-;;;; page-layout.scm -- page breaking and page layout
+;;;; layout-page-layout.scm -- page breaking and page layout
;;;;
;;;; source file of the GNU LilyPond music typesetter
;;;;
-;;;; (c) 2004--2006 Jan Nieuwenhuizen <janneke@gnu.org>
-;;;; Han-Wen Nienhuys <hanwen@cs.uu.nl>
-
-(use-modules (oop goops describe)
- (oop goops)
- (scm paper-system)
- (scm page)
- )
-
-
-
-
-
-
-;;; optimal page breaking
-
-;;; This is not optimal page breaking, this is optimal distribution of
-;;; lines over pages; line breaks are a given.
+;;;; (c) 2004--2008 Jan Nieuwenhuizen <janneke@gnu.org>
+;;;; Han-Wen Nienhuys <hanwen@xs4all.nl>
+
+(define-module (scm layout-page-layout)
+ #:use-module (srfi srfi-1)
+ #:use-module (oop goops describe)
+ #:use-module (oop goops)
+ #:use-module (scm paper-system)
+ #:use-module (scm page)
+ #:use-module (scm layout-page-dump)
+ #:use-module (lily)
+ #:export (post-process-pages optimal-page-breaks make-page-from-systems
+ page-breaking-wrapper
+ stretchable-line? ; delete me
+ ;; utilities for writing custom page breaking functions
+ line-height line-next-space line-next-padding
+ line-minimum-distance line-ideal-distance
+ first-line-position
+ line-ideal-relative-position line-minimum-relative-position
+ page-maximum-space-to-fill page-maximum-space-left space-systems))
+
+; this is for 2-pass spacing. Delete me.
+(define (stretchable-line? line)
+ "Say whether a system can be stretched."
+ (not (or (ly:prob-property? line 'is-title)
+ (let ((system-extent (paper-system-staff-extents line)))
+ (= (interval-start system-extent)
+ (interval-end system-extent))))))
+
+(define (stretch-and-draw-page paper-book systems page-number ragged
+ is-last-bookpart is-bookpart-last-page)
+ (define (max-stretch sys)
+ (if (ly:grob? sys)
+ (ly:grob-property sys 'max-stretch)
+ 0.0))
+
+ (define (stretchable? sys)
+ (and (ly:grob? sys)
+ (> (max-stretch sys) 0.0)))
+
+ (define (height-estimate sys)
+ (interval-length
+ (if (ly:grob? sys)
+ (ly:grob-property sys 'pure-Y-extent)
+ (paper-system-extent sys Y))))
+
+ (define (print-system sys)
+ (if (ly:grob? sys)
+ (ly:system-print sys)
+ sys))
+
+ (define (set-line-stretch! sorted-lines rest-height space-left)
+ (if (not (null? sorted-lines))
+ (let* ((line (first sorted-lines))
+ (height (height-estimate line))
+ (stretch (min (max-stretch line)
+ (if (positive? rest-height)
+ (/ (* height space-left) rest-height)
+ 0.0))))
+ (if (stretchable? line)
+ (ly:system-stretch line stretch))
+ (set-line-stretch! (cdr sorted-lines)
+ (if (stretchable? line)
+ (- rest-height height)
+ rest-height)
+ (- space-left stretch)))))
+
+ (define (total-padding systems)
+ (let ((layout (ly:paper-book-paper paper-book)))
+ (if (or (null? systems)
+ (null? (cdr systems)))
+ 0.0
+ (+ (line-next-padding (car systems) (cadr systems) layout)
+ (total-padding (cdr systems))))))
+
+ (let* ((page (make-page paper-book
+ 'page-number page-number
+ 'is-last-bookpart is-last-bookpart
+ 'is-bookpart-last-page is-bookpart-last-page))
+ (paper (ly:paper-book-paper paper-book))
+ (height (page-printable-height page))
+ ; there is a certain amount of impreciseness going on here:
+ ; the system heights are estimated, we aren't using skyline distances
+ ; yet, etc. If we overstretch because of underestimation, the result
+ ; is very bad. So we stick in some extra space, just to be sure.
