-SCM
-Optimal_page_breaking::solve ()
-{
- vsize end = breaks_.size () - 1;
- vsize min_sys_count = min_system_count (0, end);
- vsize max_sys_count = max_system_count (0, end);
- vsize max_page_count = INT_MAX;
- vsize cur_page_count = 0;
- Spacing_result best;
- Line_division best_division;
- Line_division lower_bound;
-
- for (vsize sys_count = min_sys_count;
- cur_page_count <= max_page_count && sys_count <= max_sys_count;
- sys_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 (end-1, 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_)
+ {
+ best_for_this_sys_count = cur;
+ bound = current_configuration (i);
+ }
+ }
+
+ if (best_for_this_sys_count.demerits_ < best.demerits_)
+ {
+ best = best_for_this_sys_count;
+ best_division = bound;
+ }
+
+ /* Check to see if we already have too few systems. There are two ways
+ we check this: if we are trying one less than the ideal number of pages
+ and the pages are stretched on average then we have too
+ few systems. If the spacing is worse than BAD_SPACING_PENALTY, then we
+ have too few systems. In either case, though, we need to continue reducing
+ the number of systems if max-systems-per-page requires it. */
+ if (!(best.system_count_status_ & SYSTEM_COUNT_TOO_MANY))
+ {
+ if (best_for_this_sys_count.page_count () < page_count
+ && best_for_this_sys_count.average_force () > 0)
+ break;
+
+ if (best_for_this_sys_count.demerits_ >= BAD_SPACING_PENALTY)
+ 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++)