src/hb-subset-cff2.cc - third_party/harfbuzz - Git at Google

 /*
  * Copyright © 2018 Adobe Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
  * all copies of this software.
  *
  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  *
  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * Adobe Author(s): Michiharu Ariza
  */

 #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"

 using namespace CFF;

 struct cff2_sub_table_offsets_t : cff_sub_table_offsets_t
 {
   cff2_sub_table_offsets_t ()
     : cff_sub_table_offsets_t (),
       varStoreOffset (0)
   {}

   unsigned int  varStoreOffset;
 };

 struct cff2_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<>
 {
   bool serialize (hb_serialize_context_t *c,
 		  const op_str_t &opstr,
 		  const cff2_sub_table_offsets_t &offsets) const
   {
     TRACE_SERIALIZE (this);

     switch (opstr.op)
     {
       case OpCode_vstore:
 	return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.varStoreOffset));

       default:
 	return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, offsets));
     }
   }

   unsigned int calculate_serialized_size (const op_str_t &opstr) const
   {
     switch (opstr.op)
     {
       case OpCode_vstore:
 	return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (opstr.op);

       default:
 	return cff_top_dict_op_serializer_t<>::calculate_serialized_size (opstr);
     }
   }
 };

 struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t>
 {
   static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
   {
     switch (op)
     {
       case OpCode_return:
       case OpCode_endchar:
 	/* dummy opcodes in CFF2. ignore */
 	break;

       case OpCode_hstem:
       case OpCode_hstemhm:
       case OpCode_vstem:
       case OpCode_vstemhm:
       case OpCode_hintmask:
       case OpCode_cntrmask:
 	if (param.drop_hints)
 	{
 	  env.clear_args ();
 	  return;
 	}
 	HB_FALLTHROUGH;

       default:
 	SUPER::flush_args_and_op (op, env, param);
 	break;
     }
   }

   static void flush_args (cff2_cs_interp_env_t &env, flatten_param_t& param)
   {
     for (unsigned int i = 0; i < env.argStack.get_count ();)
     {
       const blend_arg_t &arg = env.argStack[i];
       if (arg.blending ())
       {
       	if (unlikely (!((arg.numValues > 0) && (env.argStack.get_count () >= arg.numValues))))
       	{
 	  env.set_error ();
 	  return;
 	}
 	flatten_blends (arg, i, env, param);
 	i += arg.numValues;
       }
       else
       {
 	str_encoder_t  encoder (param.flatStr);
 	encoder.encode_num (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)
   {
     /* flatten the default values */
     str_encoder_t  encoder (param.flatStr);
     for (unsigned int j = 0; j < arg.numValues; j++)
     {
       const blend_arg_t &arg1 = env.argStack[i + j];
       if (unlikely (!((arg1.blending () && (arg.numValues == arg1.numValues) && (arg1.valueIndex == j) &&
 	      (arg1.deltas.length == env.get_region_count ())))))
       {
       	env.set_error ();
       	return;
       }
       encoder.encode_num (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]);
     }
     /* 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)
   {
     switch (op)
     {
       case OpCode_return:
       case OpCode_endchar:
 	return;
       default:
 	str_encoder_t  encoder (param.flatStr);
 	encoder.encode_op (op);
     }
   }

   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;
 };

 struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t>
 {
   static void process_op (op_code_t op, cff2_cs_interp_env_t &env, subr_subset_param_t& param)
   {
     switch (op) {

       case OpCode_return:
 	param.current_parsed_str->set_parsed ();
 	env.returnFromSubr ();
 	param.set_current_str (env, false);
 	break;

       case OpCode_endchar:
 	param.current_parsed_str->set_parsed ();
 	SUPER::process_op (op, env, param);
 	break;

       case OpCode_callsubr:
 	process_call_subr (op, CSType_LocalSubr, env, param, env.localSubrs, param.local_closure);
 	break;

       case OpCode_callgsubr:
 	process_call_subr (op, CSType_GlobalSubr, env, param, env.globalSubrs, param.global_closure);
 	break;

       default:
 	SUPER::process_op (op, env, param);
 	param.current_parsed_str->add_op (op, env.str_ref);
 	break;
     }
   }

