X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=scm%2Foutput-ps.scm;h=69f277203934985a01979476b56df1803c5a1bae;hb=b25b4262c8124b4d4279527ce00f1c7dd705a9c7;hp=f784997a40b84dc5a936870cbd6045d524c94b9b;hpb=68caaced5f48737e67beb0c9c8f4517446c06dc7;p=lilypond.git

diff --git a/scm/output-ps.scm b/scm/output-ps.scm
index f784997a40..69f2772039 100644
--- a/scm/output-ps.scm
+++ b/scm/output-ps.scm
@@ -1,445 +1,314 @@
-;;;; output-ps.scm -- implement Scheme output routines for PostScript
+;;;; This file is part of LilyPond, the GNU music typesetter.
 ;;;;
-;;;;  source file of the GNU LilyPond music typesetter
-;;;; 
-;;;; (c)  1998--2004 Jan Nieuwenhuizen <janneke@gnu.org>
-;;;;                 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+;;;; Copyright (C) 1998--2015 Jan Nieuwenhuizen <janneke@gnu.org>
+;;;;                 Han-Wen Nienhuys <hanwen@xs4all.nl>
+;;;;
+;;;; LilyPond is free software: you can redistribute it and/or modify
+;;;; it under the terms of the GNU General Public License as published by
+;;;; the Free Software Foundation, either version 3 of the License, or
+;;;; (at your option) any later version.
+;;;;
+;;;; LilyPond is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;;; GNU General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU General Public License
+;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 
 ;;;; Note: currently misused as testbed for titles with markup, see
 ;;;;       input/test/title-markup.ly
-;;;; 
+;;;;
 ;;;; TODO:
-;;;;   * papersize in header
-;;;;   * special characters, encoding.
-;;;;     + implement encoding switch (switches?  input/output??),
-;;;;     + move encoding definitions to ENCODING.ps files, or
-;;;;     + find out which program's PS(?) encoding code we can use?
+;;;;   * %% Papersize in (header ...)
 ;;;;   * text setting, kerning.
 ;;;;   * document output-interface
 
-(debug-enable 'backtrace)
-
 (define-module (scm output-ps)
-  #:re-export (quote)
-  #:export (define-fonts
-	     unknown
-	     output-paper-def
-	     output-scopes
-	     select-font
-	     blank
-	     dot
-	     beam
-	     bracket
-	     dashed-slur
-	     char
-	     dashed-line
-	     zigzag-line
-	     symmetric-x-triangle
-	     ez-ball
-	     comment
-	     end-output
-	     experimental-on
-	     repeat-slash
-	     header-end
-	     header
-	     placebox
-	     bezier-sandwich
-	     start-system
-	     stop-system
-	     stop-last-system
-	     horizontal-line
-	     filledbox
-	     round-filled-box
-	     text
-	     tuplet
-	     polygon
-	     draw-line
-	     between-system-string
-	     define-origin
-	     no-origin
-	     start-page
-	     stop-page
-	     )
-)
-(use-modules (guile)
-	     (ice-9 regex)
-	     (srfi srfi-13)
-	     (lily))
-
-;;; Global vars
-;; alist containing fontname -> fontcommand assoc (both strings)
-(define page-count 0)
-(define page-number 0)
+  #:re-export (quote))
 
-;; /lilypondpaperoutputscale 1.75729901757299 def
-;;/lily-output-units 2.83464  def  %% milimeter
-;;/output-scale lilypondpaperoutputscale lily-output-units mul def
-;;
-;; output-scale = 1.75729901757299 * 2.83464 = 4.9813100871731003736
-
-(define OUTPUT-SCALE 4.98)
-(define TOP-MARGIN 0)
+(use-modules (guile)
+             (ice-9 regex)
