TRON (disknet)

--[[
    TRON Light Cycle Game
    programmed by LDDestroier
     Get with:
    wget https://raw.githubusercontent.com/LDDestroier/CC/master/tron.lua
--]]

local port = 701
local kioskMode = false         -- disables options menu
local useLegacyMouseControl = false -- if true, click move regions will be divided into diagonal quadrants

local scr_x, scr_y = term.getSize()
local scr_mx, scr_my = scr_x / 2, scr_y / 2
local isColor = term.isColor()
local doShowByImage = true  -- show "By LDDestroier" in title

local gameDelayInit = 0.1   -- lower value = faster game. I recommend 0.1 for SMP play.
local doDrawPlayerNames = true  -- draws the names of players onscreen
local doRenderOwnName = false   -- if doDrawPlayerNames, also draws your own name
local useSetVisible = false -- use term.current().setVisible, which speeds things up at the cost of multishell
local gridID = 1        -- determines which grid is used
local mode = "menu"

local disknet = dofile("disknet.lua")

-- initial grid information, (hopefully) transferred to non-host players
local initGrid = {
    x1 = -100,
    y1 = -100,
    x2 = 100,
    y2 = 100,
    border = "#",
    voidcol = "f",
    forecol = "8",
    backcol = "7",
    edgecol = "0"
}
local resetPlayers = function()
    return {
        [1] = {
            num = 1,
            x = -3,
            y = -5,
            direction = -1,
            char = "@",
            color = {
                colors.blue,
                colors.blue,
                colors.blue,
                colors.cyan,
                colors.cyan,
                colors.lightBlue,
                colors.lightBlue,
                colors.cyan,
                colors.cyan
            },
            dead = false,
            trailLevel = 10,
            trailMax = 10,
            trailRegen = 0.1,
            putTrail = true,
            name = "BLU",
            initName = "BLU"
        },
        [2] = {
            num = 2,
            x = 3,
            y = -5,
            direction = -1,
            char = "@",
            color = {
                colors.red,
                colors.red,
                colors.red,
                colors.orange,
                colors.orange,
                colors.yellow,
                colors.yellow,
                colors.orange,
                colors.orange
            },
            dead = false,
            trailLevel = 10,
            trailMax = 10,
            trailRegen = 0.1,
            putTrail = true,
            name = "RED",
            initName = "RED"
        }
    }
end

local function interpretArgs(tInput, tArgs)
    local output = {}
    local errors = {}
    local usedEntries = {}
    for aName, aType in pairs(tArgs) do
        output[aName] = false
        for i = 1, #tInput do
            if not usedEntries[i] then
                if tInput[i] == aName and not output[aName] then
                    if aType then
                        usedEntries[i] = true
                        if type(tInput[i+1]) == aType or type(tonumber(tInput[i+1])) == aType then
                            usedEntries[i+1] = true
                            if aType == "number" then
                                output[aName] = tonumber(tInput[i+1])
                            else
                                output[aName] = tInput[i+1]
                            end
                        else
                            output[aName] = nil
                            errors[1] = errors[1] and (errors[1] + 1) or 1
                            errors[aName] = "expected " .. aType .. ", got " .. type(tInput[i+1])
                        end
                    else
                        usedEntries[i] = true
                        output[aName] = true
                    end
                end
            end
        end
    end
    for i = 1, #tInput do
        if not usedEntries[i] then
            output[#output+1] = tInput[i]
        end
    end
    return output, errors
end

local argData = {
    ["skynet"] = false, -- use Skynet HTTP multiplayer
    ["quick"] = false,  -- start one game immediately
    ["griddemo"] = false,   -- only move the grid
    ["--update"] = false,   -- updates TRON to the latest version
    ["--gridID"] = "number" -- grid ID to use
}

local gridFore, gridBack
local gridList = {
    [1] = {     -- broken up and cool looking
        {
            "+-    -+------",
            "|      |      ",
            "       |      ",
            ".      |      ",
            "+------+-   --",
            "|      |      ",
            "|             ",
            "|      .      ",
        },
        {
            "+-      -+--------",
            "|        |        ",
            "         |        ",
            "         |        ",
            "         |        ",
            "|        |        ",
            "+--------+-      -",
            "|        |        ",
            "|                 ",
            "|                 ",
            "|                 ",
            "|        |        ",
        }
    },
    [2] = {     -- flat diagonal sorta
        {
            "    /      ",
            "   /       ",
            "  /        ",
            " /         ",
            "/__________"
        },
        {
            "       /        ",
            "      /         ",
            "     /          ",
            "    /           ",
            "   /            ",
            "  /             ",
            " /              ",
            "/_______________"
        }
    },
    [3] = {     -- basic simple grid
        {
            "+-------",
            "|       ",
            "|       ",
            "|       ",
            "|       "
        },
        {
            "+------------",
            "|            ",
            "|            ",
            "|            ",
            "|            ",
            "|            ",
            "|            ",
            "|            "
        }
    },
    [4] = {     -- diamond grid
        {
            "   /\\   ",
            "  /  \\  ",
            " /    \\ ",
            "/      \\",
            "\\      /",
            " \\    / ",
            "  \\  /  ",
            "   \\/   ",
        },
        {
            "     /\\     ",
            "    /  \\    ",
            "   /    \\   ",
            "  /      \\  ",
            " /        \\ ",
            "/          \\",
            "\\          /",
            " \\        / ",
            "  \\      /  ",
            "   \\    /   ",
            "    \\  /    ",
            "     \\/     ",
        }
    },
    [5] = {     -- brick and mortar
        {
            "|          ",
            "|          ",
            "|          ",
            "|          ",
            "===========",
            "     |     ",
            "     |     ",
            "     |     ",
            "     |     ",
            "===========",
        },
        {
            "|      ",
            "|      ",
            "=======",
            "   |   ",
            "   |   ",
            "=======",
        },
    },
    [6] = {     -- pain background
        {
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@                                                   ",
            "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@SCREEN@MAX@",
        },
        {
            "%%..",
            "%%..",
            "%%..",
            "..%%",
            "..%%",
            "..%%"
        },
    },
    [7] = {     -- some
        {
            " "
        },
        {
            "+-----------------------------------------------------",
            "|   Somebody once told me the world is gonna roll me  ",
            "|   I ain't the sharpest tool in the shed / She was   ",
            "| looking kind of dumb with her finger and her thumb  ",
            "|  In the shape of an \"L\" on her forehead / Well the  ",
            "|    years start coming and they don't stop coming    ",
            "|    Fed to the rules and I hit the ground running    ",
            "| Didn't make sense not to live for fun / Your brain  ",
            "|   gets smart but your head gets dumb / So much to   ",
            "|  do, so much to see / So what's wrong with taking   ",
            "| the back streets? / You'll never know if you don't  ",
            "|   go / You'll never shine if you don't glow / Hey   ",
            "| now, you're an all-star, get your game on, go play  ",
            "|  Hey now, you're a rock star, get the show on, get  ",
            "|     paid / And all that glitters is gold / Only     ",
            "|  shooting stars break the mold / It's a cool place  ",
            "|   and they say it gets colder / You're bundled up   ",
            "|  now, wait till you get older / But the meteor men  ",
            "|      beg to differ / Judging by the hole in the     ",
            "|   satellite picture / The ice we skate is getting   ",
            "| pretty thin / The water's getting warm so you might ",
            "| as well swim / My world's on fire, how about yours? ",
            "|    That's the way I like it and I never get bored   ",
            "|  Hey now, you're an all-star, get your game on, go  ",
            "|  play / Hey now, you're a rock star, get the show   ",
            "|   on, get paid / All that glitters is gold / Only   ",
            "|   shooting stars break the mold / Hey now, you're   ",
            "|  an all-star, get your game on, go play / Hey now,  ",
            "|    you're a rock star, get the show, on get paid    ",
            "|    And all that glitters is gold / Only shooting    ",
            "|  stars... / Somebody once asked could I spare some  ",
            "|  change for gas? / I need to get myself away from   ",
            "|  this place / I said yep, what a concept / I could  ",
            "|  use a little fuel myself / And we could all use a  ",
            "|   little change / Well, the years start coming and  ",
            "|   they don't stop coming / Fed to the rules and I   ",
            "|  hit the ground running / Didn't make sense not to  ",
            "| live for fun / Your brain gets smart but your head  ",
            "|   gets dumb / So much to do, so much to see / So    ",
            "|     what's wrong with taking the back streets?      ",
            "|   You'll never know if you don't go (go!) / You'll  ",
            "|   never shine if you don't glow / Hey now, you're   ",
            "|  an all-star, get your game on, go play / Hey now,  ",
            "|    you're a rock star, get the show on, get paid    ",
            "|    And all that glitters is gold / Only shooting    ",
            "|   stars break the mold / And all that glitters is   ",
            "|      gold / Only shooting stars break the mold      ",
        }
    }
}

