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[lilypond.git] / lily / bezier.cc

diff --git a/lily/bezier.cc b/lily/bezier.cc
index b9044063baffa5d494aab1b3d8cec59eecf7a552..9a8d5ab87925d6bfe9666b7479eb15e133f5b848 100644 (file)
--- a/lily/bezier.cc
+++ b/lily/bezier.cc
@@ -1,9 +1,20 @@
 /*
-  bezier.cc -- implement Bezier and Bezier_bow
+  This file is part of LilyPond, the GNU music typesetter.
 
-  source file of the GNU LilyPond music typesetter
+  Copyright (C) 1998--2010 Jan Nieuwenhuizen <janneke@gnu.org>
 
-  (c) 1998--2009 Jan Nieuwenhuizen <janneke@gnu.org>
+  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/>.
 */
 
 #include "bezier.hh"
@@ -272,7 +283,7 @@ Bezier::reverse ()
   using deCasteljau's algorithm.
 */
 void
-Bezier::subdivide (Real t, Bezier &left_part, Bezier &right_part)
+Bezier::subdivide (Real t, Bezier *left_part, Bezier *right_part) const
 {
   Offset p[CONTROL_COUNT][CONTROL_COUNT];
 
@@ -283,8 +294,8 @@ Bezier::subdivide (Real t, Bezier &left_part, Bezier &right_part)
     p[i][j] = p[i][j+1] + t * (p[i+1][j+1] - p[i][j+1]);
   for (int i = 0; i < CONTROL_COUNT; i++)
     {
-      left_part.control_[i]=p[0][CONTROL_COUNT - 1 - i];
-      right_part.control_[i]=p[i][i];
+      left_part->control_[i]=p[0][CONTROL_COUNT - 1 - i];
+      right_part->control_[i]=p[i][i];
     }
 }
 
@@ -293,25 +304,24 @@ Bezier::subdivide (Real t, Bezier &left_part, Bezier &right_part)
 */
 
 Bezier
-Bezier::extract (Real t_min, Real t_max)
+Bezier::extract (Real t_min, Real t_max) const
 {
+  if ((t_min < 0) || (t_max) > 1)
+    programming_error
+      ("bezier extract arguments outside of limits: curve may have bad shape");
+  if (t_min >= t_max)
+    programming_error 
+      ("lower bezier extract value not less than upper value: curve may have bad shape");
   Bezier bez1, bez2, bez3, bez4;
   if (t_min == 0.0)
-    {
-      for (int i = 0; i < CONTROL_COUNT; i++)
-        bez2.control_[i] = control_[i];
-    }
+    bez2 = *this;
   else
-    {
-      subdivide (t_min, bez1, bez2);
-    }
+      subdivide (t_min, &bez1, &bez2);
   if (t_max == 1.0)
-    {
       return bez2;
-    }
   else
    {
-     bez2.subdivide ((t_max-t_min)/(1-t_min), bez3, bez4);
+     bez2.subdivide ((t_max-t_min)/(1-t_min), &bez3, &bez4);
      return bez3;
   }
 }