how to make a simple esp? [LUA]

local lp    = LocalPlayer ()
local dist  = 3000 * 3000
local col   = Color (0xFF, 0xB6, 0xC1) -- make me outside and use a pretty colour (this is lightpink :D)

hook.Add ('HUDPaint', ('%s e_spshit'):format (tostring {}), function ()

	local lppos = lp:GetPos () -- store localplayer pos as you dont need to get it everytime in a loop

	local plys = player.GetAll ()
	for a = 1, player.GetCount () do -- stop using pairs the table is sequential
		local ply = plys [a]

		if     ply == lp                              then continue end -- no self
		if not ply:Alive  ()                          then continue end -- no garry operators please
		if     ply:GetPos ():DistToSqr (lppos) > dist then continue end -- use disttosqr and dont return

		local pos = (ply:EyePos () + Vector (0, 0, 20)):ToScreen ()

		-- draw is just a buffer for surface, we arent stupid (hopefully) so we just use surface like normal human beings
		surface.SetFont      'Trebuchet18'
		surface.SetTextColor (col         )
		surface.SetTextPos   (pos.x, pos.y)
		surface.DrawText     (('[%s][%s][%s]'):format (ply:Nick (), ply:EntIndex (), ply:GetUserGroup ())) -- format is much cleaner and not as retarded as '..', use a cache and table.concat if u want "fast"
	end
end)