[instance] GDEF table: collect both varidxes and deltas

src/OT/Layout/GPOS/AnchorFormat3.hh

@@ -57,8 +57,8 @@ struct AnchorFormat3
 
   void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
   {
-    (this+xDeviceTable).collect_variation_indices (c->layout_variation_indices);
+    (this+xDeviceTable).collect_variation_indices (c);
-    (this+yDeviceTable).collect_variation_indices (c->layout_variation_indices);
+    (this+yDeviceTable).collect_variation_indices (c);
   }
 };
 

src/OT/Layout/GPOS/ValueFormat.hh

@@ -201,27 +201,27 @@ struct ValueFormat : HBUINT16
     if (format & yAdvance) i++;
     if (format & xPlaDevice)
     {
-      (base + get_device (&(values[i]))).collect_variation_indices (c->layout_variation_indices);
+      (base + get_device (&(values[i]))).collect_variation_indices (c);
       i++;
     }
 
     if (format & ValueFormat::yPlaDevice)
     {
-      (base + get_device (&(values[i]))).collect_variation_indices (c->layout_variation_indices);
+      (base + get_device (&(values[i]))).collect_variation_indices (c);
       i++;
     }
 
     if (format & ValueFormat::xAdvDevice)
     {
 
-      (base + get_device (&(values[i]))).collect_variation_indices (c->layout_variation_indices);
+      (base + get_device (&(values[i]))).collect_variation_indices (c);
       i++;
     }
 
     if (format & ValueFormat::yAdvDevice)
     {
 
-      (base + get_device (&(values[i]))).collect_variation_indices (c->layout_variation_indices);
+      (base + get_device (&(values[i]))).collect_variation_indices (c);
       i++;
     }
   }

src/hb-ot-layout-common.hh

@@ -186,6 +186,7 @@ struct hb_subset_layout_context_t :
   unsigned lookup_index_count;
 };
 
+struct VariationStore;
 struct hb_collect_variation_indices_context_t :
        hb_dispatch_context_t<hb_collect_variation_indices_context_t>
 {
@@ -194,15 +195,27 @@ struct hb_collect_variation_indices_context_t :
   static return_t default_return_value () { return hb_empty_t (); }
 
   hb_set_t *layout_variation_indices;
+  hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> *varidx_delta_map;
+  hb_font_t *font;
+  const VariationStore *var_store;
   const hb_set_t *glyph_set;
   const hb_map_t *gpos_lookups;
+  float *store_cache;
 
   hb_collect_variation_indices_context_t (hb_set_t *layout_variation_indices_,
+					  hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> *varidx_delta_map_,
+					  hb_font_t *font_,
+					  const VariationStore *var_store_,
 					  const hb_set_t *glyph_set_,
-					  const hb_map_t *gpos_lookups_) :
+					  const hb_map_t *gpos_lookups_,
+					  float *store_cache_) :
 					layout_variation_indices (layout_variation_indices_),
+					varidx_delta_map (varidx_delta_map_),
+					font (font_),
+					var_store (var_store_),
 					glyph_set (glyph_set_),
-					gpos_lookups (gpos_lookups_) {}
+					gpos_lookups (gpos_lookups_),
+					store_cache (store_cache_) {}
 };
 
 template<typename OutputArray>
@@ -3172,9 +3185,16 @@ struct VariationDevice
     return_trace (out);
   }
 
-  void record_variation_index (hb_set_t *layout_variation_indices) const
+  void collect_variation_index (hb_collect_variation_indices_context_t *c) const
   {
-    layout_variation_indices->add (varIdx);
+    c->layout_variation_indices->add (varIdx);
+    int delta = 0;
+    if (c->font && c->var_store)
+      delta = roundf (get_delta (c->font, *c->var_store, c->store_cache));
+
+    /* set new varidx to HB_OT_LAYOUT_NO_VARIATIONS_INDEX here, will remap
+     * varidx later*/
+    c->varidx_delta_map->set (varIdx, hb_pair_t<unsigned, int> (HB_OT_LAYOUT_NO_VARIATIONS_INDEX, delta));
   }
 
   bool sanitize (hb_sanitize_context_t *c) const
@@ -3286,7 +3306,7 @@ struct Device
     }
   }
 
-  void collect_variation_indices (hb_set_t *layout_variation_indices) const
+  void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
   {
     switch (u.b.format) {
 #ifndef HB_NO_HINTING
@@ -3297,7 +3317,7 @@ struct Device
 #endif
 #ifndef HB_NO_VAR
     case 0x8000:
-      u.variation.record_variation_index (layout_variation_indices);
+      u.variation.collect_variation_index (c);
       return;
 #endif
     default:

src/hb-ot-layout-gdef-table.hh

@@ -207,8 +207,8 @@ struct CaretValueFormat3
 						   hb_serialize_context_t::Head, c->plan->layout_variation_idx_map));
   }
 
