meat/game/actors/mobs/Bee.ts

import { Terrain } from "engine/world/Terrain"
import { Mesh, type Mesh as Geometry } from "engine/scene/Mesh"
import type { Material } from "engine/render/Material"
import type { ActorDefinition } from "engine/scene/Actor"
import { Mob, type MobState } from "game/actors/Mob"
import { ellipsoid, nextRand, ovoidZ, wanderHeading, wing } from "./mobkit"

export type Bee = ActorDefinition<MobState, Terrain>

export namespace Bee {
  export function create(material: Material): Bee {
    const mesh = Mesh.create()
    build(mesh)
    return {
      prototype: {
        groups: [{ mesh, material }],
        radius: 0.6,
        minY: -0.5,
        maxY: 1,
      },
      update,
      transform: Mob.transform,
      collider: (state) => Mob.collider(state, 0.5, 0.5, false),
    }
  }
}

const LEASH = 6
const SPEED = 1.7
const TURN_MIN = 0.4
const TURN_SPAN = 1
const HOVER = 1.1
const BOB_AMP = 0.18
const BOB_FREQ = 3

function build(mesh: Geometry): void {
  // Fore-aft ovoid body striped along its length, a dark head at the front, two
  // pale wings. UVs: bee texture is stripe bands (left), head-dark (mid), wing-pale
  // (right); the body maps v along z so the stripes band across it.
  ovoidZ(mesh, -0.4, 0.4, 0.24, 7, 5, 0, 0.54, 0, 1)
  ellipsoid(mesh, 0, 0.02, 0.44, 0.16, 0.16, 0.16, 5, 4, 0.6, 0.79, 0, 1)
  wing(mesh, 1, 0.83, 0.99, 0, 1)
  wing(mesh, -1, 0.83, 0.99, 0, 1)
}

function update(mob: MobState, dt: number, terrain: Terrain): void {
  mob.phase += dt
  mob.timer -= dt
  if (mob.timer <= 0) {
    mob.heading = wanderHeading(mob, LEASH, 1.4)
    mob.timer = TURN_MIN + nextRand(mob) * TURN_SPAN
  }
  mob.position.x += Math.sin(mob.heading) * SPEED * dt
  mob.position.z += Math.cos(mob.heading) * SPEED * dt
  const ground = Terrain.height(terrain, mob.position.x, mob.position.z)
  mob.position.y = ground + HOVER + Math.sin(mob.phase * BOB_FREQ) * BOB_AMP
}