Text Animation - Coders

-- Text animation
-- by @beezing

random = math.random
drawText = writeTextAtPosition

--print('Type a text:')
txt = 'CODERS is awesome' --input()
txtSize = 16 --32 is good for fullscreen size
speed = 0 --0 means auto proportional to font size (smoother)

box = {}
box.x = 4
box.y = 24
box.w = 312 --768
box.h = 740 --768

function writeLegend(isPaused)
  local txt = 'Tap screen to '
  if isPaused then
    txt = txt .. 'start animation...'
  else
    txt = txt .. 'pause animation...'
  end

  setFontSize(12)
  setColor(128,128,128)
  drawText(txt,box.x+4,box.y+16)
end

function randomColor(val)
  if val == nil then val = 255 end
  local r,g,b = random(val), random(val), random(val)
  return r,g,b
end

function setStr(txt)
  setFontSize(txtSize)
  str = {}
  str.l = string.len(txt)
  str.w, str.h = sizeOfText(txt)
  for i = 1, str.l do
    chr = {}
    chr.ch = string.sub(txt,i,i)
    chr.r, chr.g, chr.b = randomColor(192)
    chr.x, chr.y = -1, -1
    chr.w, chr.h = sizeOfText(chr.ch)
    str[i] = chr
  end
  return str
end

function spread(str, box)
  for i = 1, str.l do
    str[i].x = box.x+random(box.w-box.x-2*str[i].w)+str[i].w
    str[i].y = box.y+random(box.h-box.y-2*str[i].h)+str[i].h
  end
end

function gather(str, box)
  x = box.x+random(box.w-box.x-str.w)
  y = box.y+random(box.h-box.y-str.h)+str.h
  for i = 1, str.l do
    str[i].x, str[i].y = x,y
    x = x + str[i].w
    --y = y + str[i].h
  end
end

function animX(strFrom, strTo, animSpeed)
  if (animSpeed == 0) or (animSpeed == nil) then
    animSpeed = strFrom[1].w/2
  end

  for i = 1, strFrom.l do
    if strFrom[i].x > strTo[i].x then
      strFrom[i].x = strFrom[i].x - animSpeed
      if strFrom[i].x < strTo[i].x then
        strFrom[i].x = strTo[i].x
      end
    elseif strFrom[i].x < strTo[i].x then
      strFrom[i].x = strFrom[i].x + animSpeed
      if strFrom[i].x > strTo[i].x then
        strFrom[i].x = strTo[i].x
      end
    else
      strFrom[i].x = strTo[i].x
    end
  end
end

function animY(strFrom, strTo, animSpeed)
  if (animSpeed == 0) or (animSpeed == nil) then
    animSpeed = strFrom[1].h/2
  end

  for i = 1, strFrom.l do
    if strFrom[i].y > strTo[i].y then
      strFrom[i].y = strFrom[i].y - animSpeed
      if strFrom[i].y < strTo[i].y then
        strFrom[i].y = strTo[i].y
      end
    elseif strFrom[i].y < strTo[i].y then
      strFrom[i].y = strFrom[i].y + animSpeed
      if strFrom[i].y > strTo[i].y then
        strFrom[i].y = strTo[i].y
      end
    else
      strFrom[i].y = strTo[i].y
    end
  end
end

function anim(strFrom, strTo, isSpread, isDirect, animSpeed)
  if isDirect then
    -- simultaneous motion
    if not isDoneX(strFrom,strTo) then
      animX(strFrom,strTo,animSpeed) end
    if not isDoneY(strFrom,strTo) then
      animY(strFrom,strTo,animSpeed) end
  else
    if not isSpread then
      -- x axis motion first on merge
      if not isDoneX(strFrom,strTo) then
        animX(strFrom,strTo,animSpeed)
      else
        if not isDoneY(strFrom,strTo) then
          animY(strFrom,strTo,animSpeed) end
      end
    else
      -- y axis motion first on spread
      if not isDoneY(strFrom,strTo) then
        animY(strFrom,strTo,animSpeed)
      else
        if not isDoneX(strFrom,strTo) then
          animX(strFrom,strTo,animSpeed) end
      end
    end
  end
end

function isDoneX(strFrom, strTo)
  local done = true
  for i = 1, strFrom.l do
    done = done and (strFrom[i].x == strTo[i].x)
  end
  return done
end

function isDoneY(strFrom, strTo)
  local done = true
  for i = 1, strFrom.l do
    done = done and (strFrom[i].y == strTo[i].y)
  end
  return done
end

function isDone(strFrom, strTo)
  local done = true
  for i = 1, strFrom.l do
    done = done and (strFrom[i].x == strTo[i].x)
    done = done and (strFrom[i].y == strTo[i].y)
  end
  return done
end

function drawStr(str, col)
  setFontSize(txtSize)
  for i = 1, str.l do
    if col == nil then
      setColor(str[i].r,str[i].g,str[i].b)
    else
      setColor(col,col,col)
    end
    drawText(str[i].ch, str[i].x, str[i].y)
  end
end

function tap()
  x,y = lastTouch()
  if (x > 0) and (y > 0) then
    isPaused = not isPaused
    -- also toggle motion type
    if not isPaused then
      isDirect = not isDirect
    end
  end
end

-- init first position
strFrom = setStr(txt)
spread(strFrom,box)
strTo = setStr(txt)
gather(strTo,box)
drawStr(strFrom)

isPaused = false
isSpread = false
isDirect = false

while true do
  disableScreenRefresh()
  clear()
  tap() --tap to pause

  -- compute animation
  if not isPaused then
    anim(strFrom,strTo,isSpread,isDirect,speed)
  end

  -- draw text
  writeLegend(isPaused)
  drawStr(strTo,224)
  drawStr(strFrom)

  -- switch animation direction
  if isDone(strFrom,strTo) then
    isSpread = not isSpread
    strFrom = strTo

    strTo = setStr(txt)
    if isSpread then
      spread(strTo,box)
    else
      gather(strTo,box)
    end
  end

  enableScreenRefresh()
end