local argList = interpretArgs({...}, argData)

local useSkynet = argList["skynet"]
local useOnce = argList["quick"]
local doGridDemo = argList["griddemo"]
local doUpdateGame = argList["--update"]
if gridList[argList["--gridID"]] then
    gridID = argList["--gridID"]
end
local argumentName = argList[1]
local argumentPassword = argList[2] or ""

if useSkynet and (not http.websocket) then
    error("Skynet is not supported on this version of ComputerCraft.")
end

local skynetPath = fs.combine(fs.getDir(shell.getRunningProgram()), "skynet.lua")
local skynetURL = "https://raw.githubusercontent.com/osmarks/skynet/master/client.lua"

if argumentName then
    argumentName = argumentName:sub(1, 15) -- gotta enforce that limit
end

local toblit = {
    [0] = " ",
    [colors.white] = "0",
    [colors.orange] = "1",
    [colors.magenta] = "2",
    [colors.lightBlue] = "3",
    [colors.yellow] = "4",
    [colors.lime] = "5",
    [colors.pink] = "6",
    [colors.gray] = "7",
    [colors.lightGray] = "8",
    [colors.cyan] = "9",
    [colors.purple] = "a",
    [colors.blue] = "b",
    [colors.brown] = "c",
    [colors.green] = "d",
    [colors.red] = "e",
    [colors.black] = "f"
}
local tograyCol, tograyBlit = {
    [0] = 0,
    [colors.white] = colors.white,
    [colors.orange] = colors.lightGray,
    [colors.magenta] = colors.lightGray,
    [colors.lightBlue] = colors.white,
    [colors.yellow] = colors.white,
    [colors.lime] = colors.lightGray,
    [colors.pink] = colors.lightGray,
    [colors.gray] = colors.gray,
    [colors.lightGray] = colors.lightGray,
    [colors.cyan] = colors.lightGray,
    [colors.purple] = colors.gray,
    [colors.blue] = colors.gray,
    [colors.brown] = colors.gray,
    [colors.green] = colors.gray,
    [colors.red] = colors.white,
    [colors.black] = colors.black
}, {}

local tocolors = {}
for k,v in pairs(toblit) do
    tocolors[v] = k
end
for k,v in pairs(tograyCol) do
    tograyBlit[toblit[k]] = toblit[v]
end

local termwrite, termclear = term.write, term.clear
local termsetCursorPos, termgetCursorPos = term.setCursorPos, term.getCursorPos
local tableunpack, tableremove = unpack, table.remove
local mathfloor, mathceil, mathcos, mathsin, mathrandom, mathrad = math.floor, math.ceil, math.cos, math.sin, math.random, math.rad

local termsetTextColor = function(col)
    return term.setTextColor(isColor and col or tograyCol[col])
end

local termsetBackgroundColor = function(col)
    return term.setBackgroundColor(isColor and col or tograyCol[col])
end

local termblit = function(char, text, back)
    if isColor then
        return term.blit(char, text, back)
    else
        return term.blit(
            char,
            text:gsub(".", tograyBlit),
            back:gsub(".", tograyBlit)
        )
    end
end

local tsv = function(visible)
    if term.current().setVisible and useSetVisible then
        term.current().setVisible(visible)
    end
end

local round = function(num, places)
    return math.floor(num * 10^places + 0.5) / 10^places
end

if doUpdateGame then
    print("Downloading...")
    local net = http.get("https://github.com/LDDestroier/CC/raw/master/tron.lua")
    if net then
        local file = fs.open(shell.getRunningProgram(), "w")
        file.write(net.readAll())
        file.close()
        print("Updated!")
    else
        printError("Couldn't update!")
    end
    if useOnce then
        return
    else
        sleep(0.2)
        shell.run( shell.getRunningProgram(), table.concat({...}, " "):gsub("--update", "") )
        return
    end
end

local cwrite = function(text, y, xdiff, wordPosCheck)
    wordPosCheck = wordPosCheck or #text
    termsetCursorPos(mathfloor(scr_x / 2 - math.floor(0.5 + #text + (xdiff or 0)) / 2), y or (scr_y - 2))
    term.write(text)
    return (scr_x / 2) - (#text / 2) + wordPosCheck
end

local modem, skynet
local setUpModem = function()
    if not doGridDemo then
        --[[
        if useSkynet then
            if fs.exists(skynetPath) then
                skynet = dofile(skynetPath)
                term.clear()
                cwrite("Connecting to Skynet...", scr_y / 2)
                skynet.open(port)
            else
                term.clear()
                cwrite("Downloading Skynet...", scr_y / 2)
                local prog = http.get(skynetURL)
                if prog then
                    local file = fs.open(skynetPath, "w")
                    file.write(prog.readAll())
                    file.close()
                    skynet = dofile(skynetPath)
                    cwrite("Connecting to Skynet...", 1 + scr_y / 2)
                    skynet.open(port)
                else
                    error("Could not download Skynet.")
                end
            end
        else
            modem = peripheral.find("modem")
            if (not modem) and ccemux then
                ccemux.attach("top", "wireless_modem")
                modem = peripheral.find("modem")
            end
            if modem then
                modem.open(port)
            else
                error("You should attach a modem.")
            end
        end
        --]]
        disknet.open(port)
    end
end
setUpModem()

local transmit = function(port, message)
    disknet.send(port, message)
    --[[
    if useSkynet then
        skynet.send(port, message)
    else
        modem.transmit(port, port, message)
    end
    --]]
end

local gamename = ""
local isHost

local waitingForGame = true

-- used in skynet matches if you are player 2
local ping = 0

local copyTable
copyTable = function(tbl, ...)
    local output = {}
    for k,v in pairs(tbl) do
        if type(v) == "table" then
            output[k] = copyTable(v)
        else
            output[k] = v
        end
    end
    for i = 1, #arg do
        output[#output+1] = arg[i]
    end
    return output
end

grid = copyTable(initGrid)

local you, nou = 1, 2

local keysDown, netKeysDown = {}, {}
local miceDown = {}

local lastDirectionPressed, netLastDirectionPressed

-- the scrolling of the screen
local scrollX = 0
local scrollY = 0

-- used when panning with WASD
local scrollAdjX = 0
local scrollAdjY = 0

local lockInput = false
local player

player = resetPlayers()

