1 files changed, 300 insertions, 108 deletions

diff --git a/src/3rdparty/harfbuzz-ng/src/hb-subset-cff2.cc b/src/3rdparty/harfbuzz-ng/src/hb-subset-cff2.cc
index 896ae64016..abc108e571 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-subset-cff2.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-subset-cff2.cc
@@ -31,7 +31,6 @@
 #include "hb-open-type.hh"
 #include "hb-ot-cff2-table.hh"
 #include "hb-set.h"
-#include "hb-subset-cff2.hh"
 #include "hb-subset-plan.hh"
 #include "hb-subset-cff-common.hh"
 #include "hb-cff2-interp-cs.hh"
@@ -59,7 +58,10 @@ struct cff2_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<>
     switch (opstr.op)
     {
       case OpCode_vstore:
-	return_trace (FontDict::serialize_link4_op(c, opstr.op, info.var_store_link));
+        if (info.var_store_link)
+	  return_trace (FontDict::serialize_link4_op(c, opstr.op, info.var_store_link));
+	else
+	  return_trace (true);
 
       default:
 	return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, info));
@@ -67,9 +69,9 @@ struct cff2_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<>
   }
 };
 
-struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t>
+struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t, blend_arg_t>
 {
-  static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
+  static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
   {
     switch (op)
     {
@@ -97,7 +99,7 @@ struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatte
     }
   }
 
-  static void flush_args (cff2_cs_interp_env_t &env, flatten_param_t& param)
+  static void flush_args (cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
   {
     for (unsigned int i = 0; i < env.argStack.get_count ();)
     {
@@ -115,14 +117,14 @@ struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatte
       else
       {
 	str_encoder_t  encoder (param.flatStr);
-	encoder.encode_num (arg);
+	encoder.encode_num_cs (arg);
 	i++;
       }
     }
     SUPER::flush_args (env, param);
   }
 
-  static void flatten_blends (const blend_arg_t &arg, unsigned int i, cff2_cs_interp_env_t &env, flatten_param_t& param)
+  static void flatten_blends (const blend_arg_t &arg, unsigned int i, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
   {
     /* flatten the default values */
     str_encoder_t  encoder (param.flatStr);
@@ -135,21 +137,21 @@ struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatte
 	env.set_error ();
 	return;
       }
-      encoder.encode_num (arg1);
+      encoder.encode_num_cs (arg1);
     }
     /* flatten deltas for each value */
     for (unsigned int j = 0; j < arg.numValues; j++)
     {
       const blend_arg_t &arg1 = env.argStack[i + j];
       for (unsigned int k = 0; k < arg1.deltas.length; k++)
-	encoder.encode_num (arg1.deltas[k]);
+	encoder.encode_num_cs (arg1.deltas[k]);
     }
     /* flatten the number of values followed by blend operator */
     encoder.encode_int (arg.numValues);
     encoder.encode_op (OpCode_blendcs);
   }
 
-  static void flush_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
+  static void flush_op (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
   {
     switch (op)
     {
@@ -162,14 +164,25 @@ struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatte
     }
   }
 
+  static void flush_hintmask (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
+  {
+    SUPER::flush_hintmask (op, env, param);
+    if (!param.drop_hints)
+    {
+      str_encoder_t  encoder (param.flatStr);
+      for (unsigned int i = 0; i < env.hintmask_size; i++)
+	encoder.encode_byte (env.str_ref[i]);
+    }
+  }
+
   private:
-  typedef cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t> SUPER;
-  typedef cs_opset_t<blend_arg_t, cff2_cs_opset_flatten_t, cff2_cs_opset_flatten_t, cff2_cs_interp_env_t, flatten_param_t> CSOPSET;
+  typedef cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t, blend_arg_t> SUPER;
+  typedef cs_opset_t<blend_arg_t, cff2_cs_opset_flatten_t, cff2_cs_opset_flatten_t, cff2_cs_interp_env_t<blend_arg_t>, flatten_param_t> CSOPSET;
 };
 
-struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t>
+struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t, blend_arg_t>
 {
-  static void process_op (op_code_t op, cff2_cs_interp_env_t &env, subr_subset_param_t& param)
+  static void process_op (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, subr_subset_param_t& param)
   {
     switch (op) {
 
@@ -201,7 +214,7 @@ struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t
 
   protected:
   static void process_call_subr (op_code_t op, cs_type_t type,
-				 cff2_cs_interp_env_t &env, subr_subset_param_t& param,
+				 cff2_cs_interp_env_t<blend_arg_t> &env, subr_subset_param_t& param,
 				 cff2_biased_subrs_t& subrs, hb_set_t *closure)
   {
     byte_str_ref_t    str_ref = env.str_ref;
@@ -212,15 +225,15 @@ struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t
   }
 
   private:
-  typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t> SUPER;
+  typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t, blend_arg_t> SUPER;
 };
 
-struct cff2_subr_subsetter_t : subr_subsetter_t<cff2_subr_subsetter_t, CFF2Subrs, const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t, cff2_cs_opset_subr_subset_t>
+struct cff2_subr_subsetter_t : subr_subsetter_t<cff2_subr_subsetter_t, CFF2Subrs, const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t<blend_arg_t>, cff2_cs_opset_subr_subset_t>
 {
   cff2_subr_subsetter_t (const OT::cff2::accelerator_subset_t &acc_, const hb_subset_plan_t *plan_)
     : subr_subsetter_t (acc_, plan_) {}
 
-  static void complete_parsed_str (cff2_cs_interp_env_t &env, subr_subset_param_t& param, parsed_cs_str_t &charstring)
+  static void complete_parsed_str (cff2_cs_interp_env_t<blend_arg_t> &env, subr_subset_param_t& param, parsed_cs_str_t &charstring)
   {
     /* vsindex is inserted at the beginning of the charstring as necessary */
     if (env.seen_vsindex ())
@@ -232,43 +245,210 @@ struct cff2_subr_subsetter_t : subr_subsetter_t<cff2_subr_subsetter_t, CFF2Subrs
   }
 };
 
-struct cff2_subset_plan {
-  cff2_subset_plan ()
-    : orig_fdcount (0),
-      subset_fdcount(1),
-      subset_fdselect_size (0),
-      subset_fdselect_format (0),
-      drop_hints (false),
-      desubroutinize (false)
+struct cff2_private_blend_encoder_param_t
+{
+  cff2_private_blend_encoder_param_t (hb_serialize_context_t *c,
+				      const CFF2VariationStore *varStore,
+				      hb_array_t<int> normalized_coords) :
+    c (c), varStore (varStore), normalized_coords (normalized_coords) {}
+
+  void init () {}
+
+  void process_blend ()
+  {
+    if (!seen_blend)
+    {
+      region_count = varStore->varStore.get_region_index_count (ivs);
+      scalars.resize_exact (region_count);
+      varStore->varStore.get_region_scalars (ivs, normalized_coords.arrayZ, normalized_coords.length,
+					     &scalars[0], region_count);
+      seen_blend = true;
+    }
+  }
+
+  double blend_deltas (hb_array_t<const number_t> deltas) const
   {
-    subset_fdselect_ranges.init ();
-    fdmap.init ();
-    subset_charstrings.init ();
-    subset_globalsubrs.init ();
-    subset_localsubrs.init ();
+    double v = 0;
+    if (likely (scalars.length == deltas.length))
+    {
+      unsigned count = scalars.length;
+      for (unsigned i = 0; i < count; i++)
+	v += (double) scalars.arrayZ[i] * deltas.arrayZ[i].to_real ();
+    }
+    return v;
+  }
+
+
+  hb_serialize_context_t *c = nullptr;
+  bool seen_blend = false;
+  unsigned ivs = 0;
+  unsigned region_count = 0;
+  hb_vector_t<float> scalars;
+  const	 CFF2VariationStore *varStore = nullptr;
+  hb_array_t<int> normalized_coords;
+};
+
+struct cff2_private_dict_blend_opset_t : dict_opset_t
+{
+  static void process_arg_blend (cff2_private_blend_encoder_param_t& param,
+				 number_t &arg,
+				 const hb_array_t<const number_t> blends,
+				 unsigned n, unsigned i)
+  {
+    arg.set_int (round (arg.to_real () + param.blend_deltas (blends)));
+  }
+
+  static void process_blend (cff2_priv_dict_interp_env_t& env, cff2_private_blend_encoder_param_t& param)
+  {
+    unsigned int n, k;
+
+    param.process_blend ();
+    k = param.region_count;
+    n = env.argStack.pop_uint ();
+    /* copy the blend values into blend array of the default values */
+    unsigned int start = env.argStack.get_count () - ((k+1) * n);
+    /* let an obvious error case fail, but note CFF2 spec doesn't forbid n==0 */
+    if (unlikely (start > env.argStack.get_count ()))
+    {
+      env.set_error ();
+      return;
+    }
+    for (unsigned int i = 0; i < n; i++)
+    {
+      const hb_array_t<const number_t> blends = env.argStack.sub_array (start + n + (i * k), k);
+      process_arg_blend (param, env.argStack[start + i], blends, n, i);
+    }
+
+    /* pop off blend values leaving default values now adorned with blend values */
+    env.argStack.pop (k * n);
   }
 