   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_biased_subrs_t& subrs, hb_set_t *closure)
   {
     byte_str_ref_t    str_ref = env.str_ref;
     env.callSubr (subrs, type);
     param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);
     hb_set_add (closure, env.context.subr_num);
     param.set_current_str (env, true);
   }

   private:
   typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_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>
 {
   cff2_subr_subsetter_t (const OT::cff2::accelerator_subset_t &acc, const hb_subset_plan_t *plan)
     : subr_subsetter_t (acc, plan) {}

   static void finalize_parsed_str (cff2_cs_interp_env_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 ())
     {
       number_t  ivs;
       ivs.set_int ((int)env.get_ivs ());
       charstring.set_prefix (ivs, OpCode_vsindexcs);
     }
   }
 };

 struct cff2_subset_plan {
   cff2_subset_plan ()
     : final_size (0),
       orig_fdcount (0),
       subset_fdcount(1),
       subset_fdselect_format (0),
       drop_hints (false),
       desubroutinize (false)
   {
     subset_fdselect_ranges.init ();
     fdmap.init ();
     subset_charstrings.init ();
     subset_globalsubrs.init ();
     subset_localsubrs.init ();
     privateDictInfos.init ();
   }

   ~cff2_subset_plan ()
   {
     subset_fdselect_ranges.fini ();
     fdmap.fini ();
     subset_charstrings.fini_deep ();
     subset_globalsubrs.fini_deep ();
     subset_localsubrs.fini_deep ();
     privateDictInfos.fini ();
   }

   bool create (const OT::cff2::accelerator_subset_t &acc,
 	      hb_subset_plan_t *plan)
   {
     final_size = 0;
     orig_fdcount = acc.fdArray->count;

     drop_hints = plan->drop_hints;
     desubroutinize = plan->desubroutinize;

     /* CFF2 header */
     final_size += OT::cff2::static_size;

     /* top dict */
     {
       cff2_top_dict_op_serializer_t topSzr;
       offsets.topDictInfo.size = TopDict::calculate_serialized_size (acc.topDict, topSzr);
       final_size += offsets.topDictInfo.size;
     }

     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>
 		    flattener(acc, plan);
       if (!flattener.flatten (subset_charstrings))
 	return false;

       /* no global/local subroutines */
       offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (1, 0, 0);
     }
     else
     {
       cff2_subr_subsetter_t	subr_subsetter (acc, plan);

       /* Subset subrs: collect used subroutines, leaving all unused ones behind */
       if (!subr_subsetter.subset ())
 	return false;

       /* encode charstrings, global subrs, local subrs with new subroutine numbers */
       if (!subr_subsetter.encode_charstrings (subset_charstrings))
 	return false;

       if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))
 	return false;

       /* global subrs */
       unsigned int dataSize = subset_globalsubrs.total_size ();
       offsets.globalSubrsInfo.offSize = calcOffSize (dataSize);
       offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (offsets.globalSubrsInfo.offSize, subset_globalsubrs.length, dataSize);

       /* local subrs */
       if (!offsets.localSubrsInfos.resize (orig_fdcount))
 	return false;
       if (!subset_localsubrs.resize (orig_fdcount))
 	return false;
       for (unsigned int fd = 0; fd < orig_fdcount; fd++)
       {
 	subset_localsubrs[fd].init ();
 	offsets.localSubrsInfos[fd].init ();
 	if (fdmap.includes (fd))
 	{
 	  if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))
 	    return false;

 	  unsigned int dataSize = subset_localsubrs[fd].total_size ();
 	  if (dataSize > 0)
 	  {
 	    offsets.localSubrsInfos[fd].offset = final_size;
 	    offsets.localSubrsInfos[fd].offSize = calcOffSize (dataSize);
 	    offsets.localSubrsInfos[fd].size = CFF2Subrs::calculate_serialized_size (offsets.localSubrsInfos[fd].offSize, subset_localsubrs[fd].length, dataSize);
 	  }
 	}
       }
     }

     /* global subrs */
     offsets.globalSubrsInfo.offset = final_size;
     final_size += offsets.globalSubrsInfo.size;

     /* variation store */
     if (acc.varStore != &Null(CFF2VariationStore))
     {
       offsets.varStoreOffset = final_size;
       final_size += acc.varStore->get_size ();
     }

     /* FDSelect */
     if (acc.fdSelect != &Null(CFF2FDSelect))
     {
       offsets.FDSelectInfo.offset = final_size;
       if (unlikely (!hb_plan_subset_cff_fdselect (plan,
 				  orig_fdcount,
 				  *(const FDSelect *)acc.fdSelect,
 				  subset_fdcount,
 				  offsets.FDSelectInfo.size,
 				  subset_fdselect_format,
 				  subset_fdselect_ranges,
 				  fdmap)))
 	return false;

       final_size += offsets.FDSelectInfo.size;
     }
     else
       fdmap.identity (1);

