1 ;;;; page-layout.scm -- page breaking and page layout
3 ;;;; source file of the GNU LilyPond music typesetter
5 ;;;; (c) 2004--2005 Jan Nieuwenhuizen <janneke@gnu.org>
6 ;;;; Han-Wen Nienhuys <hanwen@cs.uu.nl>
8 (use-modules (oop goops describe)
12 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
14 (define-class <optimally-broken-page-node> ()
15 (prev #:init-value '() #:accessor node-prev #:init-keyword #:prev)
16 (page #:init-value 0 #:accessor node-page-number #:init-keyword #:pageno)
17 (force #:init-value 0 #:accessor node-force #:init-keyword #:force)
18 (penalty #:init-value 0 #:accessor node-penalty #:init-keyword #:penalty)
19 (configuration #:init-value '() #:accessor node-configuration #:init-keyword #:configuration)
20 (lines #:init-value 0 #:accessor node-lines #:init-keyword #:lines))
22 (define-method (display (node <optimally-broken-page-node>) port)
23 (map (lambda (x) (display x port))
25 "Page " (node-page-number node)
26 " Lines: " (node-lines node)
27 " Penalty " (node-penalty node)
30 (define-method (node-system-numbers (node <optimally-broken-page-node>))
31 (map ly:paper-system-number (node-lines node)))
33 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
35 (define (page-headfoot layout scopes number sym sepsym dir last?)
36 "Create a stencil including separating space."
37 (let* ((header-proc (ly:output-def-lookup layout sym))
38 (sep (ly:output-def-lookup layout sepsym))
39 (stencil (ly:make-stencil "" '(0 . 0) '(0 . 0)))
41 (if (procedure? header-proc)
42 (header-proc layout scopes number last?)
45 (if (and (number? sep)
46 (ly:stencil? head-stencil)
47 (not (ly:stencil-empty? head-stencil)))
49 (ly:stencil-combine-at-edge
50 stencil Y dir head-stencil
55 (define-public (default-page-music-height layout scopes number last?)
56 "Printable area for music and titles; matches default-page-make-stencil."
57 (let* ((h (- (ly:output-def-lookup layout 'vsize)
58 (ly:output-def-lookup layout 'topmargin)
59 (ly:output-def-lookup layout 'bottommargin)))
60 (head (page-headfoot layout scopes number 'make-header 'headsep UP last?))
61 (foot (page-headfoot layout scopes number 'make-footer 'footsep DOWN last?))
63 (- h (if (ly:stencil? head)
64 (interval-length (ly:stencil-extent head Y))
66 (if (ly:stencil? foot)
67 (interval-length (ly:stencil-extent foot Y))
70 ;; (display (list "\n available" available head foot))
73 (define-public (default-page-make-stencil
74 lines offsets layout scopes number last?)
75 "Construct a stencil representing the page from LINES.
77 Offsets is a list of increasing numbers. They must be negated to
81 (let* ((topmargin (ly:output-def-lookup layout 'topmargin))
83 ;; TODO: naming vsize/hsize not analogous to TeX.
85 (vsize (ly:output-def-lookup layout 'vsize))
86 (hsize (ly:output-def-lookup layout 'hsize))
88 (system-xoffset (ly:output-def-lookup layout 'horizontalshift 0.0))
89 (system-separator-markup (ly:output-def-lookup layout 'systemSeparatorMarkup))
90 (system-separator-stencil (if (markup? system-separator-markup)
91 (interpret-markup layout
92 (layout-extract-page-properties layout)
93 system-separator-markup)
95 (lmargin (ly:output-def-lookup layout 'leftmargin))
96 (leftmargin (if lmargin
99 (ly:output-def-lookup layout 'linewidth)) 2)))
101 (rightmargin (ly:output-def-lookup layout 'rightmargin))
102 (bottom-edge (- vsize
103 (ly:output-def-lookup layout 'bottommargin)))
105 (head (page-headfoot layout scopes number 'make-header 'headsep UP last?))
106 (foot (page-headfoot layout scopes number 'make-footer 'footsep DOWN last?))
108 (head-height (if (ly:stencil? head)
109 (interval-length (ly:stencil-extent head Y))
112 (height-proc (ly:output-def-lookup layout 'page-music-height))
114 (page-stencil (ly:make-stencil '()
115 (cons leftmargin hsize)
116 (cons (- topmargin) 0)))
119 (add-to-page (lambda (stencil y)
121 (ly:stencil-add page-stencil
122 (ly:stencil-translate stencil
125 (- 0 head-height y topmargin))
129 (lambda (stencil-position)
130 (let* ((system (car stencil-position))
131 (stencil (ly:paper-system-stencil system))
132 (y (cadr stencil-position))
133 (is-title (ly:paper-system-title?
