-;;;; page-layout.scm -- page layout functions
-;;;;
+;;; page-layout.scm -- page breaking and page layout
+;;;
;;;; source file of the GNU LilyPond music typesetter
-;;;;
+;;;;
;;;; (c) 2004 Jan Nieuwenhuizen <janneke@gnu.org>
+;;;; Han-Wen Nienhuys <hanwen@cs.uu.nl>
+
+(use-modules (oop goops describe)
+ (oop goops))
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(define-class <optimally-broken-page-node> ()
+ (prev #:init-value '() #:accessor node-prev #:init-keyword #:prev)
+ (page #:init-value 0 #:accessor node-page-number #:init-keyword #:pageno)
+ (penalty #:init-value 0 #:accessor node-penalty #:init-keyword #:penalty)
+ (lines #:init-value 0 #:accessor node-lines #:init-keyword #:lines))
+
+(define-method (display (node <optimally-broken-page-node>) port)
+ (map (lambda (x) (display x port))
+ (list
+ "Page " (node-page-number node)
+ " Lines: " (node-lines node)
+ " Penalty " (node-penalty node)
+ "\n")))
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-(define (ly:modules-lookup modules sym)
- (let ((v (module-variable (car modules) sym)))
- (if (and v (variable-bound? v) (variable-ref v))
- (variable-ref v)
- (if (module? (cdr modules)) (ly:modules-lookup (cdr modules) sym)))))
+(define TAGLINE
+ (string-append "Engraved by LilyPond (version " (lilypond-version) ")"))
+;; TODO: take <optimally-broken-page-node> iso. page-number
+;; for all of these functions ?
-(define-public (book-title paper scopes)
- "Generate book title from header strings."
+(define-public (plain-header paper scopes page-number last?)
+ "Standard header for a part: page number --outside-- and instrument--centered."
+
+ (let* ((props (page-properties paper))
+ (pnum
+ (if (ly:output-def-lookup paper 'printpagenumber)
+ (markup #:bold (number->string page-number))
+ ""
+ ))
+ (instr (ly:modules-lookup scopes 'instrument))
+
+ (line (list "" (if (markup? instr) instr "") pnum)))
+
+ (if (even? page-number)
+ (set! line (reverse line)))
+
+ (if (< 1 page-number)
+ (interpret-markup
+ paper props (make-fill-line-markup line))
+ '())
+ ))
+
+
+;; TODO: add publisher ID on non-first page.
+(define-public (plain-footer paper scopes page-number last?)
+ "Standard footer. Empty, save for first (copyright) and last (tagline) page."
- (define (get sym)
- (let ((x (ly:modules-lookup scopes sym)))
- (if (and x (not (unspecified? x))) x "")))
+ (let*
+ ((props (page-properties paper))
+ (copyright (ly:modules-lookup scopes 'copyright))
+ (tagline-var (ly:modules-lookup scopes 'tagline))
+ (tagline (if (markup? tagline-var) tagline-var TAGLINE))
+ (stencil #f))
+
+ (if last?
+ (set! stencil
+ (ly:stencil-combine-at-edge
+ stencil Y DOWN (interpret-markup paper props tagline)
+ 0.0
+ )))
+
+ (if (and (= 1 page-number)
+ (markup? copyright))
+
+ (set! stencil
+ (ly:stencil-combine-at-edge
+ stencil Y DOWN (interpret-markup paper props copyright)
+ 0.0
+ )))
+
+ stencil))
- (let ((props (list (append `((linewidth . ,(ly:paper-get-number
- paper 'linewidth))
- (font-family . roman))
- (ly:paper-lookup paper 'font-defaults)))))
- (interpret-markup
- paper props
- (markup
- #:column
- (#:override '(baseline-skip . 4)
- #:column
- (#:fill-line
- (#:latin-i (get 'dedication))
- #:fill-line
- (#:huge #:bigger #:bigger #:bigger #:bigger #:bold (get 'title))
- #:override '(baseline-skip . 3)
- #:column
- (#:fill-line
- (#:large #:bigger #:bigger #:bold (get 'subtitle))
- #:fill-line (#:bigger #:bigger #:bold (get 'subsubtitle)))
- #:override '(baseline-skip . 5)
- #:column ("")
- #:override '(baseline-skip . 2.5)
- #:column
- (#:fill-line
- (#:bigger (get 'poet) #:large #:bigger #:caps (get 'composer))
- #:fill-line (#:bigger (get 'texttranslator) #:bigger (get 'opus))
- #:fill-line
- (#:bigger (get 'meter) #:bigger (get 'arranger))
- ""
- #:fill-line (#:large #:bigger (get 'instrument))
- " "
- #:fill-line (#:large #:bigger #:caps (get 'piece) ""))))))))
-
-(define-public (user-title paper markup)
- "Generate book title from header markup."
