-;;;; 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>
-
-
-(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 (page-properties paper)
- (list (append `((linewidth . ,(ly:paper-get-number
- paper 'linewidth)))
- (ly:paper-lookup paper 'text-font-defaults))))
-
-(define-public (book-title paper scopes)
- "Generate book title from header strings."
-
- (define (get sym)
- (let ((x (ly:modules-lookup scopes sym)))
- (if (and x (not (unspecified? x))) x "")))
-
- (let ((props (page-properties paper)))
-
- (interpret-markup
- paper props
- (markup
- #:column
- (#:override '(baseline-skip . 4)
- #:column
- (#:fill-line
- (#:normalsize (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 ((props (page-properties paper))
- (baseline-skip (chain-assoc-get 'baseline-skip props 2)) )
- (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 (get sym)
- (let ((x (ly:modules-lookup scopes sym)))
- (if (and x (not (unspecified? x))) x "")))
-
- (let ((props (page-properties paper)))
-
- (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 (page-properties paper) ))
- (interpret-markup paper props
- (markup #:fill-line
- ;; FIXME: font not found
- ;; ("" #:bold (number->string page-number))))))
- ("" (number->string page-number))))))
-
-(define-public (make-footer paper page-number)
- (let ((props (page-properties paper)))
-
- (interpret-markup paper props
- (markup #:fill-line ("" (number->string page-number))))))
-
-
-(define TAGLINE
- (string-append "Engraved by LilyPond (version " (lilypond-version) ")"))
-
-(define-public (make-tagline paper scopes)
- (let* ((props (page-properties paper))
- (tagline-var (ly:modules-lookup scopes 'tagline))
- (tagline (if (markup? tagline-var) tagline-var TAGLINE)))
-
- (cond ((string? tagline)
- (if (not (equal? tagline ""))
- (interpret-markup paper props
- (markup #:fill-line (tagline "")))))
- ((markup? tagline) (interpret-markup paper props tagline)))))
-
-(define-public (make-copyright paper scopes)
- (let ((props (page-properties paper))
- (copyright (ly:modules-lookup scopes 'copyright)))
-
- (cond ((string? copyright)
- (if (not (equal? copyright ""))
- (interpret-markup paper props
- (markup #:fill-line (copyright "")))))
- ((markup? copyright) (interpret-markup paper props copyright)))))
+;;;;
+;;;; (c) 2004--2005 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)
+ (force #:init-value 0 #:accessor node-force #:init-keyword #:force)
+ (penalty #:init-value 0 #:accessor node-penalty #:init-keyword #:penalty)
+ (configuration #:init-value '() #:accessor node-configuration #:init-keyword #:configuration)
+ (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-method (node-system-numbers (node <optimally-broken-page-node>))
+ (map ly:paper-system-number (node-lines node)))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(define (page-headfoot layout scopes number sym sepsym dir last?)
+ "Create a stencil including separating space."
+ (let* ((header-proc (ly:output-def-lookup layout sym))
+ (sep (ly:output-def-lookup layout sepsym))
+ (stencil (ly:make-stencil "" '(0 . 0) '(0 . 0)))
+ (head-stencil
+ (if (procedure? header-proc)
+ (header-proc layout scopes number last?)
+ #f)))
+
+ (if (and (number? sep)
+ (ly:stencil? head-stencil)
+ (not (ly:stencil-empty? 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 layout scopes number last?)
+ "Printable area for music and titles; matches default-page-make-stencil."
+ (let* ((h (- (ly:output-def-lookup layout 'vsize)
+ (ly:output-def-lookup layout 'topmargin)
+ (ly:output-def-lookup layout 'bottommargin)))
+ (head (page-headfoot layout scopes number 'make-header 'headsep UP last?))
+ (foot (page-headfoot layout scopes number 'make-footer 'footsep DOWN last?))
+ (available
+ (- 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))))
+
+ ;; (display (list "\n available" available head foot))
+ available))
+
+(define-public (default-page-make-stencil
+ lines offsets layout scopes number last?)
