src/hb-ot-cff-common.hh

/*
 * 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
 */
#ifndef HB_OT_CFF_COMMON_HH
#define HB_OT_CFF_COMMON_HH

#include "hb-open-type.hh"
#include "hb-ot-layout-common.hh"
#include "hb-cff-interp-dict-common.hh"
#include "hb-subset-plan.hh"

namespace CFF {

using namespace OT;

#define CFF_UNDEF_CODE  0xFFFFFFFF

/* utility macro */
template<typename Type>
static inline const Type& StructAtOffsetOrNull(const void *P, unsigned int offset)
{ return offset? (* reinterpret_cast<const Type*> ((const char *) P + offset)): Null(Type); }

inline unsigned int calcOffSize(unsigned int dataSize)
{
  unsigned int size = 1;
  unsigned int offset = dataSize + 1;
  while ((offset & ~0xFF) != 0)
  {
    size++;
    offset >>= 8;
  }
  /* format does not support size > 4; caller should handle it as an error */
  return size;
}

struct code_pair_t
{
  hb_codepoint_t  code;
  hb_codepoint_t  glyph;
};

typedef hb_vector_t<unsigned char> str_buff_t;
struct str_buff_vec_t : hb_vector_t<str_buff_t>
{
  void fini () { SUPER::fini_deep (); }

  unsigned int total_size () const
  {
    unsigned int size = 0;
    for (unsigned int i = 0; i < length; i++)
      size += (*this)[i].length;
    return size;
  }

  private:
  typedef hb_vector_t<str_buff_t> SUPER;
};

/* CFF INDEX */
template <typename COUNT>
struct CFFIndex
{
  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely ((count.sanitize (c) && count == 0) || /* empty INDEX */
			  (c->check_struct (this) && offSize >= 1 && offSize <= 4 &&
			   c->check_array (offsets, offSize, count + 1) &&
			   c->check_array ((const HBUINT8*)data_base (), 1, max_offset () - 1))));
  }

  static unsigned int calculate_offset_array_size (unsigned int offSize, unsigned int count)
  { return offSize * (count + 1); }

  unsigned int offset_array_size () const
  { return calculate_offset_array_size (offSize, count); }

  static unsigned int calculate_serialized_size (unsigned int offSize, unsigned int count, unsigned int dataSize)
  {
    if (count == 0)
      return COUNT::static_size;
    else
      return min_size + calculate_offset_array_size (offSize, count) + dataSize;
  }

  bool serialize (hb_serialize_context_t *c, const CFFIndex &src)
  {
    TRACE_SERIALIZE (this);
    unsigned int size = src.get_size ();
    CFFIndex *dest = c->allocate_size<CFFIndex> (size);
    if (unlikely (dest == nullptr)) return_trace (false);
    memcpy (dest, &src, size);
    return_trace (true);
  }

  bool serialize (hb_serialize_context_t *c,
		  unsigned int offSize_,
		  const byte_str_array_t &byteArray)
  {
    TRACE_SERIALIZE (this);
    if (byteArray.length == 0)
    {
      COUNT *dest = c->allocate_min<COUNT> ();
      if (unlikely (dest == nullptr)) return_trace (false);
      dest->set (0);
    }
    else
    {
      /* serialize CFFIndex header */
      if (unlikely (!c->extend_min (*this))) return_trace (false);
      this->count.set (byteArray.length);
      this->offSize.set (offSize_);
      if (!unlikely (c->allocate_size<HBUINT8> (offSize_ * (byteArray.length + 1))))
	return_trace (false);

      /* serialize indices */
      unsigned int  offset = 1;
      unsigned int  i = 0;
      for (; i < byteArray.length; i++)
      {
	set_offset_at (i, offset);
	offset += byteArray[i].get_size ();
      }
      set_offset_at (i, offset);

      /* serialize data */
      for (unsigned int i = 0; i < byteArray.length; i++)
      {
      	const byte_str_t &bs = byteArray[i];
	unsigned char  *dest = c->allocate_size<unsigned char> (bs.length);
	if (unlikely (dest == nullptr))
	  return_trace (false);
	memcpy (dest, &bs[0], bs.length);
      }
    }
    return_trace (true);
  }

  bool serialize (hb_serialize_context_t *c,
		  unsigned int offSize_,
		  const str_buff_vec_t &buffArray)
  {
    byte_str_array_t  byteArray;
    byteArray.init ();
    byteArray.resize (buffArray.length);
    for (unsigned int i = 0; i < byteArray.length; i++)
    {
      byteArray[i] = byte_str_t (buffArray[i].arrayZ (), buffArray[i].length);
    }
    bool result = this->serialize (c, offSize_, byteArray);
    byteArray.fini ();
    return result;
  }

