Scrolling Marquee(s) with Multiple Monitors

--[[
  Scroll Program: Master

  By: Negeator

  Instructions:
  Don't touch this file! (unless you know what you are doing)
  Define all of the slave computer ids in the 'scrollNodes' file.
	Put an id on each line, this will be the order they go in.
  Define all of the lines of text in the 'scrollFile' file.
	Put the speed (higher the number, slower it scrolls, NO DECIMAL VALUES) on one line, and the text on the other.
	In case you can't count, there should be two lines in the text file for every line it displays.
  
  To Run, run all of the slaves first, then run the master program.  If you run the master before one of the slaves, you'll have to stop the master and re-run it.
]]--
sleep(1)  --Make sure slave computers boot first (for logging into a server with computers set to automatically run the program)
local mon
local timeMax
--Arrays Initialized
local nodes = { } --Slave Computer ID's
local text = { }  --Current Text for each line of each monitor
local heights = { }  --Heights of each monitor
local serverText = { }  --Current server text (Feeds one character of this at a time into the Master monitor, and then removes that character.  When the string is empty, it is replenished by being reset using storeServerText)
local storeServerText = { }  --Stored Server Text (this does not change)
local scrollSpeeds = { }  --Time it takes to scroll (1 = fastest, only whole numbers for now)
--[[ Functions ]]--
function main()
--Initialization
getNodeData()  --Load Nodes (slave computer id's) from a file
getMessageData() --Load Message (text and speeds for each line) from a file
startModem()  --Start Modem
startMon()  --Start Monitor
textInit()  --Initialize the Text arrays
getServerText()  --Initialize serverText values
timeMax = getLongestTime()  --Get longest scroll time
local currTime = 0  --Initialize the current time variable
os.startTimer(.01)  --Start the timer (currTime will increment ever .01 seconds)
print("Working!")
while true do
	drawText()
event = os.pullEvent()
if event == "timer" then
   for i = 1, #scrollSpeeds do
	 if (currTime % scrollSpeeds[i]) == 0 then
	   updateCharLine(i)
	   updateText()
	 end
   end
  
   currTime = currTime + 1
   if currTime > timeMax then
	 currTime = 0
   end
  
   os.startTimer(.01)
end
end
end
function getServerText()
  for i = 1, #storeServerText do
	serverText[i] = storeServerText[i]
  end
end
--Update all of the slaves' text
function updateText()
  for i = 1, #nodes do
	sendText(i)
  end
end
--Update text (rows) for a slave
function sendText(index)
  local sendID = nodes[index]
  rednet.send(sendID,"update")
  for i = 1, heights[index + 1] do
	if i > #storeServerText then
   rednet.send(sendID," ")
else
	  rednet.send(sendID,text[index + 1][i])
end
  end
end
--Initialize 'text' (make all of the rows the appropriate length, etc)
function textInit()
  --Add to heights and text for the first monitor (Master)
  local length, height = mon.getSize()
  table.insert(heights,height)
  table.insert(text, { })
  for a = 1, #storeServerText do
	table.insert(text[1],textCreate(length))
  end
print("a")
  --Add to heights and text for the rest of the monitors (Slaves)
  for i = 1, #nodes do
	length = getLength(nodes[i])
	height = getHeight(nodes[i])
	--Create Slave Height
	table.insert(heights,height)
	--Initialize text (rows) for Slaves
	table.insert(text,  { })
	for a = 1, #storeServerText do
	  table.insert(text[#text],textCreate(length))
	end
  end
end
--Create a blank string based on a specific length
function textCreate(len)
local ret = ""
for i = 1, len do
	ret = ret .. " "
end
return ret
end
function updateCharLine(index)
  text[1][index] = text[1][index] .. string.sub(serverText[index],1,1)
  for i = 2, #text do
	text[i][index] = text[i][index] .. string.sub(text[i - 1][index],1,1)
  end

  for i = 1, #text do
	text[i][index] = string.sub(text[i][index],2,string.len(text[i][index]))
  end