-  void collect_variation_indices (hb_set_t *layout_variation_indices) const
+  void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
-  { (this+deviceTable).collect_variation_indices (layout_variation_indices); }
+  { (this+deviceTable).collect_variation_indices (c); }
 
   bool sanitize (hb_sanitize_context_t *c) const
   {
@@ -255,14 +255,14 @@ struct CaretValue
     }
   }
 
-  void collect_variation_indices (hb_set_t *layout_variation_indices) const
+  void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
   {
     switch (u.format) {
     case 1:
     case 2:
       return;
     case 3:
-      u.format3.collect_variation_indices (layout_variation_indices);
+      u.format3.collect_variation_indices (c);
       return;
     default: return;
     }
@@ -329,7 +329,7 @@ struct LigGlyph
   void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
   {
     for (const Offset16To<CaretValue>& offset : carets.iter ())
-      (this+offset).collect_variation_indices (c->layout_variation_indices);
+      (this+offset).collect_variation_indices (c);
   }
 
   bool sanitize (hb_sanitize_context_t *c) const
@@ -846,7 +846,7 @@ struct GDEF
   { get_lig_caret_list ().collect_variation_indices (c); }
 
   void remap_layout_variation_indices (const hb_set_t *layout_variation_indices,
-				       hb_map_t *layout_variation_idx_map /* OUT */) const
+				       hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> *layout_variation_idx_delta_map /* OUT */) const
   {
     if (!has_var_store ()) return;
     if (layout_variation_indices->is_empty ()) return;
@@ -864,7 +864,11 @@ struct GDEF
       }
 
       unsigned new_idx = (new_major << 16) + new_minor;
-      layout_variation_idx_map->set (idx, new_idx);
+      if (!layout_variation_idx_delta_map->has (idx))
+        continue;
+      int delta = hb_second (layout_variation_idx_delta_map->get (idx));
+
+      layout_variation_idx_delta_map->set (idx, hb_pair_t<unsigned, int> (new_idx, delta));
       ++new_minor;
       last_major = major;
     }

src/hb-subset-plan.cc

@@ -287,6 +287,26 @@ _generate_varstore_inner_maps (const hb_set_t& varidx_set,
   }
 }
 
+static inline hb_font_t*
+_get_hb_font_with_variations (const hb_subset_plan_t *plan)
+{
+  hb_font_t *font = hb_font_create (plan->source);
+
+  hb_vector_t<hb_variation_t> vars;
+  vars.alloc (plan->user_axes_location->get_population ());
+
+  for (auto _ : *plan->user_axes_location)
+  {
+    hb_variation_t var;
+    var.tag = _.first;
+    var.value = _.second;
+    vars.push (var);
+  }
+
+  hb_font_set_variations (font, vars.arrayZ, plan->user_axes_location->get_population ());
+  return font;
+}
+
 static inline void
 _collect_layout_variation_indices (hb_subset_plan_t* plan)
 {
@@ -300,13 +320,35 @@ _collect_layout_variation_indices (hb_subset_plan_t* plan)
     return;
   }
 
+  const OT::VariationStore *var_store = nullptr;
   hb_set_t varidx_set;
-  OT::hb_collect_variation_indices_context_t c (&varidx_set, plan->_glyphset_gsub, plan->gpos_lookups);
+  hb_font_t *font = nullptr;
+  float *store_cache = nullptr;
+  bool collect_delta = plan->pinned_at_default ? false : true;
+  if (collect_delta)
+  {
+    font = _get_hb_font_with_variations (plan);
+    if (gdef->has_var_store ())
+    {
+      var_store = &(gdef->get_var_store ());
+      store_cache = var_store->create_cache ();
+    }
+  }
+
+  OT::hb_collect_variation_indices_context_t c (&varidx_set,
+                                                plan->layout_variation_idx_delta_map,
+                                                font, var_store,
+                                                plan->_glyphset_gsub,
+                                                plan->gpos_lookups,
+                                                store_cache);
   gdef->collect_variation_indices (&c);
 
   if (hb_ot_layout_has_positioning (plan->source))
     gpos->collect_variation_indices (&c);
 
+  hb_font_destroy (font);
+  var_store->destroy_cache (store_cache);
+
   gdef->remap_layout_variation_indices (&varidx_set, plan->layout_variation_idx_delta_map);
 
   unsigned subtable_count = gdef->has_var_store () ? gdef->get_var_store ().get_sub_table_count () : 0;