flower/include/direction.hh

   1 /*
   2   direction.hh -- declare Direction
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #ifndef DIRECTION_HH
  10 #define DIRECTION_HH
  11
  12 #include "axis.hh"
  13
  14 enum Direction
  15   {
  16     UP = 1,
  17     DOWN=-1,
  18     LEFT=-1,
  19     RIGHT = 1,
  20     MIN=-1,
  21     MAX = 1,
  22     CENTER = 0,
  23     SMALLER=-1,
  24     BIGGER = 1,
  25     START = -1,
  26     STOP = 1,
  27
  28     /*
  29       This is necessary to safely write loops,
  30       since
  31
  32       dir <= RIGHT
  33
  34       is otherwise transformed into true unconditionally.
  35     */
  36     DIRECTION_LIMIT = 2,
  37     DIRECTION_NEG_LIMIT = -2,
  38   };
  39
  40 inline Direction
  41 other_dir (Direction const d)
  42 {
  43   return (Direction) (-d);
  44 }
  45
  46 inline Direction
  47 operator - (Direction const d)
  48 {
  49   return other_dir (d);
  50 }
  51
  52 // huh?
  53 inline Direction
  54 flip (Direction *i)
  55 {
  56   if (*i == (Direction)1)
  57     *i = (Direction) - 1;
  58   else if (*i == (Direction) - 1)
  59     *i = (Direction)1;
  60   return *i;
  61 }
  62
  63 /**
  64    if d > 0: the max operator
  65    if d < 0: the min operator
  66 */
  67 template<class T> T minmax (Direction d, T, T);
  68
  69 // String direction_string (Direction, Axis);
  70
  71 #endif // DIRECTION_HH