Ghostscript Fontmap not updating - pdf

Question

I am currently trying to add some TrueType Fonts to my current Ghostscript setup.
(Windows 10, Ghostscript 9.25, 64bit)
I am editing the Fontmap.GS file found in the folder C:\Program Files\gs\gs9.25\Resource\Init but somehow that doesn't change the behavior. Ghostscript is still substituting Arial-BoldMT with Helvetiva-BoldMT even though I have specified a font to use in that case:
/ArialMT (arial.ttf) ;
/Arial-BoldMT (arialbd.ttf) ;
/Arial-ItalicMT (ariali.ttf) ;
/Arial-BoldItalicMT (arialbi.ttf) ;
Do you know if there is a way to update the Fontmap?
(Or maybe there is another Fontmap file that is being used and I'm editing the wrong one?)
This is the shell answer I get when converting a document that uses Arial-BoldMT (not embedded):
gswin64c -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dNOPAUSE -dBATCH -dAutoRotatePages=/None -sOutputFile=bt_c.pdf bt.pdf
GPL Ghostscript 9.25 (2018-09-13)
Copyright (C) 2018 Artifex Software, Inc. All rights reserved.
This software comes with NO WARRANTY: see the file PUBLIC for details.
Processing pages 1 through 1.
Page 1
Querying operating system for font files...
Substituting font Helvetica-Bold for Arial-BoldMT.
Loading NimbusSans-Bold font from %rom%Resource/Font/NimbusSans-Bold... 4854008 3414088 2431224 1058145 3 done.
The font files themselves are placed in C:\Program Files\gs\gs9.25\Resource\Font
Thank you so much in advance!

Answer 1

In older versions of Ghostscript we did not even ship the support files for Windows, 9.25 is the first (Windows) version where these files are actually installed without extra effort from the user.
The Windows version (and in fact all versions now) defaults to using a ROM file system. That is, the support files are compiled into the executable. What that means is that Ghostscript doesn't look at the disk files, unless you tell it to.
You need to add a -I (Include) directive to tell Ghostscript to look at the modified files on disk. In your case that would be :
-IC:/Program Files/gs/gs9.25/Resource/Init
I'd suggest that you don't put the TrueType files in the Fonts folder, leave them in the Windows/Fonts folder and modify the contents of fontmap.GS so that you include the path:
/ArialMT (c:/Windows/Fonts/arial.ttf) ;
/Arial-BoldMT (c:/Windows/Fonts/arialbd.ttf) ;
/Arial-ItalicMT (c:/Windows/Fonts/ariali.ttf) ;
/Arial-BoldItalicMT (c:/Windows/Fonts/arialbi.ttf) ;
As a couple of extra notes; many font names in PDF files don't follow the names of the original TrueType font. Its not uncommon to see Arial,Bold as a font name. You can add an alias in the fontmap.GS file for that if you've already defined Arial-BoldMT:
/Arial,Bold /Arial-BoldMT ;
I'd recommend using forward slash (/) rather then backslash characters whenever specifying paths for Ghostscript. It happily uses both, converts as required to the OS version and you don't have to worry about whether you need a double backslash or not.
Not all fonts are Fonts, sometimes they are CIDFonts, you need to edit cidfmap to add those. The format of the content is different because more information is needed to construct a replacement for a missing CIDFont.

Answer 2

Update: I was now able to solve the problem myself by passing the custom fontmap as well as the location of the font files in the command line:
-sFONTMAP='/home/MyFonts/MyFontmap.GS' -I'/home/MyFonts/'
Like this Ghostscript loads the correct FontMap file and also knows where to search for the actual font files.
I hope this is helpful for someone!

Answer 3

You have to declare "rom" in the local variable of windows and put
rom = "C: \ Program Files \ gs \ gs9.50 \"
% Rom% Resource / Font / NimbusSans-Regular
equals
C: \ Program Files \ gs \ gs9.50 \ Resource / Font / NimbusSans-Regular