  serverText[index] = string.sub(serverText[index], 2, string.len(serverText[index]))
  if serverText[index] == "" then
	serverText[index] = storeServerText[index]
  end
end
--Draw text on the Master's monitor
function drawText()
  for i = 1, #text[1] do
	if i > heights[1] then
   return
end
	mon.setCursorPos(1,i)
	mon.write(text[1][i])
  end
end
--Get the length of a slave's monitor
function getLength(index)
-- term.write(1,1,"Waiting on ".. index .." to send")
  print("Waiting on ".. index)
  rednet.send(index,"length")
  while true do
	id, message = rednet.receive()
if id == index then
   return tonumber(message)
end
  end
end
--Get the height of a slave's monitor
function getHeight(index)
  rednet.send(index,"height")
  while true do
	id, message = rednet.receive()
if id == index then
   return tonumber(message)
end
  end
end
--Start the monitor (detect side, etc)
function startMon()
  local monSide
  for i=1,#rs.getSides() do
	if peripheral.isPresent(rs.getSides()[i]) and peripheral.getType(rs.getSides()[i]) == "monitor" then
   monSide = rs.getSides()[i]
   mon = peripheral.wrap( monSide )
   return
end
  end
  error()
end
--Start the monitor (detect side, etc)
function startModem()
  local modemSide
  for i=1,#rs.getSides() do
	if peripheral.isPresent(rs.getSides()[i]) and peripheral.getType(rs.getSides()[i]) == "modem" then
	  modemSide = rs.getSides()[i]
	  rednet.open(modemSide)
	  return
	end
  end
-- error()
end
--Gets the scroll time that is the longest
function getLongestTime()
  local max = scrollSpeeds[1]
  for i = 2, #scrollSpeeds do
	if scrollSpeeds[i] > max then
	  max = scrollSpeeds[i]
	end
  end
  return max
end
--Load messages and speeds from a file
function getMessageData()
  local file, error = io.open("scrollFile", "r")
  if error then
	return error
  end

  local readText
  local boolean = true
  local num = 0

  while boolean do
	readText = file:read()
if readText ~= nil then
	  if num == 0 then
	 table.insert(scrollSpeeds,tonumber(readText))
  num = 1
   else
	 table.insert(serverText,"")
  table.insert(storeServerText,readText)
  print("  Inserting "..readText)
	 num = 0
   end
else
   boolean = false
end
  end
  file:close()
end
function getNodeData()
  local file, error = io.open("scrollNodes", "r")
  if error then
	return error
  end

  local readText
  local boolean = true
  local num = 0

  while boolean do
	readText = file:read()
if readText ~= nil then
	  table.insert(nodes,tonumber(readText))
else
   boolean = false
end
  end
  file:close()
end

--[[ Run Program ]]--
main()

2
Hello World!  This is some text ...
4
Here is another line, scrolling at another speed. The larger the number is set for this line in 'scrollFile', the slower this line will scroll...
2
Be sure to put a space or two at the end of every line.  If you don't there won't be any spaces in between the first word and the last word when this text repeats.
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

2
3
4

--[[
  Scroll Program: Slave

  By: Negeator

  Instructions:
  Set the 'serverID' variable to the id of the master computer.

]]--

local serverID = 1  -- CHANGE THIS TO THE COMPUTER ID OF THE MASTER
local mon
local text = { }
local length, height

--[[ Functions ]]--

function main()
--Initialization
startModem()
startMon()

length, height = mon.getSize()
   for i = 1, height do
	 table.insert(text,"")
   end

print("Ready!")
while true do
   drawText()
   event, id, message = os.pullEvent()
   if event == "rednet_message" then
	 if id == serverID then

  if message == "length" then
	rednet.send(serverID,tostring(length))
  elseif message == "height" then
	rednet.send(serverID, tostring(height))

  elseif message == "update" then
	for i = 1, height do
  repeat
	id2, message2 = rednet.receive()
  until id2 == id
  text[i] = message2

end
  end

end
   end

end

end

--Draw Text
function drawText()
  for i = 1, height do
	mon.setCursorPos(1,i)
	mon.write(text[i])
  end
end


--Start the monitor (detect side, etc)
function startMon()
  local monSide
  for i=1,#rs.getSides() do
	if peripheral.isPresent(rs.getSides()[i]) and peripheral.getType(rs.getSides()[i]) == "monitor" then
monSide = rs.getSides()[i]
mon = peripheral.wrap( monSide )
return
end
  end
  error()
end

function startModem()
  local modemSide
  for i=1,#rs.getSides() do
	if peripheral.isPresent(rs.getSides()[i]) and peripheral.getType(rs.getSides()[i]) == "modem" then
	  modemSide = rs.getSides()[i]
	  rednet.open(modemSide)
	  return
	end
  end
  error()
end

--[[ Run Program ]]--
main()