+++ /dev/null
-;;;; layout-page-layout.scm -- page breaking and page layout
-;;;;
-;;;; source file of the GNU LilyPond music typesetter
-;;;;
-;;;; (c) 2004--2009 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?
-;; - ragged-bottom? ragged-last-bottom?
-
-(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
- 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-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 (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* ((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))
- (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