X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fsimple-spacer.cc;h=a9c70489dd060345fd1aa0ed7ac4c92b83b78322;hb=9be810ebcf226f2e5d7445f4e647f13aa0ac29e3;hp=f6052dd08c78cff71dd7b4908a84cd5a595387a3;hpb=d9b43b93f2c885409bafdb157138158f65cc49aa;p=lilypond.git

diff --git a/lily/simple-spacer.cc b/lily/simple-spacer.cc
index f6052dd08c..a9c70489dd 100644
--- a/lily/simple-spacer.cc
+++ b/lily/simple-spacer.cc
@@ -1,33 +1,71 @@
-/*   
+/*
   simple-spacer.cc -- implement Simple_spacer
-  
+
   source file of the GNU LilyPond music typesetter
-  
-  (c) 1999--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+
+  (c) 1999--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   TODO:
   - add support for different stretch/shrink constants?
-  
 */
 
-#include <math.h>
-#include <libc-extension.hh>	// isinf
+#include <cstdio>
 
+#include "libc-extension.hh"	// isinf
 #include "simple-spacer.hh"
 #include "paper-column.hh"
 #include "spring.hh"
-#include "rod.hh"
 #include "warn.hh"
 #include "column-x-positions.hh"
 #include "spaceable-grob.hh"
 #include "dimensions.hh"
 
+/*
+  A simple spacing constraint solver. The approach:
+
+  Stretch the line uniformly until none of the constraints (rods)
+  block.  It then is very wide.
+
+  Compress until the next constraint blocks,
+
+  Mark the springs over the constrained part to be non-active.
+
+  Repeat with the smaller set of non-active constraints, until all
+  constraints blocked, or until the line is as short as desired.
+
+  This is much simpler, and much much faster than full scale
+  Constrained QP. On the other hand, a situation like this will not
+  be typeset as dense as possible, because
+
+  c4                   c4           c4                  c4
+  veryveryverylongsyllable2         veryveryverylongsyllable2
+  " "4                 veryveryverylongsyllable2        syllable4
+
+
+  can be further compressed to
+
+
+  c4    c4                        c4   c4
+  veryveryverylongsyllable2       veryveryverylongsyllable2
+  " "4  veryveryverylongsyllable2      syllable4
+
+
+  Perhaps this is not a bad thing, because the 1st looks better anyway.  */
+
+/*
+  positive force = expanding, negative force = compressing.
+*/
+
 Simple_spacer::Simple_spacer ()
 {
+  /*
+    Give an extra penalty for compression. Needed to avoid compressing
+    tightly spaced lines.
+  */
   active_count_ = 0;
-  force_f_ = 0.;
-  indent_f_ =0.0;
-  default_space_f_ = 20 PT;
+  force_ = 0.;
+  indent_ = 0.0;
+  default_space_ = 20 PT;
 }
 
 void
@@ -35,38 +73,56 @@ Simple_spacer::add_rod (int l, int r, Real dist)
 {
   if (isinf (dist) || isnan (dist))
     {
-      programming_error ("Weird minimum distance. Ignoring");
+      programming_error ("ignoring weird minimum distance");
       return;
     }
-  
-  
-  Real c = range_stiffness (l,r);
-  Real d = range_ideal_len (l,r);
+
+  Real c = range_stiffness (l, r);
+  if (isinf (c))
+    {
+      /*
+	If a spring is fixed, we have to do something here:
+	we let the rod override the spring.
+      */
+      Real total_dist = 0.;
+      for (int i = l; i < r; i++)
+	total_dist += springs_[i].ideal_;
+
+      if (total_dist < dist)
+	for (int i = l; i < r; i++)
+	  springs_[i].ideal_ *= dist / total_dist;
+
+      return;
+    }
+
+  Real d = range_ideal_len (l, r);
   Real block_stretch = dist - d;
-  
+
   Real block_force = c * block_stretch;
-  force_f_ = force_f_ >? block_force;
+  force_ = max (force_, block_force);
 