+ "Construct a stencil representing the page from LINES.
+
+ Offsets is a list of increasing numbers. They must be negated to
+create offsets.
+ "
+
+ (let* ((topmargin (ly:output-def-lookup layout 'topmargin))
+
+ ;; TODO: naming vsize/hsize not analogous to TeX.
+
+ (vsize (ly:output-def-lookup layout 'vsize))
+ (hsize (ly:output-def-lookup layout 'hsize))
+
+ (system-separator-markup (ly:output-def-lookup layout 'systemSeparatorMarkup))
+ (system-separator-stencil (if (markup? system-separator-markup)
+ (interpret-markup layout
+ (layout-extract-page-properties layout)
+ system-separator-markup)
+ #f))
+ (lmargin (ly:output-def-lookup layout 'leftmargin))
+ (leftmargin (if lmargin
+ lmargin
+ (/ (- hsize
+ (ly:output-def-lookup layout 'linewidth)) 2)))
+
+ (rightmargin (ly:output-def-lookup layout 'rightmargin))
+ (bottom-edge (- vsize
+ (ly:output-def-lookup layout 'bottommargin)))
+
+ (head (page-headfoot layout scopes number 'make-header 'headsep UP last?))
+ (foot (page-headfoot layout scopes number 'make-footer 'footsep DOWN last?))
+
+ (head-height (if (ly:stencil? head)
+ (interval-length (ly:stencil-extent head Y))
+ 0.0))
+
+ (height-proc (ly:output-def-lookup layout 'page-music-height))
+
+ (page-stencil (ly:make-stencil '()
+ (cons leftmargin hsize)
+ (cons (- topmargin) 0)))
+ (last-system #f)
+ (last-y 0.0)
+ (add-to-page (lambda (stencil y)
+ (set! page-stencil
+ (ly:stencil-add page-stencil
+ (ly:stencil-translate-axis stencil
+ (- 0 head-height y topmargin) Y)))))
+ (add-system
+ (lambda (stencil-position)
+ (let* ((system (car stencil-position))
+ (stencil (ly:paper-system-stencil system))
+ (y (cadr stencil-position))
+ (is-title (ly:paper-system-title?
+ (car stencil-position))))
+ (add-to-page stencil y)
+ (if (and (ly:stencil? system-separator-stencil)
+ last-system
+ (not (ly:paper-system-title? system))
+ (not (ly:paper-system-title? last-system)))
+ (add-to-page
+ system-separator-stencil
+ (average (- last-y
+ (car (ly:paper-system-staff-extents last-system)))
+ (- y
+ (cdr (ly:paper-system-staff-extents system))))))
+ (set! last-system system)
+ (set! last-y y)))))
+
+ (if #f
+ (display (list
+ "leftmargin " leftmargin "rightmargin " rightmargin
+ )))
+
+ (set! page-stencil (ly:stencil-combine-at-edge
+ page-stencil Y DOWN
+ (if (and
+ (ly:stencil? head)
+ (not (ly:stencil-empty? head)))
+ head
+ (ly:make-stencil "" (cons 0 0) (cons 0 0)))
+ 0. 0.))
+
+ (map add-system (zip lines offsets))
+ (if (and (ly:stencil? foot)
+ (not (ly:stencil-empty? 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 leftmargin 0))))
+
+;;; 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 MAXPENALTY 1e9)
+ (define paper (ly:paper-book-paper paper-book))
+ (define scopes (ly:paper-book-scopes paper-book))
+
+ (define (page-height page-number last?)
+ (let ((p (ly:output-def-lookup paper 'page-music-height)))
+
+ (if (procedure? p)
+ (p paper scopes page-number last?)
