pong

term.redirect(peripheral.wrap("top"))
term.setBackgroundColor(colors.black)
term.clear()
local w,h = term.getSize()
local p1y = (h/2)-2
local p2y = (h/2)-2
local score1 = 0
local score2 = 0
local ballx = w/2
local bally = h/2
local ballvx = -1
local ballvy = 1
function draw()
  term.setBackgroundColor(colors.black)
  term.clear()
  term.setBackgroundColor(colors.white)
  drawPaddle(2, p1y)
  drawPaddle(w-1, p2y)
  term.setCursorPos(ballx, bally)
  term.write(" ")
  term.setTextColor(colors.white)
  term.setBackgroundColor(colors.black)
  term.setCursorPos(2, 1)
  term.write(score1)
  term.setCursorPos(w-1, 1)
  term.write(score2)
end
function drawPaddle(x, y)
  for i=y,y+5 do
    term.setCursorPos(x, i)
    term.write(" ")
  end
end
function keyPress()
  while true do
    event, side,x, y = os.pullEvent("monitor_touch")
    if (x >= 15  and y <= 5) then
      p2y = p2y-1
    end
    if (x >= 15 and y >= 5) then
      p2y = p2y+1
    end
    if (x <= 5 and y <= 5) then
      p1y = p1y-1
    end
    if (x <= 5 and y >= 5) then
      p1y = p1y+1
    end
    draw()
  end
end
function moveball()
  while true do
    sleep(0.1)
    ballx = ballx + ballvx
    bally = bally + ballvy
    if bally > h-1 then
      ballvy = -ballvy
    end
    if bally < 1 then
      ballvy = -ballvy
    end
    if ballx > 2 and ballx < 3 and bally > p1y and bally < p1y+5 then
      ballvx = -ballvx
    end
    if ballx > w-1 and ballx < w and bally > p2y and bally < p2y+5 then
      ballvx = -ballvx
    end
    if ballx > w then
      score1 = score1+1
      ballx = w/2
      bally = h/2
      ballvx = -1
      ballvy = 1
    end
    if ballx < 1 then
      score2 = score2+1
      ballx = w/2
      bally = h/2
      ballvx = 1
      ballvy = 1
    end
    draw()
  end
end
parallel.waitForAll(keyPress, moveball)