-  for (int i=l; i < r; i++)
-    springs_[i].block_force_f_ = block_force >?
-      springs_[i].block_force_f_ ;
+  for (int i = l; i < r; i++)
+    springs_[i].block_force_ = max (block_force, springs_[i].block_force_);
 }
 
 Real
-Simple_spacer::range_ideal_len (int l, int r)   const
+Simple_spacer::range_ideal_len (int l, int r) const
 {
-  Real d =0.;
-  for (int i=l; i < r; i++)
-    d += springs_[i].ideal_f_;
+  Real d = 0.;
+  for (int i = l; i < r; i++)
+    d += springs_[i].ideal_;
   return d;
 }
 
 Real
 Simple_spacer::range_stiffness (int l, int r) const
 {
-  Real den =0.0;
-  for (int i=l; i < r; i++)
-    den += 1 / springs_[i].hooke_f_;
+  Real den = 0.0;
+  for (int i = l; i < r; i++)
+    {
+      if (springs_[i].is_active_)
+	den += 1 * springs_[i].inverse_hooke_;
+    }
 
   return 1 / den;
 }
@@ -74,76 +130,80 @@ Simple_spacer::range_stiffness (int l, int r) const
 Real
 Simple_spacer::active_blocking_force () const
 {
-  Real bf = - infinity_f; 
-  for (int i=0; i < springs_.size (); i++)
-    if (springs_[i].active_b_)
-      {
-	bf = bf >? springs_[i].block_force_f_;
-      }
+  Real bf = -infinity_f;
+  for (int i = 0; i < springs_.size (); i++)
+    if (springs_[i].is_active_)
+      bf = max (bf, springs_[i].block_force_);
   return bf;
 }
 
 Real
 Simple_spacer::active_springs_stiffness () const
 {
-  Real den = 0.0;
-  for (int i=0; i < springs_.size (); i++)
-    if (springs_[i].active_b_)
-      {
-	den += 1 / springs_[i].hooke_f_;
-      }
-  return 1/den;
+  Real stiff = range_stiffness (0, springs_.size ());
+  if (isinf (stiff))
+    {
+      /*
+	all springs are inactive. Take the stiffness of the
+	latest spring to block.
+      */
+
+      Real max_block_force = -infinity_f;
+      int max_i = -1;
+      for (int i = 0; i < springs_.size (); i++)
+	{
+	  if (springs_[i].block_force_ > max_block_force)
+	    {
+	      max_i = i;
+	      max_block_force = springs_[i].block_force_;
+	    }
+	}
+
+      stiff = 1/springs_[max_i].inverse_hooke_;
+    }
+  return stiff;
 }
 
 void
 Simple_spacer::set_active_states ()
 {
-  // safe, since
-  // force is only copied.
-  for (int i=0 ; i <springs_.size (); i++)
-    if (springs_[i].active_b_
-	&& springs_[i].block_force_f_ >= force_f_)
+  /* float comparison is safe, since force is only copied.  */
+  for (int i = 0; i < springs_.size (); i++)
+    if (springs_[i].is_active_
+	&& springs_[i].block_force_ >= force_)
       {
-	springs_[i].active_b_ = false;
-	active_count_ --; 
+	springs_[i].is_active_ = false;
+	active_count_--;
       }
-}   
+}
 
 Real
 Simple_spacer::configuration_length () const
 {
-  Real l =0.;
-  for (int i=0; i < springs_.size (); i++)
-    l += springs_[i].length (force_f_);
+  Real l = 0.;
+  for (int i = 0; i < springs_.size (); i++)
+    l += springs_[i].length (force_);
 
   return l;
 }
 
-Real
-Spring_description::length (Real f) const
-{
-  if (!active_b_)
-    f = block_force_f_;
-  return ideal_f_ + f / hooke_f_ ;
-}
-
 bool
-Simple_spacer::active_b () const
+Simple_spacer::is_active () const
 {
-  return active_count_; 
+  return active_count_;
 }
 
 void
 Simple_spacer::my_solve_linelen ()
 {
-  while (active_b ())
+  while (is_active ())
     {
-      force_f_ = active_blocking_force ();
+      force_ = active_blocking_force ();
       Real conf = configuration_length ();
 
