lily/wordwrap.cc

   1 /*
   2   wordwrap.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 "p-score.hh"
  11 #include "debug.hh"
  12 #include "p-col.hh"
  13 #include "spring-spacer.hh"
  14
  15
  16 /** el stupido. This should be done more accurately:
  17
  18    It would be nice to have a Dynamic Programming type of algorithm
  19    similar to TeX's
  20
  21    */
  22 Array<Col_hpositions>
  23 Word_wrap::do_solve()const
  24 {
  25     problem_OK();
  26     iter_top(pscore_l_->col_p_list_,curcol);
  27     Array<Col_hpositions> breaking;
  28     Line_of_cols breakpoints(find_breaks());
  29     assert(breakpoints.size()>=2);
  30
  31     int break_idx_i=0;
  32     while ( break_idx_i < breakpoints.size() -1) {
  33         Col_hpositions minimum;
  34         Col_hpositions current;
  35
  36         // do  another line
  37         PCol *post = breakpoints[break_idx_i]->postbreak_p_;
  38         current.add( post);
  39         curcol++;               // skip the breakable.
  40         break_idx_i++;
  41
  42         while (break_idx_i < breakpoints.size()) {
  43
  44             // add another measure.
  45             while (breakpoints[break_idx_i] != curcol.ptr()){
  46                 current.add(curcol);
  47                 curcol++;
  48             }
  49             current.add(breakpoints[break_idx_i]->prebreak_p_ );
  50
  51             // try to solve
  52             if (!feasible(current.cols)) {
  53                 if (!minimum.cols.size()) {
  54                     warning("Ugh, this measure is too long, breakpoint: "
  55                           + String(break_idx_i) +
  56                         " (generating stupido solution)");
  57                     current = stupid_solution(current.cols);
  58                     current.energy = - 1; // make sure we break out.
  59                 } else
  60                     current.energy = INFTY;     // make sure we go back
  61             } else {
  62                 current = solve_line(current.cols);
  63                 current.print();
  64             }
  65
  66             // update minimum, or backup.
  67             if (current.energy < minimum.energy || current.energy < 0) {
  68                 minimum = current;
  69             } else {            // we're one col too far.
  70                 break_idx_i--;
  71                 while (curcol.ptr() != breakpoints[break_idx_i])
  72                     curcol --;
  73                 break;          // do the next line.
  74             }
  75
  76
  77             // add nobreak version of breakable column
  78             current.cols.top()=breakpoints[break_idx_i];
  79             curcol ++;
  80             break_idx_i++;
  81         }
  82
  83         *mlog << "[" <<break_idx_i<<"]"<<flush;
  84         breaking.push(minimum);
  85     }
  86
  87     return breaking;
  88 }
  89
  90 Word_wrap::Word_wrap(PScore&ps)
  91     : Break_algorithm(ps)
  92 {
  93     get_line_spacer = Spring_spacer::constructor;
  94 }