+ (buffer (/ height 10.0))
+ (total-system-height (+ (apply + (map height-estimate systems))
+ (total-padding systems)))
+ (height-left (- height total-system-height buffer)))
+
+ (if (and
+ (not ragged)
+ (> height-left 0))
+ (set-line-stretch! (sort systems
+ (lambda (s1 s2)
+ (< (height-estimate s1)
+ (height-estimate s2))))
+ (apply + (map height-estimate
+ (filter stretchable? systems)))
+ height-left))
+
+ (let ((lines (map print-system systems)))
+ (page-set-property! page 'lines lines)
+ (page-set-property!
+ page 'configuration
+ (if (null? lines)
+ (list)
+ (let* ((paper (ly:paper-book-paper paper-book))
+ (max-space-to-fill (page-maximum-space-to-fill page lines paper))
+ (space-to-fill (if (ly:output-def-lookup
+ paper 'page-limit-inter-system-space #f)
+ (min max-space-to-fill
+ (* (ly:output-def-lookup
+ paper 'page-limit-inter-system-space-factor 1.4)
+ (- max-space-to-fill
+ (or (page-ideal-space-left page) 0))))
+ max-space-to-fill))
+ (spacing (space-systems space-to-fill lines ragged paper #f)))
+ (if (and (> (length lines) 1)
+ (or (not (car spacing)) (inf? (car spacing))))
+ (begin
+ (ly:warning (_ "Can't fit systems on page -- ignoring between-system-padding"))
+ (cdr (space-systems space-to-fill lines ragged paper #t)))
+ (cdr spacing)))))
+ page)))
+
+(define (page-breaking-wrapper paper-book)
+ "Compute line and page breaks by calling the page-breaking paper variable,
+ then performs the post process function using the page-post-process paper
+ variable. Finally, return the pages."
+ (let* ((paper (ly:paper-book-paper paper-book))
+ (pages ((ly:output-def-lookup paper 'page-breaking) paper-book)))
+ ((ly:output-def-lookup paper 'page-post-process) paper pages)
+ pages))
+
+(define (post-process-pages layout pages)
+ "If the write-page-layout paper variable is true, dumps page breaks
+ and tweaks."
+
+ (let*
+ ((parser (ly:modules-lookup (list (current-module)) 'parser))
+ (output-name (ly:parser-output-name parser))
+ )
+
+ (if (ly:output-def-lookup layout 'write-page-layout #f)
+ (write-page-breaks pages output-name))))
+
+;;;
+;;; Utilities for computing line distances and positions
+;;;
+(define (line-extent line)
+ "Return the extent of the line (its lowest and highest Y-coordinates)."
+ (paper-system-extent line Y))
+
+(define (line-height line)
+ "Return the system height, that is the length of its vertical extent."
+ (interval-length (line-extent line)))
+
+(define (line-next-space line next-line layout)
+ "Return space to use between `line' and `next-line'.
+ `next-line' can be #f, meaning that `line' is the last line."
+ (let* ((title (paper-system-title? line))
+ (next-title (and next-line (paper-system-title? next-line))))
+ (ly:prob-property
+ line 'next-space
+ (ly:output-def-lookup layout
+ (cond ((and title next-title) 'between-title-space)
+ (title 'after-title-space)
+ (next-title 'before-title-space)
+ (else 'between-system-space))))))
+
+(define (line-next-padding line next-line layout)
+ "Return padding to use between `line' and `next-line'.
+ `next-line' can be #f, meaning that `line' is the last line."
+ (let ((default (ly:output-def-lookup layout 'between-system-padding)))
+ (if (ly:grob? line)
+ (let* ((details (ly:grob-property line 'line-break-system-details))
+ (padding (assq 'next-padding details)))
+ (if padding
+ (cdr padding)
+ default))
+ (ly:prob-property line 'next-padding default))))
+
+
+(define (line-minimum-distance line next-line layout ignore-padding)
+ "Minimum distance between `line' reference position and `next-line'
+ reference position. If next-line is #f, return #f."
