text:
/*
 * Copyright © 1998-2004  David Turner and Werner Lemberg
 * Copyright © 2006  Behdad Esfahbod
 * Copyright © 2007,2008,2009  Red Hat, Inc.
 * Copyright © 2012,2013  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.
 *
 * Red Hat Author(s): Behdad Esfahbod
 * Google Author(s): Behdad Esfahbod
 */

#include "hb.hh"

#ifndef HB_NO_OT_LAYOUT

#ifdef HB_NO_OT_TAG
#error "Cannot compile hb-ot-layout.cc with HB_NO_OT_TAG."
#endif

#include "hb-open-type.hh"
#include "hb-ot-layout.hh"
#include "hb-ot-face.hh"
#include "hb-ot-map.hh"
#include "hb-map.hh"

#include "hb-ot-kern-table.hh"
#include "hb-ot-layout-gdef-table.hh"
#include "hb-ot-layout-gsub-table.hh"
#include "hb-ot-layout-gpos-table.hh"
#include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise.
#include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
#include "hb-ot-name-table.hh"
#include "hb-ot-os2-table.hh"

#include "hb-aat-layout-lcar-table.hh"
#include "hb-aat-layout-morx-table.hh"

#include "hb-aat-layout-opbd-table.hh" // Just so we compile it; unused otherwise.

/**
 * SECTION:hb-ot-layout
 * @title: hb-ot-layout
 * @short_description: OpenType Layout
 * @include: hb-ot.h
 *
 * Functions for querying OpenType Layout features in the font face.
 **/

/*
 * kern
 */

#ifndef HB_NO_OT_KERN
/**
 * hb_ot_layout_has_kerning:
 * @face: The #hb_face_t to work on
 *
 * Tests whether a face includes any kerning data in the 'kern' table.
 * Does NOT test for kerning lookups in the GPOS table.
 *
 * Return value: true if data found, false otherwise
 *
 **/
bool
hb_ot_layout_has_kerning (hb_face_t *face)
{
  return face->table.kern->has_data ();
}

/**
 * hb_ot_layout_has_machine_kerning:
 * @face: The #hb_face_t to work on
 *
 * Tests whether a face includes any state-machine kerning in the 'kern' table.
 * Does NOT examine the GPOS table.
 *
 * Return value: true if data found, false otherwise
 *
 **/
bool
hb_ot_layout_has_machine_kerning (hb_face_t *face)
{
  return face->table.kern->has_state_machine ();
}

/**
 * hb_ot_layout_has_cross_kerning:
 * @face: The #hb_face_t to work on
 *
 * Tests whether a face has any cross-stream kerning (i.e., kerns
 * that make adjustments perpendicular to the direction of the text
 * flow: Y adjustments in horizontal text or X adjustments in
 * vertical text) in the 'kern' table.
 *
 * Does NOT examine the GPOS table.
 *
 * Return value: true is data found, false otherwise
 *
 **/
bool
hb_ot_layout_has_cross_kerning (hb_face_t *face)
{
  return face->table.kern->has_cross_stream ();
}

void
hb_ot_layout_kern (const hb_ot_shape_plan_t *plan,
		   hb_font_t *font,
		   hb_buffer_t  *buffer)
{
  hb_blob_t *blob = font->face->table.kern.get_blob ();
  const AAT::kern& kern = *blob->as<AAT::kern> ();

  AAT::hb_aat_apply_context_t c (plan, font, buffer, blob);