local images
if _HOST then -- need to add some NFP image replacements for older versions of CC
    images = {
        logo = {
            {
                " •ƒƒƒƒƒƒƒƒƒ•—ƒƒƒƒƒƒƒ‹‹   ‡‡ƒƒƒ‹‹  Ÿ‹    •ƒƒ•",
                " •ƒƒƒ”€—ƒƒƒ•‚ƒƒƒƒƒ‹€€€Š —€Ÿƒƒƒ€” •‚‚  •€€•",
                "     •€•          ‚‚ƒƒ•€€—€€€”€€••€€‹‹ •€€•",
                "     •€•    —ƒ”‹“ƒƒ‹€€€•€€•€€€•€€••€•ˆƒ€€•",
                "     •€•    •€• ‚‹€€‹€Š€‹‡€Ÿ…•€•  ‚‚€•",
                "     •€•    •€•   ‹€‚‹ ‹‹€€€Ÿ‡‡ •€•    ‹‹•",
                "             Š  ‚‹‡       ‚…",
            },
            {
                " f7777777777777777777f   f77777f  7f    f777",
                " f99979999979999999999f 799999799 77f7  f997",
                "     799          79999f997    9977997f f997",
                "     799    7797777fffff997    9977997797997",
                "     799    799 799977f7797fff7997799  79797",
                "     799    799   7797f 797999997 799    797",
                "     777    777    7777  7777777  777     77",
            },
            {
                " 7999999999f9999999997   7999997  97    799f",
                " 7777997777f77777779997 997777997 997f  799f",
                "     997          f7777799    799f99997 799f",
                "     997    997f9997fff799    799f997ff7999f",
                "     997    997 f7999fff999777997f997  f799f",
                "     997    997   f9997 f7999977f 997    f7f",
                "     fff    fff    ffff  fffffff  fff     ff",
            }
        },
        win = {
            {
                "€•€€€€€€€••€€€€€€€€Š€€€€•€€€•",
                "€•€€€€€€€•‚€€•€ƒ€€€‚€€•€€€•",
                "€•€€‡€€€•€€€€•€€€€•‹€‹€•€€€•",
                "€•ŸŸ€‹€€•€€€€•€€€€•€‚‚…€€€•",
                "€‚€‡€‚‚€•Ÿ€€•€€€•€€€‹€€€",
                "€Ÿ€€€€‹€••€€€€€€€€•€€€€•€€€•",
            },
            {
                "55      55 555555 5      5 55",
                "55      5555 55 5 55 5   5 55",
                "55   5  55   55   5555   5 55",
                "55  55  55   55   55 5   5 55",
                "5 55 5  55 5 55   55   555  5",
                "555    555 555555 55     5 55",
            },
            {
                "5       5 5555555 55    55 5 ",
                "5       5    5    555   55 5 ",
                "5   5   5    5    5  55 55 5 ",
                "5 55 55 5    5    5   5555 5 ",
                "555   555 5  5  5 5     55 5 ",
                "5       5 5555555 5     55 5 ",
            }
        },
        lose = {
            {
                "€•€€€€€€Ÿ€€€‚€€€€€€‚€€€€€€€€",
                "€•€€€€€€€Ÿ€‚€€€—€€€‚ƒ€€•€€€‚ƒ",
                "€•€€€€€€€•€€€•€€€€ƒƒƒƒ‹€€‚ƒƒƒ”€",
                "€•€€€€€€€•€€€•€€‚ƒƒƒƒ€€€—ƒƒƒ€",
                "€•€€€€€€€‚€Ÿ€€€€€…€€€•€€€Ÿ",
                "€€€€€€€€‚€€€Ÿ€€€€€€Ÿ€€€€€€€€",
            },
            {
                "ee        eee e  eeeee  eeeeeee",
                "ee      eee e e ee   ee ee   ee",
                "ee      ee    e ee      e    e ",
                "ee      ee    e eeeee e eeeeee ",
                "ee      e e   e  e    e ee     ",
                "eeeeeee e eeeee  eeeeee eeeeeee",
            },
            {
                "e       eeeeee  eeeeeee eeeeeee",
                "e       e    ee e       e      ",
                "e       e    ee eeeeeee eeeee  ",
                "e       e    ee      ee e      ",
                "e       ee  eee e    ee e    ee",
                "eeeeeee  eeee   eeeeee  eeeeeee",
            }
        },
        tie = {
            {
                "€€€€€€€••€€€€€€€€€€€€€€€",
                "€€€€•€€€‚€•€€€ƒ€€•€€€€ƒ",
                "€€€€•€€€€€€•€€€€€€‚ƒƒƒ”€",
                "€€€€•€€€€€€•€€€€€€—ƒƒƒ€",
                "€€€€•€€€Ÿ€•€€€€€•€€€€",
                "€€€€•€€€•€€€€€€€€€€€€€€€",
            },
            {
                "77888800 0000000 0888877",
                "   88   00  0  0 08    7",
                "   88       0    0    7 ",
                "   88       0    088887 ",
                "   88    0  0    08     ",
                "   88    0000000 0888877",
            },
            {
                "7788880 00000000 0888877",
                "   8       00    0      ",
                "   8       00    08888  ",
                "   8       00    0      ",
                "   8    0  00  0 0     7",
                "   8    00000000 0888877",
            },
        },
        timeout = {
            {
                "—ƒƒƒƒ•—ƒƒƒƒ•—ƒ›Ÿ†ƒ•—ƒƒƒ”",
                "“€—Œ…“€—Œ…•€€€€••€ŒŒž",
                " •€•€€…€••€˜•€••€ˆŒŽ",
                " •€•€€•€€€€••€•€•€••€€€•",
                " ‚ƒƒ€€ƒƒƒƒƒƒƒ€ƒƒƒƒƒƒƒ",
                "   —ƒƒƒƒ••ƒ”•ƒ”•ƒƒƒƒ”",
                "   •€œ”€••€••€•ŠŒ”€œŽ",
                "   •€Š•€••€•…€• €•€•",
                "   •€€€€••€€€€• €•€•",
                "   ƒƒƒƒƒ‚ƒƒƒƒƒ€€ƒƒ",
            },
            {
                "00000000000000ff0000000f",
                "0fff000fff000ff0ff00f000",
                "0ffffffffff00f000f00ffff",
                " fffff0ffff00f0f0f00ffff",
                " 000ff000000000f00000000",
                "   000000f0ff0ff0000f",
                "   0f00f0ffffff000f00",
                "   0ff0f0ffffff7f0f0",
                "   0ffff0ffffff7f0f0",
                "   000000000000ff000",
            },
            {
                "ffffffffffffff00fffffff0",
                " 0f0fff0f0ffffffffffffff",
                " 0f0ff00f00ffffffffff000",
                " 0f0fffffffffffffffffff0",
                " fffffffffffffffffffffff",
                "   ffffff0f00f00ffff0",
                "   ffffff0f00f0ffffff",
                "   ff0fff0f00f0fffff",
                "   ffffff0ffff0fffff",
                "   fffffffffffffffff",
            },
        },
        ldd = {
            {
                "                                               ",
                " ƒŒ‹—”—”   —œ“€ƒ‚•ˆŒ‡ŒŒŸŸœ“ƒ€ƒ•ˆŒƒŒ‹",
                " €ƒ‚ ”—  €  ••••€Ÿ•Šƒ‚ •• €Œˆ••••€•Š€ƒ‚",
                " ƒƒ ‚  ŒŒ‚ƒƒ        ‚ƒ Š…   ƒƒ        ƒ ƒ",
            },
            {
                "                                               ",
                " f7ff7f7 f  fbfbbbffff9f99fff9ff9f9f9999fff9f9f",
                " 77f f7  b  fbfbbfbfff9f9f f9 99ff9f9f9ffff999f",
                " 777 77  bbbbbb        999 99 9 9 99        9 9",
            },
            {
                "                                               ",
                " 7f77f7f b  bfbfbfb999f9ff999f99f9f9ff9f999f9f9",
                " 7f7 7f  b  bfbfbbf999f9f9 9f 9f99f9f999999f9f9",
                " fff ff  ffffff        fff ff f f ff        f f",
            },
        }
    }
else
    images = {
        logo = {
            {
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
            },
            {
                "7777777777 77777777    77777777  77     77",
                "    77           777  777    777 777    77",
                "    77            777 77      77 7777   77",
                "    77     7777777    77      77 77777  77",
                "    77     77  7777   77      77 77   7777",
                "    77     77   7777  777    777 77    777",
                "    77     77    7777  77777777  77     77",
            },
            {
                "9999999999 99999999    99999999  99     99",
                "    99           999  999    999 999    99",
                "    99            999 99      99 9999   99",
                "    99     9999999    99      99 99999  99",
                "    99     99  9999   99      99 99   9999",
                "    99     99   9999  999    999 99    999",
                "    99     99    9999  99999999  99     99",
            },
        },
        win = {
            {
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
            },
            {
                "77     77 777777 77    77 77",
                "77     77 777777 777   77 77",
                "77  7  77   77   7777  77 77",
                "77 777 77   77   77 77 77 77",
                "7777 7777   77   77  7777   ",
                "777   777 777777 77   777 77",
                "77     77 777777 77    77 77",
            },
            {
                "55     55 555555 55    55 55",
                "55     55 555555 555   55 55",
                "55  5  55   55   5555  55 55",
                "55 555 55   55   55 55 55 55",
                "5555 5555   55   55  5555   ",
                "555   555 555555 55   555 55",
                "55     55 555555 55    55 55",
            },
        },
        lose = {
            {
                "                           ",
                "                           ",
                "                           ",
                "                           ",
                "                           ",
                "                           ",
                "                           ",
                "                           ",
            },
            {
                "77     777777   77777 77777",
                "77    77777777 777777 77777",
                "77    777  777 77     77   ",
                "77    77    77 77777  7777 ",
                "77    77    77  77777 77   ",
                "77    777  777     77 77   ",
                "77777 77777777 777777 77777",
                "77777  777777  77777  77777",
            },
            {
                "ee     eeeeee   eeeee eeeee",
                "ee    eeeeeeee eeeeee eeeee",
                "ee    eee  eee ee     ee   ",
                "ee    ee    ee eeeee  eeee ",
                "ee    ee    ee  eeeee ee   ",
                "ee    eee  eee     ee ee   ",
                "eeeee eeeeeeee eeeeee eeeee",
                "eeeee  eeeeee  eeeee  eeeee",
            },
        },
        tie = {
            {
                "                         ",
                "                         ",
                "                         ",
                "                         ",
                "                         ",
                "                         ",
                "                         ",
            },
            {
                "77777777 77777777 7777777",
                "   77       77    77     ",
                "   77       77    77     ",
                "   77       77    777777 ",
                "   77       77    77     ",
                "   77       77    77     ",
                "   77    77777777 7777777",
            },
            {
                "77888800 00000000 0888877",
                "   88       00    08     ",
                "   88       00    08     ",
                "   88       00    088887 ",
                "   88       00    08     ",
                "   88       00    08     ",
                "   88    00000000 0888877",
            },
        },
        timeout = {
            {
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
                "                            ",
            },
            {
                "7777777 777 777   777 777777",
                "7777777 777 7777 7777 777777",
                "7777777 777 777777777 777777",
                "  777   777 777777777 77777 ",
                "  777   777 777777777 777777",
                "  777   777 777777777 777777",
                "  777   777 777   777 777777",
                "                            ",
                "   7777777 777 777 7777777  ",
                "   7777777 777 777 7777777  ",
                "   7777777 777 777 7777777  ",
                "   777 777 777 777   777    ",
                "   777 777 777 777   777    ",
                "   7777777 7777777   777    ",
                "   7777777 7777777   777    ",
                "   7777777 7777777   777    ",
            },
            {
                "0000000 000 000   000 000000",
                "0fffff0 0f0 0ff0 0ff0 0ffff0",
                "000f000 0f0 0fff0fff0 0f0000",
                "  0f0   0f0 0f0fff0f0 0fff0 ",
                "  0f0   0f0 0f00f00f0 0f0000",
                "  0f0   0f0 0f00000f0 0ffff0",
                "  000   000 000   000 000000",
                "                            ",
                "   0000000 000 000 0000000  ",
                "   0fffff0 0f0 0f0 0fffff0  ",
                "   0f000f0 0f0 0f0 000f000  ",
                "   0f0 0f0 0f0 0f0   0f0    ",
                "   0f0 0f0 0f0 0f0   0f0    ",
                "   0f000f0 0f000f0   0f0    ",
                "   0fffff0 0fffff0   0f0    ",
                "   0000000 0000000   000    ",
            },
        },
        ldd = {
            {
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
                "                                          ",
            },
            {
                "               777 7 7                    ",
                "               7 7 7 7                    ",
                "               77   7                     ",
                "               7 7  7                     ",
                "    77  77     777  7      777 777        ",
                "7   7 7 7 7 77         777 7 7  7  777    ",
                "7   7 7 7 7 7  777 777 7 7 7 7  7  7   777",
                "7   7 7 7 7 77 7    7  77  7 7  7  77  7 7",
                "7   77  77  7  777  7  7 7 777 777 7   77 ",
                "777         77   7  7  7 7         777 7 7",
                "               777  7                  7 7",
            },
            {
                "               777 7 7                    ",
                "               7 7 7 7                    ",
                "               77   7                     ",
                "               7 7  7                     ",
                "    bb  bb     777  7      999 999        ",
                "b   b b b b 99         999 9 9  9  999    ",
                "b   b b b b 9  999 999 9 9 9 9  9  9   999",
                "b   b b b b 99 9    9  99  9 9  9  99  9 9",
                "b   bb  bb  9  999  9  9 9 999 999 9   99 ",
                "bbb         99   9  9  9 9         999 9 9",
                "               999  9                  9 9",
            },
        }
    }
end

