Animation in lua With Advanced Macros

local function anim( dur, steppers, post )
  local t = thread.new(function()
    local start = os.millis()
    local stop = start + dur
    while true do
      local p = math.map( os.millis(), start, stop, 0, 1 )
      p = math.min( 1, p )
      for i, s in ipairs( steppers ) do
        s( p )
      end
      if p == 1 then break end
    end
    post()

  end)
  t.start()
end

hud2D.clearAll()
local text = hud2D.newText("Test", 10, 10)
text.setOpacity(0)
text.enableDraw()

local a, b = 5,   25 --arbitrary values
function s1( p )
   text.setX( math.map( p, 0, 1,  a, b) )
end

function s2( p )
   text.setOpacity( p^5 )
end


anim( 1000, {s1, s2}, function() log("Done!") end )