Gravity

local star = {5,5}
--term.redirect(peripheral.wrap("right"))
local w,h = term.getSize()
local xDir = "+"
local yDir = "+"
local grav = 0
local gravActive = true

function redraw(x,y)
  draw("*",x,y)
  sleep(.05)
  draw(" ",x,y)
end

function showinfo()
  term.setCursorPos(1, 1)
  term.clearLine()
  draw(tostring(grav), w - #tostring(grav) + 1, 1)
end

function draw(words,x,y)
  term.setCursorPos(x,y)
  write(words)
end

while true do
  redraw(star[1],star[2])
  local prevPos = {posX, posY}
  local posX, posY = term.getCursorPos()
  if prevPos[2] == posY then
    gravActive = false
  end
  showinfo()
  if posX == 1 then
    xDir = "+"
  end
  if posY >= h then
    grav = (math.abs(grav) - .6)
  end
  if posX == w then
    xDir = "-"
  end
  if posY <= 1 then
    grav = -(math.abs(grav) - .6)
  end
  if xDir == "+" then
    star[1] = star[1] + 1
  else
    star[1] = star[1] - 1
  end
  if gravActive then
  star[2] = star[2] - grav
  grav = grav - .5
  end
end