- (if (markup? markup)
- (let ((BASELINE-SKIP 2)
- (props (list (append `((linewidth . ,(ly:paper-get-number
- paper 'linewidth))
- (font-family . roman))
- (ly:paper-lookup paper 'font-defaults)))))
- (stack-lines DOWN 0 BASELINE-SKIP
- (list (interpret-markup paper props markup))))))
-
-(define-public (score-title paper scopes)
- "Generate score title from header strings."
+(define (page-headfoot paper scopes number sym sepsym dir last?)
+ "Create a stencil including separating space."
+ (let*
+ ((header-proc (ly:output-def-lookup paper sym))
+ (sep (ly:output-def-lookup paper sepsym))
+ (stencil (ly:make-stencil "" '(0 . 0) '(0 . 0)))
+ (head-stencil
+ (if (procedure? header-proc)
+ (header-proc paper scopes number last?)
+ #f)))
+
+ (if (and (number? sep) (ly:stencil? head-stencil))
+ (set! head-stencil
+ (ly:stencil-combine-at-edge
+ stencil Y dir head-stencil
+ sep 0.0)))
+
+ head-stencil))
+
+(define-public (default-page-music-height paper scopes number last?)
+ "Printable area for music and titles; matches default-page-make-stencil."
+ (let*
+ ((h (- (ly:output-def-lookup paper 'vsize)
+ (ly:output-def-lookup paper 'top-margin)
+ (ly:output-def-lookup paper 'bottom-margin)))
+ (head (page-headfoot paper scopes number 'make-header 'head-sep UP last?))
+ (foot (page-headfoot paper scopes number 'make-footer 'foot-sep DOWN last?)))
+ (- h (if (ly:stencil? head)
+ (interval-length (ly:stencil-extent head Y))
+ 0)
+ (if (ly:stencil? foot)
+ (interval-length (ly:stencil-extent foot Y))
+ 0))
+ ))
+
+
+(define-public (default-page-make-stencil lines paper scopes number last? )
+ "Construct a stencil representing the page from LINES. "
+ (let*
+ ((top-margin (ly:output-def-lookup paper 'top-margin))
+
+ ;; TODO: naming vsize/hsize not analogous to TeX.
+
+ (hsize (ly:output-def-lookup paper 'hsize))
+ (left-margin (/ (- hsize
+ (ly:output-def-lookup paper 'linewidth)) 2))
+ (vsize (ly:output-def-lookup paper 'vsize))
+ (bottom-edge (- vsize
+ (ly:output-def-lookup paper 'bottom-margin)))
+
+ (head (page-headfoot paper scopes number 'make-header 'head-sep UP last?))
+ (foot (page-headfoot paper scopes number 'make-footer 'foot-sep DOWN last?))
+ (line-stencils (map ly:paper-system-stencil lines))
+ (height-proc (ly:output-def-lookup paper 'page-music-height))
+ (music-height (height-proc paper scopes number last?))
