Update fallback-font.adoc

[bai-yi-bai]

Added "Default Microsoft Windows Font Limitations" which was discussed in AsciiDoctor Zulipchat - How to Find Glyphs to satisfy Font-Fallbacks for CustomTheme.

[mojavelinux]

It appears you're suggesting to use Courier as the main font (though it's hard to tell). That's going to make the entire document monospace. That strikes me as very abnormal. I could see using Courier as the monospace font (for code and codespan), but not the main font. Is there another font from Windows 10 that you would suggest for the main font (for headings and paragraphs)? Keep in mind that the fallback font is used for any text and is not a fallback for a specific font.

It's also not clear from this addition how you are configuring the location of these fonts. Is there a common font directory on Windows 10. If so, the docs should mention it.

I'm also trying to figure out if this change is about using fonts from Windows 10, or it's about configuring a fallback font when using fonts from Windows 10. If it's the former, I think the content belongs on the "Use Custom Fonts Page" instead. That's something I still need to sort out.

[bai-yi-bai]

It appears you're suggesting to use Courier as the main font (though it's hard to tell). That's going to make the entire document monospace. That strikes me as very abnormal. I could see using Courier as the monospace font (for code and codespan), but not the main font. Is there another font from Windows 10 that you would suggest for the main font (for headings and paragraphs)? Keep in mind that the fallback font is used for any text and is not a fallback for a specific font.

It's also not clear from this addition how you are configuring the location of these fonts. Is there a common font directory on Windows 10. If so, the docs should mention it.

I'm also trying to figure out if this change is about using fonts from Windows 10, or it's about configuring a fallback font when using fonts from Windows 10. If it's the former, I think the content belongs on the "Use Custom Fonts Page" instead. That's something I still need to sort out.

I wouldn't mind adding more content about Windows-based installs.

Good point about Courier; this was my second choice to use after I found that Calibri doesn't have four separate fonts. A font with four separate files is Times New Roman (times.ttf, timesi.ttf, timesbd.ttf, and timesbi.ttf) This also makes me think I ought to also add the courier monospace font to my example. I'm working off my personal machine(Linux) and looking at my work machine (Windows).

I define the Windows font directory in my antora-assembler.yml's asciidoc, attributes section pdf-fontsdir: GEM_FONTS_DIR;c:/Windows/Fonts/;

[bai-yi-bai]

Let me put another commit together to clean all this up.

[mojavelinux]

In regard to my comment:

It's also not clear from this addition how you are configuring the location of these fonts.

Although you mention it in passing at the end, you don't actually show how it is done. Please say that pdf-fontsdir must be configured to include the Windows fonts directory using -a "pdf-fontsdir=c:/Windows/Fonts/;GEM_FONTS_DIR" or equivalent (not that GEM_FONTS_DIR should be last in the list). Antora Assembler should not be mentioned here as it's outside the scope of these docs.

[mojavelinux]

I think the content belongs on the "Use Custom Fonts Page" instead.

I still think this is true. While this advice involves the fallback font, the context is really about how to use Window's built-in fonts as custom fonts...which, in turn, requires the use of the fallback font for the reason cited.

[mojavelinux]

Thanks.

Merged as a4bba501135f81fc70df060c8b67427225d9b220. I moved the section to the Use Custom Fonts page, did a bit of revision, and added some more references. I believe with the information that's now there, someone should be able to successfully use the system fonts from Microsoft Windows with Asciidoctor PDF.