-      if (conf < line_len_f_)
+      if (conf < line_len_)
 	{
-	  force_f_ += (line_len_f_  - conf) * active_springs_stiffness ();
+	  force_ += (line_len_ - conf) * active_springs_stiffness ();
 	  break;
 	}
       else
@@ -151,155 +211,240 @@ Simple_spacer::my_solve_linelen ()
     }
 }
 
-
 void
 Simple_spacer::my_solve_natural_len ()
 {
-  while (active_b ())
+  Real line_len_force = 0.0;
+
+  while (is_active ())
     {
-      force_f_ = active_blocking_force () >? 0.0;
+      force_ = max (active_blocking_force (), 0.0);
+      Real conf = configuration_length ();
 
-      if (force_f_ < 1e-8) // ugh.,
+      if (conf < line_len_)
+	{
+	  line_len_force = force_
+	    + (line_len_ - conf)
+	    * active_springs_stiffness ();
+	}
+
+      if (force_ < 1e-8) // ugh.,
 	break;
-      
+
       set_active_states ();
     }
+
+  force_ = line_len_force;
 }
 
-void
-Simple_spacer::add_columns (Link_array<Grob> cols)
+/****************************************************************/
+
+Spring_description::Spring_description ()
 {
-  for (int i =  cols.size (); i--;)
-    if (gh_pair_p (cols[i]->get_grob_property ("between-cols")))
-      {
-	loose_cols_.push (cols[i]);
-	cols.del (i);
-      }
-  
-  spaced_cols_ = cols;
-  for (int i=0; i < cols.size () - 1; i++)
-    {
-      SCM spring_params = SCM_EOL;
-      for (SCM s = cols[i]->get_grob_property ("ideal-distances");
-	   !gh_pair_p (spring_params) && gh_pair_p (s);
-	   s = ly_cdr (s))
-	{
-	  Grob *other = unsmob_grob (ly_caar (s));
-	  if (other != cols[i+1])
-	    continue;
+  ideal_ = 0.0;
+  inverse_hooke_ = 0.0;
+  is_active_ = true;
+  block_force_ = 0.0;
+}
 
-	  spring_params = ly_cdar (s);
-	}
+bool
+Spring_description::is_sane () const
+{
+  return (inverse_hooke_ >= 0)
+    && ideal_ > 0
+    && !isinf (ideal_) && !isnan (ideal_);
+}
 
-      Spring_description desc;
-      if (gh_pair_p (spring_params))
-	{
-	  desc.ideal_f_ = gh_scm2double (ly_car (spring_params));
-	  desc.hooke_f_ = gh_scm2double (ly_cdr (spring_params));
-	}
-      else
-	{
-	  programming_error (_f("No spring between column %d and next one",
-				Paper_column::rank_i (cols[i])
-				));
-	  desc.hooke_f_ = 1.0;
-	  desc.ideal_f_ = default_space_f_;
-	}
+Real
+Spring_description::length (Real f) const
+{
+  if (!is_active_)
+    f = block_force_;
+  return ideal_ + f * inverse_hooke_;
+}
+/****************************************************************/
 
-      if (!desc.sane_b ())
-	{
-	  programming_error ("Insane spring found. Setting to unit spring.");
+/*
+  TODO: should a add penalty for widely varying spring forces (caused
+  by constraints, eg.
 
