2 page-layout-problem.cc -- space systems nicely on a page. If systems can
3 be stretched, do that too.
5 source file of the GNU LilyPond music typesetter
7 (c) 2009 Joe Neeman <joeneeman@gmail.com>
10 #include "page-layout-problem.hh"
12 #include "align-interface.hh"
13 #include "axis-group-interface.hh"
14 #include "hara-kiri-group-spanner.hh"
15 #include "international.hh"
17 #include "output-def.hh"
18 #include "paper-book.hh"
19 #include "paper-column.hh"
20 #include "pointer-group-interface.hh"
22 #include "skyline-pair.hh"
25 Page_layout_problem::Page_layout_problem (Paper_book
*pb
, SCM page_scm
, SCM systems
)
26 : bottom_skyline_ (DOWN
)
28 Prob
*page
= unsmob_prob (page_scm
);
37 Stencil
*head
= unsmob_stencil (page
->get_property ("head-stencil"));
38 Stencil
*foot
= unsmob_stencil (page
->get_property ("foot-stencil"));
40 header_height_
= head
? head
->extent (Y_AXIS
).length () : 0;
41 footer_height_
= foot
? foot
->extent (Y_AXIS
).length () : 0;
42 page_height_
= robust_scm2double (page
->get_property ("paper-height"), 100);
45 // Initially, bottom_skyline_ represents the top of the page. Make
46 // it solid, so that the top of the first system will be forced
47 // below the top of the printable area.
48 bottom_skyline_
.set_minimum_height (-header_height_
);
50 SCM between_system_spacing
= SCM_EOL
;
51 SCM between_scores_system_spacing
= SCM_EOL
;
52 SCM after_title_spacing
= SCM_EOL
;
53 SCM before_title_spacing
= SCM_EOL
;
54 SCM between_title_spacing
= SCM_EOL
;
56 // top_system_spacing controls the spring from the top of the printable
57 // area to the first staff. It allows the user to control the offset of
58 // the first staff (as opposed to the top of the first system) from the
59 // top of the page. Similarly for bottom_system_spacing.
60 SCM top_system_spacing
= SCM_EOL
;
61 SCM bottom_system_spacing
= SCM_EOL
;
64 Output_def
*paper
= pb
->paper_
;
65 between_system_spacing
= paper
->c_variable ("between-system-spacing");
66 between_scores_system_spacing
= paper
->c_variable ("between-scores-system-spacing");
67 after_title_spacing
= paper
->c_variable ("after-title-spacing");
68 before_title_spacing
= paper
->c_variable ("before-title-spacing");
69 between_title_spacing
= paper
->c_variable ("between-title-spacing");
70 bottom_system_spacing
= paper
->c_variable ("bottom-system-spacing");
71 top_system_spacing
= paper
->c_variable ("top-system-spacing");
72 if (scm_is_pair (systems
) && unsmob_prob (scm_car (systems
)))
73 top_system_spacing
= paper
->c_variable ("top-title-spacing");
75 // Note: the page height here does _not_ reserve space for headers and
76 // footers. This is because we want to anchor the top-system-spacing
77 // spring at the _top_ of the header.
