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diff --git a/graphics/pgf/base/tex/generic/graphdrawing/lua/pgf/gd/routing/NecklaceRouting.lua b/graphics/pgf/base/tex/generic/graphdrawing/lua/pgf/gd/routing/NecklaceRouting.lua
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+-- Copyright 2014 by Till Tantau
+--
+-- This file may be distributed an/or modified
+--
+-- 1. under the LaTeX Project Public License and/or
+-- 2. under the GNU Public License
+--
+-- See the file doc/generic/pgf/licenses/LICENSE for more information
+
+-- @release $Header$
+
+
+-- The class; it processes necklace hints.
+
+local NecklaceRouting = {}
+
+
+-- Namespace
+require("pgf.gd.routing").NecklaceRouting = NecklaceRouting
+
+-- Imports
+local declare = require("pgf.gd.interface.InterfaceToAlgorithms").declare
+
+local Hints = require "pgf.gd.routing.Hints"
+local Path = require "pgf.gd.model.Path"
+
+
+---
+declare {
+ key = "necklace routing",
+ algorithm = NecklaceRouting,
+
+ phase = "edge routing",
+
+ summary = "Bends all edges of a graph that lie on ``necklaces'' along these necklaces.",
+
+ documentation = [["
+ Some graph drawing algorithms lay out some or all nodes along a
+ path, which is then called a \emph{necklace}. For instance, the
+ |simple necklace layout| places all nodes on a circle and that
+ circle is the ``necklace''. When the |necklace routing| edge
+ routing algorithm is selected, all edges that connect subsequent
+ nodes on such a necklace are bend in such a way that the
+ ``follow the necklace path''. In the example case, this will
+ cause all edges that connect adjacent nodes to become arcs on
+ of the circle on which the nodes lie.
+
+ Note that local edge routing options for an edge may overrule
+ the edge routing computed by the algorithm as in the edge from 6
+ to 7 in the example.
+ "]],
+
+ examples = [["
+ \tikz \graph [simple necklace layout, node distance=1.5cm,
+ necklace routing,
+ nodes={draw,circle}, edges={>={Stealth[round,sep,bend]}}]
+ { 1 -> 2 [minimum size=30pt] <- 3 <-> 4 --
+ 5 -- 6 -- [bend left] 7 -- 1 -- 4 };
+ "]]
+}
+
+
+
+-- The implementation
+
+function NecklaceRouting:run()
+ local ugraph = self.ugraph
+
+ for _,entry in ipairs(Hints.getNecklaceHints(ugraph)) do
+ assert (entry.center) -- no other necklace types, yet
+ local prev
+ for _,vertex in ipairs(entry.necklace) do
+ if prev then
+ local a = ugraph:arc(prev, vertex)
+ if a then
+ local p = Path.new()
+ p:appendMoveto(a.tail.pos:clone())
+ p:appendArcTo(a.head.pos:clone(), entry.center, entry.clockwise)
+ a.path = p
+ end
+ end
+ prev = vertex
+ end
+ end
+end
+
+
+-- done
+
+return NecklaceRouting