-;; copy of ly:system. ly:* not available via lilypond-ps2png.scm
-(define (my-system be-verbose exit-on-error cmd)
- (define status 0)
- (if be-verbose
- (begin
- (format (current-error-port) (_ "Invoking `~a'...") cmd)
- (newline (current-error-port))))
- (set! status (system cmd))
- (if (not (= status 0))
- (begin
- (format (current-error-port)
- (format #f (_ "~a exited with status: ~S") "GS" status))
- (if exit-on-error (exit 1))))
- status)
-
-(define (scale-down-image be-verbose factor file)
- (define (with-pbm)
- (let* ((status 0)
- (old (string-append file ".old")))
-
- (rename-file file old)
- (my-system
- be-verbose #t
- (format #f
- "pngtopnm ~a | pnmscale -reduce ~a 2>/dev/null | pnmtopng -compression 9 2>/dev/null > ~a"
- old factor file))
- (delete-file old)))
-
- (with-pbm))
+(define (search-pngtopam)
+ (search-executable
+ (if (eq? PLATFORM 'windows)
+ '("pngtopam.exe" "pngtopnm.exe")
+ '("pngtopam" "pngtopnm"))))
+
+(define (search-pamscale)
+ (search-executable
+ (if (eq? PLATFORM 'windows)
+ '("pamscale.exe" "pnmscale.exe")
+ '("pamscale" "pnmscale"))))
+
+(define (search-pnmtopng)
+ (search-executable
+ (if (eq? PLATFORM 'windows)
+ '("pnmtopng.exe")
+ '("pnmtopng"))))
+
+(define (scale-down-image factor file)
+ (let* ((port-tmp1 (make-tmpfile))
+ (tmp1-name (port-filename port-tmp1))
+ (port-tmp2 (make-tmpfile))
+ (tmp2-name (port-filename port-tmp2))
+ ;; Netpbm commands (pngtopnm, pnmscale, pnmtopng)
+ ;; outputs only standard output instead of a file.
+ ;; So we need pipe and redirection.
+ ;; However, ly:system can't handle them.
+ ;; Therefore, we use ly:system-with-shell.
+ (cmd
+ (ly:format
+ "~a \"~a\" | ~a -reduce ~a | ~a -compression 9 > \"~a\""
+ (search-pngtopam) tmp1-name
+ (search-pamscale) factor
+ (search-pnmtopng)
+ tmp2-name)))
+
+ (close-port port-tmp1)
+ (close-port port-tmp2)
+ (ly:debug (_ "Copying `~a' to `~a'...") file tmp1-name)
+ (copy-binary-file file tmp1-name)
+ (ly:system-with-shell cmd)
+ (ly:debug (_ "Copying `~a' to `~a'...") tmp2-name file)
+ (copy-binary-file tmp2-name file)
+ (ly:debug (_ "Deleting `~a'...") tmp1-name)
+ (delete-file tmp1-name)
+ (ly:debug (_ "Deleting `~a'...") tmp2-name)
+ (delete-file tmp2-name)))