TRON

local isOpen=false
for k,v in pairs({"right","left","top","bottom","front","back"}) do
    if peripheral.getType(v)=="modem" then
        rednet.open(v)
        isOpen=true
    end
end
if not isOpen then
    error("no modem attached")
end
local Mx,My=term.getSize()
local Cx,Cy=math.floor(Mx/2),math.floor(My/2)
function maingame()
    local lang={"Waiting for player",{[0]="^",">","v","<"},{{"|","/","|","\\"},{"/","-","\\","-"},{"|","\\","|","/"},{"\\","-","/","-"}},"You died.","You won."}
    local board=setmetatable({},{__index=function(s,n) s[n]={} return s[n] end})
    for l1=99,-99,-1 do
        board[l1][-99]={"-",3}
    end
    for l1=99,-99,-1 do
        board[l1][99]={"|",3}
    end
    for l1=99,-99,-1 do
        board[-99][l1]={"-",3}
    end
    for l1=99,-99,-1 do
        board[99][l1]={"|",3}
    end
    board[100][100]={"/",3}
    board[100][-100]={"\\",3}
    board[-100][100]={"/",3}
    board[-100][-100]={"\\",3}
    local modem
    local initheader="TRON:"
    local pnid
    local function send(...)
        rednet.send(pnid,string.sub(textutils.serialize({...}),2,-2))
    end
    local function decode(dat)
        return textutils.unserialize("{"..dat.."}")
    end
    local col
    term.setCursorPos(math.floor(Cx-(#lang[1])/2),Cy)
    term.setTextColor(colors.orange)
    term.setBackgroundColor(colors.black)
    term.clear()
    term.write(lang[1])
    rednet.broadcast(initheader.."pingcon")
    local p1,p2
    while true do
        local p={os.pullEvent()}
        if p[1]=="rednet_message" and p[2]~=os.getComputerID() then
            if p[3]==initheader.."pingcon" then
                rednet.send(p[2],initheader.."pongcon")
                pnid=p[2]
                col={colors.blue,colors.red}
                p1={pos={x=2,y=1},dir=0}
                p2={pos={x=1,y=1},dir=0}
                break
            elseif p[3]==initheader.."pongcon" then
                pnid=p[2]
                col={colors.red,colors.blue}
                p1={pos={x=1,y=1},dir=0}
                p2={pos={x=2,y=1},dir=0}
                break
            end
        end
    end
    term.setBackgroundColor(colors.black)
    term.clear()
    local frs=0
    local fps=0 -- frame counter (debugging)
    local function render()
        frs=frs+1
        term.setTextColor(colors.gray)
        for l1=1,My do
            term.setCursorPos(1,l1)
            local pre=p1.pos.x%3
            if (l1+p1.pos.y)%3==0 then
                if pre==1 then
                    pre="--"
                elseif pre==2 then
                    pre="-"
                else
                    pre=""
                end
                term.write(pre..string.rep("+--",math.ceil(Mx/2)))
            else
                if pre==1 then
                    pre="  "
                elseif pre==2 then
                    pre=" "
                else
                    pre=""
                end
                term.write(pre..string.rep("|  ",math.ceil(Mx/2)))
            end
        end
        term.setTextColor(colors.blue)
        local num=0
        for k,v in pairs(board) do
            for l,y in pairs(v) do
                if (k-p1.pos.x)+Cx<=Mx and (k-p1.pos.x)+Cx>=1 and (l-p1.pos.y)+Cy<=My and (l-p1.pos.y)+Cy>=1 then
                    term.setTextColor(col[y[2]] or y[2])
                    term.setCursorPos((k-p1.pos.x)+Cx,(l-p1.pos.y)+Cy)
                    term.write(y[1])
                    num=num+1
                end
            end
        end
        term.setCursorPos(1,1)
        if col[1]==colors.blue then
            term.setTextColor(colors.blue)
            term.write("BLUE")
        else
            term.setTextColor(colors.red)
            term.write("RED")
        end
    end
    local odr={[p1]=p1.dir,[p2]=p2.dir}
    local function processmove(u)
        local ccol
        if u==p1 then
            ccol=col[1]
        else
            ccol=col[2]
        end
        term.setTextColor(ccol)
        if u==p1 and board[u.pos.x][u.pos.y] then
            send("DIE")
            term.setCursorPos(Cx,Cy)
            term.write("x")
            sleep(2)
            term.setCursorPos(Cx-math.floor(#lang[4]/2),Cy)
            term.setTextColor(colors.orange)
            term.clear()
            term.write(lang[4])
            sleep(5)
            term.setTextColor(colors.white)
            term.setBackgroundColor(colors.black)
            term.setCursorPos(1,1)
            term.clear()
            error("",0)
        end
        if odr[u]~=u.dir then
            board[u.pos.x][u.pos.y]={lang[3][odr[u]+1][u.dir+1],ccol}
        end
        if not board[u.pos.x][u.pos.y] then
            if u.dir%2==0 then
                board[u.pos.x][u.pos.y]={"|",ccol}
            else