+ (and next-line
+ (let ((padding (if ignore-padding
+ 0
+ (line-next-padding line next-line layout))))
+ (if (or (ly:grob? line) (ly:grob? next-line))
+ (max 0 (+ padding
+ (- (interval-start (line-extent line))
+ (interval-end (line-extent next-line)))))
+ (max 0 (+ padding
+ (ly:paper-system-minimum-distance line next-line)))))))
+
+(define (line-ideal-distance line next-line layout ignore-padding)
+ "Ideal distance between `line' reference position and `next-line'
+ reference position. If next-line is #f, return #f."
+ (and next-line
+ (max 0
+ (+ (- (+ (interval-end (paper-system-staff-extents next-line))
+ (if ignore-padding 0 (line-next-padding line next-line layout)))
+ (interval-start (paper-system-staff-extents line)))
+ (line-next-space line next-line layout)))))
+
+(define (first-line-position line layout)
+ "Position of the first line on page"
+ (max (+ (if (ly:prob-property? line 'is-title)
+ ;; do not use page-top-space if first line is a title
+ 0.0
+ (ly:output-def-lookup layout 'page-top-space))
+ (interval-end (paper-system-staff-extents line)))
+ (interval-end (line-extent line))))
+
+(define (line-ideal-relative-position line prev-line layout ignore-padding)
+ "Return ideal position of `line', relative to `prev-line' position.
+ `prev-line' can be #f, meaning that `line' is the first line."
+ (if (not prev-line)
+ ;; first line on page
+ (first-line-position line layout)
+ ;; not the first line on page
+ (max (line-minimum-distance prev-line line layout ignore-padding)
+ (line-ideal-distance prev-line line layout ignore-padding))))
+
+(define (line-minimum-relative-position line prev-line layout ignore-padding)
+ "Return position of `line', relative to `prev-line' position.
+ `prev-line' can be #f, meaning that `line' is the first line."
+ (if (not prev-line)
+ ;; first line on page
+ (first-line-position line layout)
+ ;; not the first line on page
+ (line-minimum-distance prev-line line layout ignore-padding)))
+
+(define (line-position-on-page line prev-line prev-position page relative-positionning-fn)
+ "If `line' fits on `page' after `prev-line', which position on page is
+ `prev-position', then return the line's postion on page, otherwise #f.
+ `prev-line' can be #f, meaning that `line' is the first line."
+ (let* ((layout (ly:paper-book-paper (page-property page 'paper-book)))
+ (position (+ (relative-positionning-fn line prev-line layout #f)
+ (if prev-line prev-position 0.0)))
+ (bottom-position (- position
+ (interval-start (line-extent line)))))
+ position))
+
+(define (page-maximum-space-to-fill page lines paper)
+ "Return the space between the first line top position and the last line
+ bottom position. This constitutes the maximum space to fill on `page'
+ with `lines'."
+ (let ((last-line (car (last-pair lines))))
+ (- (page-printable-height page)
+ (first-line-position (first lines) paper)
+ (ly:prob-property last-line
+ 'bottom-space 0.0)
+ (- (interval-start (line-extent last-line))))))
+
+(define (page-space-left page relative-positionning-fn)
+ (let ((paper (ly:paper-book-paper (page-property page 'paper-book))))
+ (let bottom-position ((lines (page-property page 'lines))
+ (prev-line #f)
+ (prev-position #f))
+ (if (null? lines)
+ (page-printable-height page)
+ (let* ((line (first lines))
+ (position (line-position-on-page
+ line prev-line prev-position page relative-positionning-fn)))
+ (if (null? (cdr lines))
+ (max 0
+ (- (page-printable-height page)
+ (- position
+ (interval-start (line-extent line)))))
+ (bottom-position (cdr lines) line position)))))))
+
+(define (page-maximum-space-left page)
+ (page-space-left page line-minimum-relative-position))
+
+(define (page-ideal-space-left page)
+ (page-space-left page line-ideal-relative-position))
+
+;;;
+;;; Utilities for distributing systems on a page
+;;;
+
+(define (space-systems space-to-fill lines ragged paper ignore-padding)
+ "Compute lines positions on page: return force and line positions as a pair.