     /* FDArray (FDIndex) */
     {
       offsets.FDArrayInfo.offset = final_size;
       cff_font_dict_op_serializer_t fontSzr;
       unsigned int dictsSize = 0;
       for (unsigned int i = 0; i < acc.fontDicts.length; i++)
 	if (fdmap.includes (i))
 	  dictsSize += FontDict::calculate_serialized_size (acc.fontDicts[i], fontSzr);

       offsets.FDArrayInfo.offSize = calcOffSize (dictsSize);
       final_size += CFF2Index::calculate_serialized_size (offsets.FDArrayInfo.offSize, subset_fdcount, dictsSize);
     }

     /* CharStrings */
     {
       offsets.charStringsInfo.offset = final_size;
       unsigned int dataSize = subset_charstrings.total_size ();
       offsets.charStringsInfo.offSize = calcOffSize (dataSize);
       final_size += CFF2CharStrings::calculate_serialized_size (offsets.charStringsInfo.offSize, plan->num_output_glyphs (), dataSize);
     }

     /* private dicts & local subrs */
     offsets.privateDictsOffset = final_size;
     for (unsigned int i = 0; i < orig_fdcount; i++)
     {
       if (fdmap.includes (i))
       {
 	bool  has_localsubrs = offsets.localSubrsInfos[i].size > 0;
 	cff_private_dict_op_serializer_t privSzr (desubroutinize, drop_hints);
 	unsigned int  priv_size = PrivateDict::calculate_serialized_size (acc.privateDicts[i], privSzr, has_localsubrs);
 	table_info_t  privInfo = { final_size, priv_size, 0 };
 	privateDictInfos.push (privInfo);
 	final_size += privInfo.size;

 	if (!plan->desubroutinize && has_localsubrs)
 	{
 	  offsets.localSubrsInfos[i].offset = final_size;
 	  final_size += offsets.localSubrsInfos[i].size;
 	}
       }
     }

     return true;
   }

   unsigned int get_final_size () const  { return final_size; }

   unsigned int	final_size;
   cff2_sub_table_offsets_t offsets;

   unsigned int    orig_fdcount;
   unsigned int    subset_fdcount;
   unsigned int    subset_fdselect_format;
   hb_vector_t<code_pair_t>   subset_fdselect_ranges;

   remap_t   fdmap;

   str_buff_vec_t	    subset_charstrings;
   str_buff_vec_t	    subset_globalsubrs;
   hb_vector_t<str_buff_vec_t> subset_localsubrs;
   hb_vector_t<table_info_t>  privateDictInfos;

   bool	    drop_hints;
   bool	    desubroutinize;
 };

 static inline bool _write_cff2 (const cff2_subset_plan &plan,
 				const OT::cff2::accelerator_subset_t  &acc,
 				unsigned int num_glyphs,
 				unsigned int dest_sz,
 				void *dest)
 {
   hb_serialize_context_t c (dest, dest_sz);

   OT::cff2 *cff2 = c.start_serialize<OT::cff2> ();
   if (unlikely (!c.extend_min (*cff2)))
     return false;

   /* header */
   cff2->version.major.set (0x02);
   cff2->version.minor.set (0x00);
   cff2->topDict.set (OT::cff2::static_size);

   /* top dict */
   {
     assert (cff2->topDict == (unsigned) (c.head - c.start));
     cff2->topDictSize.set (plan.offsets.topDictInfo.size);
     TopDict &dict = cff2 + cff2->topDict;
     cff2_top_dict_op_serializer_t topSzr;
     if (unlikely (!dict.serialize (&c, acc.topDict, topSzr, plan.offsets)))
     {
       DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 top dict");
       return false;
     }
   }

   /* global subrs */
   {
     assert (cff2->topDict + plan.offsets.topDictInfo.size == (unsigned) (c.head - c.start));
     CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
     if (unlikely (dest == nullptr)) return false;
     if (unlikely (!dest->serialize (&c, plan.offsets.globalSubrsInfo.offSize, plan.subset_globalsubrs)))
     {
       DEBUG_MSG (SUBSET, nullptr, "failed to serialize global subroutines");
       return false;
     }
   }

   /* variation store */
   if (acc.varStore != &Null(CFF2VariationStore))
   {
     assert (plan.offsets.varStoreOffset == (unsigned) (c.head - c.start));
     CFF2VariationStore *dest = c.start_embed<CFF2VariationStore> ();
     if (unlikely (!dest->serialize (&c, acc.varStore)))
     {
       DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 Variation Store");
       return false;
     }
   }