+             (ice-9 optargs)
+             (srfi srfi-1)
+             (srfi srfi-13)
+             (scm framework-ps)
+             (lily))
 
 ;;; helper functions, not part of output interface
-(define (escape-parentheses s)
-  (regexp-substitute/global #f "(^|[^\\])([\\(\\)])" s 'pre 1 "\\" 2 'post))
-
-(define (offset-add a b)
-  (cons (+ (car a) (car b))
-	(+ (cdr a) (cdr b))))
-
-;; WIP
-(define font-encoding-alist
-  '(("ecrm12" . "ISOLatin1Encoding")
-    ("ecmb12" . "ISOLatin1Encoding")))
-		 
-(define (ps-encoding text)
-  (escape-parentheses text))
+;;;
 
-;; FIXME: lily-def
-(define (ps-string-def prefix key val)
-  (string-append "/" prefix (symbol->string key) " ("
-		 (escape-parentheses val)
-		 ") def\n"))
 
-(define (ps-number-def prefix key val)
-  (let ((s (if (integer? val)
-	       (ly:number->string val)
-	       (ly:number->string (exact->inexact val)))))
-    (string-append "/" prefix (symbol->string key) " " s " def\n")))
+;; ice-9 format uses a lot of memory
+;; using simple-format almost halves lilypond cell usage
 
-(define (tex-font? fontname)
-  (equal? (substring fontname 0 2) "cm"))
+(define (str4 num)
+  (if (or (nan? num) (inf? num))
+      (begin
+        (ly:warning (_ "Found infinity or nan in output.  Substituting 0.0"))
+        (if (ly:get-option 'strict-infinity-checking)
+            (exit 1))
+        "0.0")
+      (ly:number->string num)))
 
+(define (number-pair->string4 numpair)
+  (ly:format "~4l" numpair))
 
 ;;;
 ;;; Lily output interface, PostScript implementation --- cleanup and docme
 ;;;
 
-;;; Output-interface functions
-(define (beam width slope thick blot)
-  (string-append
-   (ly:numbers->string (list slope width thick blot)) " draw_beam" ))
-
-;; two beziers
-(define (bezier-sandwich l thick)
-  (string-append 
-   (string-join (map ly:number-pair->string l) " ")
-   " "
-   (ly:number->string thick)
-   " draw_bezier_sandwich"))
-
-(define (bracket arch_angle arch_width arch_height  height arch_thick thick)
-  (string-append
-   (ly:numbers->string
-    (list arch_angle arch_width arch_height height arch_thick thick))
-   " draw_bracket"))
-
 (define (char font i)
-  (string-append 
-    (font-command font) " setfont " 
-   "(\\" (ly:inexact->string i 8) ") show" ))
-
-(define (comment s)
-  (string-append "% " s "\n"))
-
-(define (dashed-line thick on off dx dy)
-  (string-append 
-   (ly:number->string dx) " "
-   (ly:number->string dy) " "
-   (ly:number->string thick)
-   " [ "
-   (ly:number->string on) " "
-   (ly:number->string off)
-   " ] 0 draw_dashed_line"))
-
-;; what the heck is this interface ?
-(define (dashed-slur thick dash l)
-  (string-append 
-   (string-join (map ly:number-pair->string l) " ")
-   " "
-   (ly:number->string thick) 
-   " [ "
-   (ly:number->string dash)
-   " "
-   ;;UGH.  10 ?
-   (ly:number->string (* 10 thick))
-   " ] 0 draw_dashed_slur"))
-
-(define (font-command font)
-  (string-append
-   "magfont"
-   (string-encode-integer
-    (hashq (ly:font-name font) 1000000))
-   "m"
-   (string-encode-integer
-    (inexact->exact (round (* 1000 (ly:font-magnification font)))))))
-
-(define (define-fonts paper font-list)
-
-  (define (fontname->designsize fontname)
-    (let ((i (string-index fontname char-numeric?)))
