Matrix Screen Saver CC

--Achman741 Borrowed This
--I claim no credit for this

--[[
  File:      matrix
  Purpose:   A screensaver that emulates screens from the popular movie The Matrix. *A component of TurtleSHELL*
  Author:    da404lewzer
  Project:   http://turtlescripts.com/project/gjdh00
  License:   Creative Commons Attribution-ShareAlike 3.0 Unported License.
             http://creativecommons.org/licenses/by-sa/3.0/

  Changes:
  1.0.10     12/10/2012
             + Detached to seperate project

  1.0.0      11/27/2012
             * Cloned file from texty
]]

--User settings (Overridden by texty.settings if file is found)
local largeFont = 0.5
local smallFont = 0.5
--App-managed variables:
local tArgs = { ... }
local mon
local w, h = 1,1
local ss_running = true
local positions = {"top", "bottom", "left", "right", "front", "back"}
local mons = {}
local curMsg = {}
local curColor = {}

local skipMove = 1
function getColorMode(monitor)
    if monitor.isColor() then
        return 2
    else
        return 1
    end
end
local chars = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z","0","1","2","3","4","5","6","7","8","9", "@", "#", "$", "%", "&", "?", "!", "*"}

function regen(monID, c)
    len = math.random(2,h/2)
    mons[monID].cols[c] = {length=len, x=c, y=-math.random(1,len), speed=math.random(1,3)}
end
function update(monitor, monID)
    mon = monitor

    --if mon then
        w, h = mon.getSize()
        --mon.clear()
        mon.setBackgroundColor(colors.black)
        for c=1, w do
            if mons[monID] then
                col = mons[monID].cols[c]
                if col then
                    local x, y, i, flicker
                    local colorMode = getColorMode(mon)
                    mon.setTextColor(colors.white)
                    --tX[monID] = 2
                    --tY[monID] = 2
                    for ii=col.length, 1, -1 do
                        flicker = math.random(1, 3)
                        if colorMode == 1 then
                            mon.setTextColor(colors.black)
                        else
                            mon.setTextColor(colors.green)
                        end
                        local iii = -col.length
                        local msgText = chars[math.random(#chars)]
                        if math.random(2)==1 then
                            msgText = string.upper(msgText)
                        end
                        mon.setCursorPos(col.x, col.y-ii)
                        mon.write(msgText)
                    end
                    flicker = math.random(1, 3)
                    if colorMode == 1 then
                        if flicker == 1 then
                            mon.setTextColor(colors.black)
                        else
                            mon.setTextColor(colors.white)
                        end
                    else
                        if flicker == 1 then
                            mon.setTextColor(colors.lime)
                        elseif flicker == 2 then
                            mon.setTextColor(colors.white)
                        elseif flicker == 3 then
                            mon.setTextColor(colors.green)
                        end
                    end
                    local msgText = chars[math.random(#chars)]
                    if math.random(2)==1 then
                        msgText = string.upper(msgText)
                    end
                    mon.setCursorPos(col.x, col.y)
                    mon.write(msgText)
                    mon.setTextColor(colors.black)
                    for ii=0,col.speed do
                        mon.setCursorPos(col.x, col.y-col.length-col.speed+ii)
                        mon.write(" ")
                    end
                    if skipMove==0 then
                        col.y=col.y+col.speed
                        if col.y - col.length - col.speed > h then
                            regen(monID, c)
                        end
                    end
                else
                    regen(monID, c)
                end
            else
                regen(monID, c)
            end
        end
    --end
end
function updateTemplate(monitor, monID)
    if monitor then
        w,h = monitor.getSize()
        if w and h then
            if not mons[monID] then
                --[[if monitor ~= term then
                    if w > 7 and h > 5 then
                        monitor.setTextScale(largeFont)
                    else
                        monitor.setTextScale(smallFont)
                    end
                    w,h = monitor.getSize()
                end]]
                for c=1, w do
                    mons[monID] = {cols={}}
                    regen(monID, c)
                end
            end
            update(monitor, monID)
        end
    end
end
function updateAll()
    updateTemplate(term, 0)
    for i=1, #positions do
        if peripheral.getType(positions[i]) == "monitor" then
            updateTemplate(peripheral.wrap(positions[i]), i)
        end
    end
end
function cleanUp()
    term.clear()
    term.setCursorPos(1,1)
    for i=1, #positions do
        if peripheral.getType(positions[i]) == "monitor" then
            local mon = peripheral.wrap(positions[i])
            if mon then
                mon.setTextScale(1)
                mon.clear()
                mon.setCursorPos(1,1)
            end
        end
    end
end
local ss_timer = os.startTimer(0)
while ss_running do
    local event, p1, p2 = os.pullEvent()
    if event == "key" then
        ss_running = false
    else
        if event == "timer" and p1 == ss_timer then
            ss_timer = os.startTimer(0.05)
        end
        if ss_running then
            updateAll()
            skipMove = skipMove + 1
            if skipMove > 5 then
                skipMove = 0
            end
        end
    end
end

cleanUp()