X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=flower%2Finclude%2Fdirection.hh;h=0d36c0f7c7cca5ff25fb0a41f6917f52e1d01a83;hb=07320557cd246fd3f4837f15b4f80b098f048981;hp=5cce076c0fe8d55c7acfe6c1a828ed11b5b30e96;hpb=fd7e615444cf58b38283a59b56d3457c07778397;p=lilypond.git

diff --git a/flower/include/direction.hh b/flower/include/direction.hh
index 5cce076c0f..0d36c0f7c7 100644
--- a/flower/include/direction.hh
+++ b/flower/include/direction.hh
@@ -1,60 +1,79 @@
 /*
-  direction.hh -- declare Direction
+  This file is part of LilyPond, the GNU music typesetter.
 
-  source file of the GNU LilyPond music typesetter
+  Copyright (C) 1997--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
-  (c)  1997--1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
-*/
+  LilyPond is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  LilyPond is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
 
+  You should have received a copy of the GNU General Public License
+  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
+*/
 
 #ifndef DIRECTION_HH
 #define DIRECTION_HH
 
-#include "axes.hh"
+#include <algorithm>
+#include "axis.hh"
 
-enum Direction 
+enum Direction
 {
-  UP=1,
-  DOWN=-1,
-  LEFT=-1,
-  RIGHT=1,
-  MIN=-1,
-  MAX=1,
-  CENTER=0,
-  SMALLER=-1,
-  BIGGER=1,
+  UP = 1,
+  DOWN = -1,
+  LEFT = -1,
+  RIGHT = 1,
+  MIN = -1,
+  MAX = 1,
+  CENTER = 0,
+  SMALLER = -1,
+  BIGGER = 1,
   START = -1,
   STOP = 1,
+
+  /*
+    This is necessary to safely write loops,
+    since
+
+    dir <= RIGHT
+
+    is otherwise transformed into true unconditionally.
+  */
+  DIRECTION_LIMIT = 2,
+  DIRECTION_NEG_LIMIT = -2,
 };
 
 inline Direction
-other_dir (Direction const d)
+operator - (Direction d)
 {
-  return (Direction)(-d);
+  return Direction (- static_cast<int> (d)); // cast avoids recursion
 }
 
-inline Direction
-operator - (Direction const d)
-{
-  return other_dir (d);
-}
+#define UP_and_DOWN(d) \
+  Direction d = UP; d != CENTER; d = (d == UP ? DOWN : CENTER)
 
-// huh?
-inline Direction
-flip (Direction *i) {
-  if (*i == (Direction)1)
-    *i = (Direction)-1;
-  else if (*i == (Direction)-1)
-    *i = (Direction)1;
-  return *i;
-}
+#define DOWN_and_UP(d) \
+  Direction d = DOWN; d != CENTER; d = (d == DOWN ? UP : CENTER)
+
+#define LEFT_and_RIGHT(d) \
+  Direction d = LEFT; d != CENTER; d = (d == LEFT ? RIGHT : CENTER)
 
 /**
    if d > 0: the max operator
    if d < 0: the min operator
- */
-template<class T> T minmax (Direction d, T, T);
-
-// String direction_str (Direction, Axis);
+*/
+template<class T> T minmax (Direction d, T a, T b)
+{
+  if (d == UP)
+    return max (a, b);
+  else
+    return min (a, b);
+}
 
 #endif // DIRECTION_HH