]> git.donarmstrong.com Git - lilypond.git/blobdiff - lily/page-breaking.cc
If systems-per-page is specified and a page is overfull, don't barf.
[lilypond.git] / lily / page-breaking.cc
index 33d43fda085c0606352b58dc179b3ade3b54b367..639cbd5ceb0f3f31df17bc6e114388a0942cee76 100644 (file)
@@ -4,7 +4,7 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c) 2006--2008 Joe Neeman <joeneeman@gmail.com>
+  (c) 2006--2009 Joe Neeman <joeneeman@gmail.com>
 */
 
 #include "page-breaking.hh"
@@ -36,13 +36,12 @@ compress_lines (const vector<Line_details> &orig)
          compressed.extent_[UP] = old.extent_[UP] + orig[i].extent_.length () + old.padding_;
          compressed.space_ += old.space_;
          compressed.inverse_hooke_ += old.inverse_hooke_;
-         compressed.title_ = old.title_;
 
-         /* we don't need the force_ field for the vertical spacing,
-            so we use force_ = n to signal that the line was compressed,
-            reducing the number of lines by n (and force_ = 0 otherwise).
-            This makes uncompression much easier. */
-         compressed.force_ = old.force_ + 1;
+         compressed.compressed_lines_count_ = old.compressed_lines_count_ + 1;
+         compressed.compressed_nontitle_lines_count_ =
+           old.compressed_nontitle_lines_count_ + (compressed.title_ ? 0 : 1);
+
+         compressed.title_ = compressed.title_ && old.title_;
          ret.back () = compressed;
        }
       else
@@ -68,7 +67,7 @@ uncompress_solution (vector<vsize> const &systems_per_page,
     {
       int compressed_count = 0;
       for (vsize j = start_sys; j < start_sys + systems_per_page[i]; j++)
-       compressed_count += (int)compressed[j].force_;
+       compressed_count += compressed[j].compressed_lines_count_ - 1;
 
       ret.push_back (systems_per_page[i] + compressed_count);
       start_sys += systems_per_page[i];
@@ -102,6 +101,9 @@ Page_breaking::Page_breaking (Paper_book *pb, Break_predicate is_break)
   ragged_ = to_boolean (pb->paper_->c_variable ("ragged-bottom"));
   ragged_last_ = to_boolean (pb->paper_->c_variable ("ragged-last-bottom"));
   page_top_space_ = robust_scm2double (pb->paper_->c_variable ("page-top-space"), 0);
+  systems_per_page_ = robust_scm2int (pb->paper_->c_variable ("systems-per-page"), 0);
+  max_systems_per_page_ = robust_scm2int (pb->paper_->c_variable ("max-systems-per-page"), 0);
+
   create_system_list ();
   find_chunks_and_breaks (is_break);
 }
@@ -122,6 +124,18 @@ Page_breaking::ragged_last () const
   return ragged_last_;
 }
 
+int
+Page_breaking::systems_per_page () const
+{
+  return systems_per_page_;
+}
+
+int
+Page_breaking::max_systems_per_page () const
+{
+  return max_systems_per_page_;
+}
+
 Real
 Page_breaking::page_top_space () const
 {
@@ -688,11 +702,21 @@ Page_breaking::min_page_count (vsize configuration, vsize first_page_num)
   return ret;
 }
 
+// If systems_per_page_ is positive, we don't really try to space on N pages;
+// we just put the requested number of systems on each page and penalize
+// if the result doesn't have N pages.
 Page_spacing_result
 Page_breaking::space_systems_on_n_pages (vsize configuration, vsize n, vsize first_page_num)
 {
   Page_spacing_result ret;
 
+  if (systems_per_page_ > 0)
+    {
+      Page_spacing_result ret = space_systems_with_fixed_number_per_page (configuration, first_page_num);
+      ret.demerits_ += (ret.force_.size () == n) ? 0 : BAD_SPACING_PENALTY;
+      return ret;
+    }
+
   cache_line_details (configuration);
   bool valid_n = (n >= min_page_count (configuration, first_page_num)
                  && n <= cached_line_details_.size ());
@@ -734,12 +758,21 @@ Page_breaking::blank_page_penalty () const
   return robust_scm2double (book_->paper_->lookup_variable (penalty_sym), 0.0);
 }
 
+// If systems_per_page_ is positive, we don't really try to space on N
+// or N+1 pages; see the comment to space_systems_on_n_pages.
 Page_spacing_result
 Page_breaking::space_systems_on_n_or_one_more_pages (vsize configuration, vsize n, vsize first_page_num)
 {
   Page_spacing_result n_res;
   Page_spacing_result m_res;
 
+  if (systems_per_page_ > 0)
+    {
+      Page_spacing_result ret = space_systems_with_fixed_number_per_page (configuration, first_page_num);
+      ret.demerits_ += (ret.force_.size () == n || ret.force_.size () == (n-1)) ? 0 : BAD_SPACING_PENALTY;
+      return ret;
+    }
+
   cache_line_details (configuration);
   vsize min_p_count = min_page_count (configuration, first_page_num);
   bool valid_n = n >= min_p_count || n <= cached_line_details_.size ();
@@ -802,6 +835,52 @@ Page_breaking::space_systems_on_best_pages (vsize configuration, vsize first_pag
   return finalize_spacing_result (configuration, best);
 }
 
+Page_spacing_result
+Page_breaking::space_systems_with_fixed_number_per_page (vsize configuration,
+                                                        vsize first_page_num)
+{
+  Page_spacing_result res;
+  Page_spacing space (page_height (first_page_num, false), page_top_space_);
+  vsize line = 0;
+  vsize page = 0;
+  vsize page_first_line = 0;
+
+  cache_line_details (configuration);
+  while (line < cached_line_details_.size ())
+    {
+      page++;
+      space.clear ();
+      space.resize (page_height (first_page_num + page, false));
+
+      int system_count_on_this_page = 0;
+      while (system_count_on_this_page < systems_per_page_
+            && line < cached_line_details_.size ())
+       {
+         Line_details const &cur_line = cached_line_details_[line];
+         space.append_system (cur_line);
+         system_count_on_this_page += cur_line.compressed_nontitle_lines_count_;
+         line++;
+
+         if (cur_line.page_permission_ == ly_symbol2scm ("force"))
+           break;
+       }
+
+      res.systems_per_page_.push_back (line - page_first_line);
+
+      // Don't say that the force is infinite even if it is: if we were told to
+      // put a certain number of systems on a page then we will, even if it's bad.
+      res.force_.push_back (min (space.force_, BAD_SPACING_PENALTY));
+      res.penalty_ += cached_line_details_[line-1].page_penalty_;
+      page_first_line = line;
+    }
+
+  /* Recalculate forces for the last page because we know now that is
+     really the last page. */
+  space.resize (page_height (first_page_num + page, true));
+  res.force_.back () = min(space.force_, BAD_SPACING_PENALTY);
+  return finalize_spacing_result (configuration, res);
+}
+
 Page_spacing_result
 Page_breaking::pack_systems_on_least_pages (vsize configuration, vsize first_page_num)
 {
@@ -887,7 +966,7 @@ Page_breaking::finalize_spacing_result (vsize configuration, Page_spacing_result
     {
       Real f = res.force_[i];
       if (isinf (f) && res.systems_per_page_[i] == 1)
-       f = 20000;
+       f = BAD_SPACING_PENALTY;
 
       page_force += f * f;
     }