DOC: Add explicit font filenames for MacTeX.

QuLogic · QuLogic · commit a3003360799f · 2020-11-13T20:30:45.000-05:00
On macOS, xelatex uses the system font directories, but MacTeX fonts are
not added there. However, these files can be found by specifying the
file name instead of the font name, so do so on macOS.

On Linux, it is better to continue to specify the font name, as
different distros ship different extensions.
diff --git a/doc/conf.py b/doc/conf.py
@@ -358,10 +358,11 @@ def _check_dependencies():
 \usepackage{fontspec}
 \defaultfontfeatures[\rmfamily,\sffamily,\ttfamily]{}
 '''
+
 # Sphinx 2.0 adopts GNU FreeFont by default, but it does not have all
 # the Unicode codepoints needed for the section about Mathtext
 # "Writing mathematical expressions"
-latex_elements['fontpkg'] = r"""
+fontpkg = r"""
 \setmainfont{XITS}[
   UprightFont    = *-Regular,
   ItalicFont     = *-Italic,
@@ -382,8 +383,16 @@ def _check_dependencies():
 ]
 % needed for \mathbb (blackboard alphabet) to actually work
 \usepackage{unicode-math}
-\setmathfont{XITS Math}
+\setmathfont{XITS Math}[
+]
 """
+if sys.platform == 'darwin':
+    # With MacTeX, fonts are not in the system path, so they must be found by
+    # filename instead of font name, so add explicit extension and rename.
+    fontpkg = fontpkg.replace('[', '''[
+  Extension = .otf,''').replace('XITS Math', 'XITSMath-Regular')
+latex_elements['fontpkg'] = fontpkg
+
 # Sphinx <1.8.0 or >=2.0.0 does this by default, but the 1.8.x series
 # did not for latex_engine = 'xelatex' (as it used Latin Modern font).
 # We need this for code-blocks as FreeMono has wide glyphs.