   /* FDSelect */
   if (acc.fdSelect != &Null(CFF2FDSelect))
   {
     assert (plan.offsets.FDSelectInfo.offset == (unsigned) (c.head - c.start));

     if (unlikely (!hb_serialize_cff_fdselect (&c, num_glyphs, *(const FDSelect *)acc.fdSelect, acc.fdArray->count,
 					      plan.subset_fdselect_format, plan.offsets.FDSelectInfo.size,
 					      plan.subset_fdselect_ranges)))
     {
       DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 subset FDSelect");
       return false;
     }
   }

   /* FDArray (FD Index) */
   {
     assert (plan.offsets.FDArrayInfo.offset == (unsigned) (c.head - c.start));
     CFF2FDArray  *fda = c.start_embed<CFF2FDArray> ();
     if (unlikely (fda == nullptr)) return false;
     cff_font_dict_op_serializer_t  fontSzr;
     if (unlikely (!fda->serialize (&c, plan.offsets.FDArrayInfo.offSize,
 				   acc.fontDicts, plan.subset_fdcount, plan.fdmap,
 				   fontSzr, plan.privateDictInfos)))
     {
       DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 FDArray");
       return false;
     }
   }

   /* CharStrings */
   {
     assert (plan.offsets.charStringsInfo.offset == (unsigned) (c.head - c.start));
     CFF2CharStrings  *cs = c.start_embed<CFF2CharStrings> ();
     if (unlikely (cs == nullptr)) return false;
     if (unlikely (!cs->serialize (&c, plan.offsets.charStringsInfo.offSize, plan.subset_charstrings)))
     {
       DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 CharStrings");
       return false;
     }
   }

   /* private dicts & local subrs */
   assert (plan.offsets.privateDictsOffset == (unsigned) (c.head - c.start));
   for (unsigned int i = 0; i < acc.privateDicts.length; i++)
   {
     if (plan.fdmap.includes (i))
     {
       PrivateDict  *pd = c.start_embed<PrivateDict> ();
       if (unlikely (pd == nullptr)) return false;
       unsigned int priv_size = plan.privateDictInfos[plan.fdmap[i]].size;
       bool result;
       cff_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints);
       /* N.B. local subrs immediately follows its corresponding private dict. i.e., subr offset == private dict size */
       unsigned int  subroffset = (plan.offsets.localSubrsInfos[i].size > 0)? priv_size: 0;
       result = pd->serialize (&c, acc.privateDicts[i], privSzr, subroffset);
       if (unlikely (!result))
       {
 	DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF Private Dict[%d]", i);
 	return false;
       }
       if (plan.offsets.localSubrsInfos[i].size > 0)
       {
 	CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
 	if (unlikely (dest == nullptr)) return false;
 	if (unlikely (!dest->serialize (&c, plan.offsets.localSubrsInfos[i].offSize, plan.subset_localsubrs[i])))
 	{
 	  DEBUG_MSG (SUBSET, nullptr, "failed to serialize local subroutines");
 	  return false;
 	}
       }
     }
   }

   assert (c.head == c.end);
   c.end_serialize ();

   return true;
 }

 static bool
 _hb_subset_cff2 (const OT::cff2::accelerator_subset_t  &acc,
 		const char		      *data,
 		hb_subset_plan_t		*plan,
 		hb_blob_t		       **prime /* OUT */)
 {
   cff2_subset_plan cff2_plan;

   if (unlikely (!cff2_plan.create (acc, plan)))
   {
     DEBUG_MSG(SUBSET, nullptr, "Failed to generate a cff2 subsetting plan.");
     return false;
   }

   unsigned int  cff2_prime_size = cff2_plan.get_final_size ();
   char *cff2_prime_data = (char *) calloc (1, cff2_prime_size);

   if (unlikely (!_write_cff2 (cff2_plan, acc, plan->num_output_glyphs (),
 			      cff2_prime_size, cff2_prime_data))) {
     DEBUG_MSG(SUBSET, nullptr, "Failed to write a subset cff2.");
     free (cff2_prime_data);
     return false;
   }

   *prime = hb_blob_create (cff2_prime_data,
 			   cff2_prime_size,
 			   HB_MEMORY_MODE_READONLY,
 			   cff2_prime_data,
 			   free);
   return true;
 }

 /**
  * hb_subset_cff2:
  * Subsets the CFF2 table according to a provided plan.
  *
  * Return value: subsetted cff2 table.
  **/
 bool
 hb_subset_cff2 (hb_subset_plan_t *plan,
 		hb_blob_t       **prime /* OUT */)
 {
   hb_blob_t *cff2_blob = hb_sanitize_context_t().reference_table<CFF::cff2> (plan->source);
   const char *data = hb_blob_get_data(cff2_blob, nullptr);