-      (string->number (substring fontname i))))
-  
-  (define (define-font command fontname scaling)
-    (string-append
-     "/" command " { /" fontname " findfont "
-     ;; FIXME
-     (ly:number->string scaling) " output-scale div scalefont } bind def\n"))
-     ;;(ly:number->string scaling) " scalefont } bind def\n"))
-
-  (define (reencode-font raw encoding command)
-    (string-append
-     raw " " encoding " /" command " reencode-font\n"
-     "/" command "{ /" command " findfont 1 scalefont } bind def\n"))
-	  
-  ;; frobnicate NAME to jibe with external definitions.
-  (define (possibly-mangle-fontname fontname)
-    (cond
-     ((tex-font? fontname)
-      ;; FIXME: we need proper Fontmap for CM fonts, like so:
-      ;; /CMR10 (cmr10.pfb); 
-      ;; (string-upcase fontname)
-      (string-append fontname ".pfb"))
-     ((or (equal? (substring fontname 0 4) "feta")
-	  (equal? (substring fontname 0 4) "parm"))
-      (regexp-substitute/global
-       #f "(feta|parmesan)([a-z-]*)([0-9]+)"
-       fontname 'pre "GNU-LilyPond-" 1 2 "-" 3 'post))
-     (else fontname)))
-			 
-  (define (font-load-command paper font)
-    (let* ((command (font-command font))
-	   (fontname (ly:font-name font))
-	   (mangled (possibly-mangle-fontname fontname))
-	   (encoding (assoc-get fontname font-encoding-alist))
-	   (designsize (ly:font-design-size font))
-	   (magnification (* (ly:font-magnification font)))
-	   (ops (ly:paper-lookup paper 'outputscale))
-	   (scaling (* ops magnification designsize)) )
-
-      (if
-       #f
-       (begin
-	 (newline)
-	 (format (current-error-port) "fontname ~S\n" fontname)
-	 (format (current-error-port) "command ~S\n" command)
-	 (format (current-error-port) "mangled ~S\n" mangled)
-	 (format (current-error-port) "designsize ~S\n" designsize)
-	 (format (current-error-port) "foo-design ~S\n" foo-design)
-	 (format (current-error-port) "magnification ~S\n" magnification)
-	 (format (current-error-port) "ops ~S\n" ops)
-	 (format (current-error-port) "scaling ~S\n" scaling)))
-      
-      (if encoding
-	  ;; FIXME: should rather tag encoded font
-	  (let ((raw (string-append command "-raw")))
-	    (string-append
-	     (define-font raw mangled scaling)
-	     (reencode-font raw encoding command)))
-	  (define-font command mangled scaling))))
-  
-  (apply string-append
-	 (map (lambda (x) (font-load-command paper x)) font-list)))
-
-(define (define-origin file line col) "")
-
-(define (dot x y radius)
-  (string-append
-   " "
-   (ly:numbers->string
-    (list x y radius)) " draw_dot"))
+  (ly:format "~a (\\~a) show"
+             (ps-font-command font)
+             (ly:inexact->string i 8)))
+
+(define (circle radius thick fill)
+  (ly:format
+   "~a ~4f ~4f draw_circle"
+   (if fill
+       "true"
+       "false")
+   radius thick))
+
+(define (start-enclosing-id-node s)
+  "")
+
+(define (end-enclosing-id-node)
+  "")
+
+(define (dashed-line thick on off dx dy phase)
+  (ly:format "~4f ~4f ~4f [ ~4f ~4f ] ~4f draw_dashed_line"
+             dx
+             dy
+             thick
+             on
+             off
+             phase))
 
