Temporarly add this code back, I want to make a release

1 files changed, 26 insertions, 0 deletions

diff --git a/luaotfload.dtx b/luaotfload.dtx
index 586b8be..548251d 100644
--- a/luaotfload.dtx
+++ b/luaotfload.dtx
@@ -675,6 +675,32 @@ luatexbase.add_to_callback("find_vf_file",
                             fonts.vf.find,
                            "luaotfload.find_vf_file")
 %    \end{macrocode}
+% XXX: see https://github.com/wspr/unicode-math/issues/185
+%
+% \luatex does not provide interface to accessing
+% |(Script)ScriptPercentScaleDown| math constants, so we
+% emulate \xetex behaviour by setting |\fontdimen10| and
+% |\fontdimen11|.
+%
+%    \begin{macrocode}
+local function set_sscale_diments(fontdata)
+    local mc = fontdata.MathConstants
+    if mc then
+        if mc["ScriptPercentScaleDown"] then
+            fontdata.parameters[10] = mc.ScriptPercentScaleDown
+        else -- resort to plain TeX default
+            fontdata.parameters[10] = 70
+        end
+        if mc["ScriptScriptPercentScaleDown"] then
+            fontdata.parameters[11] = mc.ScriptScriptPercentScaleDown
+        else -- resort to plain TeX default
+            fontdata.parameters[11] = 50
+        end
+    end
+end
+
+luatexbase.add_to_callback("luaotfload.patch_font", set_sscale_diments, "unicodemath.set_sscale_diments")
+%    \end{macrocode}
 %
 % \iffalse
 %</lua>