[feat] Add feature iteration API

src/hb-aat-layout-feat-table.hh

@@ -123,6 +123,11 @@ struct FeatureName
 			  (base+settingTable).sanitize (c, nSettings)));
   }
 
+  inline hb_aat_layout_feature_type_t get_feature () const
+  { return (hb_aat_layout_feature_type_t) (unsigned int) feature; }
+
+  inline unsigned int get_name_id () const { return nameIndex; }
+
   protected:
   HBUINT16	feature;	/* Feature type. */
   HBUINT16	nSettings;	/* The number of records in the setting name array. */
@@ -143,14 +148,21 @@ struct feat
 {
   static const hb_tag_t tableTag = HB_AAT_TAG_feat;
 
-  inline const FeatureName& get_feature (hb_aat_layout_feature_type_t key) const
+  inline unsigned int get_features (unsigned int                    start_offset,
+				    unsigned int                   *record_count,
+				    hb_aat_layout_feature_record_t *record_buffer) const
   {
-    const FeatureName* feature = (FeatureName*) hb_bsearch (&key, &names,
-							    FeatureName::static_size,
-							    sizeof (FeatureName),
-							    FeatureName::cmp);
-
-    return feature ? *feature : Null (FeatureName);
+    unsigned int feature_count = featureNameCount;
+    if (record_count)
+    {
+      unsigned int len = MIN (feature_count - start_offset, *record_count);
+      for (unsigned int i = 0; i < len; i++)
+      {
+	record_buffer[i].feature = names[i + start_offset].get_feature ();
+	record_buffer[i].name_id = names[i + start_offset].get_name_id ();
+      }
+    }
+    return featureNameCount;
   }
 
   inline unsigned int get_settings (hb_aat_layout_feature_type_t           type,
@@ -159,8 +171,14 @@ struct feat
 				    unsigned int                          *selectors_count, /* IN/OUT.  May be NULL. */
 				    hb_aat_layout_feature_type_selector_t *selectors_buffer /* OUT.     May be NULL. */) const
   {
-    return get_feature (type).get_settings (this, default_setting,
-					    start_offset, selectors_count, selectors_buffer);
+    const FeatureName* feature = (FeatureName*) hb_bsearch (&type, &names,
+							    FeatureName::static_size,
+							    sizeof (FeatureName),
+							    FeatureName::cmp);
+
+    return (feature ? *feature : Null (FeatureName)).get_settings (this, default_setting,
+								   start_offset, selectors_count,
+								   selectors_buffer);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const

src/hb-aat-layout.cc

@@ -169,12 +169,6 @@ AAT::hb_aat_apply_context_t::set_ankr_table (const AAT::ankr *ankr_table_,
   ankr_table = ankr_table_;
   ankr_end = ankr_end_;
 }
-static inline const AAT::feat&
-_get_feat (hb_face_t *face)
-{
-  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return Null(AAT::feat);
-  return *(hb_ot_face_data (face)->feat.get ());
-}
 
 
 /*
@@ -309,9 +303,7 @@ _hb_aat_language_get (hb_face_t *face,
 /**
  * hb_aat_layout_get_feature_settings:
  * @face:            a font face.
- * @type:            AAT feature id you are querying, for example 1 for
- *                   "Ligatures" feature, 37 for the "Lower Case" feature,
- *                   38 for the "Upper Case" feature, etc.
+ * @feature:         AAT feature id you are querying.
  * @default_setting: (out): default value for the type. If it is HB_AAT_LAYOUT_FEATURE_TYPE_UNDEFINED
  *                          means none is selected as default and the feature is not exclusive.
  * @start_offset:    start offset, if you are iterating
@@ -324,12 +316,22 @@ _hb_aat_language_get (hb_face_t *face,
  */
 unsigned int
 hb_aat_layout_get_feature_settings (hb_face_t                             *face,
-				    hb_aat_layout_feature_type_t           type,
+				    hb_aat_layout_feature_type_t           feature,
 				    hb_aat_layout_feature_setting_t       *default_setting, /* OUT.     May be NULL. */
 				    unsigned int                           start_offset,
 				    unsigned int                          *selectors_count, /* IN/OUT.  May be NULL. */
 				    hb_aat_layout_feature_type_selector_t *selectors_buffer /* OUT.     May be NULL. */)
 {
-  return _get_feat (face).get_settings (type, default_setting,
-					start_offset, selectors_count, selectors_buffer);
+  return face->table.feat->get_settings (feature, default_setting,
+					 start_offset, selectors_count, selectors_buffer);
+}
+
+
+unsigned int
+hb_aat_layout_get_features (hb_face_t                      *face,
+			    unsigned int                    start_offset,
+			    unsigned int                   *record_count, /* IN/OUT.  May be NULL. */
+			    hb_aat_layout_feature_record_t *record_buffer /* OUT.     May be NULL. */)
+{
+  return face->table.feat->get_features (start_offset, record_count, record_buffer);
 }

src/hb-aat.h

@@ -60,6 +60,25 @@ typedef enum
   HB_AAT_LAYOUT_FEATURE_TYPE_UNDEFINED               = 0xFFFF
 } hb_aat_layout_feature_type_t;
 