for k,v in pairs(images) do
    -- give them easy-to-access x and y sizes
    v.x = #v[1][1]
    v.y = #v[1]
    -- fix white artifacting that occurs due to " " correlating to WHITE in term.blit
    for y = 1, v.y do
        for x = 1, v.x do
            if v[2][y]:sub(x,x) ~= "" and v[3][y]:sub(x,x) ~= "" then
                if (v[2][y]:sub(x,x) == " " and v[3][y]:sub(x,x) ~= " ") then
                    images[k][2][y] = v[2][y]:sub(1, x - 1) .. initGrid.voidcol .. v[2][y]:sub(x + 1)
                elseif (v[2][y]:sub(x,x) ~= " " and v[3][y]:sub(x,x) == " ") then
                    images[k][3][y] = v[3][y]:sub(1, x - 1) .. initGrid.voidcol .. v[3][y]:sub(x + 1)
                end
            end
        end
    end
end

local drawImage = function(im, x, y)
    local cx, cy = termgetCursorPos()
    termsetBackgroundColor( tocolors[initGrid.voidcol] )
    termsetTextColor(       tocolors[initGrid.voidcol] )
    for iy = 1, #im[1] do
        for ix = 1, #im[1][iy] do
            termsetCursorPos(x+(ix-1),y+(iy-1))
            if not (im[2][iy]:sub(ix,ix) == " " and im[3][iy]:sub(ix,ix) == " ") then
                termblit(
                    im[1][iy]:sub(ix,ix),
                    im[2][iy]:sub(ix,ix):gsub("[ f]",initGrid.voidcol),
                    im[3][iy]:sub(ix,ix):gsub("[ f]",initGrid.voidcol)
                )
            end
        end
    end
    termsetCursorPos(cx,cy)
end

local deadGuys = {}
local trail = {}
local lastTrails = {}
isPuttingDown = false

local putTrailXY = function(x, y, p)
    trail[y] = trail[y] or {}
    trail[y][x] = {
        player = p,
        age = 0
    }
end

local putTrail = function(p)
    putTrailXY(p.x, p.y, p.num)
end

local getTrail = function(x, y)
    if trail[y] then
        if trail[y][x] then
            return player[trail[y][x].player].char, player[trail[y][x].player].color, trail[y][x].age
        end
    end
    return false
end

local ageTrails = function()
    for y,l in pairs(trail) do
        for x,v in pairs(l) do
            trail[y][x].age = trail[y][x].age + 1
        end
    end
end

local control, revControl = {
    up = keys.up,
    down = keys.down,
    left = keys.left,
    right = keys.right,
    lookUp = keys.w,
    lookDown = keys.s,
    lookLeft = keys.a,
    lookRight = keys.d,
    release = keys.space
}, {}
for k,v in pairs(control) do
    revControl[v] = k
end

gridFore, gridBack = table.unpack(gridList[gridID])

local dirArrow = {
    [-1] = "^",
    [0] = ">",
    [1] = "V",
    [2] = "<"
}

local doesIntersectBorder = function(x, y)
    return mathfloor(x) == grid.x1 or mathfloor(x) == grid.x2 or mathfloor(y) == grid.y1 or mathfloor(y) == grid.y2
end