 (define (draw-line thick x1 y1 x2 y2)
-  (string-append 
-   "1 setlinecap 1 setlinejoin "
-   (ly:number->string thick) " setlinewidth "
-   (ly:number->string x1) " "
-   (ly:number->string y1) " moveto "
-   (ly:number->string x2) " "
-   (ly:number->string y2) " lineto stroke"))
-
-(define (end-output)
-  "\nend-lilypond-output\n")
-
-(define (ez-ball ch letter-col ball-col)
-  (string-append
-   " (" ch ") "
-   (ly:numbers->string (list letter-col ball-col))
-   " /Helvetica-Bold " ;; ugh
-   " draw_ez_ball"))
-
-(define (filledbox breapth width depth height) 
-  (string-append (ly:numbers->string (list breapth width depth height))
-		 " draw_box"))
-
-(define (header creator time-stamp page-count-)
-  (set! page-count page-count-)
-  (set! page-number 0)
-  (string-append
-   "%!PS-Adobe-3.0\n"
-   "%%Creator: " creator " " time-stamp "\n"
-   "%%Pages: " (number->string page-count) "\n"
-   "%%PageOrder: Ascend\n"
-   ;; FIXME: TODO get from paper
-   ;; "%%DocumentPaperSizes: a6\n"
-   ;;(string-append "GNU LilyPond (" (lilypond-version) "), ")
-   ;;	   (strftime "%c" (localtime (current-time))))
-   ;; FIXME: duplicated in every backend
-   (ps-string-def
-    "lilypond" 'tagline
-    (string-append "Engraved by LilyPond (version " (lilypond-version) ")"))))
-
-(define (header-end)
-  (string-append
-   (ly:gulp-file "lilyponddefs.ps")
-   (ly:gulp-file "music-drawing-routines.ps")))
-
-(define (horizontal-line x1 x2 th)
-  (draw-line th x1  0 x2 0))
-
-(define (lily-def key val)
-  (let ((prefix "lilypondpaper"))
-    (if (string=?
-	 (substring key 0 (min (string-length prefix) (string-length key)))
-	 prefix)
-	(string-append "/" key " {" val "} bind def\n")
-	(string-append "/" key " (" val ") def\n"))))
-
-(define (no-origin) "")
-
-;; FIXME: duplictates output-scopes, duplicated in other backends
-;; FIXME: silly interface name
-(define (output-paper-def pd)
-  (let ((prefix "lilypondpaper"))
-    
-    (define (scope-entry->string key var)
-      (if (variable-bound? var)
-	  (let ((val (variable-ref var)))
-	    (cond
-	     ((string? val) (ps-string-def prefix key val))
-	     ((number? val) (ps-number-def prefix key val))
-	     (else "")))
-	  ""))
-      
-    (apply
-     string-append
-     (module-map scope-entry->string (ly:output-def-scope pd)))))
-
-;; FIXME: duplicated in other output backends
-;; FIXME: silly interface name
-(define (output-scopes paper scopes fields basename)
-  (let ((prefix "lilypond"))
-
-    ;; FIXME: duplicates output-paper's scope-entry->string, mostly
-    (define (scope-entry->string key var)
-      (if (variable-bound? var)
-	  (let ((val (variable-ref var)))
-	    (if (and (memq key fields) (string? val))
-		(header-to-file basename key val))
-	    (cond
-	     ((string? val) (ps-string-def prefix key val))
-	     ((number? val) (ps-number-def prefix key val))
-	     (else "")))
-	  ""))
-    
-    (define (output-scope scope)
-      (apply string-append (module-map scope-entry->string scope)))
-
-    (string-append (apply string-append (map output-scope scopes)))))
-
-;; hmm, looks like recursing call is always last statement, does guile
-;; think so too?
