X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fpage-spacing.cc;h=17ba73d9239846e49c4e1d8e7fe23345e30e6efe;hb=88dbdd2d6b48e4d042f3aa076bdbf038ed6b3d28;hp=f78cc1795aef00d30b5811557d5269c1846fab25;hpb=bc95f4434f760d41191341ab4508b2064eb19025;p=lilypond.git

diff --git a/lily/page-spacing.cc b/lily/page-spacing.cc
index f78cc1795a..17ba73d923 100644
--- a/lily/page-spacing.cc
+++ b/lily/page-spacing.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 2006--2010 Joe Neeman <joeneeman@gmail.com>
+  Copyright (C) 2006--2011 Joe Neeman <joeneeman@gmail.com>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -31,7 +31,7 @@ Page_spacing::calc_force ()
     - breaker_->min_whitespace_at_bottom_of_page (last_line_);
 
   if (rod_height_ + last_line_.bottom_padding_ >= height)
-    force_ = infinity_f;
+    force_ = -infinity_f;
   else
     force_ = (height - rod_height_ - last_line_.bottom_padding_ - spring_len_)
       / max (0.1, inverse_spring_k_);
@@ -47,13 +47,18 @@ Page_spacing::resize (Real new_height)
 void
 Page_spacing::append_system (const Line_details &line)
 {
-  if (!rod_height_)
-    first_line_ = line;
+  if (rod_height_)
+    {
+      rod_height_ += line.tallness_;
+      spring_len_ += last_line_.spring_length (line);
 
-  rod_height_ += line.title_ ? last_line_.title_padding_ : last_line_.padding_;
+    }
+  else
+    {
+      rod_height_ += line.full_height ();
+      first_line_ = line;
+    }
 
-  rod_height_ += line.extent_.length ();
-  spring_len_ += line.space_;
   inverse_spring_k_ += line.inverse_hooke_;
 
   last_line_ = line;
@@ -65,12 +70,14 @@ void
 Page_spacing::prepend_system (const Line_details &line)
 {
   if (rod_height_)
-    rod_height_ += first_line_.title_ ? line.title_padding_ : line.padding_;
+    spring_len_ += line.spring_length (first_line_);
   else
     last_line_ = line;
 
-  rod_height_ += line.extent_.length ();
-  spring_len_ += line.space_;
+  rod_height_ -= first_line_.full_height ();
+  rod_height_ += first_line_.tallness_;
+  rod_height_ += line.full_height();
+
   inverse_spring_k_ += line.inverse_hooke_;
 
   first_line_ = line;
@@ -96,6 +103,38 @@ Page_spacer::Page_spacer (vector<Line_details> const &lines, vsize first_page_nu
   ragged_last_ = breaker->is_last () && breaker->ragged_last ();
 }
 
+Page_spacing_result
+Page_spacer::solve ()
+{
+  if (simple_state_.empty ())
+    {
+      simple_state_.resize (lines_.size ());
+      for (vsize i = 0; i < lines_.size (); ++i)
+	calc_subproblem (VPOS, i);
+    }
+
+  Page_spacing_result ret;
+  ret.penalty_ = simple_state_.back ().penalty_
+    + lines_.back ().page_penalty_ + lines_.back ().turn_penalty_;
+  ret.system_count_status_ = simple_state_.back ().system_count_status_;
+
+  vsize system = lines_.size () - 1;
+  while (system != VPOS)
+    {
+      Page_spacing_node const& cur = simple_state_[system];
+      vsize system_count = (cur.prev_ == VPOS) ? system + 1 : system - cur.prev_;
+
+      ret.force_.push_back (cur.force_);
+      ret.systems_per_page_.push_back (system_count);
+      ret.demerits_ += cur.force_ * cur.force_;
+      system = cur.prev_;
+    }
+
+  reverse (ret.force_);
+  reverse (ret.systems_per_page_);
+  return ret;
+}
+
 Page_spacing_result
 Page_spacer::solve (vsize page_count)
 {
@@ -144,6 +183,7 @@ Page_spacer::solve (vsize page_count)
 
   ret.force_.resize (page_count);
   ret.systems_per_page_.resize (page_count);
+  ret.system_count_status_ = state_.at (system, page_count-1).system_count_status_;
   ret.penalty_ = state_.at (system, page_count-1).penalty_
     + lines_.back ().page_penalty_ + lines_.back ().turn_penalty_;
 