   OT::cff2::accelerator_subset_t acc;
   acc.init(plan->source);
   bool result = likely (acc.is_valid ()) &&
 		_hb_subset_cff2 (acc, data, plan, prime);

   hb_blob_destroy (cff2_blob);
   acc.fini ();

   return result;
 }
	/*
	* Copyright © 2018 Adobe Inc.
	*
	* This is part of HarfBuzz, a text shaping library.
	*
	* Permission is hereby granted, without written agreement and without
	* license or royalty fees, to use, copy, modify, and distribute this
	* software and its documentation for any purpose, provided that the
	* above copyright notice and the following two paragraphs appear in
	* all copies of this software.
	*
	* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
	* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
	* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
	* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
	* DAMAGE.
	*
	* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
	* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
	* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
	* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
	* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
	*
	* Adobe Author(s): Michiharu Ariza
	*/

	#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"

	using namespace CFF;

	struct cff2_sub_table_offsets_t : cff_sub_table_offsets_t
	{
	cff2_sub_table_offsets_t ()
	: cff_sub_table_offsets_t (),
	varStoreOffset (0)
	{}

	unsigned int varStoreOffset;
	};

	struct cff2_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<>
	{
	bool serialize (hb_serialize_context_t *c,
	const op_str_t &opstr,
	const cff2_sub_table_offsets_t &offsets) const
	{
	TRACE_SERIALIZE (this);

	switch (opstr.op)
	{
	case OpCode_vstore:
	return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.varStoreOffset));

	default:
	return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, offsets));
	}
	}

	unsigned int calculate_serialized_size (const op_str_t &opstr) const
	{
	switch (opstr.op)
	{
	case OpCode_vstore:
	return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (opstr.op);

	default:
	return cff_top_dict_op_serializer_t<>::calculate_serialized_size (opstr);
	}
	}
	};

	struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t>
	{
	static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
	{
	switch (op)
	{
	case OpCode_return:
	case OpCode_endchar:
	/* dummy opcodes in CFF2. ignore */
	break;

	case OpCode_hstem:
	case OpCode_hstemhm:
	case OpCode_vstem:
	case OpCode_vstemhm:
	case OpCode_hintmask:
	case OpCode_cntrmask:
	if (param.drop_hints)
	{
	env.clear_args ();
	return;
	}
	HB_FALLTHROUGH;

	default:
	SUPER::flush_args_and_op (op, env, param);
	break;
	}
	}

	static void flush_args (cff2_cs_interp_env_t &env, flatten_param_t& param)
	{
	for (unsigned int i = 0; i < env.argStack.get_count ();)
	{
	const blend_arg_t &arg = env.argStack[i];
	if (arg.blending ())
	{
	if (unlikely (!((arg.numValues > 0) && (env.argStack.get_count () >= arg.numValues))))
	{
	env.set_error ();
	return;
	}
	flatten_blends (arg, i, env, param);
	i += arg.numValues;
	}
	else
	{
	str_encoder_t encoder (param.flatStr);
	encoder.encode_num (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)
	{
	/* flatten the default values */
	str_encoder_t encoder (param.flatStr);
	for (unsigned int j = 0; j < arg.numValues; j++)
	{
	const blend_arg_t &arg1 = env.argStack[i + j];
	if (unlikely (!((arg1.blending () && (arg.numValues == arg1.numValues) && (arg1.valueIndex == j) &&
	(arg1.deltas.length == env.get_region_count ())))))
	{
	env.set_error ();
	return;
	}
	encoder.encode_num (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]);
	}
	/* 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)
	{
	switch (op)
	{
	case OpCode_return:
	case OpCode_endchar:
	return;
	default:
	str_encoder_t encoder (param.flatStr);
	encoder.encode_op (op);
	}
	}

	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;
	};

	struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t>
	{
	static void process_op (op_code_t op, cff2_cs_interp_env_t &env, subr_subset_param_t& param)
	{
	switch (op) {

	case OpCode_return:
	param.current_parsed_str->set_parsed ();
	env.returnFromSubr ();
	param.set_current_str (env, false);
	break;

	case OpCode_endchar:
	param.current_parsed_str->set_parsed ();
	SUPER::process_op (op, env, param);
	break;

	case OpCode_callsubr:
	process_call_subr (op, CSType_LocalSubr, env, param, env.localSubrs, param.local_closure);
	break;

	case OpCode_callgsubr:
	process_call_subr (op, CSType_GlobalSubr, env, param, env.globalSubrs, param.global_closure);
	break;

	default:
	SUPER::process_op (op, env, param);
	param.current_parsed_str->add_op (op, env.str_ref);
	break;
	}
	}

