break.cc

   1 /*
   2     do calculations for breaking problem
   3
   4     */
   5
   6 #include "linespace.hh"
   7 #include "debug.hh"
   8 #include "line.hh"
   9 #include "pscore.hh"
  10
  11 // construct an appropriate Spacing_problem and solve it.
  12 svec<Real>
  13 PScore::solve_line(svec<const PCol *> curline) const
  14 {
  15    Spacing_problem sp;
  16    mtor << "line of " << curline.sz() << " cols\n";
  17    sp.add_column(curline[0], true, 0.0);
  18    for (int i=1; i< curline.sz()-1; i++)
  19        sp.add_column(curline[i]);
  20    sp.add_column(curline.last(), true, linewidth);
  21
  22    // misschien  moeven uit Spacing_problem?
  23    for (PCursor<Idealspacing *> i(suz); i.ok(); i++) {
  24        sp.add_ideal(i);
  25    }
  26    svec<Real> the_sol=sp.solve();
  27    return the_sol;
  28 }
  29
  30
  31 void
  32 PScore::problem_OK() const
  33 {
  34     if (!cols.size())
  35         error("PScore::problem_OK(): Score does not have any columns");
  36     PCursor<PCol *> start(cols);
  37     PCursor<PCol *> end (((PScore*)this)->cols.bottom());
  38
  39     assert(start->breakable);
  40     assert(end->breakable);
  41 }
  42
  43 struct Col_configuration {
  44     svec<const PCol*> line;
  45     svec<Real> config;
  46     Real energy;
  47
  48     Col_configuration() {
  49         energy = INFTY;
  50     }
  51     void add(const PCol*c) { line.add(c);}
  52     void setsol(svec<Real> sol) {
  53         config = sol;
  54         energy = config.last();
  55         config.pop();
  56     }
  57 };
  58
  59 /// wordwrap type algorithm
  60 /* el stupido. This should be optimised:
  61
  62    It would be nice to have a Dynamic Programming type of algorithm
  63    similar to TeX's
  64
  65     */
  66
  67 void
  68 PScore::calc_breaking()
  69 {
  70     OK();
  71     problem_OK();
  72     PCursor<PCol *> curcol(cols);
  73
  74     svec<const PCol *> breakpoints(find_breaks());
  75     assert(breakpoints.sz()>=2);
  76     for (int i=0 ; i < breakpoints.sz() -1; ) {
  77         Col_configuration minimum;
  78         Col_configuration current;
  79
  80         // do  another line
  81         current.add(breakpoints[i]->postbreak );
  82         curcol++;               // skip the breakable.
  83         i++;
  84
  85         while (i < breakpoints.sz()) {
  86
  87             // add another measure.
  88             while(breakpoints[i] !=curcol){
  89
  90                 current.add(curcol);
  91                 curcol++;
  92             }
  93             current.add(breakpoints[i]->prebreak );
  94             current.setsol(solve_line(current.line));
  95             mtor << "energy : " << current.energy << '\n';
  96
  97             if (current.energy < minimum.energy) {
  98                 minimum = current;
  99             } else {
 100                 break;
 101             }
 102
 103             current.line.last()=breakpoints[i];
 104             curcol ++;
 105             i++;
 106         }
 107         mtor << "Adding line, next breakpoint " << i << '\n';
 108         add_line(minimum.line, minimum.config);
 109     }
 110 }
 111