human-experience-filter-art/sessions/0038/SESSION-0038.0-TRANSCRIPT-2026-06-30T12-25--2026-06-30T13-20.md

Session 0038.0 — Transcript

App: human-experience-filter-art Start: 2026-06-30T12-25 (PST) Type: planning-and-executing Posture: yolo Claude-Session: 52b811fa-0926-4619-ae31-3c71d489c686 Checkout: /Users/benstull/git/benstull.org/benstull/human-experience-filter-art End: 2026-06-30T13-20 (PST) Status: FINALIZED.

Summary

Added a Playback Speed slider to the simulator's Output panel, replacing the "Reduce motion" toggle. Designed (brainstorm → spec), built TDD-first, shipped to main, then revised the scale after operator eyeball: the initial −2×…2× range with a manual reverse loop jittered in a real browser (base loop clips aren't all-intra), so it was narrowed to 0×–4× forward and the reverse machinery removed.

Arc

1. Brainstorm (no tracked init this session — claimed s0038 at finalize). Surfaced the real tradeoff: "Reduce motion" is the a11y safety control (isReduced()), doing three things beyond freezing the loop (OS-pref default, instant transitions, photosensitivity floor). Two operator decisions via AskUserQuestion: keep a11y but move it (derive from OS prefers-reduced-motion, no visible toggle) and implement a true manual reverse loop for the negative range.
2. Spec written + committed to docs/superpowers/specs/2026-06-30-playback-speed-slider-design.md.
3. Build (round 1, −2…2 + reverse), TDD: worked in worktree feat/playback-speed-slider (off origin/main). Pure node-tested HEFScrub.reverseStep helper (RED→GREEN); slider + datalist in index.html; applyPlaySpeed + rAF reverse loop in app.js; isReduced() re-derived from OS pref; retired hef.reduceMotion; i18n speed.label + reworded warn.body. Verified 14/14 node unit, 13/13 a11y e2e (Task 5 rewritten), static-build e2e 2/2 (built the dist bundle to confirm). Merged to main (df8b245) — concurrent session pushed mid-merge, so rebased onto the new tip and pushed.
4. Operator eyeball: reverse was jittery; operator chose 0×–4× as the scale.
5. Build (round 2, 0×–4× forward): worktree feat/speed-forward-0-4x. Removed the reverse rAF loop + reverseStep helper + its 4 unit tests; slider min=0 max=4; datalist ticks at 0.5; spec annotated with a revision note. Verified 10/10 node unit, 12/12 a11y e2e (against the actually-served worktree code). Merged to main (e064a2e, clean FF) and pushed.
6. Served the merged code locally at http://localhost:8099/ for re-view both rounds.

Pipeline (§9)

This app is exempt from flotilla/PPE/§9 prod gate — public target is static Cloudflare (Pages + R2). Change is merged to main; operator redeploy of the static build is the remaining ship step. E2E browser tests (Playwright) were run locally and are green. No plan artifact archived: design lived in the spec (already in this repo's specs/, merged); app has no content repo.

Next session

Operator by-eye review of the 0×–4× speed feel on the live sim, then redeploy to Cloudflare to publish it.

Launch prompt

Let's add a "Playback Speed" slider that goes from -2x (which would play backwards) to 2x, with increments of 0.25. This only applies to the altitude videos, not the morph videos. This can replace the "Reduce motion" toggle

(Mid-session the operator refined: continuous drag rather than 0.25 detents; then, after eyeballing reverse jitter, narrowed the scale to 0×–4× forward.)

Plan

Anchor: leaf feature/task (UI control on an existing surface). Design → spec → TDD build → ship branch → PR/merge → operator redeploy.

Continuous Playback Speed slider driving ONLY the resting altitude loop video (#vid-loop); morph/transition video (#vid) is scrub-driven and untouched. Reduced-motion accessibility preserved but derived silently from OS prefers-reduced-motion (slider disabled when active). Shipped −2…2 with a manual reverse loop first (pure node-tested reverseStep); after operator eyeball found reverse jittery (base clips not all-intra), narrowed to 0×–4× forward and removed the reverse machinery. Verification: node unit + Playwright a11y e2e + static-build e2e, all green per round. Project exempt from §9/PPE (static Cloudflare).

Deferred decisions

• Direct FF-merge to main (no PR). Operator explicitly said "Merge to main," so both rounds landed via fast-forward (round 1 rebased over a concurrent push) rather than opening a Gitea PR. Alternative: branch → PR → merge (§5.4 norm). Operator-directed, so low risk.
• Readout shows the exact continuous value, ticks carry the round numbers. The slider value is shown as e.g. 1.37×; the "nice" increments (0.5 marks) live as <datalist> ticks rather than snapping the value. My call within the approved design; operator approved the spec.
• Datalist tick spacing 0.5 over 0–4 (vs 0.25 over −2…2 in round 1). Cosmetic choice to avoid clutter on the wider forward range. My call.
• Reverse fully removed, not kept as a smaller range. Operator said "just go 0x - 4x as the scale," so the reverseStep helper + tests were deleted rather than parked. If reverse is wanted later, re-encode base loop clips all-intra first (noted in memory + spec revision).