# capture.ludic - someone else wants to know where the providers point (a guide's arrow): until the
# end every mark is theirs, whatever the tier, and the frame's list is left alone
export function compass_capture_begin(compass_st: mut CompassState) -> void {
  List.clear(compass_st.cmp_caught)
  compass_st.cmp_cused = 0
  compass_st.cmp_capturing = true
}

# what was caught: the compass's own list and marks, good until the next capture begins
export function compass_capture_end(compass_st: mut CompassState) -> []CompassMark {
  compass_st.cmp_capturing = false
  return compass_st.cmp_caught
}

# the capture pool's next mark, filled (one made only when the pool is short)
function cmp_catch(compass_st: mut CompassState, x: float, z: float, icon: int, colour: int, tier: int, prio: int, label: string) -> CompassMark {
  if compass_st.cmp_cused >= len(compass_st.cmp_cpool) {
    @alloc_ok("past COMPASS_POOL marks in one capture only, then kept")
    push(compass_st.cmp_cpool, new CompassMark)
  }
  compass_st.cmp_cused += 1
  return cmp_fill(compass_st.cmp_cpool[compass_st.cmp_cused - 1], x, z, icon, colour, tier, prio, label)
}