# way.ludic - where an animal walks: by the world's path to where it is going (WildlifeWorld.way, a
# navmesh by its habitat's taste in Maroon Lake), to a target about home it can reach (goal), and
# straight, as before, where the world has no answer

# face the way toward (tx, tz): the next corner of the world's path for it, asked again every
# WL_WAY_EVERY seconds or on reaching the corner; without a path, the straight line as before
const WL_WAY_EVERY: float = 0.5
function wl_head(a: WildAnimal, tx: float, tz: float, rate: float, dt: float) -> void {
  if a.crowd {
    a.goal_x = tx
    a.goal_z = tz
    return
  }
  a.way_t = a.way_t - dt
  let cx = a.wx - a.x
  let cz = a.wz - a.z
  if a.way_t <= 0.0 or cx * cx + cz * cz < 1.0 {
    a.way_t = WL_WAY_EVERY
    a.wx = tx
    a.wz = tz
    if WildlifeWorld.way(a, tx, tz) {
      a.wx = WildlifeWorld.way_x()
      a.wz = WildlifeWorld.way_z()
    }
  }
  wl_face(a, a.wx, a.wz, rate, dt)
}

# somewhere about home: a spot the world says it can walk to when it knows, seeded by the same two
# draws the old target took, so the dice are the same whether it knows or not
function wl_pick_target(wildlife_st: WildlifeState, a: WildAnimal, radius: float) -> void {
  let ang = wl_rnd(wildlife_st) * WL_TAU
  let d = wl_rnd(wildlife_st) * radius
  a.tx = a.home_x + Math.cos(ang) * d
  a.tz = a.home_z + Math.sin(ang) * d
  a.way_t = 0.0
  if WildlifeWorld.goal(a, a.home_x, a.home_z, radius, int(ang * 100000.0) + int(d * 1000.0)) {
    a.tx = WildlifeWorld.way_x()
    a.tz = WildlifeWorld.way_z()
  }
}

# a target d metres straight away from (fx, fz): where it runs or backs off to, by the world's way -
# round water and a cliff where there is one, and straight away as before where there is not
function wl_away(a: WildAnimal, fx: float, fz: float, d: float) -> void {
  var dx = a.x - fx
  var dz = a.z - fz
  let l = Math.sqrt(dx * dx + dz * dz)
  if l < 0.01 {
    dx = -Math.sin(a.yaw)
    dz = -Math.cos(a.yaw)
  } else {
    dx = dx / l
    dz = dz / l
  }
  a.tx = a.x + dx * d
  a.tz = a.z + dz * d
}