OBJ
  c : "clibsd"

dat
  score0 long 0
  score1 long 0
  ymin long 0
  center long 0

pub splash
  c.putchar(0)
  c.printf0(string("PONG\n"))
  c.printf0(string("----\n"))
  c.printf0(string("Press 'q' and 'a' to move the"))
  c.printf0(string(" left paddle up and down\n"))
  c.printf0(string("Press 'p' and 'l' to move the"))
  c.printf0(string(" right paddle up and down\n"))
  c.printf0(string("Press 'x' to exit\n"))
  c.printf0(string("Press any key to start\n"))
  c.getchar

pub updatevars(p_ymin, p_center, p_score0, p_score1)
  ymin := p_ymin
  center := p_center
  score0 := p_score0
  score1 := p_score1

pub plotit(xpos, ypos, val)
  moveto(xpos, ypos)
  c.putchar(val)

pub moveto(xpos, ypos)
  c.putchar(2)
  c.putchar(xpos)
  c.putchar(ypos)

pub kbhit | stream, handle, rxhead, rxtail
  stream := c.getstdin
  handle := long[stream][1]
  rxhead := word[handle][6]
  rxtail := word[handle][7]
  return rxhead <> rxtail

dat
  digit
  byte %111111, %110011, %110011, %110011, %111111
  byte %001100, %011100, %001100, %001100, %011110
  byte %111111, %000011, %111111, %110000, %111111
  byte %111111, %000011, %001111, %000011, %111111
  byte %110011, %110011, %111111, %000011, %000011
  byte %111111, %110000, %111111, %000011, %111111
  byte %111111, %110000, %111111, %110011, %111111
  byte %111111, %000011, %000110, %000110, %000110
  byte %111111, %110011, %111111, %110011, %111111
  byte %111111, %110011, %111111, %000011, %000011

pub getval(xpos, ypos) | ptr, val
  if xpos == center
    return "."
  if ypos < ymin + 1 or ypos > ymin + 5
    return " "
  if xpos < center - 8 or xpos > center + 8
    return " "
  if xpos > center - 3 and xpos < center + 3
    return " "
  if xpos < center
    val := score0
    xpos -= center - 8
  else
    val := score1
    xpos -= center + 3
  val := byte[@digit][val*5 + ypos - ymin - 1]
  if val & ($20 >> xpos)
    result := "#"
  else
    result := " "

pub putnum(xpos, ypos, num) | ptr, temp, i, j
  i := 5
  ptr := @digit + (num//10)*5
  repeat while i--
    j := 6
    temp := byte[ptr++]
    moveto(xpos, ypos++)
    repeat while j--
      if temp & $20
        c.putchar("#")
      else
        c.putchar(" ")
      temp <<= 1

pub plotpaddle(xpos, ypos, height) | i
  i := ypos - height
  repeat while i =< ypos + height
    plotit(xpos, i, "#")
    i++