+ force is #f if lines do not fit on page."
+ (let* ((empty-stencil (ly:make-stencil '() '(0 . 0) '(0 . 0)))
+ (empty-prob (ly:make-prob 'paper-system (list `(stencil . ,empty-stencil))))
+ (cdr-lines (append (cdr lines)
+ (if (<= (length lines) 1)
+ (list empty-prob)
+ '())))
+ (springs (map (lambda (prev-line line)
+ (list (line-ideal-distance prev-line line paper ignore-padding)
+ (line-next-space prev-line line paper)))
+ lines
+ cdr-lines))
+ (rods (map (let ((i -1))
+ (lambda (prev-line line)
+ (set! i (1+ i))
+ (list i (1+ i)
+ (line-minimum-distance prev-line line paper ignore-padding))))
+ lines
+ cdr-lines))
+ (space-result
+ (ly:solve-spring-rod-problem springs rods space-to-fill ragged)))
+ (cons (car space-result)
+ (map (let ((topskip (first-line-position (first lines) paper)))
+ (lambda (y)
+ (+ y topskip)))
+ (cdr space-result)))))
+
+
+;;;
+;;; Page breaking function
+;;;
+
+;; 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 (optimal-page-breaks lines paper-book)
- "Return pages as a list starting with 1st page. Each page is a 'page prob.
+;; - ragged-bottom? ragged-last-bottom?
-"
-
- (define MAXPENALTY 1e9)
- (define paper (ly:paper-book-paper paper-book))
- (define scopes (ly:paper-book-scopes paper-book))
- (define force-equalization-factor #f)
- (define (get-path node done)
- "Follow NODE.PREV, and return as an ascending list of pages. DONE
+(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 (page? node)
- (get-path (page-prev node) (cons node done))
- done))
-
- (define (combine-penalties force user best-paths)
- (let* ((prev-force (if (null? best-paths)
+ (if (page? node)
+ (get-path (page-prev node) (cons node done))
+ done))
+
+(define (combine-penalties force user best-paths
+ inter-system-space force-equalization-factor)
+ (let* ((prev-force (if (null? best-paths)
+ 0.0
+ (page-force (car best-paths))))
+ (prev-penalty (if (null? best-paths)
0.0
- (page-force (car best-paths))))
- (prev-penalty (if (null? best-paths)
- 0.0
- (page-penalty (car best-paths))))
- (inter-system-space (ly:output-def-lookup paper 'betweensystemspace))
+ (page-penalty (car best-paths))))
(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* ((global-inter-system-space
- (ly:output-def-lookup paper 'betweensystemspace))
- (top-space
- (ly:output-def-lookup paper 'pagetopspace))
- (global-fixed-dist (ly:output-def-lookup paper 'betweensystempadding))
-
- (system-vector (list->vector
- (append lines
- (if (= (length lines) 1)
- '(#f)
- '()))))
- (staff-extents
- (list->vector
- (append (map paper-system-staff-extents lines)
- (if (= (length lines) 1)
- '((0 . 0))
- '()))))
-
- (real-extents
- (list->vector
- (append
- (map
- (lambda (sys) (paper-system-extent sys Y)) lines)
- (if (= (length lines) 1)
- '((0 . 0))
- '()))))
-
- (system-count (vector-length real-extents))
- (topskip (max
- (+
- top-space
- (interval-end (vector-ref staff-extents 0)))
- (interval-end (vector-ref real-extents 0))
- ))
- (last-system (vector-ref system-vector (1- system-count)))
- (bottom-space (if (ly:prob? last-system)
- (ly:prob-property last-system 'bottom-space 0.0)
- 0.0))
- (space-left (- page-height
- bottom-space
- (apply + (map interval-length
- (vector->list real-extents)))))
-
- (space (- page-height
- topskip
- bottom-space
- (- (interval-start
- (vector-ref real-extents (1- system-count))))))
-
- (calc-spring
- (lambda (idx)
- (let* (
- (upper-system (vector-ref system-vector idx))
- (between-space (ly:prob-property upper-system 'next-space
- global-inter-system-space))