                board[u.pos.x][u.pos.y]={"-",ccol}
            end
        end
        local chr=board[u.pos.x][u.pos.y][1]
        local shr={x=u.pos.x,y=u.pos.y}
        if u.dir==0 then
            u.pos.y=u.pos.y-1
        elseif u.dir==1 then
            u.pos.x=u.pos.x+1
        elseif u.dir==2 then
            u.pos.y=u.pos.y+1
        else
            u.pos.x=u.pos.x-1
        end
        odr[u]=u.dir
        return chr,shr
    end
    local function renderchar(u)
        local ccol
        if u==p1 then
            ccol=col[1]
            term.setCursorPos(Cx,Cy)
        else
            ccol=col[2]
            term.setCursorPos((p2.pos.x-p1.pos.x)+Cx,(p2.pos.y-p1.pos.y)+Cy)
        end
        term.setTextColor(ccol)
        term.write(lang[2][u.dir])
    end
    function processturn(p,u)
        local dirs={[keys.up]=0,[keys.right]=1,[keys.down]=2,[keys.left]=3}
        if (odr[u]+2)%4~=dirs[p] then
            u.dir=dirs[p]
            renderchar(u)
            if u==p1 then
                send("ROT",u.dir)
            end
        end
    end
    render()
    local move=os.startTimer(0.1)
    local fct=os.startTimer(1)
    while true do
        local p={os.pullEvent()}
        if p[1]=="key" then
            if p[2]==keys.up or p[2]==keys.right or p[2]==keys.down or p[2]==keys.left then
                processturn(p[2],p1)
            end
        elseif p[1]=="timer" then
            if p[2]==move then
                local ret,ret2=processmove(p1)
                move=os.startTimer(0.1)
                send("MOVE",ret2,ret)
            elseif p[2]==fct then
                fps=frs
                frs=0
                fct=os.startTimer(1)
            end
        elseif p[1]=="rednet_message" and p[2]==pnid then
            local dat=decode(p[3])
            if dat[1]=="ROT" then
                p2.dir=dat[2]
                renderchar(p2)
            elseif dat[1]=="DIE" then
                p1.pos=p2.pos
                render()
                term.setTextColor(col[2])
                term.setCursorPos(Cx,Cy)
                term.write("x")
                sleep(2)
                term.setCursorPos(Cx-math.floor(#lang[5]/2),Cy)
                term.setTextColor(colors.orange)
                term.clear()
                term.write(lang[5])
                sleep(5)
                term.setTextColor(colors.white)
                term.setBackgroundColor(colors.black)
                term.setCursorPos(1,1)
                term.clear()
                return
            elseif dat[1]=="MOVE" then
                p2.pos=dat[2]
                board[p2.pos.x][p2.pos.y]={dat[3],col[2]}
                render()
                renderchar(p1)
                renderchar(p2)
            end
        end
    end
end
local selected=1
function rmain()
    term.setBackgroundColor(colors.black)
    term.clear()
    term.setCursorPos(1,1)
    term.setTextColor(colors.blue)
    local txt="  _  _______________     ________    __       _\n/ \\/  _____________\\   /  ____  \\  |  \\     / |\n\\_/| /    / \\       | /  /    \\  \\ |   \\ __/  |\n   | |    | |\\  ___/ |  |      |  ||    \\     |\n   | |    | | \\ \\    |  |      |  ||   __\\    |\n   | |    | |  \\ \\    \\  \\____/  / |  /   \\   |\n   \\_/    \\_/   \\_/    \\________/  |_/     \\__|"
    local cnt=1
    local cnt2=Cx-23
    for char in string.gmatch(txt,".") do
        if char~=" " and char~="\n" then
            term.setCursorPos(cnt2,cnt)
            term.write(char)
        elseif char=="\n" then
            cnt=cnt+1
            cnt2=Cx-23
        end
        cnt2=cnt2+1
    end
    local selections={"Multiplayer","Exit"}
    selected=((selected-1)%(#selections))+1
    for k,v in pairs(selections) do
        if k==selected then
            term.setTextColor(colors.blue)
            term.setCursorPos(Cx-(math.floor(#v/2)+1),k+10)
            term.write(">"..v.."<")
            term.setTextColor(colors.lightBlue)
            term.setCursorPos(Cx-math.floor(#v/2),k+10)
            term.write(v)
        else
            term.setTextColor(colors.lightBlue)
            term.setCursorPos(Cx-math.floor(#v/2),k+10)
            term.write(v)
        end
    end
end
rmain()
while true do
    p={os.pullEvent()}
    if p[1]=="key" then
        if p[2]==keys.up then
            selected=selected-1
            rmain()
        elseif p[2]==keys.down then
            selected=selected+1
            rmain()
        elseif p[2]==keys.enter then
            if selected==1 then
                a,b=pcall(maingame)
                if not a and b~="" then
                    error(b,0)
                end
                rmain()
            else
            break
            end
        end
    end
end
term.setCursorPos(1,1)
term.clear()