drawLight

args = {...}
if fs.isDir("/drawLight/") == false then --fs, like I/O APIs
   fs.makeDir("/.drawLight/")
end
term.clear()
os.loadAPI("frame") -- loads API "frame", custom API
frame.init()
local menuColor = "7"
local c = {}
c[0] = "0"; c[1] = "1"; c[2] = "2"; c[3] = "3"; c[4] = "4"; c[5] = "5"; c[6] = "6"; c[7] = "7"; c[8] = "8"; c[9] = "9"; c[10] = "a"; c[11] = "b"; c[12] = "c"; c[13] = "d"; c[14] = "e" c[15] = "f";
local d = {}
for i=0,15 do
   d[c[i]] = true
end
local MaxX,MaxY = term.getSize()
local file
local canvas = {}
local current = {}
local rainbow = false
current.brushSize = 2
do
   local y = 1
   repeat
      local x = 1
      repeat
         canvas[frame.totable(x,y)] = " "
         x = x + 1
      until x > MaxX
      y = y + 1
   until y > MaxY
end
local function load(filename) -- load a file
   local file = fs.open(args[1],"r")
   canvas = textutils.unserialize(file.readAll())
end
local function save(filename) -- save a file
   if fs.exists(filename) then
      filename = filename.."(1)"
   end
   local a = 2
   while fs.exists(filename) do
      filename = filename:sub(1,#filename).."("..a..")"
   end
   local file = fs.open(filename,"w")
   file.write(textutils.serialize(canvas))
   file.close()
end
local function import(filename) -- import a file
   if not fs.exists(filename) then
      error(filename.." does not exist!",9000)
   end
   --save("/.drawLight/drawLight_temp"..os.day()..os.time())
   local w = 1
   local h = 1
   local file = fs.open(filename,"r")
   local line = " "
   frame.setBkg("f")
   while h < MaxY+1 do
      line = file.readLine()
      w = 1
      if line ~= nil then
         repeat
            canvas[frame.totable(w,h)] = line:sub(w,w)
            if d[line:sub(w,w)] ~= true then
               canvas[frame.totable(w,h)] = "f"
            end
            w = w + 1
         until w > MaxX
      end
      h = h + 1
   end
end
local function export(filename) -- export a file
   local file = fs.open(filename,"w")
   local xc = 1
   local yc = 1
   while yc < MaxY + 1 do
      xc = 1
      while xc < MaxX + 1 do
         file.write(canvas[frame.totable(xc,yc)])
         xc = xc + 1
      end
      file.write("\n")
      yc = yc + 1
   end
   file.close()
end
current.color = "0"
local drawColor = "0"
if #args < 1 or #args > 2 then
   error("Usage: drawLight (filename) <fancy>",9000)
elseif fs.exists(args[1]) then
   local test = fs.open(args[1],"r")
   local line = test.readLine()
   if line:sub(1,1) == "{" then
      load(args[1])
   else
      import(args[1])
   end
end
current.r = 0
local function paint(x,y) -- main drawing function
   if x > 0 and x < MaxX+1 and y > 0 and y < MaxY+1 then
      current.r = current.r + 1
      if current.r == 15 then
         current.r = 0
      end
      if rainbow then
         drawColor = c[current.r]
      end
      frame.setb(x,y,current.color)
      frame.draw(x,y)
      canvas[frame.totable(x,y)] = current.color
   end
end
local function paintSize(x,y,n) -- paintbrush
   paint(x,y)
   repeat
      paint(x-n+1,y-n+1)
      paint(x-n+1,y+n-1)
      paint(x+n-1,y-n+1)
      paint(x+n-1,y+n-1)
      n = n - 1
   until n == 0
end
local function drawCanvas() -- initialize the drawing area
   frame.setCol("f")
   local y = 1
   repeat
      local x = 1
      repeat
         frame.setc(x,y,"f")
         frame.setb(x,y,canvas[frame.totable(x,y)])
         frame.sett(x,y," ")
         x = x + 1
      until x == MaxX + 1
      y = y + 1
   until y == MaxY + 1
   local t = 1
   if args[2] == "fancy" then
      local a = math.floor(MaxX/MaxY)
      repeat
         frame.drawPart(a*t,t,MaxX,t+1)
         frame.drawPart(a*t-1,t,a*t,MaxY)
         t = t + 1
