+ set_to_ideal_line_configuration (0, end);
+
+ Page_spacing_result best;
+ vsize page_count = robust_scm2int (forced_page_count, 1);
+ Line_division ideal_line_division = current_configuration (0);
+ Line_division best_division = ideal_line_division;
+ vsize min_sys_count = 1;
+ vsize ideal_sys_count = system_count ();
+
+ if (!scm_is_integer (forced_page_count))
+ {
+ /* find out the ideal number of pages */
+ message (_ ("Finding the ideal number of pages..."));
+
+ best = space_systems_on_best_pages (0, first_page_num);
+ page_count = best.systems_per_page_.size ();
+
+ ideal_sys_count = best.system_count ();
+ min_sys_count = ideal_sys_count - best.systems_per_page_.back ();
+
+ if (page_count > 1 && best.systems_per_page_[page_count - 2] > 1)
+ min_sys_count -= best.systems_per_page_[page_count - 2];
+
+ min_sys_count = max (min_sys_count, (vsize)1);
+ }
+ else
+ {
+ /* todo: the following line will spit out programming errors if the
+ ideal line spacing doesn't fit on PAGE_COUNT pages */
+ best = space_systems_on_n_pages (0, page_count, first_page_num);
+ min_sys_count = page_count;
+ }
+
+ if (page_count == 1)
+ message (_ ("Fitting music on 1 page..."));
+ else if (scm_is_integer (forced_page_count))
+ message (_f ("Fitting music on %d pages...", (int)page_count));
+ else
+ message (_f ("Fitting music on %d or %d pages...", (int)page_count-1, (int)page_count));
+
+ /* try a smaller number of systems than the ideal number for line breaking */
+ Line_division bound = ideal_line_division;
+ for (vsize sys_count = ideal_sys_count; --sys_count >= min_sys_count;)
+ {
+ Page_spacing_result best_for_this_sys_count;
+ set_current_breakpoints (0, end, sys_count, Line_division (), bound);
+
+ for (vsize i = 0; i < current_configuration_count (); i++)
+ {
+ vsize min_p_count = min_page_count (i, first_page_num);
+ Page_spacing_result cur;
+
+ if (min_p_count == page_count || scm_is_integer (forced_page_count))
+ cur = space_systems_on_n_pages (i, page_count, first_page_num);
+ else
+ cur = space_systems_on_n_or_one_more_pages (i, page_count-1, first_page_num);
+
+ if (cur.demerits_ < best_for_this_sys_count.demerits_ || isinf (best_for_this_sys_count.demerits_))
+ {
+ best_for_this_sys_count = cur;
+ bound = current_configuration (i);
+ }
+ }
+
+ if (best_for_this_sys_count.demerits_ < best.demerits_ || isinf (best.demerits_))
+ {
+ best = best_for_this_sys_count;
+ best_division = bound;
+ }
+
+ /* if the pages are stretched on average, stop trying to reduce sys_count */
+ if (best_for_this_sys_count.page_count () < page_count
+ && best_for_this_sys_count.average_force () > 0)
+ break;
+
+
+ if (isinf (best_for_this_sys_count.demerits_))
+ break;
+ }
+
+ /* try a larger number of systems than the ideal line breaking number. This
+ is more or less C&P, but the loop bounds make it difficult to try something
+ like do {...} while (flip(&d) != UP). */
+ bound = ideal_line_division;
+ for (vsize sys_count = ideal_sys_count+1; sys_count <= max_sys_count; sys_count++)