@homie-rocks/scatter

Placement policy for procedural worlds: where a thing may go, not what it looks like. A disc register that refuses a spot already taken, a capsule keep-out along a polyline, a lowest-point ground snap, arc-length stepping, weighted quotas, crowd formations and deterministic seeded layouts. It knows metres, radii and chords; it does not know a boulder, a mast or a crater, and it imports nothing, not even three, so it runs in Node with no scene graph.

Part of Homie's open game engine: the packages the Homie games are built on.

Install

npm install --save-exact @homie-rocks/[email protected]

No dependencies.

Use

import { KeepOut } from '@homie-rocks/scatter/keepout.js';
import { Corridor } from '@homie-rocks/scatter/corridor.js';

const taken = new KeepOut();
// A road as a polyline in XZ, with an 8 m keep-out either side.
const road = new Corridor([0, 100, 200], [0, 40, 0], 8);

for (let i = 0; i < 500; i++) {
  const x = Math.random() * 400 - 200;
  const z = Math.random() * 400 - 200;
  if (taken.blocked(x, z, 2) || road.blocked(x, z, 2)) continue;
  taken.claim(x, z, 6);
  // place a 6 m rock at (x, z)
}

Every function takes the caller's own RNG or seed where it draws, and each file documents its draw order, so a seeded world rebuilds identically.

Modules

| module | what it does | |---|---| | keepout.js | KeepOut: a register of claimed discs; blocked, clear, coveredAhead | | corridor.js | Corridor: a keep-out measured to a polyline's segments, not its points | | discindex.js | DiscIndex: a uniform-grid broadphase over items with a reach | | ground.js | footprintLow: found an object on the lowest ground under its footprint | | stride.js | strideSegments, firstCrossing: equal-chord stepping along a span | | polyline.js | segmentAt, polylinePoint, polylineDelta: sample a route at t | | ring.js | ladderFit, ringSlots, majorityRing, LoopMask: rings of backdrop slots | | azimuth.js | AzimuthMask: which bearings from a centre may be built on | | quota.js | zoneTickets, quotaFirst, takeWeighted: which candidates get built | | banks.js | BankRun: lines that run in banks and gaps rather than a coin flip per step | | formation.js | fileAlong, arcFacing, queueFrom, fileBetween: groups of bodies | | relax.js | relaxOverlap: one symmetric pass pushing overlapping bodies apart | | bayload.js | bayLoad: fill a rectangular bay from one end from a single seed |

and 3 more in src/ (chain.js, pairs.js, rota.js).

License

Apache-2.0. See LICENSE and NOTICE.