1 ;;; page-layout.scm -- page breaking and page layout
3 ;;;; source file of the GNU LilyPond music typesetter
5 ;;;; (c) 2004 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 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
33 (string-append "Engraved by LilyPond (version " (lilypond-version) ")"))
35 ;; TODO: take <optimally-broken-page-node> iso. page-number
36 ;; for all of these functions ?
38 (define-public (plain-header paper scopes page-number last?)
39 "Standard header for a part: page number --outside-- and instrument--centered."
41 (let* ((props (page-properties paper))
43 (if (ly:output-def-lookup paper 'printpagenumber)
44 (markup #:bold (number->string page-number))
46 (instr (ly:modules-lookup scopes 'instrument))
48 (line (list "" (if (markup? instr) instr "") pnum)))
50 (if (even? page-number)
51 (set! line (reverse line)))
53 (if (< (ly:output-def-lookup paper 'firstpagenumber) page-number)
55 paper props (make-fill-line-markup line))
58 ;; TODO: add publisher ID on non-first page.
59 (define-public (plain-footer paper scopes page-number last?)
60 "Standard footer. Empty, save for first (copyright) and last (tagline) page."
63 ((props (page-properties paper))
64 (copyright (ly:modules-lookup scopes 'copyright))
65 (tagline-var (ly:modules-lookup scopes 'tagline))
66 (tagline (if (markup? tagline-var) tagline-var TAGLINE))
71 (ly:stencil-combine-at-edge
72 stencil Y DOWN (interpret-markup paper props tagline)
76 (if (and (= 1 page-number)
80 (ly:stencil-combine-at-edge
81 stencil Y DOWN (interpret-markup paper props copyright)
87 (define (page-headfoot paper scopes number sym sepsym dir last?)
88 "Create a stencil including separating space."
90 ((header-proc (ly:output-def-lookup paper sym))
91 (sep (ly:output-def-lookup paper sepsym))
92 (stencil (ly:make-stencil "" '(0 . 0) '(0 . 0)))
94 (if (procedure? header-proc)
95 (header-proc paper scopes number last?)
98 (if (and (number? sep) (ly:stencil? head-stencil))
100 (ly:stencil-combine-at-edge
101 stencil Y dir head-stencil
106 (define-public (default-page-music-height paper scopes number last?)
107 "Printable area for music and titles; matches default-page-make-stencil."
109 ((h (- (ly:output-def-lookup paper 'vsize)
110 (ly:output-def-lookup paper 'topmargin)
111 (ly:output-def-lookup paper 'bottommargin)))
112 (head (page-headfoot paper scopes number 'make-header 'headsep UP last?))
113 (foot (page-headfoot paper scopes number 'make-footer 'footsep DOWN last?)))
114 (- h (if (ly:stencil? head)
115 (interval-length (ly:stencil-extent head Y))
117 (if (ly:stencil? foot)
118 (interval-length (ly:stencil-extent foot Y))
123 (define-public (default-page-make-stencil
124 lines offsets paper scopes number last? )
125 "Construct a stencil representing the page from LINES. "
127 ((topmargin (ly:output-def-lookup paper 'topmargin))
129 ;; TODO: naming vsize/hsize not analogous to TeX.
131 (vsize (ly:output-def-lookup paper 'vsize))
132 (hsize (ly:output-def-lookup paper 'hsize))
134 (lmargin (ly:output-def-lookup paper 'leftmargin))
135 (leftmargin (if lmargin
138 (ly:output-def-lookup paper 'linewidth)) 2)))
140 (rightmargin (ly:output-def-lookup paper 'rightmargin))
141 (bottom-edge (- vsize
142 (ly:output-def-lookup paper 'bottommargin)))
144 (head (page-headfoot paper scopes number 'make-header 'headsep UP last?))
145 (foot (page-headfoot paper scopes number 'make-footer 'footsep DOWN last?))
146 (line-stencils (map ly:paper-system-stencil lines))
147 (height-proc (ly:output-def-lookup paper 'page-music-height))
149 (page-stencil (ly:make-stencil '()
150 (cons leftmargin hsize)
151 (cons (- topmargin) 0)))
153 (add-system (lambda (stencil-position)
156 (ly:stencil-translate-axis
157 (car stencil-position)
159 (cadr stencil-position)
166 (map add-system (zip line-stencils offsets))
167 (if (ly:stencil? foot)
171 (ly:stencil-translate
175 (- (car (ly:stencil-extent foot Y)))))
178 (ly:stencil-translate page-stencil (cons leftmargin 0))
184 ;;; optimal page breaking
186 ;;; This is not optimal page breaking, this is optimal distribution of
187 ;;; lines over pages; line breaks are a given.
192 ; - separate function for word-wrap style breaking?
193 ; - raggedbottom? raggedlastbottom?
195 (define-public (ly:optimal-page-breaks
197 "Return pages as a list starting with 1st page. Each page is a list
201 (define MAXPENALTY 1e9)
202 (define bookpaper (ly:paper-book-book-paper paper-book))
203 (define scopes (ly:paper-book-scopes paper-book))
205 (define (page-height page-number last?)
207 ((p (ly:output-def-lookup bookpaper 'page-music-height)))
210 (p bookpaper scopes page-number last?)
213 (define (get-path node done)
214 "Follow NODE.PREV, and return as an ascending list of pages. DONE
215 is what have collected so far, and has ascending page numbers."
