From bc06e2805ae55f5c152dfb70ee91c75830ad8f54 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Wed, 7 Nov 2018 16:02:40 -0500
Subject: [PATCH] [kerx/kern] Add has_cross_stream()

---
 src/hb-aat-layout-kerx-table.hh | 15 +++++++++++++++
 src/hb-ot-kern-table.hh         |  9 +++++++++
 2 files changed, 24 insertions(+)

diff --git a/src/hb-aat-layout-kerx-table.hh b/src/hb-aat-layout-kerx-table.hh
index 84fa6dcd7..422120949 100644
--- a/src/hb-aat-layout-kerx-table.hh
+++ b/src/hb-aat-layout-kerx-table.hh
@@ -848,6 +848,21 @@ struct KerxTable
   /* https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern */
   inline const T* thiz (void) const { return static_cast<const T *> (this); }
 
+  inline bool has_cross_stream (void) const
+  {
+    typedef typename T::SubTable SubTable;
+
+    const SubTable *st = &thiz()->firstSubTable;
+    unsigned int count = thiz()->tableCount;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (st->u.header.coverage & st->u.header.CrossStream)
+        return true;
+      st = &StructAfter<SubTable> (*st);
+    }
+    return false;
+  }
+
   inline int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const
   {
     typedef typename T::SubTable SubTable;
diff --git a/src/hb-ot-kern-table.hh b/src/hb-ot-kern-table.hh
index 95306ece3..690532e29 100644
--- a/src/hb-ot-kern-table.hh
+++ b/src/hb-ot-kern-table.hh
@@ -273,6 +273,15 @@ struct kern
 
   inline bool has_data (void) const { return u.version32; }
 
+  inline bool has_cross_stream (void) const
+  {
+    switch (u.major) {
+    case 0: return u.ot.has_cross_stream ();
+    case 1: return u.aat.has_cross_stream ();
+    default:return false;
+    }
+  }
+
   inline int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const
   {
     switch (u.major) {