  void set_offset_at (unsigned int index, unsigned int offset)
  {
    HBUINT8 *p = offsets + offSize * index + offSize;
    unsigned int size = offSize;
    for (; size; size--)
    {
      --p;
      p->set (offset & 0xFF);
      offset >>= 8;
    }
  }

  unsigned int offset_at (unsigned int index) const
  {
    assert (index <= count);
    const HBUINT8 *p = offsets + offSize * index;
    unsigned int size = offSize;
    unsigned int offset = 0;
    for (; size; size--)
      offset = (offset << 8) + *p++;
    return offset;
  }

  unsigned int length_at (unsigned int index) const
  {
	if (likely ((offset_at (index + 1) >= offset_at (index)) &&
		    (offset_at (index + 1) <= offset_at (count))))
	  return offset_at (index + 1) - offset_at (index);
	else
	  return 0;
  }

  const unsigned char *data_base () const
  { return (const unsigned char *)this + min_size + offset_array_size (); }

  unsigned int data_size () const { return HBINT8::static_size; }

  byte_str_t operator [] (unsigned int index) const
  {
    if (likely (index < count))
      return byte_str_t (data_base () + offset_at (index) - 1, length_at (index));
    else
      return Null(byte_str_t);
  }

  unsigned int get_size () const
  {
    if (this != &Null(CFFIndex))
    {
      if (count > 0)
	return min_size + offset_array_size () + (offset_at (count) - 1);
      else
	return count.static_size;  /* empty CFFIndex contains count only */
    }
    else
      return 0;
  }

  protected:
  unsigned int max_offset () const
  {
    unsigned int max = 0;
    for (unsigned int i = 0; i < count + 1u; i++)
    {
      unsigned int off = offset_at (i);
      if (off > max) max = off;
    }
    return max;
  }

  public:
  COUNT     count;	/* Number of object data. Note there are (count+1) offsets */
  HBUINT8   offSize;      /* The byte size of each offset in the offsets array. */
  HBUINT8   offsets[VAR]; /* The array of (count + 1) offsets into objects array (1-base). */
  /* HBUINT8 data[VAR];      Object data */
  public:
  DEFINE_SIZE_ARRAY (COUNT::static_size + HBUINT8::static_size, offsets);
};

template <typename COUNT, typename TYPE>
struct CFFIndexOf : CFFIndex<COUNT>
{
  const byte_str_t operator [] (unsigned int index) const
  {
    if (likely (index < CFFIndex<COUNT>::count))
      return byte_str_t (CFFIndex<COUNT>::data_base () + CFFIndex<COUNT>::offset_at (index) - 1, CFFIndex<COUNT>::length_at (index));
    return Null(byte_str_t);
  }

  template <typename DATA, typename PARAM1, typename PARAM2>
  bool serialize (hb_serialize_context_t *c,
		  unsigned int offSize_,
		  const DATA *dataArray,
		  unsigned int dataArrayLen,
		  const hb_vector_t<unsigned int> &dataSizeArray,
		  const PARAM1 &param1,
		  const PARAM2 &param2)
  {
    TRACE_SERIALIZE (this);
    /* serialize CFFIndex header */
    if (unlikely (!c->extend_min (*this))) return_trace (false);
    this->count.set (dataArrayLen);
    this->offSize.set (offSize_);
    if (!unlikely (c->allocate_size<HBUINT8> (offSize_ * (dataArrayLen + 1))))
      return_trace (false);

    /* serialize indices */
    unsigned int  offset = 1;
    unsigned int  i = 0;
    for (; i < dataArrayLen; i++)
    {
      CFFIndex<COUNT>::set_offset_at (i, offset);
      offset += dataSizeArray[i];
    }
    CFFIndex<COUNT>::set_offset_at (i, offset);

    /* serialize data */
    for (unsigned int i = 0; i < dataArrayLen; i++)
    {
      TYPE  *dest = c->start_embed<TYPE> ();
      if (unlikely (dest == nullptr ||
		    !dest->serialize (c, dataArray[i], param1, param2)))
	return_trace (false);
    }
    return_trace (true);
  }