+ (ragged (ly:output-def-lookup paper 'raggedbottom))
+ (ragged-last (ly:output-def-lookup paper 'raggedlastbottom))
+ (ragged-bottom (or (eq? #t ragged)
+ (and last? (eq? #t ragged-last))))
+
+ (spc-left (- music-height
+ (apply + (map (lambda (x)
+ (interval-length (ly:stencil-extent x Y)))
+ line-stencils))))
+ (stretchable-lines (remove ly:paper-system-title? (cdr lines)))
+ (stretch (if (or (null? stretchable-lines)
+ (> spc-left (/ music-height 2))
+ ragged-bottom)
+ 0.0
+ (/ spc-left (length stretchable-lines))))
+
+ (page-stencil (ly:make-stencil '()
+ (cons left-margin hsize)
+ (cons (- top-margin) 0)))
+ (was-title #t))
+
+ (set! page-stencil (ly:stencil-combine-at-edge
+ page-stencil Y DOWN head 0. 0.))
+
+ (for-each
+ (lambda (l)
+ (set! page-stencil
+ (ly:stencil-combine-at-edge
+ page-stencil Y DOWN (ly:paper-system-stencil l)
+ (if was-title
+ 0.0
+ stretch)
+ ))
+
+ (set! was-title (ly:paper-system-title? l)))
+ lines)
+
+ (if (ly:stencil? foot)
+ (set! page-stencil
+ (ly:stencil-add
+ page-stencil
+ (ly:stencil-translate
+ foot
+ (cons 0
+ (+ (- bottom-edge) (- (car (ly:stencil-extent foot Y)))))
+ ))))
+
+ (ly:stencil-translate page-stencil (cons left-margin 0))
+ ))
- (define (get sym)
- (let ((x (ly:modules-lookup scopes sym)))
- (if (and x (not (unspecified? x))) x "")))
+
+
+
+;;; optimal page breaking
+
+;;; This is not optimal page breaking, this is optimal distribution of
+;;; lines over pages; line breaks are a given.
+
+; TODO:
+;
+; - density scoring
+; - separate function for word-wrap style breaking?
+; - raggedbottom? raggedlastbottom?
+
+(define-public (ly:optimal-page-breaks
+ lines paper-book)
+ "Return pages as a list starting with 1st page. Each page is a list
+of lines. "
+
+ (define (make-node prev lines page-num penalty)
+ (make <optimally-broken-page-node>
+ #:prev prev
+ #:lines lines
+ #:pageno page-num
+ #:penalty penalty))
+
+ (define MAXPENALTY 1e9)
+ (define bookpaper (ly:paper-book-book-paper paper-book))
+ (define scopes (ly:paper-book-scopes paper-book))
+ (define (line-height line)
+ (ly:paper-system-extent line Y))
+
+ ;; FIXME: may need some tweaking: square, cubic
+ (define (height-penalty available used)
+ ;; FIXME, simplistic
+ (let* ((left (- available used))
+ ;; scale-independent
+ (relative (abs (/ left available))))
+ (if (negative? left)
+
+ ;; too full, penalise more
+ (* 10 (1+ relative) relative)
+
+ ;; Convexity: two half-empty pages is better than 1 completely
+ ;; empty page
+ (* (1+ relative) relative))))
+
+ (define (page-height page-number last?)
+ (let
+ ((p (ly:output-def-lookup bookpaper 'page-music-height)))
+
+ (if (procedure? p)
+ (p bookpaper scopes page-number last?)
+ 10000)))
+
- (let ((props (list (append `((linewidth . ,(ly:paper-get-number
- paper 'linewidth))
- (font-family . roman))
- (ly:paper-lookup paper 'font-defaults)))))
-
- (interpret-markup
- paper props
- (markup
- #:column
- (#:override '(baseline-skip . 4)
- #:column
- (#:fill-line
- ("" (get 'opus))
- #:fill-line (#:large #:bigger #:caps (get 'piece) "")))))))
-
-(define-public (make-header paper page-number)
- (let ((props (list (append `((linewidth . ,(ly:paper-get-number
- paper 'linewidth))
- (font-family . roman))
- (ly:paper-lookup paper 'font-defaults)))))
-
- (interpret-markup paper props
- (markup #:fill-line ("" (number->string page-number))))))
+ (define (cumulative-height lines)
+ (apply + (map line-height lines)))
+
+ (define (get-path node done)
+ "Follow NODE.PREV, and return as an ascending list of pages. DONE
+is what have collected so far, and has ascending page numbers."