-(define (output-stencil port expr offset)
-  (if (pair? expr)
-      (let ((head (car expr)))
-	(cond
-	 ((ly:input-location? head)
-	  (display (apply define-origin (ly:input-location head)) port)
-	  (output-stencil port (cadr expr) offset))
-	 ((eq? head 'no-origin)
-	  (display (expression->string head) port)
-	  (output-stencil port (cadr expr) offset))
-	 ((eq? head 'translate-stencil)
-	  (output-stencil port (caddr expr) (offset-add offset (cadr expr))))
-	 ((eq? head 'combine-stencil)
-	  (output-stencil port (cadr expr) offset)
-	  (output-stencil port (caddr expr) offset))
-	 (else
-	  (display (placebox (car offset) (cdr offset)
-			     (expression->string expr)) port))))))
-
-(define (placebox x y s) 
-  (string-append 
-   (ly:number->string x) " " (ly:number->string y) " { " s " } place-box\n"))
-
-(define (polygon points blotdiameter)
-  (string-append
-   (ly:numbers->string points) " "
-   (ly:number->string (/ (length points) 2)) " "
-   (ly:number->string blotdiameter)
-   " draw_polygon"))
-
-(define (repeat-slash wid slope thick)
-  (string-append
-   (ly:numbers->string (list wid slope thick))
-   " draw_repeat_slash"))
-
-(define (round-filled-box x y width height blotdiam)
-   (string-append
-    (ly:numbers->string
-     (list x y width height blotdiam)) " draw_round_box"))
-
-(define (new-start-system origin dim)
-  (string-append
-   "\n" (ly:number-pair->string origin) " start-system\n"
-   "{\n"
-   "set-ps-scale-to-lily-scale\n"))
-
-(define (stem breapth width depth height) 
-  (string-append
-   (ly:numbers->string (list breapth width depth height))
-   " draw_box" ))
-
-(define (stop-system)
-  "} stop-system\n")
-
-(define stop-last-system stop-system)
-
-(define (symmetric-x-triangle thick w h)
-  (string-append
-   (ly:numbers->string (list h w thick))
-   " draw_symmetric_x_triangle"))
-
-(define (text font s)
-  
-;;  (string-append "(" (escape-parentheses s) ") show "))
-  (string-append
-
-   (font-command font) " setfont " 
-   "(" (ps-encoding s) ") show"))
-
-(define (unknown) 
+  (ly:format "~4f ~4f ~4f ~4f ~4f draw_line"
+             (- x2 x1) (- y2 y1)
+             x1 y1 thick))
+
+(define (partial-ellipse x-radius y-radius start-angle end-angle thick connect fill)
+  (ly:format "~a ~a ~4f ~4f ~4f ~4f ~4f draw_partial_ellipse"
+             (if fill "true" "false")
+             (if connect "true" "false")
+             x-radius
+             y-radius
+             start-angle
+             end-angle
+             thick))
+
+(define (ellipse x-radius y-radius thick fill)
+  (ly:format
+   "~a ~4f ~4f ~4f draw_ellipse"
+   (if fill
+       "true"
+       "false")
+   x-radius y-radius thick))
+
+(define (embedded-ps string)
+  string)
+
+(define (glyph-string pango-font
+                      postscript-font-name
+                      size
+                      cid?
+                      w-x-y-named-glyphs)
+  (define (glyph-spec w h x y g) ; h not used
+    (let ((prefix (if (string? g) "/" "")))
+      (ly:format "~4f ~4f ~4f ~a~a" w x y prefix g)))
+  (define (emglyph-spec w h x y g) ; h not used
+    (if (and (= x 0) (= y 0))
+        (ly:format "currentpoint ~a moveto ~4f 0 rmoveto" g w)
+        (ly:format "currentpoint ~4f ~4f rmoveto ~a moveto ~4f 0 rmoveto" x y g w)))
+  (if cid?
