--[[local t = tonumber(minetest.get_meta(pos):get_string("cart_touring_velocity")) 
  if not t then t=0 end
  t = 0
  if t>0 then
    local vx=math.abs(self.velocity.x)
    local vy=math.abs(self.velocity.y)
    local vz=math.abs(self.velocity.z)
    -- make v the largest of the 3 velocities
    local v=vx
    if vy>v then v=vy end
    if vz>v then v=vz end
    --
    local diff=0
    local acelordecl=0
    if v>t then
      diff=v-t
      acelordecl=-1
    elseif v<t then
      diff=t-v
      acelordecl=1
    end --v>t
    --minetest.log("action", "    on_step t1 v="..v.." t="..t.." diff="..diff.." a="..a.." acelordecl="..acelordecl)
    --adjust for grav
    if self.velocity.y<0 then --going downhill so grav will acel by extra 0.13
      --if we are decel then add an extra 0.13 to how much we need to decel
      --if we are accel then subtract an extra 0.13 from how much we need to acel
      diff=diff-(0.13*acelordecl)
    elseif self.velocity.y>0 then --going uphill grav will decl by extra 0.10
      --if we are decel then subtract 0.1 from how much we need to decel
      --if we are acel then add 0.1 to how much we need to acel
      diff=diff+(0.1*acelordecl)
    end -- self.velocity.y<0
    --so now diff is the difference between cart velocity (after this turns grav)
    --and our target touring velocity
    --minetest.log("action", "*!* on_step t2 grav v="..v.." diff="..diff.." a="..a)
    if diff<a then  --we dont want to over acel or decel
      a=diff
    elseif diff>a*4 then
      a=a*2 --if big difference, play catchup fast!
    elseif diff>a*3 then
      a=a*1.5  --if big difference, play catchup fast!
    end --diff<a
    a=a*acelordecl
  end -- if t>0--]]





--[[minetest.register_node("carts:rail_tour", {
    description = "Touring Rail",
    drawtype = "raillike",
    tiles = {"carts_rail_tour.png", "carts_rail_curved_tour.png", "carts_rail_t_junction_tour.png", "carts_rail_crossing_tour.png"},
    inventory_image = "carts_rail_tour.png",
    wield_image = "carts_rail_tour.png",
    paramtype = "light",
    sunlight_propagates = true,
    is_ground_content = true,
    walkable = false,
    selection_box = {
	type = "fixed",
	fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2},
    },
    groups = {bendy = 2, snappy = 1, dig_immediate = 2,  rail = 1, connect_to_raillike = 1},

    after_place_node = function(pos, placer, itemstack)
	if not mesecon then
	    minetest.get_meta(pos):set_string("cart_acceleration", "0.5")
	    minetest.get_meta(pos):set_string("cart_touring_velocity", cart.TARGET_TOUR_V)
	end
    end,

    mesecons = {
	effector = {
	    action_on = function(pos, node)
		minetest.get_meta(pos):set_string("cart_acceleration", "0.5")
	    end,

	    action_off = function(pos, node)
		minetest.get_meta(pos):set_string("cart_acceleration", "0")
	    end,
	},
    },
})
--]]
--[[minetest.register_craft({
	type = "shapeless",
	output = "carts:rail_tour",
	recipe = {"group:rail", "default:clay_lump"},
})--]]
--minetest.register_alias("carts:tourrail", "carts:rail_tour")




-- temporary
--[[minetest.register_abm({
	nodes = {"group:rail"},
	func = function(pos)
		local name = minetest.get_node(pos).name
		minetest.remove_node(pos)
		minetest.place_node(pos,{name = name})
	end
})--]]