-	  cout << "columns " << Paper_column::rank_i (cols[i])
-	       << " " << Paper_column::rank_i (cols[i+1]) << endl;
-	  desc.hooke_f_ = 1.0;
-	  desc.ideal_f_ = 1.0;
-	}
-      
-      desc.block_force_f_ = - desc.hooke_f_ * desc.ideal_f_; // block at distance 0
-      springs_.push (desc);
-      active_count_ ++;
-    }
-  
-  for (int i=0; i < cols.size () - 1; i++)
-    {
-      for (SCM s = Spaceable_grob::get_minimum_distances (cols[i]);
-	   gh_pair_p (s); s = ly_cdr (s))
-	{
-	  Grob * other = unsmob_grob (ly_caar (s));
-	  int oi = cols.find_i (other);
-	  if (oi >= 0)
-	    {
-	      add_rod (i, oi, gh_scm2double (ly_cdar (s)));
-	    }
-	}
-    }
 
-  /*
-    TODO: should support natural length on only the last line.
-   */
-  if (line_len_f_ < 0)
-    my_solve_natural_len ();
-  else
-    my_solve_linelen ();
-}
+  .     =====
+  .     |   |
+  .o|o|x ##x
+  .
 
+  The ## forces the notes apart; we shouldn't allow the O's to touch
+  this closely.
+*/
 void
-Simple_spacer::solve (Column_x_positions *positions) const
+Simple_spacer_wrapper::solve (Column_x_positions *positions, bool ragged)
 {
-  positions->force_f_ = force_f_;
-  
-  positions->config_.push (indent_f_);
-  for (int i=0; i <springs_.size (); i++)
+  if (ragged)
+    spacer_->my_solve_natural_len ();
+  else
+    spacer_->my_solve_linelen ();
+
+  positions->force_ = spacer_->force_;
+
+  /*
+    We used to have a penalty for compression, no matter what, but that
+    fucked up wtk1-fugue2 (taking 3 full pages.)
+  */
+  positions->config_.push (spacer_->indent_);
+  for (int i = 0; i < spacer_->springs_.size (); i++)
+    {
+      Real l = spacer_->springs_[i].length ((ragged) ? 0.0 : spacer_->force_);
+      positions->config_.push (positions->config_.top () + l);
+      /*
+	we have l>= 0 here, up to rounding errors
+      */
+    }
+
+  /*
+    For raggedright, we must have a measure of music density: this is
+    to prevent lots of short lines (which all have force = 0).
+  */
+  if (ragged)
     {
-      positions->config_.push (positions->config_.top () + springs_[i].length (force_f_));
+      positions->satisfies_constraints_
+	= positions->config_.top () < spacer_->line_len_;
     }
+  else
+    positions->satisfies_constraints_ = spacer_->is_active ();
+
   positions->cols_ = spaced_cols_;
   positions->loose_cols_ = loose_cols_;
-  
-  positions->satisfies_constraints_b_ = (line_len_f_ < 0) || active_b ();
-
 
   /*
     Check if breaking constraints are met.
-   */
+  */
   bool break_satisfy = true;
-  int sz =  positions->cols_.size ();
-  for (int i = sz; i--; )
+  int sz = positions->cols_.size ();
+  for (int i = sz; i--;)
     {
-      SCM p = positions->cols_[i]->get_grob_property( "penalty");
-      if (gh_number_p (p))
+      SCM p = positions->cols_[i]->get_property ("penalty");
+      if (scm_is_number (p))
 	{
-	  if (gh_scm2double (p) < -9999)
+	  if (scm_to_double (p) < -9999)
 	    break_satisfy = break_satisfy && (i == 0 || i == sz -1);
-	  if (gh_scm2double (p) > 9999)
-	    break_satisfy = break_satisfy && !(i == 0 || i == sz -1);
+	  if (scm_to_double (p) > 9999)
+	    break_satisfy = break_satisfy && ! (i == 0 || i == sz -1);
 	}
-      
     }
 
-  positions->satisfies_constraints_b_ =
-    positions->satisfies_constraints_b_ && break_satisfy;
+  positions->satisfies_constraints_
+    = positions->satisfies_constraints_ && break_satisfy;
 }
 
