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