+      (ly:format
+       "/~a /CIDFont findresource ~a output-scale div scalefont setfont\n~a\n~a print_glyphs"
+       postscript-font-name size
+       (string-join (map (lambda (x) (apply glyph-spec x))
+                         (reverse w-x-y-named-glyphs)) "\n")
+       (length w-x-y-named-glyphs))
+      (if (and (ly:bigpdfs) (string-startswith postscript-font-name "Emmentaler"))
+          (ly:format "/~a-O ~a output-scale div selectfont\n~a"
+                     postscript-font-name size
+                     (string-join (map (lambda (x) (apply emglyph-spec x))
+                                       w-x-y-named-glyphs) "\n"))
+          (ly:format "/~a ~a output-scale div selectfont\n~a\n~a print_glyphs"
+                     postscript-font-name size
+                     (string-join (map (lambda (x) (apply glyph-spec x))
+                                       (reverse w-x-y-named-glyphs)) "\n")
+                     (length w-x-y-named-glyphs)))))
+
+(define (grob-cause offset grob)
+  (if (ly:get-option 'point-and-click)
+      (let* ((cause (ly:grob-property grob 'cause))
+             (music-origin (if (ly:stream-event? cause)
+                               (ly:event-property cause 'origin)))
+             (point-and-click (ly:get-option 'point-and-click)))
+        (if (and
+             (ly:input-location? music-origin)
+             (cond ((boolean? point-and-click) point-and-click)
+                   ((symbol? point-and-click)
+                    (ly:in-event-class? cause point-and-click))
+                   (else (any (lambda (t)
+                                (ly:in-event-class? cause t))
+                              point-and-click))))
+            (let* ((location (ly:input-file-line-char-column music-origin))
+                   (x-ext (ly:grob-extent grob grob X))
+                   (y-ext (ly:grob-extent grob grob Y)))
+
+              (if (and (< 0 (interval-length x-ext))
+                       (< 0 (interval-length y-ext)))
+                  (ly:format "~4f ~4f ~4f ~4f (textedit://~a:~a:~a:~a) mark_URI\n"
+                             (+ (car offset) (car x-ext))
+                             (+ (cdr offset) (car y-ext))
+                             (+ (car offset) (cdr x-ext))
+                             (+ (cdr offset) (cdr y-ext))
+
+                             ;; Backslashes are not valid
+                             ;; file URI path separators.
+                             (ly:string-percent-encode
+                              (ly:string-substitute "\\" "/" (car location)))
+
+                             (cadr location)
+                             (caddr location)
+                             (1+ (cadddr location)))
+                  ""))
+            ""))
+      ""))
+
+(define (named-glyph font glyph)
+  (if (and (ly:bigpdfs) (string-startswith (ly:font-file-name font) "emmentaler"))
+      (if (string-endswith (ly:font-file-name font)"-brace")
+          (if (or (string-startswith glyph "brace1") (string-startswith glyph "brace2"))
+              (ly:format "~a ~a" (string-append (ps-font-command font) "-N" ) glyph)
+              (if (or (string-startswith glyph "brace3") (string-startswith glyph "brace4"))
+                  (ly:format "~a ~a" (string-append (ps-font-command font) "-S" ) glyph)
+                  (ly:format "~a ~a" (string-append (ps-font-command font) "-O" ) glyph)))
+          (if (string-startswith glyph "noteheads")
+              (ly:format "~a ~a" (string-append (ps-font-command font) "-N" ) glyph)
+              (if (or (string-startswith glyph "scripts") (string-startswith glyph "clefs"))
+                  (ly:format "~a ~a" (string-append (ps-font-command font) "-S" ) glyph)
+                  (ly:format "~a ~a" (string-append (ps-font-command font) "-O" ) glyph))))
+      (ly:format "~a /~a glyphshow" (ps-font-command font) glyph)))
+
+(define (no-origin)
+  "")
+
+(define (placebox x y s)
+  (if (not (string-null? s))
+      (ly:format "~4f ~4f moveto ~a\n" x y s)
+      ""))
+
+(define (polygon points blot-diameter filled?)
