# Ledger — the survey of the thirty-six plots One shared reading of the farm that everything which has to *choose* a field chooses from: the rivals pick what to eat, the dusters pick what to defend, and both answers come out consistent — a duster ends up over the ground a rival is heading for because both read the same table. Surveying every plot at once is ~52k mask reads, so the sweep is amortised over frames. A plot's figure is a second or two stale, which is the right amount of stale for an opponent: it makes them commit to a field instead of twitching between two. ```luau Ledger.reset() / Ledger.survey() -- new round; survey() is the full sweep Ledger.update(dt) -- roll the survey on, decay heat Ledger.fields() -> { Field } -- { col, row, x, z, remaining, claim, guard, heat } Ledger.at(col, row) -> Field? Ledger.pick(x, z, opts) -> Field? -- best plot for a swarm standing at x,z Ledger.pickGuard(x, z, key) -> Field? -- best plot for a duster Ledger.addHeat(x, z, dt) -- a swarm is eating here ``` Two claim channels, on purpose. `claim` is swarms: a rival avoids a plot another rival has taken. `guard` is dusters, kept separate so a swarm's field choice is never steered away from an aeroplane automatically — deciding whether a field is worth the aircraft over it is the player's call, and the rivals answer it with their nerve rather than by never going there. `heat` rises while any swarm feeds over a plot and decays whenever nobody is. It is what the dusters actually react to.

# core <!-- zero:scaffolded-readme --> <!-- Replace the line below with what this module provides and who consumes it, then delete both comment lines. --> TODO: describe this module.

# Marks — what the round puts on the farm The rules slice owns three moving things a player has to read from a distance: a rival swarm, the dust it kicks up while it works, and a crop duster with its spray trail. This module builds their meshes and materials; `Rivals` and `Sprayers` own the entities. Everything draws through one lit vertex-colour shader, so a cloud, a plume and an aircraft each cost one material and no textures. Clouds and plumes are scattered unlit triangles rather than solid volumes: sparse geometry reads as mist without needing a blend mode. ```luau Marks.material(name, tint, emissive) -- cached by the LOOK, not the label Marks.cloudMesh(n, rx, ry, rz, tri, colour, jitter, seed) Marks.columnMesh(n, radius, height, tri, colour, seed) Marks.dusterMesh() / Marks.plumeMesh() Marks.rivalCloudMesh(seed) / Marks.dustColumnMesh(seed) Marks.spawnProxy(name, parent, mesh, material) Marks.headingQuat(heading) -- heading 0 = +Z, the game's convention ``` `spawnProxy` replaces any leftover of the same name before spawning. A module hot reload re-runs the slice's init and entering play despawns temporary entities, so without it every reload would leave another dead aircraft parked over the farm.