--draws grid and background at scroll 'x' and 'y', along with trails and players
local drawGrid = function(x, y, onlyDrawGrid, useSetVisible)
    tsv(false)
    x, y = mathfloor(x + 0.5), mathfloor(y + 0.5)
    local bg = {{},{},{}}
    local foreX, foreY
    local backX, backY
    local adjX, adjY
    local trailChar, trailColor, trailAge, isPlayer, isPredict
    for sy = 1, scr_y do
        bg[1][sy] = ""
        bg[2][sy] = ""
        bg[3][sy] = ""
        for sx = 1, scr_x do
            adjX = (sx + x)
            adjY = (sy + y)
            foreX = 1 + (sx + x) % #gridFore[1]
            foreY = 1 + (sy + y) % #gridFore
            backX = 1 + mathfloor(sx + (x / 2)) % #gridBack[1]
            backY = 1 + mathfloor(sy + (y / 2)) % #gridBack
            trailChar, trailColor, trailAge = getTrail(adjX, adjY)
            isPlayer = false
            isPredict = false
            if not onlyDrawGrid then
                for i = 1, #player do
                    if player[i].x == adjX and player[i].y == adjY then
                        isPlayer = i
                        break
                    elseif (not isHost) and useSkynet and i == you and (
                        adjX == math.floor(player[i].x + (0.02 * round(ping, 0)) * math.cos(math.rad(player[i].direction * 90))) and
                        adjY == math.floor(player[i].y + (0.02 * round(ping, 0)) * math.sin(math.rad(player[i].direction * 90)))
                    ) then
                        isPredict = i
                        break
                    end
                end
            end
            if isPlayer and (not onlyDrawGrid) and (not doesIntersectBorder(adjX, adjY)) then
                bg[1][sy] = bg[1][sy] .. dirArrow[player[isPlayer].direction]
                bg[2][sy] = bg[2][sy] .. toblit[player[isPlayer].color[1]]
                bg[3][sy] = bg[3][sy] .. grid.voidcol
            elseif isPredict and (not onlyDrawGrid) and (not doesIntersectBorder(adjX, adjY)) then
                bg[1][sy] = bg[1][sy] .. "o"
                bg[2][sy] = bg[2][sy] .. grid.forecol
                bg[3][sy] = bg[3][sy] .. grid.voidcol
            else
                if (not onlyDrawGrid) and trailChar and trailColor then
                    trailColor = trailColor[1 + ((trailAge - 1) % #trailColor)]
                    bg[1][sy] = bg[1][sy] .. trailChar
                    bg[2][sy] = bg[2][sy] .. toblit[trailColor]
                    bg[3][sy] = bg[3][sy] .. grid.voidcol
                else
                    if (not onlyDrawGrid) and (adjX < grid.x1 or adjX > grid.x2 or adjY < grid.y1 or adjY > grid.y2) then
                        bg[1][sy] = bg[1][sy] .. " "
                        bg[2][sy] = bg[2][sy] .. grid.voidcol
                        bg[3][sy] = bg[3][sy] .. grid.voidcol
                    elseif (not onlyDrawGrid) and doesIntersectBorder(adjX, adjY) then
                        bg[1][sy] = bg[1][sy] .. grid.border
                        bg[2][sy] = bg[2][sy] .. grid.voidcol
                        bg[3][sy] = bg[3][sy] .. grid.edgecol
                    else
                        if gridFore[foreY]:sub(foreX,foreX) ~= " " then
                            bg[1][sy] = bg[1][sy] .. gridFore[foreY]:sub(foreX,foreX)
                            bg[2][sy] = bg[2][sy] .. grid.forecol
                            bg[3][sy] = bg[3][sy] .. grid.voidcol
                        elseif gridBack[backY]:sub(backX,backX) ~= " " then
                            bg[1][sy] = bg[1][sy] .. gridBack[backY]:sub(backX,backX)
                            bg[2][sy] = bg[2][sy] .. grid.backcol
                            bg[3][sy] = bg[3][sy] .. grid.voidcol
                        else
                            bg[1][sy] = bg[1][sy] .. " "
                            bg[2][sy] = bg[2][sy] .. grid.voidcol
                            bg[3][sy] = bg[3][sy] .. grid.voidcol
                        end
                    end
                end
            end
        end
    end
    for sy = 1, scr_y do
        termsetCursorPos(1,sy)
        termblit(
            bg[1][sy],
            bg[2][sy],
            bg[3][sy]
        )
    end
    if doDrawPlayerNames and (not onlyDrawGrid) then
        for i = 1, #player do
            if doRenderOwnName or (i ~= you) then
                termsetTextColor(player[i].color[1])
                adjX = mathfloor(player[i].x - (scrollX + scrollAdjX) - (#player[i].name / 2) + 1)
                adjY = mathfloor(player[i].y - (scrollY + scrollAdjY) - 1.5)
                for cx = adjX, adjX + #player[i].name do
                    if doesIntersectBorder(adjX + mathfloor(0.5 + scrollX + scrollAdjX), adjY + mathfloor(0.5 + scrollY + scrollAdjY)) then
                        termsetBackgroundColor(tocolors[grid.edgecol])
                    else
                        termsetBackgroundColor(tocolors[grid.voidcol])
                    end
                    termsetCursorPos(cx, adjY)
                    termwrite(player[i].name:sub(cx-adjX+1, cx-adjX+1))
                end
            end
        end
    end
    tsv(true)
end

local getTime = function()
    if os.epoch then
        return os.epoch("utc")
    else
        return 24 * os.day() + os.time()
    end
end

local render = function(useSetVisible, netTime)
    local p = player[you]
    drawGrid(scrollX + scrollAdjX, scrollY + scrollAdjY, false, useSetVisible)
    termsetCursorPos(1,1)
    termsetTextColor(player[you].color[1])
    termsetBackgroundColor(tocolors[grid.voidcol])
    term.write("P" .. you)
    term.setTextColor(colors.white)

    for x = 0, p.trailMax - 1 do
        if not (x - p.trailLevel >= -0.4) then
            if (x - p.trailLevel) > -0.7 then
                term.setTextColor(colors.gray)
                term.write("@")
            elseif (x - p.trailLevel) > -1 then
                term.setTextColor(colors.lightGray)
                term.write("@")
            else
                term.setTextColor(colors.white)
                term.write("@")
            end
        end
    end
    term.setCursorPos(1,2)
    if netTime and useSkynet then
        ping = (getTime() - netTime)
        term.setTextColor(colors.white)
        term.write(" " .. tostring(ping) .. " ms")
    end
    term.setTextColor(colors.white)
end

local pleaseWait = function()
    local periods = 1
    local maxPeriods = 5
    termsetBackgroundColor(colors.black)
    termsetTextColor(colors.gray)
    termclear()

    local tID = os.startTimer(0.2)
    local evt, txt
    if useSkynet then
        txt = "Waiting for Skynet game"
    else
        txt = "Waiting for modem game"
    end

    while true do
        cwrite("(Press 'Q' to cancel)", 2)
        cwrite(txt, scr_y - 2, maxPeriods)
        termwrite(("."):rep(periods))
        evt = {os.pullEvent()}
        if evt[1] == "timer" and evt[2] == tID then
            tID = os.startTimer(0.5)
            periods = (periods % maxPeriods) + 1
            term.clearLine()
        elseif evt[1] == "key" and evt[2] == keys.q then
            return
        end
    end
end

local startCountdown = function()
    local cName = "PLAYER " .. you
    local col = colors.white
    for k,v in pairs(colors) do
        if player[you].color[1] == v then
            cName = k:upper()
            col = v
            break
        end
    end
    local cMessage = "You are "
    scrollX = player[you].x - mathfloor(scr_x / 2)
    scrollY = player[you].y - mathfloor(scr_y / 2)
    for i = 3, 1, -1 do
        render(true)
        termsetTextColor(colors.white)
        for x = 1, #cMessage+1 do
            termsetCursorPos(-1 + x + mathfloor(scr_x / 2 - (#cMessage + #cName) / 2), mathfloor(scr_y / 2) + 2)
            if cMessage:sub(x,x) ~= " " and x <= #cMessage then
                termwrite(cMessage:sub(x,x))
            end
        end
        termsetTextColor(col)
        termwrite(player[you].name)
        termsetTextColor(colors.white)
        termsetCursorPos(mathfloor(scr_x / 2 - 2), mathfloor(scr_y / 2) + 4)
        termwrite(i .. "...")
        sleep(1)
    end
end

