--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/hb-subset-cff2.cc	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,464 @@
+/*
+ * 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.hh"
+
+#ifndef HB_NO_SUBSET_CFF
+
+#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_info_t : cff_sub_table_info_t
+{
+  cff2_sub_table_info_t ()
+    : cff_sub_table_info_t (),
+      var_store_link (0)
+  {}
+
+  objidx_t  var_store_link;
+};
+
+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_info_t &info) const
+  {
+    TRACE_SERIALIZE (this);
+
+    switch (opstr.op)
+    {
+      case OpCode_vstore:
+	return_trace (FontDict::serialize_link4_op(c, opstr.op, info.var_store_link));
+
+      default:
+	return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, info));
+    }
+  }
+};
+
+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<blend_arg_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<blend_arg_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<blend_arg_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<blend_arg_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, 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, blend_arg_t>
+{
+  static void process_op (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, subr_subset_param_t& param)
+  {
+    switch (op) {
+
+      case OpCode_return:
+	param.current_parsed_str->set_parsed ();
+	env.return_from_subr ();
+	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<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;
+    env.call_subr (subrs, type);
+    param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);
+    closure->add (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, 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<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<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 ())
+    {
+      number_t  ivs;
+      ivs.set_int ((int)env.get_ivs ());
+      charstring.set_prefix (ivs, OpCode_vsindexcs);
+    }
+  }
+};
+
+struct cff2_subset_plan {
+
+  bool create (const OT::cff2::accelerator_subset_t &acc,
+	      hb_subset_plan_t *plan)
+  {
+    orig_fdcount = acc.fdArray->count;
+
+    drop_hints = plan->flags & HB_SUBSET_FLAGS_NO_HINTING;
+    desubroutinize = plan->flags & HB_SUBSET_FLAGS_DESUBROUTINIZE;
+
+    if (desubroutinize)
+    {
+      /* Flatten global & local subrs */
+      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;
+    }
+    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;
+
+      /* local subrs */
+      if (!subset_localsubrs.resize (orig_fdcount))
+	return false;
+      for (unsigned int fd = 0; fd < orig_fdcount; fd++)
+      {
+	subset_localsubrs[fd].init ();
+	if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))
+	  return false;
+      }
+    }
+
+    /* FDSelect */
+    if (acc.fdSelect != &Null (CFF2FDSelect))
+    {
+      if (unlikely (!hb_plan_subset_cff_fdselect (plan,
+						  orig_fdcount,
+						  *(const FDSelect *)acc.fdSelect,
+						  subset_fdcount,
+						  subset_fdselect_size,
+						  subset_fdselect_format,
+						  subset_fdselect_ranges,
+						  fdmap)))
+	return false;
+    }
+    else
+      fdmap.identity (1);
+
+    return true;
+  }
+
+  cff2_sub_table_info_t info;
+
+  unsigned int    orig_fdcount = 0;
+  unsigned int    subset_fdcount = 1;
+  unsigned int	  subset_fdselect_size = 0;
+  unsigned int    subset_fdselect_format = 0;
+  hb_vector_t<code_pair_t>   subset_fdselect_ranges;
+
+  hb_inc_bimap_t   fdmap;
+
+  str_buff_vec_t	    subset_charstrings;
+  str_buff_vec_t	    subset_globalsubrs;
+  hb_vector_t<str_buff_vec_t> subset_localsubrs;
+
+  bool	    drop_hints = false;
+  bool	    desubroutinize = false;
+};
+
+static bool _serialize_cff2 (hb_serialize_context_t *c,
+			     cff2_subset_plan &plan,
+			     const OT::cff2::accelerator_subset_t  &acc,
+			     unsigned int num_glyphs)
+{
+  /* 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 ;)
+  {
+    if (plan.fdmap.has (i))
+    {
+      objidx_t	subrs_link = 0;
+
+      if (plan.subset_localsubrs[i].length > 0)
+      {
+	CFF2Subrs *dest = c->start_embed <CFF2Subrs> ();
+	if (unlikely (!dest)) return false;
+	c->push ();
+	if (likely (dest->serialize (c, plan.subset_localsubrs[i])))
+	  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)))
+      {
+	unsigned fd = plan.fdmap[i];
+	private_dict_infos[fd].size = c->length ();
+	private_dict_infos[fd].link = c->pop_pack ();
+      }
+      else
+      {
+	c->pop_discard ();
+	return false;
+      }
+    }
+  }
+
+  /* CharStrings */
+  {
+    c->push ();
+
+    unsigned total_size = CFF2CharStrings::total_size (plan.subset_charstrings);
+    if (unlikely (!c->start_zerocopy (total_size)))
+       return false;
+
+    CFF2CharStrings  *cs = c->start_embed<CFF2CharStrings> ();
+    if (unlikely (!cs)) return false;
+
+    if (likely (cs->serialize (c, plan.subset_charstrings)))
+      plan.info.char_strings_link = c->pop_pack (false);
+    else
+    {
+      c->pop_discard ();
+      return false;
+    }
+  }
+
+  /* FDSelect */
+  if (acc.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)))
+      plan.info.fd_select.link = c->pop_pack ();
+    else
+    {
+      c->pop_discard ();
+      return false;
+    }
+  }
+
+  /* FDArray (FD Index) */
+  {
+    c->push ();
+    CFF2FDArray *fda = c->start_embed<CFF2FDArray> ();
+    if (unlikely (!fda)) return false;
+    cff_font_dict_op_serializer_t fontSzr;
+    auto it =
+    + hb_zip (+ hb_iter (acc.fontDicts)
+	      | hb_filter ([&] (const cff2_font_dict_values_t &_)
+		{ return plan.fdmap.has (&_ - &acc.fontDicts[0]); }),
+	      hb_iter (private_dict_infos))
+    ;
+    if (unlikely (!fda->serialize (c, it, fontSzr))) return false;
+    plan.info.fd_array_link = c->pop_pack (false);
+  }
+
+  /* variation store */
+  if (acc.varStore != &Null (CFF2VariationStore))
+  {
+    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 (false);
+  }
+
+  OT::cff2 *cff2 = c->allocate_min<OT::cff2> ();
+  if (unlikely (!cff2)) return false;
+
+  /* header */
+  cff2->version.major = 0x02;
+  cff2->version.minor = 0x00;
+  cff2->topDict = OT::cff2::static_size;
+
+  /* top dict */
+  {
+    TopDict &dict = cff2 + cff2->topDict;
+    cff2_top_dict_op_serializer_t topSzr;
+    if (unlikely (!dict.serialize (c, acc.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;
+    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 acc (c->plan->source);
+  return acc.is_valid () && _hb_subset_cff2 (acc, c);
+}
+
+#endif