78 page_height_
-= robust_scm2double (paper
->c_variable ("top-margin"), 0)
79 + robust_scm2double (paper
->c_variable ("bottom-margin"), 0);
81 read_spacing_spec (top_system_spacing
, &header_padding_
, ly_symbol2scm ("padding"));
82 read_spacing_spec (bottom_system_spacing
, &footer_padding_
, ly_symbol2scm ("padding"));
84 bool last_system_was_title
= false;
87 for (SCM s
= systems
; scm_is_pair (s
); s
= scm_cdr (s
))
89 bool first
= (s
== systems
);
91 if (Grob
*g
= unsmob_grob (scm_car (s
)))
93 System
*sys
= dynamic_cast<System
*> (g
);
96 programming_error ("got a grob for vertical spacing that wasn't a System");
100 SCM spec
= between_system_spacing
;
102 spec
= top_system_spacing
;
103 else if (last_system_was_title
)
104 spec
= after_title_spacing
;
105 else if (0 == Paper_column::get_rank (sys
->get_bound (LEFT
)))
106 spec
= between_scores_system_spacing
;
108 Spring
spring (0, 0);
110 alter_spring_from_spacing_spec (spec
, &spring
);
111 read_spacing_spec (spec
, &padding
, ly_symbol2scm ("padding"));
113 append_system (sys
, spring
, padding
);
114 last_system_was_title
= false;
116 else if (Prob
*p
= unsmob_prob (scm_car (s
)))
118 SCM spec
= first
? top_system_spacing
119 : (last_system_was_title
? between_title_spacing
: before_title_spacing
);
120 Spring
spring (0, 0);
122 alter_spring_from_spacing_spec (spec
, &spring
);
123 read_spacing_spec (spec
, &padding
, ly_symbol2scm ("padding"));
125 append_prob (p
, spring
, padding
);
126 last_system_was_title
= true;
129 programming_error ("got a system that was neither a Grob nor a Prob");
132 Spring
last_spring (0, 0);
133 Real last_padding
= 0;
134 alter_spring_from_spacing_spec (bottom_system_spacing
, &last_spring
);
135 read_spacing_spec (bottom_system_spacing
, &last_padding
, ly_symbol2scm ("padding"));
136 last_spring
.ensure_min_distance (last_padding
- bottom_skyline_
.max_height () + footer_height_
);
137 springs_
.push_back (last_spring
);
139 if (elements_
.size ())
141 Real bottom_padding
= 0;
143 // TODO: junk bottom-space now that we have bottom-system-spacing?
144 // bottom-space has the flexibility that one can do it per-system.
145 // NOTE: bottom-space is misnamed since it is not stretchable space.
146 if (Prob
*p
= elements_
.back ().prob
)
147 bottom_padding
= robust_scm2double (p
->get_property ("bottom-space"), 0);
148 else if (elements_
.back ().staves
.size ())
150 SCM details
= get_details (elements_
.back ());
151 bottom_padding
= robust_scm2double (ly_assoc_get (ly_symbol2scm ("bottom-space"),
156 page_height_
-= bottom_padding
;
161 Page_layout_problem::set_header_height (Real height
)
163 header_height_
= height
;
167 Page_layout_problem::set_footer_height (Real height
)
169 footer_height_
= height
;
173 Page_layout_problem::append_system (System
*sys
, Spring
const& spring
, Real padding
)
175 Grob
*align
= sys
->get_vertical_alignment ();
179 align
->set_property ("positioning-done", SCM_BOOL_T
);
181 extract_grob_set (align
, "elements", all_elts
);
182 vector
<Grob
*> elts
= filter_dead_elements (all_elts
);
183 vector
<Real
> minimum_offsets
= Align_interface::get_minimum_translations (align
, elts
, Y_AXIS
,
186 Skyline
up_skyline (UP
);
187 Skyline
down_skyline (DOWN
);
188 build_system_skyline (elts
, minimum_offsets
, &up_skyline
, &down_skyline
);
190 Real minimum_distance
= up_skyline
.distance (bottom_skyline_
) + padding
;
192 Spring spring_copy
= spring
;
193 spring_copy
.ensure_min_distance (minimum_distance
);
194 springs_
.push_back (spring_copy
);
196 bottom_skyline_
= down_skyline
;
197 elements_
.push_back (Element (elts
, minimum_offsets
));
199 // Add the springs for the VerticalAxisGroups in this system.
201 // If the user has specified the offsets of the individual staves, fix the
202 // springs at the given distances. Otherwise, use stretchable springs.
203 SCM details
= get_details (elements_
.back ());
204 SCM manual_dists
= ly_assoc_get (ly_symbol2scm ("alignment-distances"), details
, SCM_EOL
);
205 vsize last_spaceable_staff
= 0;
206 bool found_spaceable_staff
= false;
207 for (vsize i
= 0; i
< elts
.size (); ++i
)
209 if (is_spaceable (elts
[i
]))
211 // We don't add a spring for the first staff, since
212 // we are only adding springs _between_ staves here.
