first_line_ = line;
}
- spring_len_ += line.space_;
+ // line.space_ measures the spring which goes from the bottom refpoint
+ // of one system to the top refpoint of the next. spring_len_ measures
+ // how much of that is stretchable.
+ Real refpoint_dist = last_line_.tallness_
+ + last_line_.refpoint_extent_[DOWN]
+ - line.refpoint_extent_[UP];
+ spring_len_ += max (0.0, line.space_ - refpoint_dist);
inverse_spring_k_ += line.inverse_hooke_;
last_line_ = line;
rod_height_ -= first_line_.full_height ();
rod_height_ += first_line_.tallness_;
rod_height_ += line.full_height();
- spring_len_ += line.space_;
+
+ Real refpoint_dist = line.tallness_
+ + line.refpoint_extent_[DOWN]
+ - first_line_.refpoint_extent_[UP];
+ spring_len_ += max (0.0, line.space_ - refpoint_dist);
inverse_spring_k_ += line.inverse_hooke_;
first_line_ = line;
bool last = line == lines_.size () - 1;
// 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. In that case,
- // the algorithm may not be optimal: if our page has a very large header then perhaps
- // we need to look ahead a few systems in order to find the best solution. But
- // we won't, because we stop once we overfill the page with the large header.
+ // 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),