アリの巣シミュレーション — フェロモンで創発する群知能

const grid = new Uint8Array(cols * rows)       // セルの種類
const pheromone = new Float32Array(cols * rows) // フェロモン濃度

enum CellType {
  Air = 0,
  Dirt = 1,
  Tunnel = 2,
  Food = 3,
  Nest = 4,
  Grass = 5,
}

enum AntState {
  Wander = 0,   // 餌を探索中
  CarryFood = 1, // 餌を運搬中
}

interface Ant {
  x: number
  y: number
  state: AntState
  dx: number  // 移動方向X
  dy: number  // 移動方向Y
  digCooldown: number
}

const PHEROMONE_STRENGTH = 0.8

// CarryFood状態のアリが毎ティック実行
const pi = ant.y * cols + ant.x
pheromone[pi] = Math.min(pheromone[pi] + PHEROMONE_STRENGTH, 1)

const PHEROMONE_DECAY = 0.997

for (let i = 0; i < pheromone.length; i++) {
  if (pheromone[i] > 0.001) {
    pheromone[i] *= PHEROMONE_DECAY
  } else {
    pheromone[i] = 0
  }
}

// 巣への方向を計算
const tdx = nest.x - ant.x
const tdy = nest.y - ant.y

let moveDx = tdx > 0 ? 1 : tdx < 0 ? -1 : 0
let moveDy = tdy > 0 ? 1 : tdy < 0 ? -1 : 0

// 20%の確率でランダムな方向に逸れる
if (Math.random() < 0.2) {
  const d = randomDir()
  moveDx = d.dx
  moveDy = d.dy
}

const nx = ant.x + ant.dx
const ny = ant.y + ant.dy

if (inBounds(nx, ny)) {
  const ci = ny * cols + nx
  const cell = grid[ci]

  if (cell === CellType.Dirt && ant.digCooldown <= 0) {
    grid[ci] = CellType.Tunnel
    ant.digCooldown = 3  // 3ティックのクールダウン
  }
}

let cx = nestX
let cy = surfaceY

while (cy < nestY - 2) {
  for (let ox = -1; ox <= 1; ox++) {
    if (inBounds(cx + ox, cy)) {
      const ci = cy * cols + (cx + ox)
      if (grid[ci] === CellType.Dirt) {
        grid[ci] = CellType.Tunnel
      }
    }
  }
  cy++
  // 30%の確率で左右にずれる → 自然な蛇行
  if (Math.random() < 0.3) {
    cx = clamp(cx + (Math.random() < 0.5 ? -1 : 1), 2, cols - 3)
  }
}

const imgData = ctx.createImageData(w * dpr, h * dpr)
const data = imgData.data

for (let y = 0; y < rows; y++) {
  for (let x = 0; x < cols; x++) {
    const gi = y * cols + x
    const cell = grid[gi]
    const ph = pheromone[gi]

    let r = 0, g = 0, b = 0
    // セル種別ごとに色を決定...

    // フェロモンオーバーレイ（線形補間）
    if (ph > 0.01 && (cell === CellType.Tunnel || cell === CellType.Air)) {
      const alpha = Math.min(ph, 0.6)
      r = Math.floor(r * (1 - alpha) + 120 * alpha)
      g = Math.floor(g * (1 - alpha) + 180 * alpha)
      b = Math.floor(b * (1 - alpha) + 255 * alpha)
    }

    // セルをスケーリングしてImageDataに書き込み
  }
}

ctx.putImageData(imgData, 0, 0)

const loop = () => {
  const ticks = speedRef.current
  for (let i = 0; i < ticks; i++) {
    simulate()
  }
  render()
  rafRef.current = requestAnimationFrame(loop)
}