flower/include/direction.hh

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #ifndef DIRECTION_HH
  21 #define DIRECTION_HH
  22
  23 #include "axis.hh"
  24
  25 enum Direction
  26   {
  27     UP = 1,
  28     DOWN=-1,
  29     LEFT=-1,
  30     RIGHT = 1,
  31     MIN=-1,
  32     MAX = 1,
  33     CENTER = 0,
  34     SMALLER=-1,
  35     BIGGER = 1,
  36     START = -1,
  37     STOP = 1,
  38
  39     /*
  40       This is necessary to safely write loops,
  41       since
  42
  43       dir <= RIGHT
  44
  45       is otherwise transformed into true unconditionally.
  46     */
  47     DIRECTION_LIMIT = 2,
  48     DIRECTION_NEG_LIMIT = -2,
  49   };
  50
  51 inline Direction
  52 other_dir (Direction const d)
  53 {
  54   return (Direction) (-d);
  55 }
  56
  57 inline Direction
  58 operator - (Direction const d)
  59 {
  60   return other_dir (d);
  61 }
  62
  63 // huh?
  64 inline Direction
  65 flip (Direction *i)
  66 {
  67   if (*i == (Direction)1)
  68     *i = (Direction) - 1;
  69   else if (*i == (Direction) - 1)
  70     *i = (Direction)1;
  71   return *i;
  72 }
  73
  74 /**
  75    if d > 0: the max operator
  76    if d < 0: the min operator
  77 */
  78 template<class T> T minmax (Direction d, T, T);
  79
  80 // String direction_string (Direction, Axis);
  81
  82 #endif // DIRECTION_HH