/*
- spring.cc -- declare Spring
+ This file is part of LilyPond, the GNU music typesetter.
- source file of the GNU LilyPond music typesetter
+ Copyright (C) 2007--2010 Joe Neeman <joeneeman@gmail.com>
- (c) 2007--2009 Joe Neeman <joeneeman@gmail.com>
+ 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 "spring.hh"
{
distance_ = 1.0;
min_distance_ = 1.0;
+ inverse_stretch_strength_ = 1.0;
+ inverse_compress_strength_ = 1.0;
set_distance (dist);
set_min_distance (min_dist);
blocking_force_ = (min_distance_ - distance_) / inverse_compress_strength_;
// If the spring is fixed, it's not clear what the natural value
- // of blocking_force_ would be. -infinity_f works fine for now.
+ // of blocking_force_ would be (because it always blocks).
+ // -infinity_f works fine for now.
+ // If inverse_stretch_strength > 0, the spring is not fixed (because it can stretch).
if (isnan (blocking_force_) || blocking_force_ == infinity_f)
- blocking_force_ = -infinity_f;
+ blocking_force_ = (inverse_stretch_strength_ > 0) ? 0.0 : -infinity_f;
if (blocking_force_ >= 0)
inverse_compress_strength_ = 0;
void
Spring::set_default_strength ()
+{
+ set_default_stretch_strength ();
+ set_default_compress_strength ();
+}
+
+void
+Spring::set_default_compress_strength ()
{
inverse_compress_strength_ = (distance_ >= min_distance_) ? distance_ - min_distance_ : 0;
- inverse_stretch_strength_ = distance_;
update_blocking_force ();
}
+void
+Spring::set_default_stretch_strength ()
+{
+ inverse_stretch_strength_ = distance_;
+}
+
Real
Spring::length (Real f) const
{