134 (car stencil-position))))
135 (add-to-page stencil y)
136 (if (and (ly:stencil? system-separator-stencil)
138 (not (ly:paper-system-title? system))
139 (not (ly:paper-system-title? last-system)))
141 system-separator-stencil
143 (car (ly:paper-system-staff-extents last-system)))
145 (cdr (ly:paper-system-staff-extents system))))))
146 (set! last-system system)
151 "leftmargin " leftmargin "rightmargin " rightmargin
154 (set! page-stencil (ly:stencil-combine-at-edge
158 (not (ly:stencil-empty? head)))
160 (ly:make-stencil "" (cons 0 0) (cons 0 0)))
163 (map add-system (zip lines offsets))
164 (if (and (ly:stencil? foot)
165 (not (ly:stencil-empty? foot)))
169 (ly:stencil-translate
173 (- (car (ly:stencil-extent foot Y)))))))))
175 (ly:stencil-translate page-stencil (cons leftmargin 0))))
177 ;;; optimal page breaking
179 ;;; This is not optimal page breaking, this is optimal distribution of
180 ;;; lines over pages; line breaks are a given.
185 ;; - separate function for word-wrap style breaking?
186 ;; - raggedbottom? raggedlastbottom?
188 (define-public (ly:optimal-page-breaks
190 "Return pages as a list starting with 1st page. Each page is a list
194 (define MAXPENALTY 1e9)
195 (define paper (ly:paper-book-paper paper-book))
196 (define scopes (ly:paper-book-scopes paper-book))
198 (define (page-height page-number last?)
199 (let ((p (ly:output-def-lookup paper 'page-music-height)))
202 (p paper scopes page-number last?)
205 (define (get-path node done)
206 "Follow NODE.PREV, and return as an ascending list of pages. DONE
207 is what have collected so far, and has ascending page numbers."
209 (if (is-a? node <optimally-broken-page-node>)
210 (get-path (node-prev node) (cons node done))
213 (define (combine-penalties force user best-paths)
214 (let* ((prev-force (if (null? best-paths)
216 (node-force (car best-paths))))
217 (prev-penalty (if (null? best-paths)
219 (node-penalty (car best-paths))))
220 (inter-system-space (ly:output-def-lookup paper 'betweensystemspace))
221 (force-equalization-factor 0.3)
222 (relative-force (/ force inter-system-space))
223 (abs-relative-force (abs relative-force)))
226 (+ (* abs-relative-force (+ abs-relative-force 1))
228 (* force-equalization-factor (/ (abs (- prev-force force)) inter-system-space))
231 (define (space-systems page-height lines ragged?)
232 (let* ((inter-system-space
233 (ly:output-def-lookup paper 'betweensystemspace))
234 (system-vector (list->vector
236 (if (= (length lines) 1)
241 (append (map ly:paper-system-staff-extents lines)
242 (if (= (length lines) 1)
249 (lambda (sys) (ly:paper-system-extent sys Y)) lines)
250 (if (= (length lines) 1)
253 (no-systems (vector-length real-extents))
254 (topskip (interval-end (vector-ref real-extents 0)))
255 (space-left (- page-height
256 (apply + (map interval-length (vector->list real-extents)))))
258 (space (- page-height
260 (- (interval-start (vector-ref real-extents (1- no-systems))))))
262 (fixed-dist (ly:output-def-lookup paper 'betweensystempadding))
265 (let* ((this-system-ext (vector-ref staff-extents idx))
266 (next-system-ext (vector-ref staff-extents (1+ idx)))
267 (fixed (max 0 (- (+ (interval-end next-system-ext)
269 (interval-start this-system-ext))))
270 (title1? (and (vector-ref system-vector idx)
271 (ly:paper-system-title? (vector-ref system-vector idx))))
273 (vector-ref system-vector (1+ idx))
274 (ly:paper-system-title? (vector-ref system-vector (1+ idx)))))
277 ((and title2? title1?)
278 (ly:output-def-lookup paper 'betweentitlespace))
280 (ly:output-def-lookup paper 'aftertitlespace))
282 (ly:output-def-lookup paper 'beforetitlespace))
283 (else inter-system-space))
285 (hooke (/ 1 (- ideal fixed))))
286 (list ideal hooke))))
288 (springs (map calc-spring (iota (1- no-systems))))
291 (let* ((this-system-ext (vector-ref real-extents idx))
292 (next-system-ext (vector-ref real-extents (1+ idx)))
293 (distance (max (- (+ (interval-end next-system-ext)
295 (interval-start this-system-ext)
297 (entry (list idx (1+ idx) distance)))
299 (rods (map calc-rod (iota (1- no-systems))))
301 ;; we don't set ragged based on amount space left.