	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_biased_subrs_t& subrs, hb_set_t *closure)
	{
	byte_str_ref_t str_ref = env.str_ref;
	env.callSubr (subrs, type);
	param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);
	hb_set_add (closure, env.context.subr_num);
	param.set_current_str (env, true);
	}

	private:
	typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_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>
	{
	cff2_subr_subsetter_t (const OT::cff2::accelerator_subset_t &acc, const hb_subset_plan_t *plan)
	: subr_subsetter_t (acc, plan) {}

	static void finalize_parsed_str (cff2_cs_interp_env_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 ())
	{
	number_t ivs;
	ivs.set_int ((int)env.get_ivs ());
	charstring.set_prefix (ivs, OpCode_vsindexcs);
	}
	}
	};

	struct cff2_subset_plan {
	cff2_subset_plan ()
	: final_size (0),
	orig_fdcount (0),
	subset_fdcount(1),
	subset_fdselect_format (0),
	drop_hints (false),
	desubroutinize (false)
	{
	subset_fdselect_ranges.init ();
	fdmap.init ();
	subset_charstrings.init ();
	subset_globalsubrs.init ();
	subset_localsubrs.init ();
	privateDictInfos.init ();
	}

	~cff2_subset_plan ()
	{
	subset_fdselect_ranges.fini ();
	fdmap.fini ();
	subset_charstrings.fini_deep ();
	subset_globalsubrs.fini_deep ();
	subset_localsubrs.fini_deep ();
	privateDictInfos.fini ();
	}

	bool create (const OT::cff2::accelerator_subset_t &acc,
	hb_subset_plan_t *plan)
	{
	final_size = 0;
	orig_fdcount = acc.fdArray->count;

	drop_hints = plan->drop_hints;
	desubroutinize = plan->desubroutinize;

	/* CFF2 header */
	final_size += OT::cff2::static_size;

	/* top dict */
	{
	cff2_top_dict_op_serializer_t topSzr;
	offsets.topDictInfo.size = TopDict::calculate_serialized_size (acc.topDict, topSzr);
	final_size += offsets.topDictInfo.size;
	}

	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>
	flattener(acc, plan);
	if (!flattener.flatten (subset_charstrings))
	return false;

	/* no global/local subroutines */
	offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (1, 0, 0);
	}
	else
	{
	cff2_subr_subsetter_t subr_subsetter (acc, plan);

	/* Subset subrs: collect used subroutines, leaving all unused ones behind */
	if (!subr_subsetter.subset ())
	return false;

	/* encode charstrings, global subrs, local subrs with new subroutine numbers */
	if (!subr_subsetter.encode_charstrings (subset_charstrings))
	return false;

	if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))
	return false;

	/* global subrs */
	unsigned int dataSize = subset_globalsubrs.total_size ();
	offsets.globalSubrsInfo.offSize = calcOffSize (dataSize);
	offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (offsets.globalSubrsInfo.offSize, subset_globalsubrs.length, dataSize);

	/* local subrs */
	if (!offsets.localSubrsInfos.resize (orig_fdcount))
	return false;
	if (!subset_localsubrs.resize (orig_fdcount))
	return false;
	for (unsigned int fd = 0; fd < orig_fdcount; fd++)
	{
	subset_localsubrs[fd].init ();
	offsets.localSubrsInfos[fd].init ();
	if (fdmap.includes (fd))
	{
	if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))
	return false;

	unsigned int dataSize = subset_localsubrs[fd].total_size ();
	if (dataSize > 0)
	{
	offsets.localSubrsInfos[fd].offset = final_size;
	offsets.localSubrsInfos[fd].offSize = calcOffSize (dataSize);
	offsets.localSubrsInfos[fd].size = CFF2Subrs::calculate_serialized_size (offsets.localSubrsInfos[fd].offSize, subset_localsubrs[fd].length, dataSize);
	}
	}
	}
	}

	/* global subrs */
	offsets.globalSubrsInfo.offset = final_size;
	final_size += offsets.globalSubrsInfo.size;

	/* variation store */
	if (acc.varStore != &Null(CFF2VariationStore))
	{
	offsets.varStoreOffset = final_size;
	final_size += acc.varStore->get_size ();
	}

	/* FDSelect */
	if (acc.fdSelect != &Null(CFF2FDSelect))
	{
	offsets.FDSelectInfo.offset = final_size;
	if (unlikely (!hb_plan_subset_cff_fdselect (plan,
	orig_fdcount,
	(const FDSelect )acc.fdSelect,
	subset_fdcount,
	offsets.FDSelectInfo.size,
	subset_fdselect_format,
	subset_fdselect_ranges,
	fdmap)))
	return false;

	final_size += offsets.FDSelectInfo.size;
	}
	else
	fdmap.identity (1);

