Patriotism

os.loadAPI( "partTerm" )

commands.kill( "@e[type=ArmorStand,CustomName=coordfinder]" )

--make an armor stand for us
commands.summon( "ArmorStand ~ ~ ~ {Invisible:1b,CustomName:coordfinder,NoGravity:1}" )

local function getPosition()
        commands.execAsync( "tp @e[type=ArmorStand,CustomName=coordfinder] @p" )
        local ok, result = commands.tp( "@e[type=ArmorStand,CustomName=coordfinder] ~ ~ ~" )
        local x, y, z = result[ 1 ]:match( "to (%S+), (%S+), (%S+)" )
        return tonumber( x ), tonumber( y ), tonumber( z )
end

local x, y, z = getPosition()
local oldX, oldZ = x, z
local win = partTerm.createWindow( x, y + 3.5, z, 15, 7)
win.center(false)

local oldTerm = term.redirect( win )
paintutils.drawImage(paintutils.loadImage( "flag" ), 1,1 )
term.redirect(oldTerm)

parallel.waitForAny(
        function()
                while true do
                        local newX, newY, newZ = getPosition()

                        if newX ~= x or newZ ~= z then
                                oldX, oldY, oldZ = x, y, z
                                x, y, z = newX, newY, newZ
                                win.setAngles(partTerm.getHorizontalAngle(oldX, oldZ, x, z))
                                win.reposition( x, y + 3.5, z )
                        elseif newY ~= y then
                                y = newY
                                win.reposition( x, y + 3.5, z )
                        end

                        sleep( 0.5 )
                end
        end,

        partTerm.render )