+  (ly:format "~a ~4l ~a ~4f draw_polygon"
+             (if filled? "true" "false")
+             points
+             (- (/ (length points) 2) 1)
+             blot-diameter))
+
+(define (round-filled-box left right bottom top blotdiam)
+  (let* ((halfblot (/ blotdiam 2))
+         (x (- halfblot left))
+         (width (- right (+ halfblot x)))
+         (y (- halfblot bottom))
+         (height (- top (+ halfblot y))))
+    (ly:format  "~4l draw_round_box"
+                (list width height x y blotdiam))))
+
+;; save current color on stack and set new color
+(define (setcolor r g b)
+  (ly:format "gsave ~4l setrgbcolor\n"
+             (list r g b)))
+
+;; restore color from stack
+(define (resetcolor) "grestore\n")
+
+;; rotation around given point
+(define (setrotation ang x y)
+  (ly:format "gsave ~4l translate ~a rotate ~4l translate\n"
+             (list x y)
+             ang
+             (list (* -1 x) (* -1 y))))
+
+(define (resetrotation ang x y)
+  "grestore  ")
+
+(define (unknown)
   "\n unknown\n")
 
-(define (zigzag-line centre? zzw zzh thick dx dy)
-  (string-append
-    (if centre? "true" "false") " "
-    (ly:number->string zzw) " "
-    (ly:number->string zzh) " "
-    (ly:number->string thick) " "
-    "0 0 "
-    (ly:number->string dx) " "
-    (ly:number->string dy)
-    " draw_zigzag_line"))
-
-(define (start-page)
-  (set! page-number (+ page-number 1))
-  (string-append
-   "%%Page: " (number->string page-number) " " (number->string page-count) "\n"
-  "start-page\n"))
-
-(define (stop-page last?)
-  (if last?
-      "\nstop-last-page\n"
-      "\nstop-page\n"))
+(define (url-link url x y)
+  (ly:format "~a ~a currentpoint vector_add  ~a ~a currentpoint vector_add (~a) mark_URI"
+             (car x)
+             (car y)
+             (cdr x)
+             (cdr y)
+             url))
+
+(define (page-link page-no x y)
+  (if (number? page-no)
+      (ly:format "~a ~a currentpoint vector_add  ~a ~a currentpoint vector_add ~a mark_page_link"
+                 (car x)
+                 (car y)
+                 (cdr x)
+                 (cdr y)
+                 page-no)
+      ""))
+
+(define* (path thickness exps #:optional (cap 'round) (join 'round) (fill? #f))
+  (define (convert-path-exps exps)
+    (if (pair? exps)
+        (let*
+            ((head (car exps))
+             (rest (cdr exps))
+             (arity
+              (cond
+               ((memq head '(rmoveto rlineto lineto moveto)) 2)
+               ((memq head '(rcurveto curveto)) 6)
+               ((eq? head 'closepath) 0)
+               (else 1)))
+             (args (take rest arity))
+             )
+
+          ;; WARNING: this is a vulnerability: a user can output arbitrary PS code here.
+          (cons (ly:format
+                 "~l ~a "
+                 args
+                 head)
+                (convert-path-exps (drop rest arity))))
+        '()))
+
+  (let ((cap-numeric (case cap ((butt) 0) ((round) 1) ((square) 2)
+                           (else (begin
+                                   (ly:warning (_ "unknown line-cap-style: ~S")
+                                               (symbol->string cap))
+                                   1))))
+        (join-numeric (case join ((miter) 0) ((round) 1) ((bevel) 2)
+                            (else (begin
+                                    (ly:warning (_ "unknown line-join-style: ~S")
+                                                (symbol->string join))
+                                    1)))))
+     (ly:format
+      "gsave currentpoint translate
+~a setlinecap ~a setlinejoin ~a setlinewidth
+~l ~a grestore"
+      cap-numeric
+      join-numeric
+      thickness
+      (convert-path-exps exps)
+      ;; print outline contour only if there is no fill or if
+      ;; contour is explicitly requested with a thickness > 0
+      (cond ((not fill?) "stroke")
+            ((positive? thickness) "gsave stroke grestore fill")
+            (else "fill")))))
+
+
+(define (setscale x y)
+  (ly:format "gsave ~4l scale\n"
+             (list x y)))
+
+(define (resetscale)
+  "grestore\n")