213 if (!found_spaceable_staff
)
215 found_spaceable_staff
= true;
216 last_spaceable_staff
= i
;
220 Spring
spring (0.5, 0.0);
221 SCM spec
= elts
[last_spaceable_staff
]->get_property ("next-staff-spacing");
222 alter_spring_from_spacing_spec (spec
, &spring
);
224 springs_
.push_back (spring
);
225 Real min_distance
= (found_spaceable_staff
? minimum_offsets
[last_spaceable_staff
] : 0) - minimum_offsets
[i
];
226 springs_
.back ().ensure_min_distance (min_distance
);
228 if (scm_is_pair (manual_dists
))
230 if (scm_is_number (scm_car (manual_dists
)))
232 Real dy
= scm_to_double (scm_car (manual_dists
));
234 springs_
.back ().set_distance (dy
);
235 springs_
.back ().set_min_distance (dy
);
236 springs_
.back ().set_inverse_stretch_strength (0);
238 manual_dists
= scm_cdr (manual_dists
);
240 last_spaceable_staff
= i
;
244 // Corner case: there was only one staff, and it wasn't spaceable.
245 // Mark it spaceable, because we do not allow non-spaceable staves
246 // to be at the top or bottom of a system.
247 if (!found_spaceable_staff
&& elts
.size ())
248 mark_as_spaceable (elts
[0]);
252 Page_layout_problem::append_prob (Prob
*prob
, Spring
const& spring
, Real padding
)
254 Skyline_pair
*sky
= Skyline_pair::unsmob (prob
->get_property ("vertical-skylines"));
255 Real minimum_distance
= 0;
256 bool tight_spacing
= to_boolean (prob
->get_property ("tight-spacing"));
260 minimum_distance
= (*sky
)[UP
].distance (bottom_skyline_
);
261 bottom_skyline_
= (*sky
)[DOWN
];
263 else if (Stencil
*sten
= unsmob_stencil (prob
->get_property ("stencil")))
265 Interval iv
= sten
->extent (Y_AXIS
);
266 minimum_distance
= iv
[UP
] - bottom_skyline_
.max_height ();
268 bottom_skyline_
.clear ();
269 bottom_skyline_
.set_minimum_height (iv
[DOWN
]);
272 Spring spring_copy
= spring
;
275 spring_copy
.set_min_distance (minimum_distance
);
276 spring_copy
.set_inverse_stretch_strength (0.0);
277 spring_copy
.set_distance (0.0);
280 spring_copy
.ensure_min_distance (minimum_distance
+ padding
);
282 springs_
.push_back (spring_copy
);
283 elements_
.push_back (Element (prob
));
287 Page_layout_problem::solve_rod_spring_problem (bool ragged
)
289 Simple_spacer spacer
;
291 for (vsize i
= 0; i
< springs_
.size (); ++i
)
292 spacer
.add_spring (springs_
[i
]);
294 spacer
.solve (page_height_
, ragged
);
295 solution_
= spacer
.spring_positions ();
298 // The solution_ vector stores the position of every live VerticalAxisGroup
299 // and every title. From that information,
300 // 1) within each system, stretch the staves so they land at the right position
301 // 2) find the offset of each system (relative to the printable area of the page).
302 // TODO: this function is getting too long, maybe split it up?
304 Page_layout_problem::find_system_offsets ()
306 SCM system_offsets
= SCM_EOL
;
307 SCM
*tail
= &system_offsets
;
309 // spring_idx 0 is the top of the page. Interesting values start from 1.
310 vsize spring_idx
= 1;
311 vector
<Grob
*> loose_lines
;
312 vector
<Real
> loose_line_min_distances
;
313 Grob
*last_spaceable_line
= 0;
314 Real last_spaceable_line_translation
= 0;
315 for (vsize i
= 0; i
< elements_
.size (); ++i
)
317 if (elements_
[i
].prob
)
319 *tail
= scm_cons (scm_from_double (solution_
[spring_idx
]), SCM_EOL
);
320 tail
= SCM_CDRLOC (*tail
);
322 // Lay out any non-spaceable lines between this line and
324 if (loose_lines
.size ())
326 Interval loose_extent
= loose_lines
.back ()->extent (loose_lines
.back (), Y_AXIS
);
327 Interval prob_extent
= unsmob_stencil (elements_
[i
].prob
->get_property ("stencil"))->extent (Y_AXIS
);
328 Real min_distance
= -loose_extent
[DOWN
] + prob_extent
[UP
]; // TODO: include padding/minimum-distance
330 loose_line_min_distances
.push_back (min_distance
);
331 loose_lines
.push_back (0);
333 distribute_loose_lines (loose_lines
, loose_line_min_distances
,
334 last_spaceable_line_translation
, -solution_
[spring_idx
]);
335 loose_lines
.clear ();
336 loose_line_min_distances
.clear ();
339 last_spaceable_line
= 0;
340 last_spaceable_line_translation
= -solution_
[spring_idx
];
345 // Getting this signs right here is a little tricky. The configuration
346 // we return has zero at the top of the page and positive numbers further
347 // down, as does the solution_ vector. Within a staff, however, positive
349 // TODO: perhaps change the way the page 'configuration variable works so
350 // that it is consistent with the usual up/down sign conventions in
351 // Lilypond. Then this would be less confusing.