  kern.apply (&c);
}
#endif

/*
 * GDEF
 */

bool
OT::GDEF::is_blacklisted (hb_blob_t *blob,
			  hb_face_t *face) const
{
#ifdef HB_NO_OT_LAYOUT_BLACKLIST
  return false;
#endif
  /* The ugly business of blacklisting individual fonts' tables happen here!
   * See this thread for why we finally had to bend in and do this:
   * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
   *
   * In certain versions of Times New Roman Italic and Bold Italic,
   * ASCII double quotation mark U+0022 has wrong glyph class 3 (mark)
   * in GDEF.  Many versions of Tahoma have bad GDEF tables that
   * incorrectly classify some spacing marks such as certain IPA
   * symbols as glyph class 3. So do older versions of Microsoft
   * Himalaya, and the version of Cantarell shipped by Ubuntu 16.04.
   *
   * Nuke the GDEF tables of to avoid unwanted width-zeroing.
   *
   * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925
   *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279693
   *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279875
   */
  switch HB_CODEPOINT_ENCODE3(blob->length,
			      face->table.GSUB->table.get_length (),
			      face->table.GPOS->table.get_length ())
  {
    /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */
    case HB_CODEPOINT_ENCODE3 (442, 2874, 42038):
    /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */
    case HB_CODEPOINT_ENCODE3 (430, 2874, 40662):
    /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */
    case HB_CODEPOINT_ENCODE3 (442, 2874, 39116):
    /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */
    case HB_CODEPOINT_ENCODE3 (430, 2874, 39374):
    /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */
    case HB_CODEPOINT_ENCODE3 (490, 3046, 41638):
    /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */
    case HB_CODEPOINT_ENCODE3 (478, 3046, 41902):
    /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c  tahoma.ttf from Windows 8 */
    case HB_CODEPOINT_ENCODE3 (898, 12554, 46470):
    /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc  tahomabd.ttf from Windows 8 */
    case HB_CODEPOINT_ENCODE3 (910, 12566, 47732):
    /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e  tahoma.ttf from Windows 8.1 */
    case HB_CODEPOINT_ENCODE3 (928, 23298, 59332):
    /* sha1sum:6d400781948517c3c0441ba42acb309584b73033  tahomabd.ttf from Windows 8.1 */
    case HB_CODEPOINT_ENCODE3 (940, 23310, 60732):
    /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
    case HB_CODEPOINT_ENCODE3 (964, 23836, 60072):
    /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
    case HB_CODEPOINT_ENCODE3 (976, 23832, 61456):
    /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846  tahoma.ttf from Windows 10 */
    case HB_CODEPOINT_ENCODE3 (994, 24474, 60336):
    /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343  tahomabd.ttf from Windows 10 */
    case HB_CODEPOINT_ENCODE3 (1006, 24470, 61740):
    /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
    case HB_CODEPOINT_ENCODE3 (1006, 24576, 61346):
    /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
    case HB_CODEPOINT_ENCODE3 (1018, 24572, 62828):
    /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5  tahoma.ttf from Windows 10 AU */
    case HB_CODEPOINT_ENCODE3 (1006, 24576, 61352):
    /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2  tahomabd.ttf from Windows 10 AU */
    case HB_CODEPOINT_ENCODE3 (1018, 24572, 62834):
    /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7  Tahoma.ttf from Mac OS X 10.9 */
    case HB_CODEPOINT_ENCODE3 (832, 7324, 47162):
    /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba  Tahoma Bold.ttf from Mac OS X 10.9 */
    case HB_CODEPOINT_ENCODE3 (844, 7302, 45474):
    /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc  himalaya.ttf from Windows 7 */
    case HB_CODEPOINT_ENCODE3 (180, 13054, 7254):
    /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0  himalaya.ttf from Windows 8 */
    case HB_CODEPOINT_ENCODE3 (192, 12638, 7254):
    /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427  himalaya.ttf from Windows 8.1 */
    case HB_CODEPOINT_ENCODE3 (192, 12690, 7254):
    /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44  cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */
    /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371  cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */
    case HB_CODEPOINT_ENCODE3 (188, 248, 3852):
    /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f  cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */
    /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b  cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */
    case HB_CODEPOINT_ENCODE3 (188, 264, 3426):
    /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */
    case HB_CODEPOINT_ENCODE3 (1058, 47032, 11818):
    /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/
    case HB_CODEPOINT_ENCODE3 (1046, 47030, 12600):
    /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */
    case HB_CODEPOINT_ENCODE3 (1058, 71796, 16770):
    /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */
    case HB_CODEPOINT_ENCODE3 (1046, 71790, 17862):
    /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */
    case HB_CODEPOINT_ENCODE3 (1046, 71788, 17112):
    /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */
    case HB_CODEPOINT_ENCODE3 (1058, 71794, 17514):
    /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */
    case HB_CODEPOINT_ENCODE3 (1330, 109904, 57938):
    /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */
    case HB_CODEPOINT_ENCODE3 (1330, 109904, 58972):
    /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85  Padauk.ttf
     *  "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */
    case HB_CODEPOINT_ENCODE3 (1004, 59092, 14836):
      return true;
  }
  return false;
}

static void
_hb_ot_layout_set_glyph_props (hb_font_t *font,
			       hb_buffer_t *buffer)
{
  _hb_buffer_assert_gsubgpos_vars (buffer);

  const OT::GDEF &gdef = *font->face->table.GDEF->table;
  unsigned int count = buffer->len;
  for (unsigned int i = 0; i < count; i++)
  {
    _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
    _hb_glyph_info_clear_lig_props (&buffer->info[i]);
    buffer->info[i].syllable() = 0;
  }
}