302 ;; raggedbottomlast = ##T is much more predictable
303 (result (ly:solve-spring-rod-problem
315 (display (list "\n# systems: " no-systems
316 "\nreal-ext" real-extents "\nstaff-ext" staff-extents
317 "\ninterscore" inter-system-space
318 "\nspace-letf" space-left
319 "\nspring,rod" springs rods
322 "\npage-height" page-height
326 "\npositions" positions "\n"))))
328 (cons force positions)))
330 (define (walk-paths done-lines best-paths current-lines last? current-best)
331 "Return the best optimal-page-break-node that contains
332 CURRENT-LINES. DONE-LINES.reversed ++ CURRENT-LINES is a consecutive
333 ascending range of lines, and BEST-PATHS contains the optimal breaks
334 corresponding to DONE-LINES.
336 CURRENT-BEST is the best result sofar, or #f."
338 (let* ((this-page-num (if (null? best-paths)
339 (ly:output-def-lookup paper 'firstpagenumber)
340 (1+ (node-page-number (car best-paths)))))
342 (ragged-all? (eq? #t (ly:output-def-lookup paper 'raggedbottom)))
343 (ragged-last? (eq? #t (ly:output-def-lookup paper 'raggedlastbottom)))
344 (ragged? (or ragged-all?
347 (page-height (page-height this-page-num last?))
348 (vertical-spacing (space-systems page-height current-lines ragged?))
349 (satisfied-constraints (car vertical-spacing))
350 (force (if satisfied-constraints
351 (if (and last? ragged-last?)
353 satisfied-constraints)
355 (positions (cdr vertical-spacing))
356 (user-nobreak-penalties
358 (apply + (filter negative?
359 (map ly:paper-system-break-before-penalty
360 (cdr current-lines))))))
363 (max (ly:paper-system-break-before-penalty (car current-lines)) 0.0)
364 user-nobreak-penalties))
365 (total-penalty (combine-penalties
372 (< total-penalty (node-penalty current-best))))
373 (new-best (if better?
374 (make <optimally-broken-page-node>
375 #:prev (if (null? best-paths)
378 #:lines current-lines
379 #:pageno this-page-num
381 #:configuration positions
382 #:penalty total-penalty)
388 "\nuser pen " user-penalty
389 "\nsatisfied-constraints" satisfied-constraints
390 "\nlast? " last? "ragged?" ragged?
391 "\nbetter? " better? " total-penalty " total-penalty "\n"
392 "\nconfig " positions
394 "\nlines: " current-lines "\n")))
397 (display (list "\nnew-best is " (node-lines new-best)
399 (if (null? best-paths)
401 (node-lines (car best-paths))))))
403 (if (and (pair? done-lines)
404 ;; if this page is too full, adding another line won't help
405 satisfied-constraints)
406 (walk-paths (cdr done-lines) (cdr best-paths)
407 (cons (car done-lines) current-lines)
411 (define (walk-lines done best-paths todo)
412 "Return the best page breaking as a single
413 <optimal-page-break-node> for optimally breaking TODO ++
414 DONE.reversed. BEST-PATHS is a list of break nodes corresponding to
418 (let* ((this-line (car todo))
419 (last? (null? (cdr todo)))
420 (next (walk-paths done best-paths (list this-line) last? #f)))
422 ;; (display "\n***************")
423 (walk-lines (cons this-line done)
424 (cons next best-paths)
427 (define (line-number node)
428 (ly:paper-system-number (car (node-lines node))))
430 (ly:message (_ "Calculating page breaks..."))
432 (let* ((best-break-node (walk-lines '() '() lines))
433 (break-nodes (get-path best-break-node '()))
434 (last-node (car (last-pair break-nodes))))
436 (define (node->page-stencil node)
437 (if (not (eq? node last-node))
440 ((ly:output-def-lookup paper 'page-make-stencil)
442 (node-configuration node)
445 (node-page-number node)
446 (eq? node best-break-node))))
447 (if (not (eq? node last-node))
449 (ly:progress (number->string
450 (car (last-pair (node-system-numbers node)))))
454 (if #f; (ly:get-option 'verbose)
457 "\nbreaks: " (map line-number break-nodes))
458 "\nsystems " (map node-lines break-nodes)
459 "\npenalties " (map node-penalty break-nodes)
460 "\nconfigs " (map node-configuration break-nodes))))
462 (let ((stencils (map node->page-stencil break-nodes)))