New page breaking function: ly:minimal-breaking, which first computes

[lilypond.git] / lily / page-breaking.cc

diff --git a/lily/page-breaking.cc b/lily/page-breaking.cc
index 9ad833610aeebce6acf8e1138a337d1b39b4046a..b6951925ad7ce7cc518b6b68f90efc225201eb78 100644 (file)
--- a/lily/page-breaking.cc
+++ b/lily/page-breaking.cc
@@ -526,6 +526,7 @@ Page_breaking::cache_line_details (vsize configuration_index)
 {
   if (cached_configuration_index_ != configuration_index)
     {
+      cached_configuration_index_ = configuration_index;
       SCM padding_scm = book_->paper_->c_variable ("page-breaking-between-system-padding");
       if (!scm_is_number (padding_scm))
        padding_scm = book_->paper_->c_variable ("between-system-padding");
@@ -758,6 +759,65 @@ Page_breaking::space_systems_on_best_pages (vsize configuration, vsize first_pag
   return finalize_spacing_result (configuration, best);
 }
 
+Page_spacing_result
+Page_breaking::pack_systems_on_least_pages (vsize configuration, vsize first_page_num)
+{
+  Page_spacing_result res;
+  vsize page = 0;
+  vsize page_first_line = 0;
+  Page_spacing space (page_height (first_page_num, false));
+
+  cache_line_details (configuration);
+  for (vsize line = 0; line < cached_line_details_.size (); line++)
+    {
+      Real prev_force = space.force_;
+      space.append_system (cached_line_details_[line]);
+      if ((line > page_first_line)
+         && (isinf (space.force_)
+             || ((line > 0)
+                  && (cached_line_details_[line-1].page_permission_ == ly_symbol2scm ("force")))))
+       {
+         res.systems_per_page_.push_back (line - page_first_line);
+         res.force_.push_back (prev_force);
+          res.penalty_ += cached_line_details_[line-1].page_penalty_;
+         page++;
+         space.resize (page_height (first_page_num + page, false));
+         space.clear ();
+          space.append_system (cached_line_details_[line]);
+         page_first_line = line;
+       }
+
+      if (line == cached_line_details_.size () - 1)
+       {
+         /* This is the last line */
+         /* When the last page height was computed, we did not know yet that it
+          * was the last one. If the systems put on it don't fit anymore, the last
+          * system is moved to a new page */
+         space.resize (page_height (first_page_num + page, true));
+         if ((line > page_first_line) && (isinf (space.force_)))
+           {
+             res.systems_per_page_.push_back (line - page_first_line);
+             res.force_.push_back (prev_force);
+             /* the last page containing the last line */
+             space.resize (page_height (first_page_num + page + 1, true));
+             space.clear ();
+             space.append_system (cached_line_details_[line]);
+             res.systems_per_page_.push_back (1);
+             res.force_.push_back (space.force_);
+              res.penalty_ += cached_line_details_[line-1].page_penalty_;
+              res.penalty_ += cached_line_details_[line].page_penalty_;
+           }
+         else
+           {
+             res.systems_per_page_.push_back (line + 1 - page_first_line);
+             res.force_.push_back (space.force_);
+              res.penalty_ += cached_line_details_[line].page_penalty_;
+           }
+       }
+    }
+  return finalize_spacing_result (configuration, res);
+}
+
 /* Calculate demerits and fix res.systems_per_page_ so that
    it refers to the original line numbers, not the ones given by compress_lines (). */
 Page_spacing_result