2 constrained-breaking.hh -- declare a line breaker that
3 supports limits on the number of systems
5 source file of the GNU LilyPond music typesetter
7 (c) 2006 Joe Neeman <joeneeman@gmail.com>
10 #ifndef CONSTRAINED_BREAKING_HH
11 #define CONSTRAINED_BREAKING_HH
13 #include "lily-guile.hh"
19 Interval extent_; /* Y-extent of the system */
20 Real padding_; /* compulsory space after this system (if we're not last on a page) */
22 Real space_; /* spring length */
25 SCM break_permission_;
39 break_permission_ = ly_symbol2scm ("allow");
40 page_permission_ = ly_symbol2scm ("allow");
41 turn_permission_ = ly_symbol2scm ("allow");
47 Line_details (Prob *pb)
50 extent_ = unsmob_stencil (pb->get_property ("stencil")) ->extent (Y_AXIS);
54 break_permission_ = ly_symbol2scm ("allow");
55 page_permission_ = pb->get_property ("page-break-permission");
56 turn_permission_ = pb->get_property ("page-turn-permission");
58 page_penalty_ = robust_scm2double (pb->get_property ("page-break-penalty"), 0);
59 turn_penalty_ = robust_scm2double (pb->get_property ("page-turn-penalty"), 0);
64 Helper to trace back an optimal path
66 struct Constrained_break_node
68 /* the number of bars in all the systems before this one
72 /* unlike the Gourlay breaker, this is the sum of all demerits up to,
73 * and including, this line */
75 struct Line_details details_;
77 Constrained_break_node ()
80 demerits_ = infinity_f;
85 printf ("prev break %d, demerits %f\n", prev_, demerits_);
90 A dynamic programming solution to breaking scores into lines
92 class Constrained_breaking
95 vector<Column_x_positions> solve ();
96 Constrained_breaking (Paper_score *ps);
97 Constrained_breaking (Paper_score *ps, vector<vsize> const &start_col_posns);
99 vector<Column_x_positions> get_solution (vsize start, vsize end, vsize sys_count);
100 vector<Column_x_positions> get_best_solution (vsize start, vsize end);
101 vector<Line_details> get_details (vsize start, vsize end, vsize sys_count);
102 int get_max_systems (vsize start, vsize end);
103 int get_min_systems (vsize start, vsize end);
105 void resize (vsize systems);
108 Paper_score *pscore_;
109 vsize valid_systems_;
114 /* the (i,j)th entry is the configuration for breaking between
116 Matrix<Line_details> lines_;
118 /* the [i](j,k)th entry is the score for fitting the first k bars onto the
119 first j systems, starting at the i'th allowed starting column */
120 vector<Matrix<Constrained_break_node> > state_;
122 vector<vsize> start_; /* the columns at which we might be asked to start breaking */
123 vector<vsize> starting_breakpoints_; /* the corresponding index in breaks_ */
126 vector<vsize> breaks_;
130 Column_x_positions space_line (vsize start_col, vsize end_col);
131 vsize prepare_solution (vsize start, vsize end, vsize sys_count);
133 Real combine_demerits (Real force, Real prev_force);
135 bool calc_subproblem(vsize start, vsize systems, vsize max_break_index);
137 #endif /* CONSTRAINED_BREAKING_HH */