-  ~cff2_subset_plan ()
+  static void process_op (op_code_t op, cff2_priv_dict_interp_env_t& env, cff2_private_blend_encoder_param_t& param)
   {
-    subset_fdselect_ranges.fini ();
-    fdmap.fini ();
-    subset_charstrings.fini_deep ();
-    subset_globalsubrs.fini_deep ();
-    subset_localsubrs.fini_deep ();
+    switch (op) {
+      case OpCode_StdHW:
+      case OpCode_StdVW:
+      case OpCode_BlueScale:
+      case OpCode_BlueShift:
+      case OpCode_BlueFuzz:
+      case OpCode_ExpansionFactor:
+      case OpCode_LanguageGroup:
+      case OpCode_BlueValues:
+      case OpCode_OtherBlues:
+      case OpCode_FamilyBlues:
+      case OpCode_FamilyOtherBlues:
+      case OpCode_StemSnapH:
+      case OpCode_StemSnapV:
+	break;
+      case OpCode_vsindexdict:
+	env.process_vsindex ();
+	param.ivs = env.get_ivs ();
+	env.clear_args ();
+	return;
+      case OpCode_blenddict:
+	process_blend (env, param);
+	return;
+
+      default:
+	dict_opset_t::process_op (op, env);
+	if (!env.argStack.is_empty ()) return;
+	break;
+    }
+
+    if (unlikely (env.in_error ())) return;
+
+    // Write args then op
+
+    str_buff_t str;
+    str_encoder_t encoder (str);
+
+    unsigned count = env.argStack.get_count ();
+    for (unsigned i = 0; i < count; i++)
+      encoder.encode_num_tp (env.argStack[i]);
+
+    encoder.encode_op (op);
+
+    auto bytes = str.as_bytes ();
+    param.c->embed (&bytes, bytes.length);
+
+    env.clear_args ();
   }
+};
+
+struct cff2_private_dict_op_serializer_t : op_serializer_t
+{
+  cff2_private_dict_op_serializer_t (bool desubroutinize_, bool drop_hints_, bool pinned_,
+				     const CFF::CFF2VariationStore* varStore_,
+				     hb_array_t<int> normalized_coords_)
+    : desubroutinize (desubroutinize_), drop_hints (drop_hints_), pinned (pinned_),
+      varStore (varStore_), normalized_coords (normalized_coords_) {}
+
+  bool serialize (hb_serialize_context_t *c,
+		  const op_str_t &opstr,
+		  objidx_t subrs_link) const
+  {
+    TRACE_SERIALIZE (this);
 