	/* FDArray (FDIndex) */
	{
	offsets.FDArrayInfo.offset = final_size;
	cff_font_dict_op_serializer_t fontSzr;
	unsigned int dictsSize = 0;
	for (unsigned int i = 0; i < acc.fontDicts.length; i++)
	if (fdmap.includes (i))
	dictsSize += FontDict::calculate_serialized_size (acc.fontDicts[i], fontSzr);

	offsets.FDArrayInfo.offSize = calcOffSize (dictsSize);
	final_size += CFF2Index::calculate_serialized_size (offsets.FDArrayInfo.offSize, subset_fdcount, dictsSize);
	}

	/* CharStrings */
	{
	offsets.charStringsInfo.offset = final_size;
	unsigned int dataSize = subset_charstrings.total_size ();
	offsets.charStringsInfo.offSize = calcOffSize (dataSize);
	final_size += CFF2CharStrings::calculate_serialized_size (offsets.charStringsInfo.offSize, plan->num_output_glyphs (), dataSize);
	}

	/* private dicts & local subrs */
	offsets.privateDictsOffset = final_size;
	for (unsigned int i = 0; i < orig_fdcount; i++)
	{
	if (fdmap.includes (i))
	{
	bool has_localsubrs = offsets.localSubrsInfos[i].size > 0;
	cff_private_dict_op_serializer_t privSzr (desubroutinize, drop_hints);
	unsigned int priv_size = PrivateDict::calculate_serialized_size (acc.privateDicts[i], privSzr, has_localsubrs);
	table_info_t privInfo = { final_size, priv_size, 0 };
	privateDictInfos.push (privInfo);
	final_size += privInfo.size;

	if (!plan->desubroutinize && has_localsubrs)
	{
	offsets.localSubrsInfos[i].offset = final_size;
	final_size += offsets.localSubrsInfos[i].size;
	}
	}
	}

	return true;
	}

	unsigned int get_final_size () const { return final_size; }

	unsigned int final_size;
	cff2_sub_table_offsets_t offsets;

	unsigned int orig_fdcount;
	unsigned int subset_fdcount;
	unsigned int subset_fdselect_format;
	hb_vector_t<code_pair_t> subset_fdselect_ranges;

	remap_t fdmap;

	str_buff_vec_t subset_charstrings;
	str_buff_vec_t subset_globalsubrs;
	hb_vector_t<str_buff_vec_t> subset_localsubrs;
	hb_vector_t<table_info_t> privateDictInfos;

	bool drop_hints;
	bool desubroutinize;
	};

	static inline bool _write_cff2 (const cff2_subset_plan &plan,
	const OT::cff2::accelerator_subset_t &acc,
	unsigned int num_glyphs,
	unsigned int dest_sz,
	void *dest)
	{
	hb_serialize_context_t c (dest, dest_sz);

	OT::cff2 *cff2 = c.start_serialize<OT::cff2> ();
	if (unlikely (!c.extend_min (*cff2)))
	return false;

	/* header */
	cff2->version.major.set (0x02);
	cff2->version.minor.set (0x00);
	cff2->topDict.set (OT::cff2::static_size);

	/* top dict */
	{
	assert (cff2->topDict == (unsigned) (c.head - c.start));
	cff2->topDictSize.set (plan.offsets.topDictInfo.size);
	TopDict &dict = cff2 + cff2->topDict;
	cff2_top_dict_op_serializer_t topSzr;
	if (unlikely (!dict.serialize (&c, acc.topDict, topSzr, plan.offsets)))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 top dict");
	return false;
	}
	}

	/* global subrs */
	{
	assert (cff2->topDict + plan.offsets.topDictInfo.size == (unsigned) (c.head - c.start));
	CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
	if (unlikely (dest == nullptr)) return false;
	if (unlikely (!dest->serialize (&c, plan.offsets.globalSubrsInfo.offSize, plan.subset_globalsubrs)))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize global subroutines");
	return false;
	}
	}

	/* variation store */
	if (acc.varStore != &Null(CFF2VariationStore))
	{
	assert (plan.offsets.varStoreOffset == (unsigned) (c.head - c.start));
	CFF2VariationStore *dest = c.start_embed<CFF2VariationStore> ();
	if (unlikely (!dest->serialize (&c, acc.varStore)))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 Variation Store");
	return false;
	}
	}