@@ -199,29 +239,61 @@ Page_spacer::resize (vsize page_count)
 // we have previously called calc_subproblem(page-1, k) for every k < LINE.
 //
 // This algorithm is similar to the constrained-breaking algorithm.
+//
+// If page == VPOS, we act on simple_state_ instead of state_.  This is useful if
+// we don't want to constrain the number of pages that the solution has.  In this
+// case, the algorithm looks more like the page-turn-page-breaking algorithm.  But
+// the subproblems look similar for both, so we reuse this method.
 bool
 Page_spacer::calc_subproblem (vsize page, vsize line)
 {
   bool last = line == lines_.size () - 1;
-  Page_spacing space (breaker_->page_height (page + first_page_num_, last),
+
+  // Note: if page == VPOS then we don't actually know yet which page number we're
+  // working on, so we have to recalculate the page height in the loop.  Therefore
+  // our early-exit condition from the loop depends on paper_height rather than
+  // page_height (ie. we break only if we would overfill a page without margins
+  // or headers/footers).  Otherwise, the algorithm would not be optimal:
+  // if our page has a very large header then perhaps
+  // we should look ahead a few systems in order to find the best solution.  A
+  // good example of this is input/regression/page-spacing-tall-headfoot.ly
+  vsize page_num = page == VPOS ? 0 : page;
+  Real paper_height = breaker_->paper_height ();
+  Page_spacing space (breaker_->page_height (page_num + first_page_num_, last),
 		      breaker_);
-  Page_spacing_node &cur = state_.at (line, page);
+  Page_spacing_node &cur = page == VPOS ? simple_state_[line] : state_.at (line, page);
   bool ragged = ragged_ || (ragged_last_ && last);
   int line_count = 0;
 
-  for (vsize page_start = line+1; page_start > page && page_start--;)
+  for (vsize page_start = line+1; page_start > page_num && page_start--;)
     {
-      Page_spacing_node const *prev = page > 0 ? &state_.at (page_start-1, page-1) : 0;
+      Page_spacing_node const *prev = 0;
+
+      if (page == VPOS)
+	{
+	  if (page_start > 0)
+	    {
+	      prev = &simple_state_[page_start-1];
+	      space.resize (breaker_->page_height (prev->page_ + 1, last));
+	    }
+	  else
+	    space.resize (breaker_->page_height (first_page_num_, last));
+	}
+      else if (page > 0)
+	prev = &state_.at (page_start-1, page-1);
 
       space.prepend_system (lines_[page_start]);
 
+      bool overfull = (space.rod_height_ > paper_height
+		       || (ragged
+			   && (space.rod_height_ + space.spring_len_ > paper_height)));
       // This 'if' statement is a little hard to parse. It won't consider this configuration
       // if it is overfull unless the current configuration is the first one with this start
       // point. We also make an exception (and consider this configuration) if the previous
       // configuration we tried had fewer lines than min-systems-per-page.
       if (!breaker_->too_few_lines (line_count)
 	  && page_start < line
-	  && (isinf (space.force_) || (space.force_ < 0 && ragged)))
+	  && overfull)
 	break;
 
       line_count += lines_[page_start].compressed_nontitle_lines_count_;
@@ -234,10 +306,11 @@ Page_spacer::calc_subproblem (vsize page, vsize line)
 	    space.force_ = 0;
 
 	  Real demerits = space.force_ * space.force_;
-	  /* If a single line is taller than a page, we need to consider it as
-	     a possible solution (but we give it a very bad score). */
-	  if (isinf (space.force_) && page_start == line)
-	    demerits = BAD_SPACING_PENALTY;
+
+	  // Clamp the demerits at BAD_SPACING_PENALTY, even if the page
+	  // is overfull.  This ensures that TERRIBLE_SPACING_PENALTY takes
+	  // precedence over overfull pages.
+	  demerits = min (demerits, BAD_SPACING_PENALTY);
 	  demerits += (prev ? prev->demerits_ : 0);
 
 	  Real penalty = breaker_->line_count_penalty (line_count);
@@ -266,6 +339,7 @@ Page_spacer::calc_subproblem (vsize page, vsize line)
 	      cur.system_count_status_ = breaker_->line_count_status (line_count)
 		| (prev ? prev->system_count_status_ : 0);
 	      cur.prev_ = page_start - 1;
+	      cur.page_ = prev ? prev->page_ + 1 : first_page_num_;
 	    }
 	}