+    if (drop_hints && dict_opset_t::is_hint_op (opstr.op))
+      return_trace (true);
+
+    if (opstr.op == OpCode_Subrs)
+    {
+      if (desubroutinize || !subrs_link)
+	return_trace (true);
+      else
+	return_trace (FontDict::serialize_link2_op (c, opstr.op, subrs_link));
+    }
+
+    if (pinned)
+    {
+      // Reinterpret opstr and process blends.
+      cff2_priv_dict_interp_env_t env {hb_ubytes_t (opstr.ptr, opstr.length)};
+      cff2_private_blend_encoder_param_t param (c, varStore, normalized_coords);
+      dict_interpreter_t<cff2_private_dict_blend_opset_t, cff2_private_blend_encoder_param_t, cff2_priv_dict_interp_env_t> interp (env);
+      return_trace (interp.interpret (param));
+    }
+
+    return_trace (copy_opstr (c, opstr));
+  }
+
+  protected:
+  const bool desubroutinize;
+  const bool drop_hints;
+  const bool pinned;
+  const CFF::CFF2VariationStore* varStore;
+  hb_array_t<int> normalized_coords;
+};
+
+
+namespace OT {
+struct cff2_subset_plan
+{
   bool create (const OT::cff2::accelerator_subset_t &acc,
 	      hb_subset_plan_t *plan)
   {
+    /* make sure notdef is first */
+    hb_codepoint_t old_glyph;
+    if (!plan->old_gid_for_new_gid (0, &old_glyph) || (old_glyph != 0)) return false;
+
+    num_glyphs = plan->num_output_glyphs ();
     orig_fdcount = acc.fdArray->count;
 
     drop_hints = plan->flags & HB_SUBSET_FLAGS_NO_HINTING;
-    desubroutinize = plan->flags & HB_SUBSET_FLAGS_DESUBROUTINIZE;
+    pinned = (bool) plan->normalized_coords;
+    desubroutinize = plan->flags & HB_SUBSET_FLAGS_DESUBROUTINIZE ||
+		     pinned; // For instancing we need this path
+
+ #ifdef HB_EXPERIMENTAL_API
+    min_charstrings_off_size = (plan->flags & HB_SUBSET_FLAGS_IFTB_REQUIREMENTS) ? 4 : 0;
+ #else
+    min_charstrings_off_size = 0;
+ #endif
 
     if (desubroutinize)
     {
       /* Flatten global & local subrs */
-      subr_flattener_t<const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t, cff2_cs_opset_flatten_t>
+      subr_flattener_t<const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t<blend_arg_t>, cff2_cs_opset_flatten_t>
 		    flattener(acc, plan);
       if (!flattener.flatten (subset_charstrings))
 	return false;
@@ -282,7 +462,7 @@ struct cff2_subset_plan {
 	return false;
 
       /* encode charstrings, global subrs, local subrs with new subroutine numbers */
-      if (!subr_subsetter.encode_charstrings (subset_charstrings))
+      if (!subr_subsetter.encode_charstrings (subset_charstrings, !pinned))
 	return false;
 
       if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))
@@ -320,10 +500,12 @@ struct cff2_subset_plan {
 
   cff2_sub_table_info_t info;
 
-  unsigned int    orig_fdcount;
-  unsigned int    subset_fdcount;
-  unsigned int	  subset_fdselect_size;
-  unsigned int    subset_fdselect_format;
+  unsigned int    num_glyphs;
+  unsigned int    orig_fdcount = 0;
+  unsigned int    subset_fdcount = 1;
+  unsigned int    subset_fdselect_size = 0;
+  unsigned int    subset_fdselect_format = 0;
+  bool            pinned = false;
   hb_vector_t<code_pair_t>   subset_fdselect_ranges;
 
   hb_inc_bimap_t   fdmap;
@@ -332,20 +514,52 @@ struct cff2_subset_plan {
   str_buff_vec_t	    subset_globalsubrs;
   hb_vector_t<str_buff_vec_t> subset_localsubrs;
 
-  bool	    drop_hints;
-  bool	    desubroutinize;
+  bool	    drop_hints = false;
+  bool	    desubroutinize = false;
+
+  unsigned  min_charstrings_off_size = 0;
 };
+} // namespace OT
 