+ 10000)))
+
+ (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 force user best-paths)
+ (let* ((prev-force (if (null? best-paths)
+ 0.0
+ (node-force (car best-paths))))
+ (prev-penalty (if (null? best-paths)
+ 0.0
+ (node-penalty (car best-paths))))
+ (inter-system-space (ly:output-def-lookup paper 'betweensystemspace))
+ (force-equalization-factor 0.3)
+ (relative-force (/ force inter-system-space))
+ (abs-relative-force (abs relative-force)))
+
+
+ (+ (* abs-relative-force (+ abs-relative-force 1))
+ prev-penalty
+ (* force-equalization-factor (/ (abs (- prev-force force)) inter-system-space))
+ user)))
+
+ (define (space-systems page-height lines ragged?)
+ (let* ((inter-system-space
+ (ly:output-def-lookup paper 'betweensystemspace))
+ (system-vector (list->vector
+ (append lines
+ (if (= (length lines) 1)
+ '(#f)
+ '()))))
+ (staff-extents
+ (list->vector
+ (append (map ly:paper-system-staff-extents lines)
+ (if (= (length lines) 1)
+ '((0 . 0))
+ '()))))
+ (real-extents
+ (list->vector
+ (append
+ (map
+ (lambda (sys) (ly:paper-system-extent sys Y)) lines)
+ (if (= (length lines) 1)
+ '((0 . 0))
+ '()))))
+ (no-systems (vector-length real-extents))
+ (topskip (interval-end (vector-ref real-extents 0)))
+ (space-left (- page-height
+ (apply + (map interval-length (vector->list real-extents)))))
+
+ (space (- page-height
+ topskip
+ (- (interval-start (vector-ref real-extents (1- no-systems))))))
+
+ (fixed-dist (ly:output-def-lookup paper 'betweensystempadding))
+ (calc-spring
+ (lambda (idx)
+ (let* ((this-system-ext (vector-ref staff-extents idx))
+ (next-system-ext (vector-ref staff-extents (1+ idx)))
+ (fixed (max 0 (- (+ (interval-end next-system-ext)
+ fixed-dist)
+ (interval-start this-system-ext))))
+ (title1? (and (vector-ref system-vector idx)
+ (ly:paper-system-title? (vector-ref system-vector idx))))
+ (title2? (and
+ (vector-ref system-vector (1+ idx))
+ (ly:paper-system-title? (vector-ref system-vector (1+ idx)))))
+ (ideal (+
+ (cond
+ ((and title2? title1?)
+ (ly:output-def-lookup paper 'betweentitlespace))
+ (title1?
+ (ly:output-def-lookup paper 'aftertitlespace))
+ (title2?
+ (ly:output-def-lookup paper 'beforetitlespace))
+ (else inter-system-space))
+ fixed))
+ (hooke (/ 1 (- ideal fixed))))
+ (list ideal hooke))))
+
+ (springs (map calc-spring (iota (1- no-systems))))
+ (calc-rod
+ (lambda (idx)
+ (let* ((this-system-ext (vector-ref real-extents idx))
+ (next-system-ext (vector-ref real-extents (1+ idx)))
+ (distance (max (- (+ (interval-end next-system-ext)
+ fixed-dist)
+ (interval-start this-system-ext)
+ ) 0))
+ (entry (list idx (1+ idx) distance)))
+ entry)))
+ (rods (map calc-rod (iota (1- no-systems))))
+
+ ;; we don't set ragged based on amount space left.
+ ;; raggedbottomlast = ##T is much more predictable
+ (result (ly:solve-spring-rod-problem
+ springs rods space
+ ragged?))
+
+ (force (car result))
+ (positions
+ (map (lambda (y)
+ (+ y topskip))
+ (cdr result))))
+
+ (if #f ;; debug.
+ (begin
+ (display (list "\n# systems: " no-systems
+ "\nreal-ext" real-extents "\nstaff-ext" staff-extents
+ "\ninterscore" inter-system-space
+ "\nspace-letf" space-left
+ "\nspring,rod" springs rods
+ "\ntopskip " topskip
+ " space " space
+ "\npage-height" page-height
+ "\nragged" ragged?