	/* FDSelect */
	if (acc.fdSelect != &Null(CFF2FDSelect))
	{
	assert (plan.offsets.FDSelectInfo.offset == (unsigned) (c.head - c.start));

	if (unlikely (!hb_serialize_cff_fdselect (&c, num_glyphs, (const FDSelect )acc.fdSelect, acc.fdArray->count,
	plan.subset_fdselect_format, plan.offsets.FDSelectInfo.size,
	plan.subset_fdselect_ranges)))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 subset FDSelect");
	return false;
	}
	}

	/* FDArray (FD Index) */
	{
	assert (plan.offsets.FDArrayInfo.offset == (unsigned) (c.head - c.start));
	CFF2FDArray *fda = c.start_embed<CFF2FDArray> ();
	if (unlikely (fda == nullptr)) return false;
	cff_font_dict_op_serializer_t fontSzr;
	if (unlikely (!fda->serialize (&c, plan.offsets.FDArrayInfo.offSize,
	acc.fontDicts, plan.subset_fdcount, plan.fdmap,
	fontSzr, plan.privateDictInfos)))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 FDArray");
	return false;
	}
	}

	/* CharStrings */
	{
	assert (plan.offsets.charStringsInfo.offset == (unsigned) (c.head - c.start));
	CFF2CharStrings *cs = c.start_embed<CFF2CharStrings> ();
	if (unlikely (cs == nullptr)) return false;
	if (unlikely (!cs->serialize (&c, plan.offsets.charStringsInfo.offSize, plan.subset_charstrings)))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 CharStrings");
	return false;
	}
	}

	/* private dicts & local subrs */
	assert (plan.offsets.privateDictsOffset == (unsigned) (c.head - c.start));
	for (unsigned int i = 0; i < acc.privateDicts.length; i++)
	{
	if (plan.fdmap.includes (i))
	{
	PrivateDict *pd = c.start_embed<PrivateDict> ();
	if (unlikely (pd == nullptr)) return false;
	unsigned int priv_size = plan.privateDictInfos[plan.fdmap[i]].size;
	bool result;
	cff_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints);
	/* N.B. local subrs immediately follows its corresponding private dict. i.e., subr offset == private dict size */
	unsigned int subroffset = (plan.offsets.localSubrsInfos[i].size > 0)? priv_size: 0;
	result = pd->serialize (&c, acc.privateDicts[i], privSzr, subroffset);
	if (unlikely (!result))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF Private Dict[%d]", i);
	return false;
	}
	if (plan.offsets.localSubrsInfos[i].size > 0)
	{
	CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
	if (unlikely (dest == nullptr)) return false;
	if (unlikely (!dest->serialize (&c, plan.offsets.localSubrsInfos[i].offSize, plan.subset_localsubrs[i])))
	{
	DEBUG_MSG (SUBSET, nullptr, "failed to serialize local subroutines");
	return false;
	}
	}
	}
	}

	assert (c.head == c.end);
	c.end_serialize ();

	return true;
	}

	static bool
	_hb_subset_cff2 (const OT::cff2::accelerator_subset_t &acc,
	const char *data,
	hb_subset_plan_t *plan,
	hb_blob_t *prime / OUT */)
	{
	cff2_subset_plan cff2_plan;

	if (unlikely (!cff2_plan.create (acc, plan)))
	{
	DEBUG_MSG(SUBSET, nullptr, "Failed to generate a cff2 subsetting plan.");
	return false;
	}

	unsigned int cff2_prime_size = cff2_plan.get_final_size ();
	char cff2_prime_data = (char ) calloc (1, cff2_prime_size);

	if (unlikely (!_write_cff2 (cff2_plan, acc, plan->num_output_glyphs (),
	cff2_prime_size, cff2_prime_data))) {
	DEBUG_MSG(SUBSET, nullptr, "Failed to write a subset cff2.");
	free (cff2_prime_data);
	return false;
	}

	*prime = hb_blob_create (cff2_prime_data,
	cff2_prime_size,
	HB_MEMORY_MODE_READONLY,
	cff2_prime_data,
	free);
	return true;
	}

	/**
	* hb_subset_cff2:
	* Subsets the CFF2 table according to a provided plan.
	*
	* Return value: subsetted cff2 table.
	**/
	bool
	hb_subset_cff2 (hb_subset_plan_t *plan,
	hb_blob_t *prime / OUT */)
	{
	hb_blob_t *cff2_blob = hb_sanitize_context_t().reference_table<CFF::cff2> (plan->source);
	const char *data = hb_blob_get_data(cff2_blob, nullptr);

	OT::cff2::accelerator_subset_t acc;
	acc.init(plan->source);
	bool result = likely (acc.is_valid ()) &&
	_hb_subset_cff2 (acc, data, plan, prime);

	hb_blob_destroy (cff2_blob);
	acc.fini ();

	return result;
	}