+/**
+ * hb_aat_layout_feature_record_t:
+ *
+ * Feature record and
+ *
+ * Since: REPLACEME
+ **/
+typedef struct hb_aat_layout_feature_record_t
+{
+  hb_aat_layout_feature_type_t feature;
+  hb_ot_name_id_t name_id;
+} hb_aat_layout_feature_record_t;
+
+HB_EXTERN unsigned int
+hb_aat_layout_get_features (hb_face_t                      *face,
+			    unsigned int                    start_offset,
+			    unsigned int                   *record_count, /* IN/OUT.  May be NULL. */
+			    hb_aat_layout_feature_record_t *record_buffer /* OUT.     May be NULL. */);
+
 /**
  * hb_aat_feature_t:
  *
@@ -72,7 +91,7 @@ typedef unsigned int hb_aat_layout_feature_setting_t;
 /**
  * hb_aat_layout_feature_type_selector_t:
  *
- * Feature type record
+ * Feature type selector
  *
  * Since: REPLACEME
  **/
@@ -84,7 +103,7 @@ typedef struct hb_aat_layout_feature_type_selector_t
 
 HB_EXTERN unsigned int
 hb_aat_layout_get_feature_settings (hb_face_t                             *face,
-				    hb_aat_layout_feature_type_t           type,
+				    hb_aat_layout_feature_type_t           feature,
 				    hb_aat_layout_feature_setting_t       *default_setting, /* OUT.     May be NULL. */
 				    unsigned int                           start_offset,
 				    unsigned int                          *selectors_count, /* IN/OUT.  May be NULL. */

test/api/test-aat-layout.c

@@ -30,6 +30,23 @@
 
 /* Unit tests for hb-aat.h */
 
+static hb_face_t *face;
+static hb_face_t *sbix;
+
+static void
+test_aat_get_features (void)
+{
+  hb_aat_layout_feature_record_t records[3];
+  unsigned int record_count = 3;
+  g_assert_cmpuint (11, ==, hb_aat_layout_get_features (face, 0, &record_count, records));
+  g_assert_cmpuint (1, ==, records[0].feature);
+  g_assert_cmpuint (258, ==, records[0].name_id);
+  g_assert_cmpuint (3, ==, records[1].feature);
+  g_assert_cmpuint (261, ==, records[1].name_id);
+  g_assert_cmpuint (6, ==, records[2].feature);
+  g_assert_cmpuint (265, ==, records[2].name_id);
+}
+
 static void
 test_aat_get_feature_settings (void)
 {
@@ -37,10 +54,8 @@ test_aat_get_feature_settings (void)
   hb_aat_layout_feature_type_selector_t records[3];
   unsigned int count = 3;
 
-  hb_face_t *face = hb_test_open_font_file ("fonts/aat-feat.ttf");
-
-  g_assert_cmpuint (4, ==, hb_aat_layout_get_feature_settings (face, 18, &default_setting,
-							0, &count, records));
+  g_assert_cmpuint (4, ==, hb_aat_layout_get_feature_settings (face, (hb_aat_layout_feature_type_t) 18,
+							       &default_setting, 0, &count, records));
   g_assert_cmpuint (3, ==, count);
   g_assert_cmpuint (0, ==, default_setting);
 
@@ -54,8 +69,8 @@ test_aat_get_feature_settings (void)
   g_assert_cmpuint (296, ==, records[2].name_id);
 
   count = 3;
-  g_assert_cmpuint (4, ==, hb_aat_layout_get_feature_settings (face, 18, &default_setting,
-							3, &count, records));
+  g_assert_cmpuint (4, ==, hb_aat_layout_get_feature_settings (face, (hb_aat_layout_feature_type_t) 18,
+							       &default_setting, 3, &count, records));
   g_assert_cmpuint (1, ==, count);
   g_assert_cmpuint (0, ==, default_setting);
 
@@ -64,8 +79,8 @@ test_aat_get_feature_settings (void)
 
 
   count = 1;
-  g_assert_cmpuint (1, ==, hb_aat_layout_get_feature_settings (face, 14, &default_setting,
-							0, &count, records));
+  g_assert_cmpuint (1, ==, hb_aat_layout_get_feature_settings (face, HB_AAT_LAYOUT_FEATURE_TYPE_TYPOGRAPHIC_EXTRAS,
+							       &default_setting, 0, &count, records));
   g_assert_cmpuint (1, ==, count);
   g_assert_cmpuint (HB_AAT_LAYOUT_FEATURE_TYPE_UNDEFINED, ==, default_setting);
 
@@ -74,16 +89,12 @@ test_aat_get_feature_settings (void)
 
 
   count = 100;
-  g_assert_cmpuint (0, ==, hb_aat_layout_get_feature_settings (face, 32, NULL,
-							0, &count, records));
+  g_assert_cmpuint (0, ==, hb_aat_layout_get_feature_settings (face, HB_AAT_LAYOUT_FEATURE_TYPE_UNDEFINED,
+							       NULL, 0, &count, records));
   g_assert_cmpuint (0, ==, count);
 
-  hb_face_destroy (face);
-
-  hb_face_t *sbix = hb_test_open_font_file ("fonts/chromacheck-sbix.ttf");
-  g_assert_cmpuint (0, ==, hb_aat_layout_get_feature_settings (sbix, 100, NULL,
-							0, &count, records));
-  hb_face_destroy (sbix);
+  g_assert_cmpuint (0, ==, hb_aat_layout_get_feature_settings (sbix, HB_AAT_LAYOUT_FEATURE_TYPE_UNDEFINED, NULL,
+							       0, &count, records));
 }
 
 int
@@ -91,7 +102,13 @@ main (int argc, char **argv)
 {
   hb_test_init (&argc, &argv);
 
+  hb_test_add (test_aat_get_features);
   hb_test_add (test_aat_get_feature_settings);
 
-  return hb_test_run();
+  face = hb_test_open_font_file ("fonts/aat-feat.ttf");
+  sbix = hb_test_open_font_file ("fonts/chromacheck-sbix.ttf");
+  unsigned int status = hb_test_run ();
+  hb_face_destroy (sbix);
+  hb_face_destroy (face);
+  return status;
 }