  /* in parallel to above */
  template <typename DATA, typename PARAM>
  static unsigned int calculate_serialized_size (unsigned int &offSize_ /* OUT */,
						 const DATA *dataArray,
						 unsigned int dataArrayLen,
						 hb_vector_t<unsigned int> &dataSizeArray, /* OUT */
						 const PARAM &param)
  {
    /* determine offset size */
    unsigned int  totalDataSize = 0;
    for (unsigned int i = 0; i < dataArrayLen; i++)
    {
      unsigned int dataSize = TYPE::calculate_serialized_size (dataArray[i], param);
      dataSizeArray[i] = dataSize;
      totalDataSize += dataSize;
    }
    offSize_ = calcOffSize (totalDataSize);

    return CFFIndex<COUNT>::calculate_serialized_size (offSize_, dataArrayLen, totalDataSize);
  }
};

/* Top Dict, Font Dict, Private Dict */
struct Dict : UnsizedByteStr
{
  template <typename DICTVAL, typename OP_SERIALIZER, typename PARAM>
  bool serialize (hb_serialize_context_t *c,
		  const DICTVAL &dictval,
		  OP_SERIALIZER& opszr,
		  PARAM& param)
  {
    TRACE_SERIALIZE (this);
    for (unsigned int i = 0; i < dictval.get_count (); i++)
    {
      if (unlikely (!opszr.serialize (c, dictval[i], param)))
	return_trace (false);
    }
    return_trace (true);
  }

  /* in parallel to above */
  template <typename DICTVAL, typename OP_SERIALIZER, typename PARAM>
  static unsigned int calculate_serialized_size (const DICTVAL &dictval,
						 OP_SERIALIZER& opszr,
						 PARAM& param)
  {
    unsigned int size = 0;
    for (unsigned int i = 0; i < dictval.get_count (); i++)
      size += opszr.calculate_serialized_size (dictval[i], param);
    return size;
  }

  template <typename DICTVAL, typename OP_SERIALIZER>
  static unsigned int calculate_serialized_size (const DICTVAL &dictval,
						 OP_SERIALIZER& opszr)
  {
    unsigned int size = 0;
    for (unsigned int i = 0; i < dictval.get_count (); i++)
      size += opszr.calculate_serialized_size (dictval[i]);
    return size;
  }

  template <typename INTTYPE, int minVal, int maxVal>
  static bool serialize_int_op (hb_serialize_context_t *c, op_code_t op, int value, op_code_t intOp)
  {
    // XXX: not sure why but LLVM fails to compile the following 'unlikely' macro invocation
    if (/*unlikely*/ (!serialize_int<INTTYPE, minVal, maxVal> (c, intOp, value)))
      return false;

    TRACE_SERIALIZE (this);
    /* serialize the opcode */
    HBUINT8 *p = c->allocate_size<HBUINT8> (OpCode_Size (op));
    if (unlikely (p == nullptr)) return_trace (false);
    if (Is_OpCode_ESC (op))
    {
      p->set (OpCode_escape);
      op = Unmake_OpCode_ESC (op);
      p++;
    }
    p->set (op);
    return_trace (true);
  }

  static bool serialize_uint4_op (hb_serialize_context_t *c, op_code_t op, int value)
  { return serialize_int_op<HBUINT32, 0, 0x7FFFFFFF> (c, op, value, OpCode_longintdict); }

  static bool serialize_uint2_op (hb_serialize_context_t *c, op_code_t op, int value)
  { return serialize_int_op<HBUINT16, 0, 0x7FFF> (c, op, value, OpCode_shortint); }

  static bool serialize_offset4_op (hb_serialize_context_t *c, op_code_t op, int value)
  {
    return serialize_uint4_op (c, op, value);
  }

  static bool serialize_offset2_op (hb_serialize_context_t *c, op_code_t op, int value)
  {
    return serialize_uint2_op (c, op, value);
  }
};

struct TopDict : Dict {};
struct FontDict : Dict {};
struct PrivateDict : Dict {};

struct table_info_t
{
  void init () { offSize = offset = size = 0; }

  unsigned int    offset;
  unsigned int    size;
  unsigned int    offSize;
};

/* used to remap font index or SID from fullset to subset.
 * set to CFF_UNDEF_CODE if excluded from subset */
struct remap_t : hb_vector_t<hb_codepoint_t>
{
  void init () { SUPER::init (); }

  void fini () { SUPER::fini (); }

  bool reset (unsigned int size)
  {
    if (unlikely (!SUPER::resize (size)))
      return false;
    for (unsigned int i = 0; i < length; i++)
      (*this)[i] = CFF_UNDEF_CODE;
    count = 0;
    return true;
  }

  bool identity (unsigned int size)
  {
    if (unlikely (!SUPER::resize (size)))
      return false;
    unsigned int i;
    for (i = 0; i < length; i++)
      (*this)[i] = i;
    count = i;
    return true;
  }

  bool excludes (hb_codepoint_t id) const
  { return (id < length) && ((*this)[id] == CFF_UNDEF_CODE); }