353 // These two positions are relative to the page (with positive numbers being
355 Real first_staff_position
= solution_
[spring_idx
];
356 Real first_staff_min_translation
= elements_
[i
].min_offsets
.size () ? elements_
[i
].min_offsets
[0] : 0;
357 Real system_position
= first_staff_position
+ first_staff_min_translation
;
359 // Position the staves within this system.
360 Real translation
= 0;
361 vector
<Real
> const& min_offsets
= elements_
[i
].min_offsets
;
362 bool found_spaceable_staff
= false;
363 for (vsize staff_idx
= 0; staff_idx
< elements_
[i
].staves
.size (); ++staff_idx
)
365 Grob
*staff
= elements_
[i
].staves
[staff_idx
];
366 staff
->set_property ("system-Y-offset", scm_from_double (-system_position
));
368 if (is_spaceable (staff
))
370 // this is relative to the system: negative numbers are down.
371 translation
= system_position
- solution_
[spring_idx
];
374 // Lay out any non-spaceable lines between this line and
376 if (loose_lines
.size ())
378 loose_line_min_distances
.push_back (min_offsets
[staff_idx
-1] - min_offsets
[staff_idx
]);
379 loose_lines
.push_back (staff
);
381 distribute_loose_lines (loose_lines
, loose_line_min_distances
,
382 last_spaceable_line_translation
, translation
- system_position
);
383 loose_lines
.clear ();
384 loose_line_min_distances
.clear ();
386 last_spaceable_line
= staff
;
387 // Negative is down but the translation is relative to the whole page.
388 last_spaceable_line_translation
= -system_position
+ translation
;
390 staff
->translate_axis (translation
, Y_AXIS
);
391 found_spaceable_staff
= true;
395 if (loose_lines
.empty ())
396 loose_lines
.push_back (last_spaceable_line
);
399 loose_line_min_distances
.push_back (min_offsets
[staff_idx
-1] - min_offsets
[staff_idx
]);
403 if (loose_lines
.back ())
404 min_dist
= Axis_group_interface::minimum_distance (loose_lines
.back (),
407 else // distance to the top margin
408 min_dist
= header_padding_
+ header_height_
+ staff
->extent (staff
, Y_AXIS
)[UP
];
410 loose_line_min_distances
.push_back (min_dist
);
412 loose_lines
.push_back (staff
);
416 // Corner case: even if a system has no live staves, it still takes up
417 // one spring (a system with one live staff also takes up one spring),
418 // which we need to increment past.
419 if (!found_spaceable_staff
)
422 *tail
= scm_cons (scm_from_double (system_position
), SCM_EOL
);
423 tail
= SCM_CDRLOC (*tail
);
427 if (loose_lines
.size ())
429 Grob
*last
= loose_lines
.back ();
430 Interval last_ext
= last
->extent (last
, Y_AXIS
);
431 loose_line_min_distances
.push_back (-last_ext
[DOWN
] + footer_height_
+ footer_padding_
);
432 loose_lines
.push_back (0);
434 distribute_loose_lines (loose_lines
, loose_line_min_distances
,
435 last_spaceable_line_translation
, -page_height_
);
439 assert (spring_idx
== solution_
.size () - 1);
440 return system_offsets
;
443 // Given two lines that are already spaced (the first and last
444 // elements of loose_lines), distribute some unspaced lines between
447 Page_layout_problem::distribute_loose_lines (vector
<Grob
*> const &loose_lines
,
448 vector
<Real
> const &min_distances
,
449 Real first_translation
, Real last_translation
)
451 Simple_spacer spacer
;
452 for (vsize i
= 0; i
+ 1 < loose_lines
.size (); ++i
)
454 SCM spec
= get_spacing_spec (loose_lines
[i
], loose_lines
[i
+1]);
455 Spring
spring (1.0, 0.0);
456 alter_spring_from_spacing_spec (spec
, &spring
);
457 spring
.ensure_min_distance (min_distances
[i
]);
458 spacer
.add_spring (spring
);
461 // Remember: offsets are decreasing, since we're going from UP to DOWN!