+ (if (is-a? node <optimally-broken-page-node>)
+ (get-path (node-prev node) (cons node done))
+ done))
+
+ (define (combine-penalties user page prev)
+ (+ prev page user))
+
+ (define (walk-paths done-lines best-paths current-lines last? current-best)
+ "Return the best optimal-page-break-node that contains
+CURRENT-LINES. DONE-LINES.reversed ++ CURRENT-LINES is a consecutive
+ascending range of lines, and BEST-PATHS contains the optimal breaks
+corresponding to DONE-LINES.
+
+CURRENT-BEST is the best result sofar, or #f."
+
+ (let* ((this-page-num (if (null? best-paths)
+ 1
+ (1+ (node-page-number (car best-paths)))))
+ (prev-penalty (if (null? best-paths)
+ 0.0
+ (node-penalty (car best-paths))))
+ (page-height (page-height this-page-num last?))
+ (space-used (cumulative-height current-lines))
+ (this-page-penalty (height-penalty page-height space-used))
+ (user-penalty (ly:paper-system-break-penalty (car current-lines)))
+ (total-penalty (combine-penalties
+ user-penalty this-page-penalty prev-penalty))
+ (better? (or
+ (not current-best)
+ (< total-penalty (node-penalty current-best))))
+ (new-best (if better?
+ (make-node (if (null? best-paths)
+ #f
+ (car best-paths))
+ current-lines
+ this-page-num total-penalty)
+ current-best)))
+
+ (if #f ;; debug
+ (display
+ (list
+ "user pen " user-penalty " prev-penalty "
+ prev-penalty "\n"
+ "better? " better? " total-penalty " total-penalty "\n"
+ "height " page-height " spc used: " space-used "\n"
+ "pen " this-page-penalty " lines: " current-lines "\n")))
+ (if (and (pair? done-lines)
+ ;; if this page is too full, adding another line won't help
+ (< this-page-penalty MAXPENALTY))
+ (walk-paths (cdr done-lines) (cdr best-paths)
+ (cons (car done-lines) current-lines)
+ last? new-best)
+ new-best)))
-(define-public (make-footer paper page-number)
- (let ((props (list (append `((linewidth . ,(ly:paper-get-number
- paper 'linewidth))
- (font-family . roman))
- (ly:paper-lookup paper 'font-defaults)))))
+ (define (walk-lines done best-paths todo)
+ "Return the best page breaking as a single
+<optimal-page-break-node> for optimally breaking TODO ++
+DONE.reversed. BEST-PATHS is a list of break nodes corresponding to
+DONE."
+ (if (null? todo)
+ (car best-paths)
+ (let* ((this-line (car todo))
+ (last? (null? (cdr todo)))
+ (next (walk-paths done best-paths (list this-line) last? #f)))
+
+ (walk-lines (cons this-line done)
+ (cons next best-paths)
+ (cdr todo)))))
+
+ (define (line-number node)
+ (ly:paper-system-number (car (node-lines node))))
+
+ (let* ((best-break-node (walk-lines '() '() lines))
+ (break-nodes (get-path best-break-node '()))
+ )
+
+ (if (ly:get-option 'verbose)
+ (begin
+ (format (current-error-port) "breaks: ~S\n" (map line-number break-nodes))
+ (force-output (current-error-port))))
+
+
+ ; create stencils.
- (interpret-markup paper props
- (markup #:fill-line ("" (number->string page-number))))))
+ (map (lambda (node)
+ ((ly:output-def-lookup bookpaper 'page-make-stencil)
+ (node-lines node)
+ bookpaper
+ scopes
+ (node-page-number node)
+ (eq? node best-break-node)))
+ break-nodes)))
+