- (fixed-dist (ly:prob-property upper-system 'next-padding
- global-fixed-dist))
-
- (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)
- (paper-system-title? (vector-ref system-vector idx)
- )))
- (title2? (and
- (vector-ref system-vector (1+ idx))
- (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 between-space))
- fixed))
- (hooke (/ 1 (- ideal fixed))))
- (list ideal hooke))))
-
- (springs (map calc-spring (iota (1- system-count))))
- (calc-rod
- (lambda (idx)
- (let* (
- (upper-system (vector-ref system-vector idx))
- (fixed-dist (ly:prob-property upper-system 'next-padding
- global-fixed-dist))
- (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- system-count))))
-
- ;; 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: " system-count
- "\nreal-ext" real-extents "\nstaff-ext" staff-extents
- "\ninterscore" global-inter-system-space
- "\nspace-left" 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
+ (+ (* abs-relative-force (+ abs-relative-force 1))
+ prev-penalty
+ (* force-equalization-factor (/ (abs (- prev-force force))
+ inter-system-space))
+ user)))
+
+(define (walk-paths done-lines best-paths current-lines is-last-bookpart
+ is-bookpart-last-page current-best paper-book page-alist)
+ "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+ (page-page-number (car best-paths)))))
-
- (this-page (make-page
- 'paper-book paper-book
- 'is-last last?
- 'page-number this-page-num))
-
- (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?)))
- (height (page-height this-page))
- (vertical-spacing (space-systems 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))
- (get-break-penalty (lambda (sys)
- (ly:prob-property sys 'penalty 0.0)))
- (user-nobreak-penalties
- (-
- (apply + (filter negative?
- (map get-break-penalty
- (cdr current-lines))))))
- (user-penalty
- (+
- (max (get-break-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 (page-penalty current-best))))
- (new-best (if better?
- (begin
- (map
- (lambda (x)
- (page-set-property! this-page
- (car x)
- (cdr x)))
- (list
- (cons 'prev (if (null? best-paths)
- #f
- (car best-paths)))
- (cons 'lines current-lines)
- (cons 'force force)
- (cons 'configuration positions)
- (cons 'penalty total-penalty)))
- this-page)
- current-best)))
-
-;; (display total-penalty) (newline)
- (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 " (page-lines new-best)
- "\ncontinuation of "
- (if (null? best-paths)
- "start"
- (page-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
+ (let* ((paper (ly:paper-book-paper paper-book))
+ (this-page (make-page
+ paper-book
+ 'is-last-bookpart is-last-bookpart
+ 'is-bookpart-last-page is-bookpart-last-page
+ 'page-number (if (null? best-paths)
+ (ly:output-def-lookup paper 'first-page-number)
+ (1+ (page-page-number (first best-paths))))))
+ (ragged-all (eq? #t (ly:output-def-lookup paper 'ragged-bottom)))
+ (ragged-last (eq? #t (ly:output-def-lookup paper 'ragged-last-bottom)))
+ (ragged (or ragged-all (and ragged-last is-bookpart-last-page)))
+ (space-to-fill (page-maximum-space-to-fill this-page current-lines paper))
+ (vertical-spacing (space-systems space-to-fill current-lines ragged paper #f))
+ (satisfied-constraints (car vertical-spacing))
+ (force (if satisfied-constraints
+ (if (and is-bookpart-last-page ragged-last)
+ 0.0
+ satisfied-constraints)
+ 10000))
+ (positions (cdr vertical-spacing))
+ (get-break-penalty (lambda (sys)
+ (ly:prob-property sys 'penalty 0.0)))
+ (user-nobreak-penalties (- (apply + (filter negative?
