hb-ot-post-table.hh

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/*
 * Copyright © 2016  Google, 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.
 *
 * Google Author(s): Behdad Esfahbod
 */
 
#ifndef HB_OT_POST_TABLE_HH
#define HB_OT_POST_TABLE_HH
 
#include "hb-open-type.hh"
 
#define HB_STRING_ARRAY_NAME format1_names
#define HB_STRING_ARRAY_LIST "hb-ot-post-macroman.hh"
#include "hb-string-array.hh"
#undef HB_STRING_ARRAY_LIST
#undef HB_STRING_ARRAY_NAME
 
/*
 * post -- PostScript
 * https://docs.microsoft.com/en-us/typography/opentype/spec/post
 */
#define HB_OT_TAG_post HB_TAG('p','o','s','t')
 
 
namespace OT {
 
 
struct postV2Tail
{
  friend struct post;
 
  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (glyphNameIndex.sanitize (c));
  }
 
  template<typename Iterator>
  bool serialize (hb_serialize_context_t *c,
                  Iterator it,
                  const void* _post) const;
 
  bool subset (hb_subset_context_t *c) const;
 
  protected:
  Array16Of<HBUINT16>   glyphNameIndex; /* This is not an offset, but is the
                     * ordinal number of the glyph in 'post'
                     * string tables. */
/*UnsizedArrayOf<HBUINT8>
            namesX;*/   /* Glyph names with length bytes [variable]
                     * (a Pascal string). */
 
  public:
  DEFINE_SIZE_ARRAY (2, glyphNameIndex);
};
 
struct post
{
  static constexpr hb_tag_t tableTag = HB_OT_TAG_post;
 
  bool serialize (hb_serialize_context_t *c, bool glyph_names) const
  {
    TRACE_SERIALIZE (this);
    post *post_prime = c->allocate_min<post> ();
    if (unlikely (!post_prime))  return_trace (false);
 
    memcpy (post_prime, this, post::min_size);
    if (!glyph_names)
      return_trace (c->check_assign (post_prime->version.major, 3,
                                     HB_SERIALIZE_ERROR_INT_OVERFLOW)); // Version 3 does not have any glyph names.
 
    return_trace (true);
  }
 
  bool subset (hb_subset_context_t *c) const
  {
    TRACE_SUBSET (this);
    post *post_prime = c->serializer->start_embed<post> ();
    if (unlikely (!post_prime)) return_trace (false);
 
    bool glyph_names = c->plan->flags & HB_SUBSET_FLAGS_GLYPH_NAMES;
    if (!serialize (c->serializer, glyph_names))
      return_trace (false);
 
    if (glyph_names && version.major == 2)
      return_trace (v2X.subset (c));
 
    return_trace (true);
  }
 
  struct accelerator_t
  {
    friend struct postV2Tail;
 
    accelerator_t (hb_face_t *face)
    {
      table = hb_sanitize_context_t ().reference_table<post> (face);
      unsigned int table_length = table.get_length ();
 
      version = table->version.to_int ();
      if (version != 0x00020000) return;
 
      const postV2Tail &v2 = table->v2X;
 
      glyphNameIndex = &v2.glyphNameIndex;
      pool = &StructAfter<uint8_t> (v2.glyphNameIndex);
 
      const uint8_t *end = (const uint8_t *) (const void *) table + table_length;
      for (const uint8_t *data = pool;
       index_to_offset.length < 65535 && data < end && data + *data < end;
       data += 1 + *data)
    index_to_offset.push (data - pool);
    }
    ~accelerator_t ()
    {
      hb_free (gids_sorted_by_name.get ());
      table.destroy ();
    }
 
    bool get_glyph_name (hb_codepoint_t glyph,
             char *buf, unsigned int buf_len) const
    {
      hb_bytes_t s = find_glyph_name (glyph);
      if (!s.length) return false;
      if (!buf_len) return true;
      unsigned int len = hb_min (buf_len - 1, s.length);
      strncpy (buf, s.arrayZ, len);
      buf[len] = '\0';
      return true;
    }
 
    bool get_glyph_from_name (const char *name, int len,
                  hb_codepoint_t *glyph) const
    {
      unsigned int count = get_glyph_count ();
      if (unlikely (!count)) return false;
 
      if (len < 0) len = strlen (name);
 
      if (unlikely (!len)) return false;
 
    retry:
      uint16_t *gids = gids_sorted_by_name.get ();
 
      if (unlikely (!gids))
      {
    gids = (uint16_t *) hb_malloc (count * sizeof (gids[0]));
    if (unlikely (!gids))
      return false; /* Anything better?! */
 
    for (unsigned int i = 0; i < count; i++)
      gids[i] = i;
    hb_qsort (gids, count, sizeof (gids[0]), cmp_gids, (void *) this);
 
