# draw.ludic - the recording backend: every UiBackend primitive a line of the frame's draw list
# (protocol-v1.md, "The draw list"), in the order ludic.ui draws them
function pv_backend() -> UiBackend {
  let b = new UiBackend
  b.rect = fn pv_rect
  b.round = fn pv_round
  b.ring = fn pv_ring
  b.text = fn pv_text_draw
  b.measure = fn pv_measure_be
  b.image = fn pv_image
  b.image_w = fn pv_image_w
  b.image_h = fn pv_image_h
  b.nine = fn pv_nine
  b.clip = fn pv_clip
  b.unclip = fn pv_unclip
  b.scale = fn pv_scale
  b.now = fn pv_now
  b.translate = fn pv_translate
  b.sound = fn pv_sound
  b.read = fn pv_read
  b.said = fn pv_said
  b.emitted = fn pv_emitted
  b.input = false
  return b
}
function pv_box(o: PvOut, x: float, y: float, w: float, h: float) -> void {
  pv_num(o, x)
  pv_num(o, y)
  pv_num(o, w)
  pv_num(o, h)
}
function pv_rect(pv: mut PvState, x: float, y: float, w: float, h: float, c: int, a: float) -> void {
  pv_s(pv.out, "rect")
  pv_box(pv.out, x, y, w, h)
  pv_rgba(pv.out, c, a)
  pv_nl(pv.out)
}
function pv_round(pv: mut PvState, x: float, y: float, w: float, h: float, r: float, c: int, a: float) -> void {
  pv_s(pv.out, "round")
  pv_box(pv.out, x, y, w, h)
  pv_num(pv.out, r)
  pv_rgba(pv.out, c, a)
  pv_nl(pv.out)
}
function pv_ring(pv: mut PvState, x: float, y: float, w: float, h: float, r: float, t: float, c: int, a: float) -> void {
  pv_s(pv.out, "ring")
  pv_box(pv.out, x, y, w, h)
  pv_num(pv.out, r)
  pv_num(pv.out, t)
  pv_rgba(pv.out, c, a)
  pv_nl(pv.out)
}
function pv_text_draw(pv: mut PvState, x: float, y: float, s: string, size: float, c: int, a: float) -> void {
  pv_s(pv.out, "text")
  pv_num(pv.out, x)
  pv_num(pv.out, y)
  pv_num(pv.out, size)
  pv_num(pv.out, pv_measure(pv, s, size))
  pv_rgba(pv.out, c, a)
  pv_q(pv.out, s)
  pv_nl(pv.out)
}
function pv_measure_be(pv: PvState, s: string, size: float) -> float { return pv_measure(pv, s, size) }
function pv_clip(pv: mut PvState, x: float, y: float, w: float, h: float) -> void {
  pv_s(pv.out, "clip")
  pv_box(pv.out, x, y, w, h)
  pv_nl(pv.out)
}
function pv_unclip(pv: mut PvState) -> void {
  pv_s(pv.out, "unclip")
  pv_nl(pv.out)
}
# screen pixels a design pixel: the viewport's own, else render3d's (the height over 1080)
function pv_scale(pv: PvState) -> float {
  if pv.vs > 0.0 { return pv.vs }
  return pv.vh / 1080.0
}
function pv_now(pv: PvState) -> float { return pv.t }
function pv_translate(i18n_st: mut I18nState, s: string) -> string { return L(i18n_st, s) }