artlegend/HANDOFF_2026-05-07.md

Agent Handoff — May 7, 2026

Session Summary

This session was design-focused, not implementation-focused. Two things were accomplished:

1. The Corridor Scroll module mechanics were fully described and documented.
2. The Vector Drawing module design conversation was started but not finished — bill had to leave mid-discussion.

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What Was Accomplished

Documentation

• Created MODULES.md — the authoritative module design reference. This file exists specifically because design decisions were being re-explained from scratch each session. Keep it updated.
• Updated README.md — module list now reflects Corridor Scroll (not "Line Corridor"), added Stroke-to-Drawing, updated the vision paragraph to describe the scroll mechanic properly, and linked to MODULES.md.

Corridor Scroll — design is settled

Full mechanics documented in MODULES.md. Summary:

• Guitar Hero-style scrolling corridor, player tracks it with the stylus
• Scroll direction angle changes over time — full 360° range at high difficulty, no angle changes at low difficulty
• Difficulty knobs: scroll speed, corridor width, angle change frequency/severity, lookahead distance
• Scoring: running tally of fill coverage (rewarded) + wall crossings (penalized). No pressure component.
• Early levels: straight corridor only. Later levels: any angle including full reversals.

Code change from this session

LineScore was updated to replace pressureConsistency with anglePrecision (straightness 60%, angle 40%). This was done before the full corridor scroll mechanic was described — this scoring model is now likely wrong for the module as designed. The corridor scroll is real-time tracking, not a single-stroke grade. The scoring architecture will need to be rethought when implementation resumes. Don't build on top of the current LineScore/computeScore() without revisiting it first.

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In Progress: Vector Drawing Module Design

This conversation started but was not finished. Here is where it was left.

What was proposed (by the agent — not yet agreed with bill)

Three sub-exercises, each isolating a different aspect of vector tool use:

1. Anchor placement — target curve shown, player repositions pre-suggested anchor points. Teaches where joints belong (corners, inflection points, extrema).
2. Handle pulling — anchors pre-placed, player drags handles to shape the curve against a target. Teaches handle angle/length intuition.
3. Full trace — player places anchors and pulls handles from scratch. Scored on fidelity to target AND anchor economy (fewer anchors = better, if fidelity holds).

Difficulty progression proposed:

• Easy: target visible while working, simple open curves, loose tolerance, no economy pressure.
• Hard: target shown briefly then hidden, complex closed shapes, tight tolerance, economy weighted heavily.

Open questions — bill had not yet answered these

These need to be discussed before MODULES.md is updated with the vector module design:

1. Simulate a specific tool or abstract it? Should exercises feel like practicing for Illustrator's pen tool specifically (with its handle-breaking behavior etc.), or be a simplified universal bezier model that transfers to any app?

2. Anchor economy in scoring? Good habit to teach, but may frustrate beginners. Should economy only factor in at higher difficulty, or always be part of the score?

3. Target content — abstract curves and blobs, or recognizable things like letterforms and simple character shapes? Recognizable is more motivating but harder to generate procedurally.

4. Target visibility — should seeing the target while you trace always be available as a beginner/accessibility option, or does the module intentionally remove it as difficulty increases?

5. Does pressure matter here? Real vector tools ignore pressure. But this is an S-Pen trainer. Should the module ignore pressure entirely, or is there a creative angle (e.g. calligraphic vector mode where handle length is pressure-driven)?

Where to pick up

Resume by getting bill's answers to the five questions above. Once agreed, write the Vector Drawing section in MODULES.md using the same format as the Corridor Scroll section. Do not write any implementation code until the design is settled and documented.

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Broader Reminders for Next Agent

• Design before code. Bill has explicitly said assumptions get made when mechanics aren't written out. When something is ambiguous, discuss and document first.
• Keep MODULES.md updated. It exists to prevent re-explanation. Every settled design decision goes there.
• The current LineCorridorScreen and LineScore are placeholders, not the real implementation of Corridor Scroll. The real mechanic (scrolling corridor, real-time tracking) is fundamentally different from what's coded (static corridor, single stroke scored on lift).
• Build command: JAVA_HOME="/Users/blindmouse/Applications/IntelliJ IDEA.app/Contents/jbr/Contents/Home" ./gradlew :android:assembleDebug
• APK output: android/build/outputs/apk/debug/android-debug.apk
• AL-009 (on-device smoke test) is still the only open sprint ticket — needs a physical device.