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--2007 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);
55 break_permission_ = ly_symbol2scm ("allow");
56 page_permission_ = pb->get_property ("page-break-permission");
57 turn_permission_ = pb->get_property ("page-turn-permission");
59 page_penalty_ = robust_scm2double (pb->get_property ("page-break-penalty"), 0);
60 turn_penalty_ = robust_scm2double (pb->get_property ("page-turn-penalty"), 0);
65 Helper to trace back an optimal path
67 struct Constrained_break_node
69 /* the number of bars in all the systems before this one
73 /* unlike the Gourlay breaker, this is the sum of all demerits up to,
74 * and including, this line */
76 struct Line_details details_;
78 Constrained_break_node ()
81 demerits_ = infinity_f;
86 printf ("prev break %d, demerits %f\n", prev_, demerits_);
91 A dynamic programming solution to breaking scores into lines
93 class Constrained_breaking
96 vector<Column_x_positions> solve (vsize start, vsize end, vsize sys_count);
97 vector<Column_x_positions> best_solution (vsize start, vsize end);
98 vector<Line_details> line_details (vsize start, vsize end, vsize sys_count);
100 Constrained_breaking (Paper_score *ps);
101 Constrained_breaking (Paper_score *ps, vector<vsize> const &start_col_posns);
103 int max_system_count (vsize start, vsize end);
104 int min_system_count (vsize start, vsize end);
107 Paper_score *pscore_;
108 vsize valid_systems_;
113 /* the (i,j)th entry is the configuration for breaking between
115 Matrix<Line_details> lines_;
117 /* the [i](j,k)th entry is the score for fitting the first k bars onto the
118 first j systems, starting at the i'th allowed starting column */
119 vector<Matrix<Constrained_break_node> > state_;
121 vector<vsize> start_; /* the columns at which we might be asked to start breaking */
122 vector<vsize> starting_breakpoints_; /* the corresponding index in breaks_ */
125 vector<vsize> breaks_;
128 void resize (vsize systems);
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 */