  bool includes (hb_codepoint_t id) const
  { return !excludes (id); }

  unsigned int add (unsigned int i)
  {
    if ((*this)[i] == CFF_UNDEF_CODE)
      (*this)[i] = count++;
    return (*this)[i];
  }

  hb_codepoint_t get_count () const { return count; }

  protected:
  hb_codepoint_t  count;

  private:
  typedef hb_vector_t<hb_codepoint_t> SUPER;
};

template <typename COUNT>
struct FDArray : CFFIndexOf<COUNT, FontDict>
{
  /* used by CFF1 */
  template <typename DICTVAL, typename OP_SERIALIZER>
  bool serialize (hb_serialize_context_t *c,
		  unsigned int offSize_,
		  const hb_vector_t<DICTVAL> &fontDicts,
		  OP_SERIALIZER& opszr)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (*this))) return_trace (false);
    this->count.set (fontDicts.length);
    this->offSize.set (offSize_);
    if (!unlikely (c->allocate_size<HBUINT8> (offSize_ * (fontDicts.length + 1))))
      return_trace (false);

    /* serialize font dict offsets */
    unsigned int  offset = 1;
    unsigned int fid = 0;
    for (; fid < fontDicts.length; fid++)
    {
      CFFIndexOf<COUNT, FontDict>::set_offset_at (fid, offset);
      offset += FontDict::calculate_serialized_size (fontDicts[fid], opszr);
    }
    CFFIndexOf<COUNT, FontDict>::set_offset_at (fid, offset);

    /* serialize font dicts */
    for (unsigned int i = 0; i < fontDicts.length; i++)
    {
      FontDict *dict = c->start_embed<FontDict> ();
      if (unlikely (!dict->serialize (c, fontDicts[i], opszr, fontDicts[i])))
	return_trace (false);
    }
    return_trace (true);
  }

  /* used by CFF2 */
  template <typename DICTVAL, typename OP_SERIALIZER>
  bool serialize (hb_serialize_context_t *c,
		  unsigned int offSize_,
		  const hb_vector_t<DICTVAL> &fontDicts,
		  unsigned int fdCount,
		  const remap_t &fdmap,
		  OP_SERIALIZER& opszr,
		  const hb_vector_t<table_info_t> &privateInfos)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (*this))) return_trace (false);
    this->count.set (fdCount);
    this->offSize.set (offSize_);
    if (!unlikely (c->allocate_size<HBUINT8> (offSize_ * (fdCount + 1))))
      return_trace (false);

    /* serialize font dict offsets */
    unsigned int  offset = 1;
    unsigned int  fid = 0;
    for (unsigned i = 0; i < fontDicts.length; i++)
      if (fdmap.includes (i))
      {
	CFFIndexOf<COUNT, FontDict>::set_offset_at (fid++, offset);
	offset += FontDict::calculate_serialized_size (fontDicts[i], opszr);
      }
    CFFIndexOf<COUNT, FontDict>::set_offset_at (fid, offset);

    /* serialize font dicts */
    for (unsigned int i = 0; i < fontDicts.length; i++)
      if (fdmap.includes (i))
      {
	FontDict *dict = c->start_embed<FontDict> ();
	if (unlikely (!dict->serialize (c, fontDicts[i], opszr, privateInfos[fdmap[i]])))
	  return_trace (false);
      }
    return_trace (true);
  }

  /* in parallel to above */
  template <typename OP_SERIALIZER, typename DICTVAL>
  static unsigned int calculate_serialized_size (unsigned int &offSize_ /* OUT */,
						 const hb_vector_t<DICTVAL> &fontDicts,
						 unsigned int fdCount,
						 const remap_t &fdmap,
						 OP_SERIALIZER& opszr)
  {
    unsigned int dictsSize = 0;
    for (unsigned int i = 0; i < fontDicts.len; i++)
      if (fdmap.includes (i))
	dictsSize += FontDict::calculate_serialized_size (fontDicts[i], opszr);

    offSize_ = calcOffSize (dictsSize);
    return CFFIndex<COUNT>::calculate_serialized_size (offSize_, fdCount, dictsSize);
  }
};

/* FDSelect */
struct FDSelect0 {
  bool sanitize (hb_sanitize_context_t *c, unsigned int fdcount) const
  {
    TRACE_SANITIZE (this);
    if (unlikely (!(c->check_struct (this))))
      return_trace (false);
    for (unsigned int i = 0; i < c->get_num_glyphs (); i++)
      if (unlikely (!fds[i].sanitize (c)))
	return_trace (false);

    return_trace (true);
  }

  hb_codepoint_t get_fd (hb_codepoint_t glyph) const
  {
    return (hb_codepoint_t)fds[glyph];
  }

  unsigned int get_size (unsigned int num_glyphs) const
  { return HBUINT8::static_size * num_glyphs; }

