tower / files / src / terrain / worker.ts
worker.ts
| 1 | /** |
| 2 | * A terrain worker. See world-generation.md §5. |
| 3 | * |
| 4 | * Holds one compiled world and answers questions about it: build this tile, render |
| 5 | * these rows of the map. The first worker in the pool also compiles, reporting each |
| 6 | * step as it starts so the status dialog can say what is being made. |
| 7 | */ |
| 8 | import { expose, transfer } from 'comlink' |
| 9 | import type { World } from '../world/schema.js' |
| 10 | import { type CompiledWorld, compileWorld } from './compile.js' |
| 11 | import { type Runtime, prepare } from './field.js' |
| 12 | import { renderMapRows } from './map-image.js' |
| 13 | import { type TileData, type TileGrid, type TileKey, buildTile } from './tile.js' |
| 14 | |
| 15 | let runtime: Runtime | null = null |
| 16 | let generation = -1 |
| 17 | |
| 18 | const api = { |
| 19 | /** Answers once the worker's code has loaded: the pool's check that it is alive. */ |
| 20 | ping(): true { |
| 21 | return true |
| 22 | }, |
| 23 | |
| 24 | compile(world: World, onStep: (label: string) => void): CompiledWorld { |
| 25 | return compileWorld(world, onStep) |
| 26 | }, |
| 27 | |
| 28 | load(world: CompiledWorld, gen: number): void { |
| 29 | runtime = prepare(world) |
| 30 | generation = gen |
| 31 | }, |
| 32 | |
| 33 | /** Null when the world has moved on since the request was made: the tile is stale. */ |
| 34 | tile(gen: number, t: TileKey, n: TileGrid): TileData | null { |
| 35 | if (!runtime || gen !== generation) return null |
| 36 | const data = buildTile(runtime, t, n) |
| 37 | const buffers: Transferable[] = [data.positions.buffer, data.normals.buffer, data.materials.buffer] |
| 38 | if (data.water) buffers.push(data.water.positions.buffer, data.water.attrs.buffer, data.water.indices.buffer) |
| 39 | if (data.canopy) buffers.push(data.canopy.positions.buffer, data.canopy.attrs.buffer, data.canopy.indices.buffer) |
| 40 | return transfer(data, buffers) |
| 41 | }, |
| 42 | |
| 43 | mapRows(gen: number, width: number, height: number, y0: number, y1: number, origin: number): Uint8ClampedArray | null { |
| 44 | if (!runtime || gen !== generation) return null |
| 45 | const rows = renderMapRows(runtime, width, height, y0, y1, origin) |
| 46 | return transfer(rows, [rows.buffer]) |
| 47 | }, |
| 48 | } |
| 49 | |
| 50 | export type WorkerApi = typeof api |
| 51 | expose(api) |