Wall & zones

The wall is a runtime setting

Walls are built from panels and installations differ in size, so neither side may hard-code the wall. The engine owns the physical installation and reports it once at startup, before any mode is loaded:

/wall/config   iiiiiiff   columns rows panelColumns panelRows
                          areaFirstColumn areaColumns widthMeters heightMeters
/wall/blanks   i*         every grid position with no hold

Both are rate: state, sent in one bundle, and re-sent on /sys/sync. Every hold index anywhere in the protocol means “an index into the most recent /wall/config” — holdCount is columns × rows.

The numbers in schema/protocol.yaml describe a reference installation. They drive this site, the mock sender and the monitor’s defaults. They are not constants, and the generated code does not present them as constants:

• SuperCollider: ~oscWall starts as the reference wall, and the generated /wall/config responder overwrites it before your handler runs.
• Engine: the helpers take the live geometry as arguments (Osc.HoldIndex(column, row, columns)); the reference values sit in a separate Osc.ReferenceWall class for tests.

Hold numbering

Unchanged from 0.1: zero-based, bottom-left origin, row-major, across the whole wall — decorative columns included. The index of a hold therefore never changes when the interactive area is reconfigured, and a saved route survives a change of play area.

The interactive area

The use cases distinguish the central, mappable area from decorative columns either side — Draw & Climb prints only the central part, and the side columns show a gradient. The protocol makes that a wall property rather than a Draw & Climb detail, because every mode needs to know where gameplay can happen:

• Modes place gameplay holds only inside the area.
• Zones split the area, not the whole wall.
• The decorative columns still report touches through /wall/hold/touch; it is up to the mode whether they mean anything.

A wall with no decorative columns simply sends areaFirstColumn 0 and areaColumns = columns.

Zones

Chase the Shape and Mirror split the area into 1–4 equal vertical strips, one child per strip. Zone 0 is leftmost.

zone z of n covers columns
  areaFirstColumn + floor(z × areaColumns / n)
  .. areaFirstColumn + floor((z + 1) × areaColumns / n) − 1

The split is computed, never sent. The zone count is a mode init param (zoneCount), and both sides derive the strips from it with generated helpers — ~zoneColumns / ~holdZone in SuperCollider, Osc.ZoneColumns / Osc.ZoneOfColumn in the engine — so they cannot disagree about which zone a hold belongs to.

Do not invert the formula by hand

floor(column × n / areaColumns) looks like the inverse and is wrong whenever the columns do not divide evenly: with 16 columns in 3 zones it puts column 5 in zone 0 when it belongs to zone 1. Checked by brute force over every width up to 64, the naive inverse misplaces 699 columns. The generated helpers search the zone ranges instead. Use them.

Zone indices in messages are declared ref: zone, so the monitor checks them against the zoneCount of the last /mode/load it saw.

The reference wall: 240 holds, 20 × 12, built from 4 × 2 panels of 5 × 6. Hold 0 (circled) is bottom-left; numbering runs along each row, then up, across the whole wall including decorative columns. Columns 2–17 are the interactive area. Shaded strips show a 4-zone split. Real walls report their own size with /wall/config.

Physical size

widthMeters and heightMeters let SuperCollider place a sound between the speakers by real distance rather than hold count — on a 12-metre wall a hold two columns from the edge is a very different place from the same hold on a 3-metre one.

Speakers

Speakers are SuperCollider’s hardware, not the engine’s, so their layout lives in SuperCollider’s own configuration; the reference layout is on the map above. The engine only trims levels during installation with /audio/speaker/volume. Nothing in play addresses a speaker — SuperCollider pans sounds to holds, and works out which speakers that means.