second editor gates—228 is the live-ops fest promotion milestone on BUILD_RECEIPT.

Beginner path (cold-tab fest smoke)

Time: ~68 minutes first fest lane; ~12 minutes when 203 + parity guides are pinned.

Developer path (gates F1–F6)

Child receipt crosswalk (F1)

Do not duplicate W3/W4 proof inside the fest receipt—reference the child path:

"child_receipts": {
  "fmod_webgl_snapshot": "release-evidence/audio/FMOD_WEBGL_SNAPSHOT_RECEIPT.json"
}

fmod_webgl_fest_snapshot_receipt_v1.json

{
  "schema": "fmod_webgl_fest_snapshot_receipt_v1",
  "build_label": "fest-demo-2027-01-14-rc1",
  "surface": "itch_public",
  "fest_url": "https://YOURGAME.itch.io/demo",
  "fmod_studio_version": "2.03.xx",
  "child_receipts": {
    "fmod_webgl_snapshot": "release-evidence/audio/FMOD_WEBGL_SNAPSHOT_RECEIPT.json"
  },
  "fest_session_probe": {
    "browser": "chrome_guest",
    "pre_gesture_silent": true,
    "post_gesture_snapshot": "exploration",
    "menu_loop_seconds": 90,
    "combat_snapshot_heard": false
  },
  "parity": {
    "desktop_combat_duck_db": -6.1,
    "webgl_combat_duck_db": -5.7,
    "delta_db": 0.4,
    "within_tolerance": true
  },
  "gates": {
    "F1_child_snapshot": "pass",
    "F2_cold_tab_pre_gesture": "pass",
    "F3_menu_exploration": "pass",
    "F4_itch_label": "pass",
    "F5_parity": "pass",
    "F6_build_receipt": "pass"
  },
  "fest_snapshot_pass": true,
  "fest_promotion_allowed": true
}

Pin under release-evidence/audio/FMOD_WEBGL_FEST_SNAPSHOT_RECEIPT.json.

Fest menu loop script (F3)

Archive fest_audio_smoke.log with build_label, surface, and FMOD bus meter CSV export.

BUILD_RECEIPT row (F6)

ALTER TABLE release_publish_gate ADD COLUMN IF NOT EXISTS
  fmod_webgl_fest_snapshot_blocked BOOLEAN NOT NULL DEFAULT false;

CI verify_fmod_webgl_fest_snapshot_v1 fails when fest_url is non-empty in publish manifest and fest_snapshot_pass is false.

Relationship to Lesson 203 (not a repeat)

If 203 is RED, do not file 228—fix boot order first via bank-load preflight.

Key takeaways

1. 203 GREEN is mandatory—fest receipt wraps boot proof, does not replace it.
2. Cold guest tab catches cached AudioContext false positives.
3. First 90 s must sound like your storefront menu, not combat debug.
4. itch_public surface ties to triple-channel labels.
5. Gesture parity preflight satisfies F5 when filed same build_label.
6. Wednesday demo smoke should include guest-tab audio capture.
7. Q1 capstone 229 wires 228 with 224–227.
8. Windows audio is Lesson 226—do not conflate middleware receipts.

Common mistakes

• Promoting itch while 203 receipt still shows Awake() registration fail.
• Testing in the same browser profile that already clicked “Start”.
• Leaving Combat snapshot parameter at 1 in menu scene.
• Proving duck on desktop only for a fest HTML5 URL.
• fest_url uses GX embed host but receipt says itch_public.
• Skipping Bevy wasm build_label when Rust wasm SKU ships same fest week.

Troubleshooting

Mini exercise (68 minutes)

1. Break F3 (leave Combat=1); confirm fest_snapshot_pass: false.
2. Fix menu snapshot; pass cold-tab F2–F3.
3. Attach child 203 JSON path; verify F1 crosswalk.
4. Run F5 parity row; document exception if > 1.5 dB.
5. Commit fest receipt; set BUILD_RECEIPT fmod_webgl_fest_snapshot GREEN.

Continuity — Q1 2027 post-fest recovery (224–229)

Previous: Lesson 227 — Steam review-key press demo scope
Next: Lesson 229 — Q1 post-fest capstone receipt — Q1 arc 224–229 closed.

FAQ

Same as Lesson 203?
203 is boot registration; 228 is fest promotion with child receipt + 90 s menu policy.

Same as gesture parity guide?
Guide is ninety-second F5 evidence; this lesson files BUILD_RECEIPT fest row.

Godot FMOD bridge?
Same F1–F6 semantics; swap Unity hooks—fest receipt schema unchanged.

A loud combat bed on the itch menu is a fest refund mood—203 GREEN, cold-tab click, exploration for 90 seconds, then fmod_webgl_fest_snapshot_receipt.