2 gourlay-breaking.cc -- implement Gourlay_breaking
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
9 #include "gourlay-breaking.hh"
10 #include "column-x-positions.hh"
12 #include "paper-column.hh"
13 #include "paper-score.hh"
14 #include "paper-def.hh"
15 #include "simple-spacer.hh"
17 #include "killing-cons.tcc"
19 /// How often to print operator pacification marks?
20 const int HAPPY_DOTS_I = 3;
23 Helper to trace back an optimal path
26 /** this was the previous. If negative, this break should not be
27 considered: this path has infinite energy
32 Which system number so far?
37 Column_x_positions line_config_;
48 This algorithms is adapted from the OSU Tech report on breaking lines.
50 Array<Column_x_positions>
51 Gourlay_breaking::do_solve () const
53 Array<Break_node> optimal_paths;
54 Line_of_cols all = pscore_l_->col_l_arr_ ;
55 Array<int> breaks = find_break_indices ();
57 optimal_paths.set_size (breaks.size ());
59 Break_node first_node ;
60 first_node.line_config_.energy_f_ = 0;
62 optimal_paths[0] = first_node;
65 for (; break_idx< breaks.size (); break_idx++)
68 start with a short line, add measures. At some point
69 the line becomes infeasible. Then we don't try to add more
71 int minimal_start_idx = -1;
72 Column_x_positions minimal_sol;
73 Column_x_positions backup_sol;
75 Real minimal_demerits = infinity_f;
77 for (int start_idx = break_idx; start_idx--;)
79 Line_of_cols line = all.slice (breaks[start_idx], breaks[break_idx]+1);
81 line[0] = dynamic_cast<Paper_column*>(line[0]->find_broken_piece (RIGHT));
82 line.top () = dynamic_cast<Paper_column*>(line.top ()->find_broken_piece (LEFT));
84 Column_x_positions cp;
88 = pscore_l_->paper_l_->line_dimensions_int (optimal_paths[start_idx].line_i_);
89 Simple_spacer * sp = generate_spacing_problem (line, line_dims);
93 if (start_idx == break_idx - 1)
94 backup_sol = cp; // in case everything fucks up
95 if (!cp.satisfies_constraints_b_)
100 if (optimal_paths[start_idx].demerits_f_ >= infinity_f)
101 this_demerits = infinity_f;
103 this_demerits = combine_demerits (optimal_paths[start_idx].line_config_, cp)
104 + optimal_paths[start_idx].demerits_f_;
106 if (this_demerits < minimal_demerits)
108 minimal_start_idx = start_idx;
110 minimal_demerits = this_demerits;
114 int prev =break_idx - 1;
115 if (minimal_start_idx < 0)
117 optimal_paths[break_idx].demerits_f_ = infinity_f;
118 optimal_paths[break_idx].line_config_ = backup_sol;
122 prev = minimal_start_idx;
123 optimal_paths[break_idx].line_config_ = minimal_sol;
124 optimal_paths[break_idx].demerits_f_ = minimal_demerits;
126 optimal_paths[break_idx].prev_break_i_ = prev;
127 optimal_paths[break_idx].line_i_ = optimal_paths[prev].line_i_ + 1;
129 if (! (break_idx % HAPPY_DOTS_I))
130 *mlog << "[" << break_idx << "]" << flush;
133 /* do the last one */
134 if (break_idx % HAPPY_DOTS_I)
135 *mlog << "[" << break_idx << "]";
139 Array<int> final_breaks;
140 Array<Column_x_positions> lines;
142 /* skip 0-th element, since it is a "dummy" elt*/
143 for (int i = optimal_paths.size ()-1; i> 0;)
145 final_breaks.push (i);
146 int prev = optimal_paths[i].prev_break_i_;
151 if (optimal_paths.top ().demerits_f_ >= infinity_f)
152 warning (_ ("No feasible line breaking found"));
154 for (int i= final_breaks.size (); i--;)
155 lines.push (optimal_paths[final_breaks[i]].line_config_);
161 Gourlay_breaking::Gourlay_breaking ()
163 energy_bound_f_ = infinity_f;
164 max_measures_i_ = INT_MAX;
168 Gourlay_breaking::do_set_pscore ()
170 max_measures_i_ =int (rint (pscore_l_->paper_l_->get_var ("gourlay_maxmeasures")));
175 TODO: uniformity parameter to control rel. importance of spacing differences.
178 Gourlay_breaking::combine_demerits (Column_x_positions const &prev,
179 Column_x_positions const &this_one) const
181 Real break_penalties = 0.0;
182 Paper_column * pc = this_one.cols_.top ();
185 SCM pen = pc->get_elt_property (penalty_scm_sym);
186 if (pen != SCM_BOOL_F)
188 break_penalties += gh_scm2double (SCM_CDR(pen));
192 return abs (this_one.force_f_) + abs (prev.force_f_ - this_one.force_f_)