local makeMenu = function(x, fromX, y, options, doAnimate, scrollInfo, _cpos)
    local cpos = _cpos or 1
    local xmod = 0
    local cursor = "> "
    local gsX, gsY = (scrollInfo or {})[2] or 0, (scrollInfo or {})[3] or 0
    local step = (scrollInfo or {})[1] or 0
    local lastPos = cpos
    local image
    if not doAnimate then
        drawImage(images.logo, mathceil(scr_x / 2 - images.logo.x / 2), 2)
        if useSkynet then
            term.setTextColor(colors.lightGray)
            cwrite("Skynet Enabled", 2 + images.logo.y)
        end
    end
    local rend = function()
        if (step % 150 > 100) and doShowByImage then
            image = images.ldd
        else
            image = images.logo
        end
        if doAnimate then
            drawImage(
                image,
                mathceil(scr_x / 2 - image.x / 2),
                2
            )
            if useSkynet then
                term.setTextColor(colors.lightGray)
                cwrite("Skynet Enabled", 2 + image.y)
            end
        end
        for i = 1, #options do
            if i == cpos then
                termsetCursorPos(fromX + xmod, y + (i - 1))
                termsetTextColor(colors.white)
                termwrite(cursor .. options[i])
            else
                if i == lastPos then
                    termsetCursorPos(fromX + xmod, y + (i - 1))
                    termwrite((" "):rep(#cursor))
                    lastPos = nil
                else
                    termsetCursorPos(fromX + xmod + #cursor, y + (i - 1))
                end
                termsetTextColor(colors.gray)
                termwrite(options[i])
            end
        end
    end
    local gstID, evt = mathrandom(1,65535)
    if doAnimate then
        os.queueEvent("timer", gstID)
    end
    rend()
    local tID = os.startTimer(0.05)
    while true do
        evt = {os.pullEvent()}
        if evt[1] == "key" then
            if evt[2] == keys.up then
                lastPos = cpos
                cpos = (cpos - 2) % #options + 1
            elseif evt[2] == keys.down then
                lastPos = cpos
                cpos = (cpos % #options) + 1
            elseif evt[2] == keys.home then
                lastPos = cpos
                cpos = 1
            elseif evt[2] == keys["end"] then
                lastPos = cpos
                cpos = #options
            elseif evt[2] == keys.enter then
                return cpos, {step, gsX, gsY}
            end
        elseif evt[1] == "mouse_click" then
            if evt[4] >= y and evt[4] < y+#options then
                if cpos == evt[4] - (y - 1) then
                    return cpos, {step, gsX, gsY}
                else
                    cpos = evt[4] - (y - 1)
                    doRend = true
                end
            end
        elseif evt[1] == "timer" then
            if evt[2] == gstID then
                gstID = os.startTimer(gameDelayInit)
                drawGrid(gsX, gsY, true)
                step = step + 1
                if mathceil(step / 100) % 2 == 1 then
                    gsX = gsX + 1
                else
                    gsY = gsY - 1
                end
                doRend = true
            elseif evt[2] == tID then
                if x > fromX and xmod < x - fromX then
                    xmod = math.min(xmod + 1, x - fromX)
                    drawGrid(gsX, gsY, true)
                    tID = os.startTimer(0.05)
                elseif xmod > x - fromX then
                    xmod = math.max(xmod - 1, x - fromX)
                    drawGrid(gsX, gsY, true)
                    tID = os.startTimer(0.05)
                end
                doRend = true
            end
        end
        if lastPos ~= cpos or doRend then
            rend()
            doRend = false
        end
    end
end

local specialRead = function(scrollInfo, specialNames, message, preInput)
    specialNames = specialNames or {}
    local gsX, gsY = (scrollInfo or {})[2] or 0, (scrollInfo or {})[3] or 0
    local step = (scrollInfo or {})[1] or 0
    local tID = os.startTimer(gameDelayInit)
    local buff = {}
    local cpos = 1
    local maxSize = 15
    local evt
    for x = 1, #preInput do
        buff[x] = preInput:sub(x, x)
        cpos = cpos + 1
    end
    term.setCursorBlink(true)
    local rend = function()
        drawGrid(gsX, gsY, true)
        term.setTextColor(colors.white)
        cwrite(message, scr_y - 5)
        term.setTextColor(specialNames[table.concat(buff):lower()] or colors.white)
        term.setCursorPos( cwrite(table.concat(buff), scr_y - 3, nil, cpos) - 1, scr_y - 3)
        term.setTextColor(colors.white)
    end
    while true do
        evt = {os.pullEvent()}
        if evt[1] == "timer" and evt[2] == tID then
            -- render the bg
            tID = os.startTimer(gameDelayInit)
            step = step + 1
            if mathceil(step / 100) % 2 == 1 then
                gsX = gsX + 1
            else
                gsY = gsY - 1
            end
            rend()
        elseif evt[1] == "char" then
            if #buff < maxSize then
                table.insert(buff, cpos, evt[2])
                cpos = cpos + 1
                rend()
            end
        elseif evt[1] == "key" then
            if evt[2] == keys.left then
                cpos = math.max(1, cpos - 1)
            elseif evt[2] == keys.right then
                cpos = math.min(#buff + 1, cpos + 1)
            elseif evt[2] == keys.home then
                cpos = 1
            elseif evt[2] == keys["end"] then
                cpos = #buff
            elseif evt[2] == keys.backspace then
                if cpos > 1 then
                    table.remove(buff, cpos - 1)
                    cpos = cpos - 1
                    rend()
                end
            elseif evt[2] == keys.delete then
                if buff[cpos] then
                    table.remove(buff, cpos)
                    rend()
                end
            elseif evt[2] == keys.enter then
                term.setCursorBlink(false)
                return table.concat(buff), {step, gsX, gsY}
            end
        end
    end
end

local passwordChange = function(scrollInfo)
    return specialRead(scrollInfo, {}, "Enter a password.", argumentPassword or "") or ""
end

local nameChange = function(scrollInfo)
    -- this has no functional significance. just some shoutouts
    local specialNames = {
        ["blu"] = colors.blue,
        ["red"] = colors.red,
        ["ldd"] = colors.orange,
        ["lddestroier"] = colors.orange,
        ["hydraz"] = colors.yellow,
        ["hugeblank"] = colors.orange,
        ["bagel"] = colors.orange,
        ["3d6"] = colors.lime,
        ["lyqyd"] = colors.red,
        ["squiddev"] = colors.cyan,
        ["oeed"] = colors.lime,
        ["dog"] = colors.purple,
        ["nothy"] = colors.lightGray,
        ["kepler"] = colors.cyan,
        ["kepler155c"] = colors.cyan,
        ["anavrins"] = colors.blue,
        ["redmatters"] = colors.red,
        ["fatmanchummy"] = colors.purple,
        ["crazed"] = colors.lightBlue,
        ["ape"] = colors.brown,
        ["everyos"] = colors.red,
        ["dan200"] = colors.lightGray,
        ["dantwohundred"] = colors.lightGray,
        ["lemmmy"] = colors.red,
        ["yemmel"] = colors.red,
        ["apemanzilla"] = colors.brown,
        ["osmarks"] = colors.green,
        ["gollark"] = colors.green,
        ["dece"] = colors.cyan,
        ["hpwebcamable"] = colors.lightGray,
        ["theoriginalbit"] = colors.blue,
        ["bombbloke"] = colors.red,
        ["kingofgamesyami"] = colors.lightBlue,
        ["pixeltoast"] = colors.lime,
        ["creator"] = colors.yellow,
        ["dannysmc"] = colors.purple,
        ["dannysmc95"] = colors.purple,
        ["kingdaro"] = colors.blue,
        ["valithor"] = colors.orange,
        ["logandark"] = colors.lightGray,
        ["lupus590"] = colors.lightGray,
        ["nitrogenfingers"] = colors.green,
        ["gravityscore"] = colors.lime,
        ["1lann"] = colors.gray,
        ["konlab"] = colors.brown,
        ["elvishjerricco"] = colors.pink
    }
    return specialRead(scrollInfo, specialNames, "Enter your name.", argumentName or player[you].initName)
end

local titleScreen = function()
    termclear()
    local menuOptions, options, choice, scrollInfo
    if kioskMode then
        menuOptions = {
            "Start Game",
            "How to Play",
        }
    else
        menuOptions = {
            "Start Game",
            "How to Play",
            "Options...",
            "Exit"
        }
    end
    local currentX = 2
    while true do
        choice, scrollInfo = makeMenu(2, currentX, scr_y - #menuOptions, menuOptions, true, scrollInfo)
        currentX = 2
        if choice == 1 then
            return "start"
        elseif choice == 2 then
            return "help"
        elseif choice == 3 then
            local _cpos
            while true do
                options = {
                    "Grid Demo",
                    "Change Name",
                    "Change Grid",
                    "Change Password",
                    (useSkynet and "Disable" or "Enable") .. " Skynet",
                    "Back..."
                }
                choice, scrollInfo = makeMenu(8, currentX, scr_y - #options, options, true, scrollInfo, _cpos)
                currentX = 8
                _cpos = choice
                if choice == 1 then
                    return "demo"
                elseif choice == 2 then
                    local newName = nameChange(scrollInfo)
                    if #newName > 0 then
                        if newName:upper() == "BLU" or newName:upper() == "RED" or newName:gsub(" ","") == "" then
                            argumentName = nil
                        else
                            argumentName = newName
                        end
                    else
                        argumentName = nil
                    end
                elseif choice == 3 then
                    gridID = (gridID % #gridList) + 1
                    gridFore, gridBack = table.unpack(gridList[gridID])
                elseif choice == 4 then
                    argumentPassword = passwordChange(scrollInfo)
                elseif choice == 5 then
                    if http.websocket then
                        useSkynet = not useSkynet
                        setUpModem()
                        if skynet and not useSkynet then
                            skynet.socket.close()
                        end
                    else
                        term.clear()
                        term.setTextColor(colors.white)
                        cwrite("Alas, this version of CC",  -2 + scr_y / 2)
                        cwrite("does not support Skynet.",  -1 + scr_y / 2)
                        term.setTextColor(colors.lightGray)
                        cwrite("Use CC:Tweaked or CCEmuX",   1 + scr_y / 2)
                        cwrite("instead for netplay.",       2 + scr_y / 2)
                        cwrite("Press any key to go back.",  4 + scr_y / 2)
                        sleep(0.1)
                        os.pullEvent("key")
                    end
                elseif choice == 6 then
                    break
                end
            end
        elseif choice == 4 then
            return "exit"
        end
    end
end