    if (unlikely (!gids_sorted_by_name.cmpexch (nullptr, gids)))
    {
      hb_free (gids);
      goto retry;
    }
      }
 
      hb_bytes_t st (name, len);
      auto* gid = hb_bsearch (st, gids, count, sizeof (gids[0]), cmp_key, (void *) this);
      if (gid)
      {
    *glyph = *gid;
    return true;
      }
 
      return false;
    }
 
    hb_blob_ptr_t<post> table;
 
    protected:
 
    unsigned int get_glyph_count () const
    {
      if (version == 0x00010000)
    return format1_names_length;
 
      if (version == 0x00020000)
    return glyphNameIndex->len;
 
      return 0;
    }
 
    static int cmp_gids (const void *pa, const void *pb, void *arg)
    {
      const accelerator_t *thiz = (const accelerator_t *) arg;
      uint16_t a = * (const uint16_t *) pa;
      uint16_t b = * (const uint16_t *) pb;
      return thiz->find_glyph_name (b).cmp (thiz->find_glyph_name (a));
    }
 
    static int cmp_key (const void *pk, const void *po, void *arg)
    {
      const accelerator_t *thiz = (const accelerator_t *) arg;
      const hb_bytes_t *key = (const hb_bytes_t *) pk;
      uint16_t o = * (const uint16_t *) po;
      return thiz->find_glyph_name (o).cmp (*key);
    }
 
    hb_bytes_t find_glyph_name (hb_codepoint_t glyph) const
    {
      if (version == 0x00010000)
      {
    if (glyph >= format1_names_length)
      return hb_bytes_t ();
 
    return format1_names (glyph);
      }
 
      if (version != 0x00020000 || glyph >= glyphNameIndex->len)
    return hb_bytes_t ();
 
      unsigned int index = glyphNameIndex->arrayZ[glyph];
      if (index < format1_names_length)
    return format1_names (index);
      index -= format1_names_length;
 
      if (index >= index_to_offset.length)
    return hb_bytes_t ();
      unsigned int offset = index_to_offset[index];
 
      const uint8_t *data = pool + offset;
      unsigned int name_length = *data;
      data++;
 
      return hb_bytes_t ((const char *) data, name_length);
    }
 
    private:
    uint32_t version;
    const Array16Of<HBUINT16> *glyphNameIndex = nullptr;
    hb_vector_t<uint32_t> index_to_offset;
    const uint8_t *pool = nullptr;
    hb_atomic_ptr_t<uint16_t *> gids_sorted_by_name;
  };
 
  bool has_data () const { return version.to_int (); }
 
  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
              (version.to_int () == 0x00010000 ||
               (version.to_int () == 0x00020000 && v2X.sanitize (c)) ||
               version.to_int () == 0x00030000)));
  }
 
  public:
  FixedVersion<>version;        /* 0x00010000 for version 1.0
                     * 0x00020000 for version 2.0
                     * 0x00025000 for version 2.5 (deprecated)
                     * 0x00030000 for version 3.0 */
  HBFixed   italicAngle;        /* Italic angle in counter-clockwise degrees
                     * from the vertical. Zero for upright text,
                     * negative for text that leans to the right
                     * (forward). */
  FWORD     underlinePosition;  /* This is the suggested distance of the top
                     * of the underline from the baseline
                     * (negative values indicate below baseline).
                     * The PostScript definition of this FontInfo
                     * dictionary key (the y coordinate of the
                     * center of the stroke) is not used for
                     * historical reasons. The value of the
                     * PostScript key may be calculated by
                     * subtracting half the underlineThickness
                     * from the value of this field. */
  FWORD     underlineThickness; /* Suggested values for the underline
                       thickness. */
  HBUINT32  isFixedPitch;       /* Set to 0 if the font is proportionally
                     * spaced, non-zero if the font is not
                     * proportionally spaced (i.e. monospaced). */
  HBUINT32  minMemType42;       /* Minimum memory usage when an OpenType font
                     * is downloaded. */
  HBUINT32  maxMemType42;       /* Maximum memory usage when an OpenType font
                     * is downloaded. */
  HBUINT32  minMemType1;        /* Minimum memory usage when an OpenType font
                     * is downloaded as a Type 1 font. */
  HBUINT32  maxMemType1;        /* Maximum memory usage when an OpenType font
                     * is downloaded as a Type 1 font. */
  postV2Tail    v2X;
  DEFINE_SIZE_MIN (32);
};
 
struct post_accelerator_t : post::accelerator_t {
  post_accelerator_t (hb_face_t *face) : post::accelerator_t (face) {}
};
 
 
} /* namespace OT */
 
 
#endif /* HB_OT_POST_TABLE_HH */