From d13bbbc5ebf910f72e81cb043bffbe67e7e78c7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20Fabian=20Kr=C3=BCger?= <zauguin@gmail.com>
Date: Wed, 1 Jul 2020 14:28:22 +0200
Subject: [PATCH] Add package for microtype compatibility

---
 luametalatex-microtype.sty | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 luametalatex-microtype.sty

diff --git a/luametalatex-microtype.sty b/luametalatex-microtype.sty
new file mode 100644
index 0000000..de796d0
--- /dev/null
+++ b/luametalatex-microtype.sty
@@ -0,0 +1,34 @@
+% To be loaded *after* microtype
+%
+% Patching \pickup@font to emulate LuaTeX's font expansion interface using \adjustspacing...
+\RequirePackage{microtype}% Just to ensure it isn't loaded in the wrong position. Normally this shouldn't be necessary
+\def\luametalatex@@setexpansion#-#1#2#3#-\relax{%
+  \adjustspacingstretch #1
+  \adjustspacingshrink #2
+  \adjustspacingstep #3
+}%
+\newluafunction\luametalatex@@expandglyphsinfont
+\protected\luadef\pdffontexpand\luametalatex@@expandglyphsinfont
+\def\luametalatex@@everyjobandnow#1{\toksapp\everyjob{#1}#1}%
+%
+\begingroup
+\catcode`\!=\catcode`\%
+\catcode`\%=12
+\expanded{!
+  \endgroup
+  \def\noexpand\pickup@font{!
+    \unexpanded\expandafter{\pickup@font
+      \expandafter\expandafter\expandafter\luametalatex@@setexpansion\csname pickup@font@@hook@luametalatex@microtype@\the\fontid\font@name\endcsname{0}{0}{0}\relax
+    }!
+  }!
+  \noexpand\luametalatex@@everyjobandnow{\noexpand\directlua{!
+    lua.get_functions_table()[\the\luametalatex@@expandglyphsinfont] = function()
+      token.put_next(token.create'fontid')
+      local font = token.scan_int()
+      local stretch = token.scan_int()
+      local shrink = token.scan_int()
+      local step = token.scan_int()
+      token.set_macro('pickup@font@@hook@luametalatex@microtype@' .. font, string.format("{}{%i}{%i}{%i}", stretch, shrink, step), "global")
+    end
+  }}
+}%