lily/word-wrap.cc

   1 /*
   2   word-wrap.cc -- implement Word_wrap
   3
   4   source file of the LilyPond music typesetter
   5
   6   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7 */
   8
   9 #include "word-wrap.hh"
  10 #include "paper-def.hh"
  11 #include "p-score.hh"
  12 #include "debug.hh"
  13 #include "p-col.hh"
  14 #include "spring-spacer.hh"
  15
  16
  17 /** el stupido.
  18
  19
  20    A Dynamic Programming type of algorithm
  21    similar to TeX's is in Gourlay_breaking
  22
  23    */
  24 Array<Col_hpositions>
  25 Word_wrap::do_solve() const
  26 {
  27   problem_OK();
  28
  29   PCursor<Paper_column*> curcol (pscore_l_->col_p_list_.top());
  30   Array<Col_hpositions> breaking;
  31   Line_of_cols breakpoints (find_breaks());
  32   assert (breakpoints.size()>=2);
  33
  34   int break_idx_i=0;
  35   int line_no_i = 0;
  36   while (break_idx_i < breakpoints.size() -1)
  37     {
  38       Col_hpositions minimum;
  39       Col_hpositions current;
  40
  41       // do  another line
  42       line_no_i ++;
  43       Paper_column *post = breakpoints[break_idx_i]->postbreak_l();
  44       current.add (post);
  45       curcol++;         // skip the breakable.
  46       break_idx_i++;
  47
  48       while (break_idx_i < breakpoints.size())
  49         {
  50
  51           // add another measure.
  52           while (breakpoints[break_idx_i] != curcol.ptr())
  53             {
  54               current.add (curcol);
  55               curcol++;
  56             }
  57           current.add (breakpoints[break_idx_i]->prebreak_l());
  58
  59           current.spacer_l_ = generate_spacing_problem (current.cols,
  60             pscore_l_->paper_l_->line_dimensions_int (line_no_i));
  61
  62           // try to solve
  63           if (!feasible (current.cols))
  64             {
  65               if (!minimum.cols.size())
  66                 {
  67                   warning (_("Ugh, this measure is too long, breakpoint: ")
  68                            + String (break_idx_i) +
  69                            _(" (generating stupido solution)"));
  70                   current.stupid_solution();
  71                   current.energy_f_ = - 1; // make sure we break out.
  72                 }
  73               else
  74                 current.energy_f_ = infinity_f; // make sure we go back
  75             }
  76           else
  77             {
  78
  79               current.solve_line();
  80               current.print();
  81             }
  82
  83           delete current.spacer_l_;
  84           current.spacer_l_ =0;
  85
  86           // update minimum, or backup.
  87           if (current.energy_f_ < minimum.energy_f_ || current.energy_f_ < 0)
  88             {
  89               minimum = current;
  90             }
  91           else {                // we're one col too far.
  92             break_idx_i--;
  93             while (curcol.ptr() != breakpoints[break_idx_i])
  94               curcol --;
  95             break;              // do the next line.
  96           }
  97
  98
  99           // add nobreak version of breakable column
 100           current.cols.top()=breakpoints[break_idx_i];
 101           curcol ++;
 102           break_idx_i++;
 103         }
 104
 105       *mlog << "[" <<break_idx_i<<"]"<<flush;
 106       breaking.push (minimum);
 107     }
 108   return breaking;
 109 }
 110
 111 Word_wrap::Word_wrap()
 112 {
 113   get_line_spacer = Spring_spacer::constructor;
 114 }