NL Bullettracer (LWv4)

local eye_pos1 = {}
client.add_callback(
    "on_shot",
    function(shot)
        if shot.result ~= nil then
            eye_pos = entitylist.get_local_player():get_origin()
            eye_pos1[#eye_pos1 + 1] = {p_x = eye_pos.x, p_y = eye_pos.y, p_z = eye_pos.z + offset, a = 255}
        end
    end
)
events.register_event(
    "bullet_impact",
    function(e)
        if engine.get_player_for_user_id(e:get_int("userid")) == engine.get_local_player_index() then
            bullet_x, bullet_y, bullet_z = e:get_float("x"), e:get_float("y"), e:get_float("z")
        end
    end
)

local function trace()
    if entitylist.get_local_player() == nil then
        return
    end
    offset = entitylist.get_local_player():get_prop_float("CBasePlayer", "m_vecViewOffset[2]")

    for i, b in pairs(eye_pos1) do
        if b.a > 0 then
            b.a = b.a - 1
            local p2s = render.world_to_screen(vector.new(b.p_x, b.p_y, b.p_z))
            local w2s = render.world_to_screen(vector.new(bullet_x, bullet_y, bullet_z))
            if w2s.x == 0 and w2s.y == 0 then
                goto continue
            end
            if p2s.x == 0 and p2s.y == 0 then
                goto continue
            end
            render.draw_line(p2s.x, p2s.y, w2s.x, w2s.y, color.new(179, 255, 0, b.a))
            ::continue::
        else
            eye_pos1[i] = nil
        end
    end
end
client.add_callback("on_paint", trace)