+ "\nforce" force
+ "\nres" (cdr result)
+ "\npositions" positions "\n"))))
+
+ (cons force positions)))
+
+ (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)
+ (ly:output-def-lookup paper 'firstpagenumber)
+ (1+ (node-page-number (car best-paths)))))
+
+ (ragged-all? (eq? #t (ly:output-def-lookup paper 'raggedbottom)))
+ (ragged-last? (eq? #t (ly:output-def-lookup paper 'raggedlastbottom)))
+ (ragged? (or ragged-all?
+ (and ragged-last?
+ last?)))
+ (page-height (page-height this-page-num last?))
+ (vertical-spacing (space-systems page-height current-lines ragged?))
+ (satisfied-constraints (car vertical-spacing))
+ (force (if satisfied-constraints
+ (if (and last? ragged-last?)
+ 0.0
+ satisfied-constraints)
+ 10000))
+ (positions (cdr vertical-spacing))
+ (user-nobreak-penalties
+ (-
+ (apply + (filter negative?
+ (map ly:paper-system-break-before-penalty
+ (cdr current-lines))))))
+ (user-penalty
+ (+
+ (max (ly:paper-system-break-before-penalty (car current-lines)) 0.0)
+ user-nobreak-penalties))
+ (total-penalty (combine-penalties
+ force user-penalty
+ best-paths))
+
+
+ (better? (or
+ (not current-best)
+ (< total-penalty (node-penalty current-best))))
+ (new-best (if better?
+ (make <optimally-broken-page-node>
+ #:prev (if (null? best-paths)
+ #f
+ (car best-paths))
+ #:lines current-lines
+ #:pageno this-page-num
+ #:force force
+ #:configuration positions
+ #:penalty total-penalty)
+ current-best)))
+
+ (if #f ;; debug
+ (display
+ (list
+ "\nuser pen " user-penalty
+ "\nsatisfied-constraints" satisfied-constraints
+ "\nlast? " last? "ragged?" ragged?
+ "\nbetter? " better? " total-penalty " total-penalty "\n"
+ "\nconfig " positions
+ "\nforce " force
+ "\nlines: " current-lines "\n")))
+
+ (if #f ; debug
+ (display (list "\nnew-best is " (node-lines new-best)
+ "\ncontinuation of "
+ (if (null? best-paths)
+ "start"
+ (node-lines (car best-paths))))))
+
+ (if (and (pair? done-lines)
+ ;; if this page is too full, adding another line won't help
+ satisfied-constraints)
+ (walk-paths (cdr done-lines) (cdr best-paths)
+ (cons (car done-lines) current-lines)
+ last? new-best)
+ new-best)))
+
+ (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)))
+
+ ;; (display "\n***************")
+ (walk-lines (cons this-line done)
+ (cons next best-paths)
+ (cdr todo)))))
+
+ (define (line-number node)
+ (ly:paper-system-number (car (node-lines node))))
+
+ (ly:message (_ "Calculating page breaks..."))
+
+ (let* ((best-break-node (walk-lines '() '() lines))
+ (break-nodes (get-path best-break-node '()))
+ (last-node (car (last-pair break-nodes))))
+
+ (define (node->page-stencil node)
+ (if (not (eq? node last-node))
+ (ly:progress "["))
+ (let ((stencil
+ ((ly:output-def-lookup paper 'page-make-stencil)
+ (node-lines node)
+ (node-configuration node)
+ paper
+ scopes
+ (node-page-number node)
+ (eq? node best-break-node))))
+ (if (not (eq? node last-node))
+ (begin
+ (ly:progress (number->string
+ (car (last-pair (node-system-numbers node)))))
+ (ly:progress "]")))
+ stencil))
+ (if #f; (ly:get-option 'verbose)
+ (begin
+ (display (list
+ "\nbreaks: " (map line-number break-nodes))
+ "\nsystems " (map node-lines break-nodes)
+ "\npenalties " (map node-penalty break-nodes)
+ "\nconfigs " (map node-configuration break-nodes))))
+ (let ((stencils (map node->page-stencil break-nodes)))
+ (ly:progress "\n")
+ stencils)))