-static bool _serialize_cff2 (hb_serialize_context_t *c,
+static bool _serialize_cff2_charstrings (hb_serialize_context_t *c,
 			     cff2_subset_plan &plan,
-			     const OT::cff2::accelerator_subset_t  &acc,
-			     unsigned int num_glyphs)
+			     const OT::cff2::accelerator_subset_t  &acc)
+{
+  c->push ();
+
+  unsigned data_size = 0;
+  unsigned total_size = CFF2CharStrings::total_size (plan.subset_charstrings, &data_size, plan.min_charstrings_off_size);
+  if (unlikely (!c->start_zerocopy (total_size)))
+    return false;
+
+  auto *cs = c->start_embed<CFF2CharStrings> ();
+  if (unlikely (!cs->serialize (c, plan.subset_charstrings, &data_size, plan.min_charstrings_off_size)))
+  {
+    c->pop_discard ();
+    return false;
+  }
+
+  plan.info.char_strings_link = c->pop_pack (false);
+  return true;
+}
+
+bool
+OT::cff2::accelerator_subset_t::serialize (hb_serialize_context_t *c,
+					   struct cff2_subset_plan &plan,
+					   hb_array_t<int> normalized_coords) const
 {
+  /* push charstrings onto the object stack first which will ensure it packs as the last
+     object in the table. Keeping the chastrings last satisfies the requirements for patching
+     via IFTB. If this ordering needs to be changed in the future, charstrings should be left
+     at the end whenever HB_SUBSET_FLAGS_ITFB_REQUIREMENTS is enabled. */
+  if (!_serialize_cff2_charstrings(c, plan, *this))
+    return false;
+
   /* private dicts & local subrs */
   hb_vector_t<table_info_t>  private_dict_infos;
   if (unlikely (!private_dict_infos.resize (plan.subset_fdcount))) return false;
 
-  for (int i = (int)acc.privateDicts.length; --i >= 0 ;)
+  for (int i = (int)privateDicts.length; --i >= 0 ;)
   {
     if (plan.fdmap.has (i))
     {
@@ -353,22 +567,19 @@ static bool _serialize_cff2 (hb_serialize_context_t *c,
 
       if (plan.subset_localsubrs[i].length > 0)
       {
-	CFF2Subrs *dest = c->start_embed <CFF2Subrs> ();
-	if (unlikely (!dest)) return false;
-	c->push ();
+	auto *dest = c->push <CFF2Subrs> ();
 	if (likely (dest->serialize (c, plan.subset_localsubrs[i])))
-	  subrs_link = c->pop_pack ();
+	  subrs_link = c->pop_pack (false);
 	else
 	{
 	  c->pop_discard ();
 	  return false;
 	}
       }
-      PrivateDict *pd = c->start_embed<PrivateDict> ();
-      if (unlikely (!pd)) return false;
-      c->push ();
-      cff_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints);
-      if (likely (pd->serialize (c, acc.privateDicts[i], privSzr, subrs_link)))
+      auto *pd = c->push<PrivateDict> ();
+      cff2_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints, plan.pinned,
+						 varStore, normalized_coords);
+      if (likely (pd->serialize (c, privateDicts[i], privSzr, subrs_link)))
       {
 	unsigned fd = plan.fdmap[i];
 	private_dict_infos[fd].size = c->length ();
@@ -382,27 +593,14 @@ static bool _serialize_cff2 (hb_serialize_context_t *c,
     }
   }
 
-  /* CharStrings */
-  {
-    CFF2CharStrings  *cs = c->start_embed<CFF2CharStrings> ();
-    if (unlikely (!cs)) return false;
-    c->push ();
-    if (likely (cs->serialize (c, plan.subset_charstrings)))
-      plan.info.char_strings_link = c->pop_pack ();
-    else
-    {
-      c->pop_discard ();
-      return false;
-    }
-  }
-
   /* FDSelect */
-  if (acc.fdSelect != &Null (CFF2FDSelect))
+  if (fdSelect != &Null (CFF2FDSelect))
   {
     c->push ();
-    if (likely (hb_serialize_cff_fdselect (c, num_glyphs, *(const FDSelect *)acc.fdSelect, 					      plan.orig_fdcount,
-					    plan.subset_fdselect_format, plan.subset_fdselect_size,
-					    plan.subset_fdselect_ranges)))
+    if (likely (hb_serialize_cff_fdselect (c, plan.num_glyphs, *(const FDSelect *)fdSelect,
+					   plan.orig_fdcount,
+					   plan.subset_fdselect_format, plan.subset_fdselect_size,
+					   plan.subset_fdselect_ranges)))
       plan.info.fd_select.link = c->pop_pack ();
     else
     {
@@ -413,27 +611,33 @@ static bool _serialize_cff2 (hb_serialize_context_t *c,
 
