# num.ludic - numbers and colours written into the reply: a space, then the number
# a whole number, in decimal
function pv_int(o: PvOut, n: int) -> void {
  pv_byte(o, 32)
  pv_digits(o, n)
}
function pv_digits(o: PvOut, n0: int) -> void {
  var n = n0
  if n < 0 {
    pv_byte(o, 45)
    n = 0 - n
  }
  if n >= 10 { pv_digits(o, n / 10) }
  pv_byte(o, 48 + n % 10)
}
# a real number rounded to thousandths, with no trailing zeros: 12, 12.5, -0.125
function pv_num(o: PvOut, x: float) -> void {
  pv_byte(o, 32)
  var a = x
  var neg = false
  if a < 0.0 {
    a = 0.0 - a
    neg = true
  }
  if a > 2000000.0 {                 # past what thousandths hold in an int: whole units
    if neg { pv_byte(o, 45) }
    pv_digits(o, int(a))
    return
  }
  let c = int(a * 1000.0 + 0.5)
  if neg and c != 0 { pv_byte(o, 45) }
  pv_digits(o, c / 1000)
  var f = c % 1000
  if f == 0 { return }
  pv_byte(o, 46)
  var d = 100
  while f > 0 {
    pv_byte(o, 48 + f / d)
    f = f % d
    d = d / 10
  }
}
# a colour, 0xRRGGBB, as #rrggbb (lower case); a negative (none, inherit) is #000000
function pv_hex(o: PvOut, c0: int) -> void {
  pv_byte(o, 32)
  pv_byte(o, 35)
  var c = c0
  if c < 0 { c = 0 }
  var shift = 1048576
  for i in 0 .. 6 {
    pv_byte(o, pv_hexch((c / shift) % 16))
    shift = shift / 16
  }
}
# a colour and its alpha, as every primitive and style line carries them
function pv_rgba(o: PvOut, c: int, a: float) -> void {
  pv_hex(o, c)
  pv_num(o, a)
}