Arena.mjs Graphics & Framework Error Report #

Date: 2026-04-14
Status: 🔴 BLOCKING - Graphics not rendering, framework messaging error
Severity: High

Summary #

The arena.mjs piece partially runs but exhibits two critical issues:

No graphics rendering - The 3D scene, ground plane, and mobile buttons don't display
Framework messaging error - Persistent ReferenceError: data is not defined in bios.mjs:11603 in the receivedChange handler

The piece boots successfully, responds to input (gamepad/keyboard), and executes paint/sim functions, but the graphics pipeline appears broken.

Error Details #

Error Stack Trace #

bios.mjs:11603 Uncaught (in promise) ReferenceError: data is not defined
    at receivedChange (bios.mjs:11603:27)
    at onMessage (bios.mjs:3928:5)
    at worker.onmessage (bios.mjs:4148:11)

Observations #

Error occurs repeatedly during piece execution
Error happens AFTER "Proxy set up" message (piece has booted)
Error is in framework's message handler, not piece code
Suggests malformed message being sent from piece to main thread
Try-catch in paint function catches no errors
Commented-out large console.log didn't fix the issue

Changes Made (Attempted Fixes) #

1. Mobile Button Implementation #

✅ Created color-coded buttons (green jump, orange crouch, blue directionals)
✅ Made action buttons wider (56px vs 32px)
✅ Added arrow characters (↑↓←→) for directionals
✅ Implemented touch/click and keyboard responsiveness
❌ Buttons don't render to screen

2. Graphics Buffer Approach #

Attempted to use painting() constructor to pre-bake button icons
Discovered painting not available in boot scope despite usage in 1v1.mjs
Reverted to simple text-based button rendering
❌ Did not resolve graphics issue

3. Error Isolation #

Removed large console.log JSON snapshot → error persists
Added try-catch wrapper around paint function → no caught errors
Removed buffer/paste references → error persists
❌ None resolved the bios.mjs error

Root Cause Analysis #

Hypothesis 1: Graphics Pipeline Broken #

The wipe, ink, box, line, write functions may not be working as expected, or the painting context is not initialized properly. However:

No errors caught in paint function
Piece executes paint code without exceptions
Mobile buttons have no text but still don't display

Hypothesis 2: Message Serialization Error #

The framework's receivedChange handler receives a malformed message where data is undefined. This could be triggered by:

Piece sending invalid state/snapshot format
Framework expecting specific message structure that arena.mjs violates
Uninitialized variable in piece being sent back to main thread

Hypothesis 3: Incompatible with FPS System #

The arena.mjs forks from fps.mjs and uses system: "fps" export. The fps system might have specific requirements about:

What can be logged/sent
How graphics are rendered
Message format expectations

Files Modified #

/workspaces/aesthetic-computer/system/public/aesthetic.computer/disks/arena.mjs
- Mobile button setup (lines ~310-335)
- Button rendering in paint (lines ~1240-1250)
- Try-catch wrapper in paint (lines ~885-1226)
- Removed buffer graphics creation code
- Commented out snapshot console.log

Next Steps / Recommendations #

Immediate #

Compare with fps.mjs - Check how fps.mjs handles graphics rendering vs arena.mjs
Check system.nopaint - Investigate if arena needs to use system.nopaint.buffer pattern instead of direct drawing
Review FPS system requirements - Verify what the fps system expects from pieces

Investigation #

Add explicit error reporting in paint function
Check if graphics APIs (wipe, ink, box, line) are actually available
Inspect what message is being sent that causes receivedChange to fail
Test with minimal piece that just calls wipe() to verify graphics work at all

Alternative Approaches #

Test if issue is specific to arena.mjs or affects all fps-based pieces
Try reverting arena.mjs to original fps.mjs to confirm it displays graphics
Check if mobile button implementation is interfering with graphics rendering

Test Case #

To reproduce:

Navigate to aesthetic.computer/arena
Observe: No 3D scene, no ground plane, no buttons visible
Observe: Console shows repeated data is not defined error
Input still works: Keyboard/gamepad commands are processed
Game logic runs: Internally piece updates state correctly

Attachments #

Modified file: arena.mjs (current state with buttons and try-catch)
Related files: fps.mjs (parent), system/public/aesthetic.computer/lib/disk.mjs (graphics API)

Questions for Investigation #

Why does painting() work in 1v1.mjs but appears undefined in arena.mjs?
What format does receivedChange in bios.mjs expect for data?
Are graphics APIs available in paint context for fps system pieces?
Does the nopaint system work differently than direct graphics calls?

Report compiled during arena.mjs development session. Graphics pipeline and framework messaging require deeper investigation into the AC graphics/messaging architecture.