+ (map get-break-penalty
+ (cdr current-lines))))))
+ (user-penalty (+ (max (get-break-penalty (car current-lines)) 0.0)
+ user-nobreak-penalties))
+ (total-penalty (combine-penalties
+ force user-penalty best-paths
+ (ly:output-def-lookup paper 'between-system-space)
+ (ly:output-def-lookup paper 'verticalequalizationfactor 0.3)))
+ (new-best (if (or (not current-best)
+ (and satisfied-constraints
+ (< total-penalty (page-penalty current-best))))
+ (begin
+ (map (lambda (x)
+ (page-set-property! this-page
+ (car x)
+ (cdr x)))
+ (list (cons 'prev (if (null? best-paths)
+ #f
+ (car best-paths)))
+ (cons 'lines current-lines)
+ (cons 'force force)
+ (cons 'configuration positions)
+ (cons 'penalty total-penalty)))
+ this-page)
+ current-best)))
+ (if #f ;; debug
+ (display
+ (list
+ "\nuser pen " user-penalty
+ "\nsatisfied-constraints" satisfied-constraints
+ "\nlast? " is-bookpart-last-page "ragged?" ragged
+ "\nis-better " is-better " total-penalty " total-penalty "\n"
+ "\nconfig " positions
+ "\nforce " force
+ "\nlines: " current-lines "\n")))
+ (if #f ; debug
+ (display (list "\nnew-best is " (page-lines new-best)
+ "\ncontinuation of "
+ (if (null? best-paths)
+ "start"
+ (page-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)
+ is-last-bookpart is-bookpart-last-page new-best
+ paper-book page-alist)
+ new-best)))
+
+(define (walk-lines done best-paths todo paper-book page-alist is-last-bookpart)
+ "Return the best page breaking as a single
page 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:prob-property (car (page-lines node)) 'number))
-
- (ly:message (_ "Calculating page breaks..."))
- (set! force-equalization-factor
- (ly:output-def-lookup paper 'verticalequalizationfactor 0.3))
-
- (let* ((best-break-node (walk-lines '() '() lines))
- (break-nodes (get-path best-break-node '()))
- )
-
-
- (set! (page-property (car (last-pair break-nodes)) 'is-last) #t)
-
- (if #f; (ly:get-option 'verbose)
- (begin
- (display (list
- "\nbreaks: " (map line-number break-nodes))
- "\nsystems " (map page-lines break-nodes)
- "\npenalties " (map page-penalty break-nodes)
- "\nconfigs " (map page-configuration break-nodes))))
-
- (let ((stencils (map page-stencil break-nodes)))
- (ly:progress "\n")
- stencils)))
+ (if (null? todo)
+ (car best-paths)
+ (let* ((this-line (car todo))
+ (is-bookpart-last-page (null? (cdr todo)))
+ (next (walk-paths done best-paths (list this-line) is-last-bookpart
+ is-bookpart-last-page #f paper-book page-alist)))
+ (walk-lines (cons this-line done)
+ (cons next best-paths)
+ (cdr todo)
+ paper-book
+ page-alist
+ is-last-bookpart))))
+
+(define-public (optimal-page-breaks paper-book)
+ "Return pages as a list starting with 1st page. Each page is a 'page Prob."
+ (let* ((paper (ly:paper-book-paper paper-book))
+ (lines (ly:paper-book-systems paper-book))
+ (page-alist (layout->page-init paper))
+ (force-equalization-factor (ly:output-def-lookup
+ paper 'verticalequalizationfactor 0.3))
+ (is-last-bookpart (ly:output-def-lookup paper 'is-last-bookpart)))
+ (ly:message (_ "Calculating page breaks..."))
+ (let* ((best-break-node (walk-lines '() '() lines paper-book page-alist is-last-bookpart))
+ (break-nodes (get-path best-break-node '())))
+ (if #f; (ly:get-option 'verbose)
+ (begin
+ (display (list
+ "\nbreaks: " (map (lambda (node)
+ (ly:prob-property (car (page-lines node))
+ 'number))
+ break-nodes)
+ "\nsystems " (map page-lines break-nodes)
+ "\npenalties " (map page-penalty break-nodes)
+ "\nconfigs " (map page-configuration break-nodes)))))
+ ;; construct page stencils.
+ (for-each page-stencil break-nodes)
+ break-nodes)))
projects / lilypond.git / blobdiff