      until t == MaxY+1
      frame.drawPart(1,1,1,MaxY)
   else
      frame.drawAll()
   end
   frame.setCol(menuColor)
   frame.setText(MaxX-14,MaxY,"Press left Ctrl")
   frame.drawPart(MaxX-15,MaxY,MaxX,MaxY)
end
local function drawMenu() -- initialize the menu
   frame.init()
   frame.setCol("4")
   local TopScreen = "drawLight: "..args[1]
   frame.setText(math.floor((MaxX-#TopScreen)/2)+1,1,TopScreen)
   frame.setText(1,MaxY-4,"Current Color:")
   frame.setText(1,MaxY-3,"Colors:")
   frame.setText(1,MaxY-2,"Save - Export - Import")
   frame.setText(1,MaxY-1,"Quit")
   frame.setText(MaxX-14,MaxY,"Press left Ctrl")
   frame.setBkg(menuColor)
   local a = 0
   local x = 9
   frame.setb(15,MaxY-4,drawColor)
   repeat
      frame.setb(x,MaxY-3,c[a])
      a = a + 1
      x = x + 1
   until a == 16
      frame.setText(25,MaxY-3,"Rainbow")
   if args[2] == "fancy" then
      local t = MaxY
      local a = math.floor(MaxX/MaxY)
      repeat
         frame.drawPart(a*t,t,MaxX,t+1)
         frame.drawPart(a*t-1,t,a*t,MaxY)
         t = t - 1
      until t == -1
      frame.drawPart(1,1,1,MaxY)
   else
      frame.drawAll()
   end
end
local function cleanUp(msg) -- for exiting the program
   term.clear()
   term.setCursorPos(1,1)
   error(msg,9000)
end
local function input() -- main event handler
   e = {os.pullEvent()}
   if menu and e[1] == "mouse_click" then
      if e[4] == MaxY-3 and e[3] > 8 and e[3] < 25 then
         drawColor = c[e[3]-9]
         rainbow = false
      elseif e[4] == MaxY-3 and e[3] > 24 and e[3] < 32 then
         rainbow = true
      elseif e[4] == MaxY-2 and e[3] < 5 then
         save(args[1])
      elseif e[4] == MaxY-2 and e[3] > 16 and e[3] < 23 then
         term.setCursorPos(MaxX/2-5,2)
         term.setBackgroundColor(colors.gray)
         import(read())
      elseif e[4] == MaxY-2 and e[3] > 6 and e[3] < 16 then
         export(args[1])
      elseif e[4] == MaxY-1 and e[3] < 6 then
         local userID
         if os.computerLabel() ~= nil then
            userID = "\""..os.getComputerLabel().."\""
         else
            userID = "computer"
         end
         save("/.drawLight/drawLight_temp"..os.day()..os.time())
         cleanUp(shell.getRunningProgram().." Quit by "..userID.." user.")
      end
   end
   if menu == false then
      if e[1] == "mouse_click" or e[1] == "mouse_drag" then
         if e[2] == 1 then
            current.color = drawColor
            paintSize(e[3],e[4],current.brushSize)
         elseif e[2] == 2 then
            current.color = "f"
            paintSize(e[3],e[4],current.brushSize)
         end
      end
   end
      --frame.drawPart(MaxX-10,MaxY,MaxX,MaxY)
   if e[1] == "key_up" and e[2] == keys.leftCtrl then
      if menu == true then
         menu = false
      else
         menu = true
      end
   end
   if e[1] == "key_up" and e[2] == keys.f1 then
      save("/.drawLight/drawLight_temp"..os.day()..os.time())
      local userID
      if os.computerLabel() ~= nil then
         userID = "\""..os.getComputerLabel().."\""
      else
         userID = "computer"
      end
      cleanUp(shell.getRunningProgram().." Quit by "..userID.." user.")
   end
   if e[1] == "mouse_scroll" then
      if e[2] == -1 and current.brushSize < 15 then
         current.brushSize = current.brushSize + 1
      elseif e[2] == 1 and current.brushSize > 1 then
         current.brushSize = current.brushSize - 1
      end
   end
end
while true do -- main loop structure
   drawMenu() -- menu
   repeat
      input()
      frame.setb(15,MaxY-4,drawColor)
      frame.draw(15,MaxY-4)
   until menu == false
   drawCanvas() -- drawing area
   repeat
      input()
   until menu
end