manual/connector.tex

   1 \chapter{Module connector}
   2 \label{connector}
   3
   4 This module provides classes for connecting two \verb|box|-instances with
   5 lines, arcs or curves.
   6 All constructors of the following connector-classes take two
   7 \verb|box|-instances as first arguments. They return a
   8 \verb|normpath|-instance from the first to the second box, starting/ending at
   9 the boxes' outline \verb|path|. The behaviour of the path is determined by the
  10 boxes' center and some angle- and distance-keywords. The resulting path will
  11 additionally be shortened by lengths given in the \verb|boxdists|-keyword (a
  12 list of two lengths, default \verb|[0,0]|).
  13
  14 \section{Class line}
  15
  16 The constructor of the \verb|line| class accepts only boxes and the
  17 \verb|boxdists|-keyword.
  18
  19 \section{Class arc}
  20
  21 The constructor also takes either the \verb|relangle|-keyword or a combination
  22 of \verb|relbulge| and \verb|absbulge|. The ``bulge'' is the greatest distance
  23 between the connecting arc and the straight connecting line.
  24 (Default: \verb|relangle=45|, \verb|relbulge=None|,
  25 \verb|absbulge=None|)\medskip
  26
  27 Note that the bulge-keywords override the angle-keyword. When both
  28 \verb|relbulge| and \verb|absbulge| are given they will be added.
  29
  30 \section{Class curve}
  31
  32 The constructor takes both angle- and bulge-keywords. Here, the bulges are
  33 used as distances between bezier-curve control points:\medskip
  34
  35 \verb|absangle1| or \verb|relangle1|\\
  36 \verb|absangle2| or \verb|relangle2|, where the absolute angle overrides the
  37 relative if both are given. (Default: \verb|relangle1=45|,
  38 \verb|relangle2=45|, \verb|absangle1=None|, \verb|absangle2=None|)\medskip
  39
  40 \verb|absbulge| and \verb|relbulge|, where they will be added if both are
  41 given.\\ (Default: \verb|absbulge|=None, \verb|relbulge|=0.39; these default
  42 values produce output similar to the defaults of the arc-class.)\medskip
  43
  44
  45 Note that relative angle-keywords are counted in the following way:
  46 \verb|relangle1| is counted in negative direction, starting at the straight
  47 connector line, and \verb|relangle2| is counted in positive direction.
  48 Therefore, the outcome with two positive relative angles will always leave the
  49 straight connector at its left and will not cross it.
  50
  51 \section{Class twolines}
  52
  53 This class returns two connected straight lines. There is a vast variety of
  54 combinations for angle- and length-keywords. The user has to make sure to
  55 provide a non-ambiguous set of keywords:\medskip
  56
  57 \verb|absangle1| or \verb|relangle1| for the first angle,\\
  58 \verb|relangleM| for the middle angle and\\
  59 \verb|absangle2| or \verb|relangle2| for the ending angle.
  60 Again, the absolute angle overrides the relative if both are given. (Default:
  61 all five angles are \verb|None|)\medskip
  62
  63 \verb|length1| and \verb|length2| for the lengths of the connecting lines.
  64 (Default: \verb|None|)
  65