summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/model/Edge.lua
diff options
context:
space:
mode:
Diffstat (limited to 'Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/model/Edge.lua')
-rw-r--r--Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/model/Edge.lua205
1 files changed, 205 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/model/Edge.lua b/Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/model/Edge.lua
new file mode 100644
index 00000000000..a91979d0ad5
--- /dev/null
+++ b/Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/model/Edge.lua
@@ -0,0 +1,205 @@
+-- Copyright 2012 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: /cvsroot/pgf/pgf/generic/pgf/graphdrawing/lua/pgf/gd/model/Edge.lua,v 1.6 2013/12/20 14:44:47 tantau Exp $
+
+
+---
+-- An |Edge| is a ``syntactic'' connection between two
+-- vertices that represents a connection present in the syntactic
+-- digraph. Unlike an |Arc|, |Edge| objects are not controlled by the
+-- |Digraph| class. Also unlike |Arc| objects, there can be several
+-- edges betwen the same vertices, namely whenever several such edges
+-- are present in the syntactic digraph.
+--
+-- In detail, the relationship between arcs and edges is as follows:
+-- If there is an |Edge| between two vertices $u$ and $v$ in the
+-- syntactic digraph, there will be an |Arc| from $u$ to $v$ and the
+-- array |syntactic_edges| of this |Arc| object will contain the
+-- |Edge| object. In particular, if there are several edges between
+-- the same vertices, all of these edges will be part of the array in
+-- a single |Arc| object.
+--
+-- Edges, like arcs, are always directed from a |tail| vertex to a
+-- |head| vertex; this is true even for undirected vertices. The
+-- |tail| vertex will always be the vertex that came first in the
+-- syntactic specification of the edge, the |head| vertex is the
+-- second one. Whether
+-- an edge is directed or not depends on the |direction| of the edge, which
+-- may be one of the following:
+--
+-- \begin{enumerate}
+-- \item |"->"|
+-- \item |"--"|
+-- \item |"<-"|
+-- \item |"<->"|
+-- \item |"-!-"|
+-- \end{enumerate}
+--
+--
+-- @field head The head vertex of this edge.
+--
+-- @field tail The tail vertex of this edge.
+--
+-- @field event The creation |Event| of this edge.
+--
+-- @field options A table of options that contains user-defined options.
+--
+-- @field direction One of the directions named above.
+--
+-- @field path A |Path| object that describes the path of the
+-- edge. The path's coordinates are interpreted \emph{absolutely}.
+--
+-- @field generated_options This is an options array that is generated
+-- by the algorithm. When the edge is rendered later on, this array
+-- will be passed back to the display layer. The syntax is the same as
+-- for the |declare_parameter_sequence| function, see
+-- |InterfaceToAlgorithms|.
+
+local Edge = {}
+Edge.__index = Edge
+
+
+-- Namespace
+
+require("pgf.gd.model").Edge = Edge
+
+
+-- Imports
+
+local Path = require "pgf.gd.model.Path"
+
+
+---
+-- Create a new edge. The |initial| parameter allows you to setup
+-- some initial values.
+--
+-- @usage
+--\begin{codeexample}[code only, tikz syntax=false]
+--local v = Edge.new { tail = v1, head = v2 }
+--\end{codeexample}
+--
+-- @param initial Values to override defaults. --
+-- @return A new edge object.
+--
+function Edge.new(values)
+ local new = {}
+ for k,v in pairs(values) do
+ new[k] = v
+ end
+ new.generated_options = new.generated_options or {}
+ if not new.path then
+ local p = Path.new ()
+ p:appendMoveto(Edge.tailAnchorForEdgePath(new))
+ p:appendLineto(Edge.headAnchorForEdgePath(new))
+ new.path = p
+ end
+
+ return setmetatable(new, Edge)
+end
+
+
+
+
+---
+-- This method returns a ``coordinate factory'' that can be used as
+-- the coordinate of a |moveto| at the beginning of a path starting at
+-- the |tail| of the arc. Suppose you want to create a path starting
+-- at the tail vertex, going to the coordinate $(10,10)$ and ending at
+-- the head vertex. The trouble is that when you create the path
+-- corresponding to this route, you typically do not know where the
+-- tail vertex is going to be. In this case, you use this
+-- method to get a function that will, later on, compute the correct
+-- position of the anchor as needed.
+--
+-- Note that you typically do not use this function, but use the
+-- corresponding function of the |Arc| class. Use this function only
+-- if there are multiple edges between two vertices that need to be
+-- routed differently.
+--
+-- Here is the code you would use to create the abovementioned path:
+--
+--\begin{codeexample}[code only, tikz syntax=false]
+--local a = g:connect(tail,head)
+--local e = a.syntactic_edges[1]
+--...
+--e.path = Path.new()
+--e.path:appendMoveto(e:tailAnchorForEdgePath())
+--e.path:appendLineto(10, 10)
+--e.path:appendLineto(e:headAnchorForEdgePath())
+--\end{codeexample}
+--
+-- As for the |Arc| class, you can also setup a polyline more easily:
+--
+--\begin{codeexample}[code only, tikz syntax=false]
+--e:setPolylinePath { Coordinate.new (10, 10) }
+--\end{codeexample}
+
+function Edge:tailAnchorForEdgePath()
+ return function ()
+ local a = self.options['tail anchor']
+ if a == "" then
+ a = "center"
+ end
+ return self.tail:anchor(a) + self.tail.pos
+ end
+end
+
+---
+-- See |Arc:tailAnchorForArcPath|.
+
+function Edge:headAnchorForEdgePath()
+ return function ()
+ local a = self.options['head anchor']
+ if a == "" then
+ a = "center"
+ end
+ return self.head:anchor(a) + self.head.pos
+ end
+end
+
+
+
+---
+-- Setup the |path| field of an edge in such a way that it corresponds
+-- to a sequence of straight line segments starting at the tail's
+-- anchor and ending at the head's anchor.
+--
+-- @param coordinates An array of |Coordinates| through which the line
+-- will go through.
+
+function Edge:setPolylinePath(coordinates)
+ local p = Path.new ()
+
+ p:appendMoveto(self:tailAnchorForEdgePath())
+
+ for _,c in ipairs(coordinates) do
+ p:appendLineto(c)
+ end
+
+ p:appendLineto(self:headAnchorForEdgePath())
+
+ self.path = p
+end
+
+
+
+--
+-- Returns a string representation of an edge. This is mainly for debugging.
+--
+-- @return The Edge as a string.
+--
+function Edge:__tostring()
+ return tostring(self.tail) .. self.direction .. tostring(self.head)
+end
+
+
+-- Done
+
+return Edge \ No newline at end of file