217 (if (is-a? node <optimally-broken-page-node>)
218 (get-path (node-prev node) (cons node done))
221 (define (combine-penalties force user best-paths)
223 ((prev-force (if (null? best-paths)
225 (node-force (car best-paths))))
226 (prev-penalty (if (null? best-paths)
228 (node-penalty (car best-paths))))
229 (inter-system-space (ly:output-def-lookup bookpaper 'betweensystemspace))
230 (force-equalization-factor 0.3)
231 (relative-force (/ force inter-system-space))
232 (abs-relative-force (abs relative-force))
236 (+ (* abs-relative-force (+ abs-relative-force 1))
238 (* force-equalization-factor (/ (abs (- prev-force force)) inter-system-space))
241 (define (space-systems page-height lines ragged?)
244 (ly:output-def-lookup bookpaper 'betweensystemspace))
249 ly:paper-system-staff-extents
251 (if (= (length lines) 1)
259 (lambda (sys) (ly:paper-system-extent sys Y)) lines)
260 (if (= (length lines) 1)
264 (no-systems (vector-length real-extents))
265 (topskip (cdr (vector-ref real-extents 0)))
266 (space-left (- page-height
267 (apply + (map interval-length (vector->list real-extents)))
271 (space (- page-height
273 (- (car (vector-ref real-extents (1- no-systems))))
279 ((this-system-ext (vector-ref staff-extents idx))
280 (next-system-ext (vector-ref staff-extents (1+ idx)))
281 (fixed (- (cdr next-system-ext)
282 (car this-system-ext)))
283 (ideal (+ inter-system-space fixed))
284 (hooke (/ 1 (- ideal fixed)))
289 (springs (map calc-spring (iota (1- no-systems))))
290 (fixed-dist (ly:output-def-lookup bookpaper 'betweensystempadding))
294 ((this-system-ext (vector-ref real-extents idx))
295 (next-system-ext (vector-ref real-extents (1+ idx)))
296 (distance (- (+ (cdr next-system-ext)
298 (car this-system-ext)
300 (entry (list idx (1+ idx) distance)))
302 (rods (map calc-rod (iota (1- no-systems))))
303 (page-very-empty (> space-left (/ page-height 3)))
304 (result (ly:solve-spring-rod-problem
316 (display (list "\n# systems: " no-systems
317 "\nreal-ext" real-extents "\nstaff-ext" staff-extents
318 "\ninterscore" inter-system-space
319 "\nspace-letf" space-left
320 "\npage empty" page-very-empty
321 "\nspring,rod" springs rods
324 "\npage-height" page-height
328 "\npositions" positions "\n"))))
330 (cons force positions)))
332 (define (walk-paths done-lines best-paths current-lines last? current-best)
333 "Return the best optimal-page-break-node that contains
334 CURRENT-LINES. DONE-LINES.reversed ++ CURRENT-LINES is a consecutive
335 ascending range of lines, and BEST-PATHS contains the optimal breaks
336 corresponding to DONE-LINES.
338 CURRENT-BEST is the best result sofar, or #f."
340 (let* ((this-page-num (if (null? best-paths)
341 (ly:output-def-lookup bookpaper 'firstpagenumber)
342 (1+ (node-page-number (car best-paths)))))
345 (ragged? (or (eq? #t (ly:output-def-lookup bookpaper 'raggedbottom))
346 (and (eq? #t (ly:output-def-lookup bookpaper 'raggedlastbottom))
348 (page-height (page-height this-page-num last?))
350 (vertical-spacing (space-systems page-height current-lines ragged?))
351 (satisfied-constraints (car vertical-spacing))
352 (force (if satisfied-constraints satisfied-constraints 10000))
353 (positions (cdr vertical-spacing))
354 (user-penalty (ly:paper-system-break-penalty (car current-lines)))
355 (total-penalty (combine-penalties
362 (< total-penalty (node-penalty current-best))))
363 (new-best (if better?
364 (make <optimally-broken-page-node>
365 #:prev (if (null? best-paths)
368 #:lines current-lines
369 #:pageno this-page-num
371 #:configuration positions
372 #:penalty total-penalty)
378 "\nuser pen " user-penalty
379 "\nsatisfied-constraints" satisfied-constraints
380 "\nlast? " last? "ragged?" ragged?
381 "\nbetter? " better? " total-penalty " total-penalty "\n"
382 "\nconfig " positions
384 "\nlines: " current-lines "\n")))
387 (display (list "\nnew-best is " (node-lines new-best)
389 (if (null? best-paths)
391 (node-lines (car best-paths))))))
393 (if (and (pair? done-lines)
394 ;; if this page is too full, adding another line won't help
395 satisfied-constraints)
396 (walk-paths (cdr done-lines) (cdr best-paths)
397 (cons (car done-lines) current-lines)
402 (define (walk-lines done best-paths todo)
403 "Return the best page breaking as a single
404 <optimal-page-break-node> for optimally breaking TODO ++
405 DONE.reversed. BEST-PATHS is a list of break nodes corresponding to
409 (let* ((this-line (car todo))
410 (last? (null? (cdr todo)))
411 (next (walk-paths done best-paths (list this-line) last? #f)))
413 ; (display "\n***************")
414 (walk-lines (cons this-line done)
415 (cons next best-paths)
418 (define (line-number node)
419 (ly:paper-system-number (car (node-lines node))))
421 (let* ((best-break-node (walk-lines '() '() lines))
422 (break-nodes (get-path best-break-node '())))
424 (if #f; (ly:get-option 'verbose)
427 "\nbreaks: " (map line-number break-nodes))
428 "\nsystems " (map node-lines break-nodes)
429 "\npenalties " (map node-penalty break-nodes)
430 "\nconfigs " (map node-configuration break-nodes))))
436 ((ly:output-def-lookup bookpaper 'page-make-stencil)
438 (node-configuration node)
441 (node-page-number node)
442 (eq? node best-break-node)))