  HBUINT8     fds[VAR];

  DEFINE_SIZE_MIN (1);
};

template <typename GID_TYPE, typename FD_TYPE>
struct FDSelect3_4_Range {
  bool sanitize (hb_sanitize_context_t *c, const void */*nullptr*/, unsigned int fdcount) const
  {
    TRACE_SANITIZE (this);
    return_trace (first < c->get_num_glyphs () && (fd < fdcount));
  }

  GID_TYPE    first;
  FD_TYPE     fd;

  DEFINE_SIZE_STATIC (GID_TYPE::static_size + FD_TYPE::static_size);
};

template <typename GID_TYPE, typename FD_TYPE>
struct FDSelect3_4 {
  unsigned int get_size () const
  { return GID_TYPE::static_size * 2 + ranges.get_size (); }

  bool sanitize (hb_sanitize_context_t *c, unsigned int fdcount) const
  {
    TRACE_SANITIZE (this);
    if (unlikely (!c->check_struct (this) || !ranges.sanitize (c, nullptr, fdcount) ||
    		  (nRanges () == 0) || ranges[0].first != 0))
      return_trace (false);

    for (unsigned int i = 1; i < nRanges (); i++)
    {
      if (unlikely (ranges[i - 1].first >= ranges[i].first))
	  return_trace (false);
    }

    if (unlikely (!sentinel().sanitize (c) || (sentinel() != c->get_num_glyphs ())))
      return_trace (false);

    return_trace (true);
  }

  hb_codepoint_t get_fd (hb_codepoint_t glyph) const
  {
    unsigned int i;
    for (i = 1; i < nRanges (); i++)
      if (glyph < ranges[i].first)
	break;

    return (hb_codepoint_t)ranges[i - 1].fd;
  }

  GID_TYPE &nRanges () { return ranges.len; }
  GID_TYPE nRanges () const { return ranges.len; }
  GID_TYPE &sentinel ()  { return StructAfter<GID_TYPE> (ranges[nRanges () - 1]); }
  const GID_TYPE &sentinel () const  { return StructAfter<GID_TYPE> (ranges[nRanges () - 1]); }

  ArrayOf<FDSelect3_4_Range<GID_TYPE, FD_TYPE>, GID_TYPE> ranges;
  /* GID_TYPE sentinel */

  DEFINE_SIZE_ARRAY (GID_TYPE::static_size, ranges);
};

typedef FDSelect3_4<HBUINT16, HBUINT8> FDSelect3;
typedef FDSelect3_4_Range<HBUINT16, HBUINT8> FDSelect3_Range;

struct FDSelect {
  bool sanitize (hb_sanitize_context_t *c, unsigned int fdcount) const
  {
    TRACE_SANITIZE (this);

    return_trace (likely (c->check_struct (this) && (format == 0 || format == 3) &&
			  (format == 0)?
			  u.format0.sanitize (c, fdcount):
			  u.format3.sanitize (c, fdcount)));
  }

  bool serialize (hb_serialize_context_t *c, const FDSelect &src, unsigned int num_glyphs)
  {
    TRACE_SERIALIZE (this);
    unsigned int size = src.get_size (num_glyphs);
    FDSelect *dest = c->allocate_size<FDSelect> (size);
    if (unlikely (dest == nullptr)) return_trace (false);
    memcpy (dest, &src, size);
    return_trace (true);
  }

  unsigned int calculate_serialized_size (unsigned int num_glyphs) const
  { return get_size (num_glyphs); }

  unsigned int get_size (unsigned int num_glyphs) const
  {
    unsigned int size = format.static_size;
    if (format == 0)
      size += u.format0.get_size (num_glyphs);
    else
      size += u.format3.get_size ();
    return size;
  }

  hb_codepoint_t get_fd (hb_codepoint_t glyph) const
  {
    if (this == &Null(FDSelect))
      return 0;
    if (format == 0)
      return u.format0.get_fd (glyph);
    else
      return u.format3.get_fd (glyph);
  }

  HBUINT8       format;
  union {
    FDSelect0   format0;
    FDSelect3   format3;
  } u;

  DEFINE_SIZE_MIN (1);
};

template <typename COUNT>
struct Subrs : CFFIndex<COUNT>
{
  typedef COUNT count_type;
  typedef CFFIndex<COUNT> SUPER;
};

} /* namespace CFF */

#endif /* HB_OT_CFF_COMMON_HH */