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--2008 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 */
21 Real padding_; /* compulsory space after this system (if we're not
24 Real space_; /* spring length */
27 SCM break_permission_;
43 break_permission_ = ly_symbol2scm ("allow");
44 page_permission_ = ly_symbol2scm ("allow");
45 turn_permission_ = ly_symbol2scm ("allow");
52 Line_details (Prob *pb)
55 extent_ = unsmob_stencil (pb->get_property ("stencil")) ->extent (Y_AXIS);
56 padding_ = robust_scm2double (pb->get_property ("next-padding"), 0);
58 space_ = robust_scm2double (pb->get_property ("next-space"), 1.0);
60 break_permission_ = ly_symbol2scm ("allow");
61 page_permission_ = pb->get_property ("page-break-permission");
62 turn_permission_ = pb->get_property ("page-turn-permission");
64 page_penalty_ = robust_scm2double (pb->get_property ("page-break-penalty"), 0);
65 turn_penalty_ = robust_scm2double (pb->get_property ("page-turn-penalty"), 0);
66 title_ = to_boolean (pb->get_property ("is-title"));
71 Helper to trace back an optimal path
73 struct Constrained_break_node
75 /* the number of bars in all the systems before this one
79 /* unlike the Gourlay breaker, this is the sum of all demerits up to,
80 * and including, this line */
82 struct Line_details details_;
84 Constrained_break_node ()
87 demerits_ = infinity_f;
92 printf ("prev break %d, demerits %f\n", prev_, demerits_);
97 A dynamic programming solution to breaking scores into lines
99 class Constrained_breaking
102 vector<Column_x_positions> solve (vsize start, vsize end, vsize sys_count);
103 vector<Column_x_positions> best_solution (vsize start, vsize end);
104 vector<Line_details> line_details (vsize start, vsize end, vsize sys_count);
106 Constrained_breaking (Paper_score *ps);
107 Constrained_breaking (Paper_score *ps, vector<vsize> const &start_col_posns);
109 int max_system_count (vsize start, vsize end);
110 int min_system_count (vsize start, vsize end);
113 Paper_score *pscore_;
114 vsize valid_systems_;
119 /* the (i,j)th entry is the configuration for breaking between
121 Matrix<Line_details> lines_;
123 /* the [i](j,k)th entry is the score for fitting the first k bars onto the
124 first j systems, starting at the i'th allowed starting column */
125 vector<Matrix<Constrained_break_node> > state_;
127 vector<vsize> start_; /* the columns at which we might be asked to start breaking */
128 vector<vsize> starting_breakpoints_; /* the corresponding index in breaks_ */
131 vector<vsize> breaks_;
134 void resize (vsize systems);
136 Column_x_positions space_line (vsize start_col, vsize end_col);
137 vsize prepare_solution (vsize start, vsize end, vsize sys_count);
139 Real combine_demerits (Real force, Real prev_force);
141 bool calc_subproblem(vsize start, vsize systems, vsize max_break_index);
143 #endif /* CONSTRAINED_BREAKING_HH */