From 4806b3800d77603c203e8bb2e88baeb2b3a14f05 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Sat, 25 Aug 2018 15:56:07 -0700
Subject: [PATCH] [cmap] Add hb_subset_collect_variation_selectors()

To be moved to hb-face later.
---
 src/hb-ot-cmap-table.hh | 20 ++++++++++++++++----
 src/hb-subset.cc        | 30 ++++++++++++++++++++++++++----
 src/hb-subset.h         |  8 +++++++-
 3 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/src/hb-ot-cmap-table.hh b/src/hb-ot-cmap-table.hh
index bf9874a3e..2f115e2e4 100644
--- a/src/hb-ot-cmap-table.hh
+++ b/src/hb-ot-cmap-table.hh
@@ -594,7 +594,7 @@ struct UnicodeValueRange
   }
 
   HBUINT24	startUnicodeValue;	/* First value in this range. */
-  HBUINT8		additionalCount;	/* Number of additional values in this
+  HBUINT8	additionalCount;	/* Number of additional values in this
 					 * range. */
   public:
   DEFINE_SIZE_STATIC (4);
@@ -675,6 +675,13 @@ struct CmapSubtableFormat14
     return record[record.bsearch(variation_selector)].get_glyph (codepoint, glyph, this);
   }
 
+  inline void collect_variation_selectors (hb_set_t *out) const
+  {
+    unsigned int count = record.len;
+    for (unsigned int i = 0; i < count; i++)
+      out->add (record.arrayZ[i].varSelector);
+  }
+
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -977,7 +984,7 @@ struct cmap
       /* Meh. */
       if (!subtable_uvs) subtable_uvs = &Null(CmapSubtableFormat14);
 
-      this->uvs_table = subtable_uvs;
+      this->subtable_uvs = subtable_uvs;
 
       this->get_glyph_data = subtable;
       if (unlikely (symbol))
@@ -1018,7 +1025,7 @@ struct cmap
 				     hb_codepoint_t  variation_selector,
 				     hb_codepoint_t *glyph) const
     {
-      switch (this->uvs_table->get_glyph_variant (unicode,
+      switch (this->subtable_uvs->get_glyph_variant (unicode,
 						  variation_selector,
 						  glyph))
       {
@@ -1034,6 +1041,10 @@ struct cmap
     {
       subtable->collect_unicodes (out);
     }
+    inline void collect_variation_selectors (hb_set_t *out) const
+    {
+      subtable_uvs->collect_variation_selectors (out);
+    }
 
     protected:
     typedef bool (*hb_cmap_get_glyph_func_t) (const void *obj,
@@ -1073,12 +1084,13 @@ struct cmap
 
     private:
     const CmapSubtable *subtable;
+    const CmapSubtableFormat14 *subtable_uvs;
+
     hb_cmap_get_glyph_func_t get_glyph_func;
     const void *get_glyph_data;
 
     CmapSubtableFormat4::accelerator_t format4_accel;
 
-    const CmapSubtableFormat14 *uvs_table;
     hb_blob_t *blob;
   };
 
diff --git a/src/hb-subset.cc b/src/hb-subset.cc
index 2e991de20..01d9b89a2 100644
--- a/src/hb-subset.cc
+++ b/src/hb-subset.cc
@@ -238,14 +238,36 @@ hb_subset (hb_face_t *source,
 
 /**
  * hb_subset_collect_unicodes:
- * @source: font face data to load.
- * @out: set to add the all codepoints covered by font face, source.
+ * @face: font face.
+ * @out: set to add Unicode characters covered by @face to.
+ *
+ * Since: REPLACEME
  */
 void
-hb_subset_collect_unicodes (hb_face_t *source, hb_set_t *out)
+hb_subset_collect_unicodes (hb_face_t *face, hb_set_t *out)
 {
+  /* XXX Use saved accel. */
   OT::cmap::accelerator_t cmap;
-  cmap.init (source);
+  cmap.init (face);
   cmap.collect_unicodes (out);
   cmap.fini();
 }
+
+/**
+ * hb_subset_collect_variation_selectors:
+ * @face: font face.
+ * @out: set to add Variation Selector characters covered by @face to.
+ *
+ *
+ *
+ * Since: REPLACEME
+ */
+void
+hb_subset_collect_variation_selectors (hb_face_t *face, hb_set_t *out)
+{
+  /* XXX Use saved accel. */
+  OT::cmap::accelerator_t cmap;
+  cmap.init (face);
+  cmap.collect_variation_selectors (out);
+  cmap.fini();
+}
diff --git a/src/hb-subset.h b/src/hb-subset.h
index b79b80946..745bacf23 100644
--- a/src/hb-subset.h
+++ b/src/hb-subset.h
@@ -80,10 +80,16 @@ hb_subset (hb_face_t *source,
 	   hb_subset_profile_t *profile,
            hb_subset_input_t *input);
 
-/* hb_subset_collect_unicodes */
+
+/* TODO Move to hb-face.h. */
+
 HB_EXTERN void
 hb_subset_collect_unicodes (hb_face_t *source, hb_set_t *out);
 
+HB_EXTERN void
+hb_subset_collect_variation_selectors (hb_face_t *source, hb_set_t *out);
+
+
 HB_END_DECLS
 
 #endif /* HB_SUBSET_H */