+ ;; page layout - what to do with (printer specific!) margin settings?
+ ((paper-default (eval-carefully
+ (assoc-get
+ (ly:get-option 'paper-size)
+ paper-alist
+ #f
+ #t)
+ m
+ (cons w h)))
+ ;; Horizontal margins, marked with 'preserve, are stored
+ ;; in renamed variables because they must not be overwritten.
+ ;; Output_def::normalize () needs to know
+ ;; whether the user set the value or not.
+ (scaleable-values `((("left-margin" . ,w) . preserve)
+ (("right-margin" . ,w) . preserve)
+ (("inner-margin" . ,w) . preserve)
+ (("outer-margin" . ,w) . preserve)
+ (("binding-offset" . ,w) . '())
+ (("top-margin" . ,h) . '())
+ (("bottom-margin" . ,h) . '())
+ (("indent" . ,w) . '())
+ (("short-indent" . ,w) . '())))
+ (scaled-values
+ (map
+ (lambda (entry)
+ (let ((entry-symbol
+ (string->symbol
+ (string-append (caar entry) "-default")))
+ (orientation (cdar entry)))
+ (if paper-default
+ (cons (if (eq? (cdr entry) 'preserve)
+ (string-append (caar entry) "-default-scaled")
+ (caar entry))
+ (round (* orientation
+ (/ (eval-carefully entry-symbol m 0)
+ (if (= orientation w)
+ (car paper-default)
+ (cdr paper-default))))))
+ entry)))
+ scaleable-values)))
+
+ (module-define! m 'paper-width w)
+ (module-define! m 'paper-height h)
+ ;; Sometimes, lilypond-book doesn't estimate a correct line-width.
+ ;; Therefore, we need to unset line-width.
+ (module-remove! m 'line-width)
+
+ (for-each
+ (lambda (value)
+ (let ((value-symbol (string->symbol (car value)))
+ (number (cdr value)))
+ (module-define! m value-symbol number)))
+ scaled-values)))
+
+(define (internal-set-paper-size module name landscape?)
+ (define (swap x)
+ (cons (cdr x) (car x)))
+
+ (let* ((entry (assoc-get name paper-alist))
+ (is-paper? (module-defined? module 'is-paper))
+ (mm (eval 'mm module)))
+
+ (cond
+ ((not is-paper?)
+ (ly:warning (_ "This is not a \\layout {} object, ~S") module))
+ (entry
+
+ (set! entry (eval entry module))
+ (if landscape?
+ (set! entry (swap entry)))
+ (set-paper-dimensions module (car entry) (cdr entry))
+
+ (module-define! module 'papersizename name)
+ (module-define! module 'landscape
+ (if landscape? #t #f)))
+ (else
+ (ly:warning (_ "Unknown paper size: ~a") name)))))
+
+(define-safe-public (set-default-paper-size name . rest)
+ (internal-set-paper-size
+ (ly:output-def-scope (eval '$defaultpaper (current-module)))
+ name
+ (memq 'landscape rest)))
+
+(define-public (set-paper-size name . rest)
+ (if (module-defined? (current-module) 'is-paper)
+ (internal-set-paper-size (current-module) name
+ (memq 'landscape rest))
+
+ ;;; TODO: should raise (generic) exception with throw, and catch
+ ;;; that in parse-scm.cc
+ (ly:warning (_ "Must use #(set-paper-size .. ) within \\paper { ... }"))))
+
+(define-public (scale-layout paper scale)
+ "Return a clone of the paper, scaled by the given scale factor."
+ (let* ((new-paper (ly:output-def-clone paper))
+ (dim-vars (ly:output-def-lookup paper 'dimension-variables))
+ (old-scope (ly:output-def-scope paper))
+ (scope (ly:output-def-scope new-paper)))
+
+ (for-each
+ (lambda (v)
+ (let* ((var (module-variable old-scope v))
+ (val (if (variable? var) (variable-ref var) #f)))
+
+ (if (number? val)
+ (module-define! scope v (/ val scale))
+ ;; Cannot warn for non-numbers, eg. for paper-width, paper-height.
+ )))
+ dim-vars)
+ ;; Mark the clone.
+ (ly:output-def-set-variable! new-paper 'cloned #t)
+ new-paper))