local cleanExit = function()
    termsetBackgroundColor(colors.black)
    termsetTextColor(colors.white)
    termclear()
    cwrite("Thanks for playing!", 2)
    termsetCursorPos(1, scr_y)
end

local parseMouseInput = function(button, x, y, direction)
    local output = false
    local cx = x - scr_mx
    local cy = y - scr_my

    if useLegacyMouseControl or mode == "demo" then -- outdated mouse input, useful for grid demo though
        cx = cx * (scr_y / scr_x)
        if cx > cy then
            if -cx > cy then
                output = "up"
            else
                output = "right"
            end
        else
            if -cx < cy then
                output = "down"
            else
                output = "left"
            end
        end
    else
        cx = cx + scrollAdjX
        cy = cy + scrollAdjY
        if button == 1 then -- move player
            if direction % 2 == 0 then -- moving horizontally
                if cy > 0 then
                    output = "down"
                elseif cy < 0 then
                    output = "up"
                end
            else -- moving vertically
                if cx > 0 then
                    output = "right"
                elseif cx < 0 then
                    output = "left"
                end
            end
        elseif button == 2 then -- release trail
            output = "release"
        end
    end

    return control[output]
end

local getInput = function()
    local evt
    local mkey = -1
    while true do
        evt = {os.pullEvent()}
        if lockInput then
            keysDown = {}
            miceDown = {}
        else
            if evt[1] == "key" then
                if (not keysDown[evt[2]]) and (
                    evt[2] == control.up or
                    evt[2] == control.down or
                    evt[2] == control.left or
                    evt[2] == control.right
                ) then
                    lastDirectionPressed = revControl[evt[2]]
                end
                keysDown[evt[2]] = true
            elseif evt[1] == "key_up" then
                keysDown[evt[2]] = false
            elseif evt[1] == "mouse_click" or (useLegacyMouseControl and evt[1] == "mouse_drag") then
                if evt[1] == "mouse_drag" then
                    keysDown[mkey] = false
                end
                miceDown[evt[2]] = {evt[3], evt[4]}
                mkey = parseMouseInput(evt[2], evt[3], evt[4], player[you].direction) or -1
                lastDirectionPressed = revControl[mkey]
                keysDown[mkey] = true
            elseif evt[1] == "mouse_drag" then
                miceDown[evt[2]] = {evt[3], evt[4]}
            elseif evt[1] == "mouse_up" then
                keysDown[mkey] = false
                miceDown[evt[2]] = nil
                mkey = parseMouseInput(evt[2], evt[3], evt[4], player[you].direction) or -1
                keysDown[mkey] = false
            end
        end
    end
end

local scrollToPosition = function(x, y)
    for i = 1, 16 do
        scrollX = (scrollX + x - (scr_x/2)) / 2
        scrollY = (scrollY + y - (scr_y/2)) / 2
        render(true)
        sleep(0.05)
    end
end

local gridDemo = function()
    keysDown = {}
    miceDown = {}
    scrollX, scrollY = math.floor(scr_x * -0.5), math.floor(scr_y * -0.75)
    while true do
        if keysDown[keys.left] then
            scrollX = scrollX - 1
        end
        if keysDown[keys.right] then
            scrollX = scrollX + 1
        end
        if keysDown[keys.up] then
            scrollY = scrollY - 1
        end
        if keysDown[keys.down] then
            scrollY = scrollY + 1
        end
        if keysDown[keys.q] then
            return "end"
        end
        drawGrid(scrollX, scrollY, false, true)
        ageTrails()
        sleep(0.05)
    end
end

local sendInfo = function(gameID, doSendTime)
    transmit(port, {
        player = isHost and player or nil,
        name = player[you].name,
        putTrail = isPuttingDown,
        gameID = gameID,
        time = doSendTime and getTime(),
        keysDown = isHost and nil or keysDown,
        trail = isHost and lastTrails or nil,
        deadGuys = isHost and deadGuys or nil,
        lastDir = lastDirectionPressed
    })
end

local waitForKey = function(time, blockMouse)
    sleep(time or 0.5)
    local evt
    repeat
        evt = os.pullEvent()
    until evt == "key" or ((not blockMouse) and evt == "mouse_click")
end

local imageAnim = function(image)
    while true do
        drawImage(image, mathceil(scr_x / 2 - image.x / 2), mathfloor(scr_y / 2 - image.y / 2))
        sleep(0.5)
        render(true)
        sleep(0.5)
    end
end

local deadAnimation = function(doSend)
    for k,v in pairs(deadGuys) do
        player[k].char = "X"
        lockInput = true
    end
    if doSend then
        sendInfo(gamename, isHost)
    end
    if deadGuys[you] or deadGuys[nou] then
        termsetTextColor(colors.white)
        if deadGuys[you] and deadGuys[nou] then
            os.queueEvent("tron_complete", "tie", isHost, player[nou].name)
            scrollToPosition(player[nou].x, player[nou].y)
            scrollToPosition(player[you].x, player[you].y)
            parallel.waitForAny(function() imageAnim(images.tie) end, waitForKey)
            return "end"
        else
            if deadGuys[you] then
                scrollX, scrollY = player[nou].x - scr_x / 2, player[nou].y - scr_y / 2
                os.queueEvent("tron_complete", "lose", isHost, player[nou].name)
                scrollToPosition(player[you].x, player[you].y)
                parallel.waitForAny(function() imageAnim(images.lose) end, waitForKey)
                return "end"
            elseif deadGuys[nou] then
                os.queueEvent("tron_complete", "win", isHost, player[nou].name)
                scrollToPosition(player[nou].x, player[nou].y)
                parallel.waitForAny(function() imageAnim(images.win) end, waitForKey)
                return "end"
            end
        end
    end
end

local debugMoveMode = false -- only works if host
local moveTick = function(doSend)
    local p
    local hasMoved
    for i = 1, #player do
        p = player[i]
        hasMoved = false
        if not p.dead then
            if isHost then
                if debugMoveMode then
                    if (i == 1 and keysDown[control.left]) or (i == 2 and netKeysDown[control.left]) then
                        p.x = p.x - 1
                        hasMoved = true
                    end
                    if (i == 1 and keysDown[control.right]) or (i == 2 and netKeysDown[control.right]) then
                        p.x = p.x + 1
                        hasMoved = true
                    end
                    if (i == 1 and keysDown[control.up]) or (i == 2 and netKeysDown[control.up]) then
                        p.y = p.y - 1
                        hasMoved = true
                    end
                    if (i == 1 and keysDown[control.down]) or (i == 2 and netKeysDown[control.down]) then
                        p.y = p.y + 1
                        hasMoved = true
                    end
                else
                    p.x = p.x + mathfloor(mathcos(mathrad(p.direction * 90)))
                    p.y = p.y + mathfloor(mathsin(mathrad(p.direction * 90)))
                    hasMoved = true
                end
                if hasMoved and (doesIntersectBorder(p.x, p.y) or getTrail(p.x, p.y)) then
                    p.dead = true
                    deadGuys[i] = true
                else
                    if p.putTrail or (p.trailLevel < 1) then
                        if hasMoved then
                            putTrail(p)
                            lastTrails[#lastTrails+1] = {p.x, p.y, p.num}
                            if #lastTrails > #player then
                                tableremove(lastTrails, 1)
                            end
                        end
                        if p.putTrail then
                            p.trailLevel = math.min(p.trailLevel + p.trailRegen, p.trailMax)
                        else
                            p.trailLevel = math.max(p.trailLevel - 1, 0)
                        end
                    else
                        p.trailLevel = math.max(p.trailLevel - 1, 0)
                    end
                end
            end
            for a = 1, #player do
                if (a ~= i) and (player[a].x == p.x and player[a].y == p.y) then
                    p.dead = true
                    deadGuys[i] = true
                    if (p.direction + 2) % 4 == player[a].direction % 4 then
                        player[a].dead = true
                        deadGuys[a] = true
                    end
                    break
                end
            end
        end
    end
    return deadAnimation(doSend)
end