   /* FDArray (FD Index) */
   {
-    c->push ();
-    CFF2FDArray *fda = c->start_embed<CFF2FDArray> ();
-    if (unlikely (!fda)) return false;
+    auto *fda = c->push<CFF2FDArray> ();
     cff_font_dict_op_serializer_t fontSzr;
     auto it =
-    + hb_zip (+ hb_iter (acc.fontDicts)
+    + hb_zip (+ hb_iter (fontDicts)
 	      | hb_filter ([&] (const cff2_font_dict_values_t &_)
-		{ return plan.fdmap.has (&_ - &acc.fontDicts[0]); }),
+		{ return plan.fdmap.has (&_ - &fontDicts[0]); }),
 	      hb_iter (private_dict_infos))
     ;
-    if (unlikely (!fda->serialize (c, it, fontSzr))) return false;
-    plan.info.fd_array_link = c->pop_pack ();
+    if (unlikely (!fda->serialize (c, it, fontSzr)))
+    {
+      c->pop_discard ();
+      return false;
+    }
+    plan.info.fd_array_link = c->pop_pack (false);
   }
 
   /* variation store */
-  if (acc.varStore != &Null (CFF2VariationStore))
+  if (varStore != &Null (CFF2VariationStore) &&
+      !plan.pinned)
   {
-    c->push ();
-    CFF2VariationStore *dest = c->start_embed<CFF2VariationStore> ();
-    if (unlikely (!dest || !dest->serialize (c, acc.varStore))) return false;
-    plan.info.var_store_link = c->pop_pack ();
+    auto *dest = c->push<CFF2VariationStore> ();
+    if (unlikely (!dest->serialize (c, varStore)))
+    {
+      c->pop_discard ();
+      return false;
+    }
+    plan.info.var_store_link = c->pop_pack (false);
   }
 
   OT::cff2 *cff2 = c->allocate_min<OT::cff2> ();
@@ -448,37 +652,25 @@ static bool _serialize_cff2 (hb_serialize_context_t *c,
   {
     TopDict &dict = cff2 + cff2->topDict;
     cff2_top_dict_op_serializer_t topSzr;
-    if (unlikely (!dict.serialize (c, acc.topDict, topSzr, plan.info))) return false;
+    if (unlikely (!dict.serialize (c, topDict, topSzr, plan.info))) return false;
     cff2->topDictSize = c->head - (const char *)&dict;
   }
 
   /* global subrs */
   {
-    CFF2Subrs *dest = c->start_embed <CFF2Subrs> ();
-    if (unlikely (!dest)) return false;
+    auto *dest = c->start_embed <CFF2Subrs> ();
     return dest->serialize (c, plan.subset_globalsubrs);
   }
 }
 
-static bool
-_hb_subset_cff2 (const OT::cff2::accelerator_subset_t  &acc,
-		 hb_subset_context_t	*c)
-{
-  cff2_subset_plan cff2_plan;
-
-  if (unlikely (!cff2_plan.create (acc, c->plan))) return false;
-  return _serialize_cff2 (c->serializer, cff2_plan, acc, c->plan->num_output_glyphs ());
-}
-
 bool
-hb_subset_cff2 (hb_subset_context_t *c)
+OT::cff2::accelerator_subset_t::subset (hb_subset_context_t *c) const
 {
-  OT::cff2::accelerator_subset_t acc;
-  acc.init (c->plan->source);
-  bool result = likely (acc.is_valid ()) && _hb_subset_cff2 (acc, c);
-  acc.fini ();
+  cff2_subset_plan cff2_plan;
 
-  return result;
+  if (unlikely (!cff2_plan.create (*this, c->plan))) return false;
+  return serialize (c->serializer, cff2_plan,
+		    c->plan->normalized_coords.as_array ());
 }
 
 #endif