# walked.ludic - what a step leaves behind (a print every 2.8 m), how often a step was refused, and
# the crowd's side (phase 18): a crowd walker only says where and how fast, and is handed back where
# the crowd put it. Nothing here allocates: it runs for every walker every frame.

# how many steps were refused and turned from since the start: how often the way was not enough
export function wildlife_turned(wildlife_st: WildlifeState) -> int { return wildlife_st.wl_turned }
# of those, how many for water ahead and how many for a climb (the rest: pushed back by a still thing)
export function wildlife_turned_wet(wildlife_st: WildlifeState) -> int { return wildlife_st.wl_turned_wet }
export function wildlife_turned_steep(wildlife_st: WildlifeState) -> int { return wildlife_st.wl_turned_steep }

# d metres covered: a print when it has gone far enough since the last
function wl_walked(wildlife_st: mut WildlifeState, a: WildAnimal, s: WildSpecies, d: float) -> void {
  a.track_d = a.track_d + d
  if s.tracks and a.track_d > 2.8 {
    a.track_d = 0.0
    wl_fact(wildlife_st, WILD_PRINT, a)
  }
}

# a crowd walker's step: its want is where it faces or heads (goal_x / _z) at this tick's speed
function wl_crowd_step(a: WildAnimal) -> bool {
  a.goal_speed = a.speed
  return true
}

# walked by a crowd as its walker `id`, or by its own step again with -1 (it keeps where it was left)
export function wildlife_set_crowd(a: WildAnimal, id: int) -> void {
  a.crowd_id = id
  a.crowd = id >= 0
}

# where the crowd put a walker, and how fast it went: its place, its heading from its velocity, its
# ground from the world's, and its prints as it goes
export function wildlife_moved(wildlife_st: mut WildlifeState, a: WildAnimal, x: float, z: float, vx: float, vz: float) -> void {
  let dx = x - a.x
  let dz = z - a.z
  let d = Math.sqrt(dx * dx + dz * dz)
  a.x = x
  a.z = z
  a.y = WildlifeWorld.ground(x, z)
  if vx * vx + vz * vz > 0.01 { a.yaw = Math.atan2(-vx, -vz) }
  let r = wl_row(a)
  if r >= 0 { tb_set_xz(a.tab, WA_X, WA_Z, r, x, z) }
  wl_walked(wildlife_st, a, wl_sp(wildlife_st, a.sp), d)
}

# still one of this state's animals: false once cleared, reloaded or removed (a crowd lets it go)
export function wildlife_listed(wildlife_st: WildlifeState, a: WildAnimal) -> bool { return a != null and a.tab == wildlife_st.wl.tab and wl_row(a) >= 0 }