+void
+Simple_spacer::add_spring (Real ideal, Real inverse_hooke)
+{
+  Spring_description desc;
 
+  desc.ideal_ = ideal;
+  desc.inverse_hooke_ = inverse_hooke;
+  if (!desc.is_sane ())
+    {
+      programming_error ("insane spring found, setting to unit");
 
+      desc.inverse_hooke_ = 1.0;
+      desc.ideal_ = 1.0;
+    }
 
+  if (!inverse_hooke)
+    desc.is_active_ = false;
+  else
+    {
+      /*
+	desc.is_active_ ?
+      */
+      desc.block_force_ = -desc.ideal_ / desc.inverse_hooke_;
+      // block at distance 0
 
+      active_count_++;
+    }
+  springs_.push (desc);
+}
 
-Spring_description::Spring_description ()
+static int
+compare_paper_column_rank (Grob *const &a,
+			   Grob *const &b)
 {
-  ideal_f_ =0.0;
-  hooke_f_ =0.0;
-  active_b_ = true;
-  block_force_f_ = 0.0;
+  return Paper_column::get_rank (a) - Paper_column::get_rank (b);
 }
 
+void
+Simple_spacer_wrapper::add_columns (Link_array<Grob> const &icols)
+{
+  Link_array<Grob> cols (icols);
+  cols.clear ();
 
-bool
-Spring_description::sane_b () const
+  for (int i = 0; i < icols.size (); i++)
+    if (scm_is_pair (icols[i]->get_object ("between-cols")))
+      loose_cols_.push (icols[i]);
+    else
+      cols.push (icols[i]);
+
+  spaced_cols_ = cols;
+  for (int i = 0; i < cols.size () - 1; i++)
+    {
+      Spring_smob *spring = 0;
+
+      for (SCM s = cols[i]->get_object ("ideal-distances");
+	   !spring && scm_is_pair (s);
+	   s = scm_cdr (s))
+	{
+	  Spring_smob *sp = unsmob_spring (scm_car (s));
+
+	  if (sp->other_ == cols[i + 1])
+	    spring = sp;
+	}
+
+      if (!spring)
+	programming_error (_f ("No spring between column %d and next one",
+			       Paper_column::get_rank (cols[i])));
+
+      Real ideal = (spring) ? spring->distance_ : spacer_->default_space_;
+      Real inverse_hooke = (spring) ? spring->inverse_strength_ : 1.0;
+
+      spacer_->add_spring (ideal, inverse_hooke);
+    }
+
+  for (int i = 0; i < cols.size () - 1; i++)
+    {
+      for (SCM s = Spaceable_grob::get_minimum_distances (cols[i]);
+	   scm_is_pair (s); s = scm_cdr (s))
+	{
+	  Grob *other = unsmob_grob (scm_caar (s));
+	  int j = binsearch_links (cols, other, &compare_paper_column_rank);
+	  if (j >= 0 && cols[j] == other)
+	    spacer_->add_rod (i, j, scm_to_double (scm_cdar (s)));
+	}
+
+      if (i
+	  && to_boolean (cols[i]->get_property ("keep-inside-line")))
+	{
+	  Interval e = cols[i]->extent (cols[i], X_AXIS);
+	  if (!e.is_empty ())
+	    {
+	      spacer_->add_rod (i, cols.size () - 1, e[RIGHT]);
+	      spacer_->add_rod (0, i, e[LEFT]);
+	    }
+	}
+    }
+}
+
+Simple_spacer_wrapper::Simple_spacer_wrapper ()
 {
-  return (hooke_f_ > 0) &&  ! isinf (ideal_f_) && !isnan (ideal_f_);
+  spacer_ = new Simple_spacer ();
 }
 
+Simple_spacer_wrapper::~Simple_spacer_wrapper ()
+{
+  delete spacer_;
+}
 
+Simple_spacer_wrapper::Simple_spacer_wrapper (Simple_spacer_wrapper const &)
+{
+}