462 spacer
.solve (first_translation
- last_translation
, false);
464 vector
<Real
> solution
= spacer
.spring_positions ();
465 for (vsize i
= 1; i
+ 1 < solution
.size (); ++i
)
467 Real system_offset
= scm_to_double (loose_lines
[i
]->get_property ("system-Y-offset"));
468 loose_lines
[i
]->translate_axis (first_translation
- solution
[i
] - system_offset
, Y_AXIS
);
473 Page_layout_problem::solution (bool ragged
)
475 solve_rod_spring_problem (ragged
);
476 return find_system_offsets ();
479 // Build upper and lower skylines for a system. We don't yet know the positions
480 // of the staves within the system, so we make the skyline as conservative as
481 // possible. That is, for the upper skyline, we pretend that all of the staves
482 // in the system are packed together close to the top system; for the lower
483 // skyline, we pretend that all of the staves are packed together close to
484 // the bottom system.
486 // The upper skyline is relative to the top staff; the lower skyline is relative to
489 Page_layout_problem::build_system_skyline (vector
<Grob
*> const& staves
,
490 vector
<Real
> const& minimum_translations
,
494 if (minimum_translations
.empty ())
497 assert (staves
.size () == minimum_translations
.size ());
498 Real first_translation
= minimum_translations
[0];
499 Real last_spaceable_dy
= 0;
500 Real first_spaceable_dy
= 0;
501 bool found_spaceable_staff
= false;
503 for (vsize i
= 0; i
< staves
.size (); ++i
)
505 Real dy
= minimum_translations
[i
] - first_translation
;
507 Skyline_pair
*sky
= Skyline_pair::unsmob (g
->get_property ("vertical-skylines"));
511 up
->merge ((*sky
)[UP
]);
515 down
->merge ((*sky
)[DOWN
]);
518 if (is_spaceable (staves
[i
]))
520 if (!found_spaceable_staff
)
522 found_spaceable_staff
= true;
523 first_spaceable_dy
= dy
;
525 last_spaceable_dy
= dy
;
529 // Leave the up skyline at a position relative
530 // to the top spaceable staff.
531 up
->raise (-first_spaceable_dy
);
533 // Leave the down skyline at a position
534 // relative to the bottom spaceable staff.
535 down
->raise (-last_spaceable_dy
);
539 Page_layout_problem::prob_extent (Prob
*p
)
541 Stencil
*sten
= unsmob_stencil (p
->get_property ("stencil"));
542 return sten
? sten
->extent (Y_AXIS
) : Interval (0, 0);
546 Page_layout_problem::first_staff_extent (Element
const& e
)
549 return prob_extent (e
.prob
);
550 else if (e
.staves
.size ())
551 return e
.staves
[0]->extent (e
.staves
[0], Y_AXIS
);
553 return Interval (0, 0);
557 Page_layout_problem::last_staff_extent (Element
const& e
)
560 return prob_extent (e
.prob
);
561 else if (e
.staves
.size ())
562 return e
.staves
.back ()->extent (e
.staves
.back (), Y_AXIS
);
564 return Interval (0, 0);
568 Page_layout_problem::get_details (Element
const& elt
)
570 if (elt
.staves
.empty ())
573 return get_details (elt
.staves
.back ()->get_system ());
577 Page_layout_problem::get_details (Grob
*g
)
579 Grob
*left_bound
= dynamic_cast<Spanner
*> (g
)->get_bound (LEFT
);
580 return left_bound
->get_property ("line-break-system-details");
584 Page_layout_problem::is_spaceable (Grob
*g
)
586 return !scm_is_number (g
->get_property ("staff-affinity"));
590 Page_layout_problem::mark_as_spaceable (Grob
*g
)
592 g
->set_property ("staff-affinity", SCM_BOOL_F
);
596 Page_layout_problem::read_spacing_spec (SCM spec
, Real
* dest
, SCM sym
)
598 SCM pair
= scm_sloppy_assq (sym
, spec
);
599 if (scm_is_pair (pair
) && scm_is_number (scm_cdr (pair
)))
601 *dest
= scm_to_double (scm_cdr (pair
));
608 add_stretchability (SCM alist
, Real stretch
)
610 if (!scm_is_pair (scm_sloppy_assq (ly_symbol2scm ("stretchability"), alist
)))
611 return scm_acons (ly_symbol2scm ("stretchability"), scm_from_double (stretch
), alist
);
616 // We want to put a large stretch between a non-spaceable line and its
617 // non-affinity staff. We want to put an even larger stretch between
618 // a non-spaceable line and the top/bottom of the page. That way,
619 // a spacing-affinity UP line at the bottom of the page will still be
620 // placed close to its staff.
