if _G.rope then
    for k,v in pairs(rope.ActiveRopes) do
        for k,v in pairs(v.points) do
            if v.type == 2 then
                v.obj:SetDieTime(0)
            else
                SafeRemoveEntity(v.ent)
            end
        end
    end
end

rope = {}

rope.ActiveRopes = {}

local tempvec = Vector()
local tempvecn = Vector()
local sqrt = math.sqrt

local x,y,z = 0,0,0
local ox,oy,oz = 0,0,0
local len = 0

local THINKTIME = 0
local DELTA = 1
local SPEED = 100

local function calc(a, b)
    ---local offset = a.obj:GetPos() - b.obj:GetPos()
    --local len = offset:Length()

    local apos = a.obj:GetPos()
    local bpos = b.obj:GetPos()

    local avel = a.obj:GetVelocity()
    local bvel = b.obj:GetVelocity()

    ox = apos.x - bpos.x
    oy = apos.y - bpos.y
    oz = apos.z - bpos.z
    len = (ox*ox) + (oy*oy) + (oz*oz)

    --force = (a.obj:GetVelocity() - b.obj:GetVelocity()) * -200
    x = (avel.x - bvel.x) * -100
    y = (avel.y - bvel.y) * -100
    z = (avel.z - bvel.z) * -100

    if len ~= 0 then
        --force = force + offset:GetNormalized() * (len) * (-7000)
        len = sqrt(len)

        x = x + ((ox / len) * (len) * (-10000) * DELTA)
        y = y + ((oy / len) * (len) * (-10000) * DELTA)
        z = z + ((oz / len) * (len) * (-10000) * DELTA)
    end


    if a.type == 1 then
        x = (x * 0.1 / 100)
        y = (y * 0.1 / 100)
        z = (z * 0.1 / 100)

        tempvec.x = x
        tempvec.y = y
        tempvec.z = z

        tempvecn.x = -x
        tempvecn.y = -y
        tempvecn.z = -z

        a.obj:ApplyForceCenter(tempvec)
        b.obj:ApplyForceCenter(tempvecn) -- does unm create a new vector?????
    elseif a.type == 2 then
        x = (x * 0.1 / 50)
        y = (y * 0.1 / 50)
        z = (z * 0.1 / 50)

        tempvec.x = avel.x + x
        tempvec.y = avel.y + y
        tempvec.z = avel.z + z

        tempvecn.x = bvel.x - x
        tempvecn.y = bvel.y - y
        tempvecn.z = bvel.z - z

        a.obj:SetVelocity(tempvec)
        b.obj:SetVelocity(tempvecn)
    end
end

local a
local b
local vec
local T = 0
local last

function rope.Think()

    DELTA = math.Clamp(FrameTime() * 30, 0, 0.4)

    --local T = SysTime()
    --last = last or T

    --if last < T then

        for key, rope in pairs(rope.ActiveRopes) do
            for i = 2, #rope.points do
                calc(rope.points[i - 1], rope.points[i])
            end
        end

        --DELTA = (T-last) * SPEED
        --last = T + THINKTIME
    --end

    for key, rope in pairs(rope.ActiveRopes) do
        for i, var in pairs(rope.attachments) do
            local point = rope.points[i]

            if point then
                point.obj:SetPos(type(var) == "function" and var() or var)
                point.obj:SetVelocity(vector_origin)
            end
        end
    end
end

local color_white = color_white
local sprite_mat = Material("particle/particle_sphere")

function rope.Draw()
    for key, rope in pairs(rope.ActiveRopes) do
        local count = #rope.points

        render.SetMaterial(rope.mat or sprite_mat)

        render.StartBeam(count)
            for i = 1, count do
                render.AddBeam(rope.points[i].obj:GetPos(), 1, (i/count), color_white)
            end
        render.EndBeam()

        render.SetMaterial(sprite_mat)
    end
end

function rope.Create(points, attachments, mat, ent_type)
    ent_type = ent_type or 2
    points = points or 128
    mat = mat or Material("trails/laser")
    attachments = attachments or {[1] = function() return LocalPlayer():EyePos() end, [#points] = function() return Vector(0,0,0) end}

    local data = {}

    data.mat = mat
    data.points = {}
    data.attachments = attachments

    local pos = select(2, next(attachments))
    pos = type(pos) == "function" and pos() or pos

    for i = 1, points do
        local obj

        if ent_type == 2 then
            rope.emitter = rope.emitter or ParticleEmitter(Vector())
            ent = rope.emitter:Add("particle/snow", pos)
            ent:SetVelocity(VectorRand())
            ent:SetDieTime(1000)
            ent:SetLifeTime(0)
            ent:SetStartSize(0)
            ent:SetEndSize(0)
            ent:SetGravity(physenv.GetGravity())
            ent:SetCollide(true)
            ent:SetAirResistance(100)
        elseif ent_type == 1 then
            ent = ents.CreateClientProp()
            ent:SetCollisionGroup(COLLISION_GROUP_INTERACTIVE_DEBRIS)
            ent:Spawn()
            ent:PhysicsInitSphere(1)


            local phys = ent:GetPhysicsObject()
            phys:SetMass(1)
            phys:SetMaterial("jeeptire")
            phys:SetDamping(0.2, 0)
            phys:EnableGravity(true)
            ent:SetVelocity(VectorRand())

            ent = phys
        end

        ent:SetPos(pos)

        data.points[i] = {
            obj = ent,
            type = ent_type
        }
    end

    data.id = table.insert(rope.ActiveRopes, data)
    data.Remove = function()
        table.remove(rope.ActiveRopes, data.id)
    end

    return data
end

timer.Create("rope", 0, 0, rope.Think)

-- hacky optimization
-- allows only the last draw call

local function setup_suppress()
    local last_framenumber = 0
    local current_frame = 0
    local current_frame_count = 0

    return function()
        local frame_number = FrameNumber()

        if frame_number == last_framenumber then
            current_frame = current_frame + 1
        else
            last_framenumber = frame_number

            if current_frame_count ~= current_frame then
                current_frame_count = current_frame
            end

            current_frame = 1
        end

        return current_frame < current_frame_count
    end
end
-- hacky optimization

local uh = setup_suppress()

hook.Add("PostDrawTranslucentRenderables", "rope", function()
    if uh() then return end
    rope.Think()
    rope.Draw()
end)


local chess = chess
rope.Create(64, {[1] = function() return me:EyePos() end, [64] = function() return chess:EyePos() end}, nil, 1)