local setDirection = function(p, checkDir, lastDir)
    if (lastDir == control.left) and (checkDir or p.direction) ~= 0 then
        p.direction = 2
        return true
    elseif (lastDir == control.right) and (checkDir or p.direction) ~= 2 then
        p.direction = 0
        return true
    elseif (lastDir == control.up) and (checkDir or p.direction) ~= 1 then
        p.direction = -1
        return true
    elseif (lastDir == control.down) and (checkDir or p.direction) ~= -1 then
        p.direction = 1
        return true
    elseif isPuttingDown == keysDown[control.release] then
        return true
    else
        return false
    end
end

local game = function()
    local outcome
    local p, np, timeoutID, tID, evt, netTime
    while true do
        netTime = nil
        if isHost then
            sleep(gameDelay)
        else
            timeoutID = os.startTimer(3)
            repeat
                evt, tID = os.pullEvent()
            until evt == "move_tick" or (evt == "timer" and tID == timeoutID)
            if evt == "timer" then
                os.queueEvent("tron_complete", "timeout", isHost, player[nou].name)
                parallel.waitForAny(function() imageAnim(images.timeout) end, waitForKey)
                return
            elseif evt == "move_tick" then
                netTime = tID
            end
        end
        p  = player[you]
        np = player[nou]

        if isHost then
            setDirection(p, nil, control[lastDirectionPressed])
            setDirection(np, nil, control[netLastDirectionPressed])
            p.putTrail = not keysDown[control.release]
        else
            setDirection(p, nil, control[lastDirectionPressed])
            isPuttingDown = not keysDown[control.release]
            sendInfo(gamename, isHost)
        end

        if miceDown[3] then
            scrollAdjX = scrollAdjX + (miceDown[3][1] - scr_x / 2) / (scr_x / 4)
            scrollAdjY = scrollAdjY + (miceDown[3][2] - scr_y / 2) / (scr_y / 2.795)
        else
            if keysDown[control.lookLeft] then
                scrollAdjX = scrollAdjX - 2
            end
            if keysDown[control.lookRight] then
                scrollAdjX = scrollAdjX + 2
            end
            if keysDown[control.lookUp] then
                scrollAdjY = scrollAdjY - 1.25
            end
            if keysDown[control.lookDown] then
                scrollAdjY = scrollAdjY + 1.25
            end
        end

        scrollAdjX = scrollAdjX * 0.8
        scrollAdjY = scrollAdjY * 0.8

        if isHost then
            outcome = moveTick(true)
        else
            outcome = deadAnimation(false)
        end
        ageTrails()
        if outcome == "end" then
            return
        else
            scrollX = p.x - mathfloor(scr_x / 2)
            scrollY = p.y - mathfloor(scr_y / 2)
            render(true, (not isHost) and netTime)
        end
    end
end

local cTime -- current UTC time when looking for game
local networking = function()
    local evt, side, channel, repchannel, msg, distance
    while true do
        --[[
        if useSkynet then
            evt, channel, msg = os.pullEvent("skynet_message")
        else
            evt, side, channel, repchannel, msg, distance = os.pullEvent("modem_message")
        end
        --]]
        msg, channel = disknet.receive(channel)
        if channel == port and type(msg) == "table" then
            if type(msg.gameID) == "string" then
                if waitingForGame and (type(msg.time) == "number") then
                    if msg.password == argumentPassword or (argumentPassword == "" and not msg.password) then

                        -- called while waiting for match
                        if msg.time < cTime then
                            isHost = false
                            you, nou = nou, you
                            gamename = msg.gameID
                            gameDelay = tonumber(msg.gameDelay) or gameDelayInit
                            grid = msg.grid or copyTable(initGrid)
                            player = msg.player or player
                            player[you].name = argumentName or player[you].initName
                        else
                            isHost = true
                        end

                        player[nou].name = msg.name or player[nou].initName

                        transmit(port, {
                            player = player,
                            gameID = gamename,
                            time = cTime,
                            name = argumentName,
                            password = argumentPassword,
                            grid = initGrid
                        })
                        waitingForGame = false
                        netKeysDown = {}
                        os.queueEvent("new_game", gameID)
                        return gameID
                    end

                elseif msg.gameID == gamename then

                    -- called during gameplay
                    if not isHost then
                        if type(msg.player) == "table" then
                            player[nou].name = msg.name or player[nou].name
                            player = msg.player
                            if msg.trail then
                                for i = 1, #msg.trail do
                                    putTrailXY(table.unpack(msg.trail[i]))
                                end
                            end
                            deadGuys = msg.deadGuys
                            os.queueEvent("move_tick", msg.time)
                        end
                    elseif type(msg.keysDown) == "table" then
                        netKeysDown = msg.keysDown
                        netLastDirectionPressed = msg.lastDir
                        player[nou].putTrail = msg.putTrail
                        player[nou].name = msg.name or "???" --player[nou].name
                    end

                end
            end
        end
    end
end

local helpScreen = function()
    termsetBackgroundColor(colors.black)
    termsetTextColor(colors.white)
    termclear()
    termsetCursorPos(1,2)
    print([[
    Move your lightcycle with WASD
     or by tapping left click.

    Pan the camera with arrows
     or by holding middle click.

    Release the trail with spacebar
     or by holding right click.

    If you're P2 (red), a gray circle
    will indicate where you'll turn,
    to help with Skynet's netlag.

    Press any key to go back.
    ]])
    waitForKey(0.25)
end

local startGame = function()
    -- reset all info between games
    keysDown = {}
    miceDown = {}
    scrollAdjX = 0
    scrollAdjY = 0

    trail = {}
    deadGuys = {}
    lastDirectionPressed = nil
    netLastDirectionPressed = nil
    gameDelay = gameDelayInit
    grid = copyTable(initGrid)
    player = resetPlayers()
    you, nou = 1, 2
    gamename = ""
    for i = 1, 32 do
        gamename = gamename .. string.char(mathrandom(1,126))
    end

    waitingForGame = true
    cTime = getTime()
    transmit(port, {
        player = player,
        gameID = gamename,
        gameDelay = gameDelayInit,
        time = cTime,
        password = argumentPassword,
        name = argumentName,
        grid = initGrid
    })
    rVal = parallel.waitForAny( pleaseWait, networking )
    sleep(0.1)
    player[you].name = argumentName or player[you].initName
    if rVal == 2 then
        startCountdown()
        parallel.waitForAny( getInput, game, networking )
    end
end

local decision

local main = function()
    return pcall(function()
        local rVal
        while true do
            mode = "menu"
            decision = titleScreen()
            lockInput = false
            if decision == "start" then
                mode = "game"
                if useSkynet then
                    parallel.waitForAny(startGame, skynet.listen)
                else
                    startGame()
                end
            elseif decision == "help" then
                mode = "help"
                helpScreen()
            elseif decision == "demo" then
                mode = "demo"
                parallel.waitForAny( getInput, gridDemo )
            elseif decision == "exit" then
                return cleanExit()
            end
        end
    end)
end

if doGridDemo then
    parallel.waitForAny(function()
        local step, gsX, gsY = 0, 0, 0
        while true do
            drawGrid(gsX, gsY, true)
            step = step + 1
            if mathceil(step / 100) % 2 == 1 then
                gsX = gsX + 1
            else
                gsY = gsY - 1
            end
            sleep(0.05)
        end
    end, function()
        sleep(0.1)
        local evt, key
        repeat
            evt, key = os.pullEvent("key")
        until key == keys.q
        sleep(0.1)
    end)
else
    if useOnce then
        term.setCursorBlink(false)
        if useSkynet then
            parallel.waitForAny(startGame, skynet.listen)
            skynet.socket.close()
        else
            startGame()
        end
        term.setCursorPos(1, scr_y)
    else
        main()
        if skynet then
            skynet.socket.close()
        end
    end
end