621 const double LARGE_STRETCH
= 10e5
;
622 const double HUGE_STRETCH
= 10e7
;
624 // Returns the spacing spec connecting BEFORE to AFTER.
626 Page_layout_problem::get_spacing_spec (Grob
*before
, Grob
*after
)
628 // If there are no spacing wishes, return a very flexible spring.
629 // This will occur, for example, if there are lyrics at the bottom of
630 // the page, in which case we don't want the spring from the lyrics to
631 // the bottom of the page to have much effect.
632 if (!before
|| !after
)
633 return add_stretchability (SCM_EOL
, HUGE_STRETCH
);
635 if (is_spaceable (before
))
637 if (is_spaceable (after
))
638 return before
->get_property ("next-staff-spacing");
641 Direction affinity
= to_dir (after
->get_property ("staff-affinity"));
642 return (affinity
== DOWN
)
643 ? add_stretchability (after
->get_property ("non-affinity-spacing"), LARGE_STRETCH
)
644 : after
->get_property ("inter-staff-spacing");
649 if (is_spaceable (after
))
651 Direction affinity
= to_dir (before
->get_property ("staff-affinity"));
652 return (affinity
== UP
)
653 ? add_stretchability (before
->get_property ("non-affinity-spacing"), LARGE_STRETCH
)
654 : before
->get_property ("inter-staff-spacing");
658 Direction before_affinity
= to_dir (before
->get_property ("staff-affinity"));
659 Direction after_affinity
= to_dir (after
->get_property ("staff-affinity"));
660 if (after_affinity
> before_affinity
)
662 warning (_ ("staff-affinities should only decrease"));
663 after_affinity
= before_affinity
;
665 if (before_affinity
!= UP
)
666 return before
->get_property ("inter-loose-line-spacing");
667 else if (after_affinity
!= DOWN
)
668 return before
->get_property ("inter-loose-line-spacing");
669 return add_stretchability (before
->get_property ("non-affinity-spacing"), LARGE_STRETCH
);
678 Page_layout_problem::alter_spring_from_spacing_spec (SCM spec
, Spring
* spring
)
683 if (read_spacing_spec (spec
, &space
, ly_symbol2scm ("space")))
684 spring
->set_distance (space
);
685 if (read_spacing_spec (spec
, &min_dist
, ly_symbol2scm ("minimum-distance")))
686 spring
->set_min_distance (min_dist
);
687 spring
->set_default_strength ();
689 if (read_spacing_spec (spec
, &stretch
, ly_symbol2scm ("stretchability")))
691 spring
->set_inverse_stretch_strength (stretch
);
692 spring
->set_inverse_compress_strength (stretch
);
697 Page_layout_problem::filter_dead_elements (vector
<Grob
*> const& input
)
699 vector
<Grob
*> output
;
700 for (vsize i
= 0; i
< input
.size (); ++i
)
702 if (Hara_kiri_group_spanner::has_interface (input
[i
]))
703 Hara_kiri_group_spanner::consider_suicide (input
[i
]);
705 if (input
[i
]->is_live ())
706 output
.push_back (input
[i
]);