/* Public API */

/**
 * hb_ot_layout_has_glyph_classes:
 * @face: #hb_face_t to work upon
 *
 * Tests whether a face has any glyph classes defined in its GDEF table.
 *
 * Return value: true if data found, false otherwise
 *
 **/
hb_bool_t
hb_ot_layout_has_glyph_classes (hb_face_t *face)
{
  return face->table.GDEF->table->has_glyph_classes ();
}

/**
 * hb_ot_layout_get_glyph_class:
 * @face: The #hb_face_t to work on
 * @glyph: The #hb_codepoint_t code point to query
 *
 * Fetches the GDEF class of the requested glyph in the specified face.
 *
 * Return value: The #hb_ot_layout_glyph_class_t glyph class of the given code
 * point in the GDEF table of the face.
 *
 * Since: 0.9.7
 **/
hb_ot_layout_glyph_class_t
hb_ot_layout_get_glyph_class (hb_face_t      *face,
			      hb_codepoint_t  glyph)
{
  return (hb_ot_layout_glyph_class_t) face->table.GDEF->table->get_glyph_class (glyph);
}

/**
 * hb_ot_layout_get_glyphs_in_class:
 * @face: The #hb_face_t to work on
 * @klass: The #hb_ot_layout_glyph_class_t GDEF class to retrieve
 * @glyphs: (out): The #hb_set_t set of all glyphs belonging to the requested
 *          class.
 *
 * Retrieves the set of all glyphs from the face that belong to the requested
 * glyph class in the face's GDEF table.
 *
 * Since: 0.9.7
 **/
void
hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
				  hb_ot_layout_glyph_class_t  klass,
				  hb_set_t                   *glyphs /* OUT */)
{
  return face->table.GDEF->table->get_glyphs_in_class (klass, glyphs);
}

#ifndef HB_NO_LAYOUT_UNUSED
/**
 * hb_ot_layout_get_attach_points:
 * @face: The #hb_face_t to work on
 * @glyph: The #hb_codepoint_t code point to query
 * @start_offset: offset of the first attachment point to retrieve
 * @point_count: (inout) (allow-none): Input = the maximum number of attachment points to return;
 *               Output = the actual number of attachment points returned (may be zero)
 * @point_array: (out) (array length=point_count): The array of attachment points found for the query
 *
 * Fetches a list of all attachment points for the specified glyph in the GDEF
 * table of the face. The list returned will begin at the offset provided.
 *
 * Useful if the client program wishes to cache the list.
 *
 **/
unsigned int
hb_ot_layout_get_attach_points (hb_face_t      *face,
				hb_codepoint_t  glyph,
				unsigned int    start_offset,
				unsigned int   *point_count /* IN/OUT */,
				unsigned int   *point_array /* OUT */)
{
  return face->table.GDEF->table->get_attach_points (glyph,
						     start_offset,
						     point_count,
						     point_array);
}
/**
 * hb_ot_layout_get_ligature_carets:
 * @font: The #hb_font_t to work on
 * @direction: The #hb_direction_t text direction to use
 * @glyph: The #hb_codepoint_t code point to query
 * @start_offset: offset of the first caret position to retrieve
 * @caret_count: (inout) (allow-none): Input = the maximum number of caret positions to return;
 *               Output = the actual number of caret positions returned (may be zero)
 * @caret_array: (out) (array length=caret_count): The array of caret positions found for the query
 *
 * Fetches a list of the caret positions defined for a ligature glyph in the GDEF
 * table of the font. The list returned will begin at the offset provided.
 *
 **/
unsigned int
hb_ot_layout_get_ligature_carets (hb_font_t      *font,
				  hb_direction_t  direction,
				  hb_codepoint_t  glyph,
				  unsigned int    start_offset,
				  unsigned int   *caret_count /* IN/OUT */,
				  hb_position_t  *caret_array /* OUT */)
{
  unsigned int result_caret_count = 0;
  unsigned int result = font->face->table.GDEF->table->get_lig_carets (font, direction, glyph, start_offset, &result_caret_count, caret_array);
  if (result)
  {
    if (caret_count) *caret_count = result_caret_count;
  }
  else
  {
#ifndef HB_NO_AAT
    result = font->face->table.lcar->get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
#else
    if (caret_count) *caret_count = 0;
#endif
  }
  return result;
}
#endif

/*
 * GSUB/GPOS
 */

bool
OT::GSUB::is_blacklisted (hb_blob_t *blob HB_UNUSED,
			  hb_face_t *face) const
{
#ifdef HB_NO_OT_LAYOUT_BLACKLIST
  return false;
#endif
  return false;
}

bool
OT::GPOS::is_blacklisted (hb_blob_t *blob HB_UNUSED,
			  hb_face_t *face HB_UNUSED) const
{
#ifdef HB_NO_OT_LAYOUT_BLACKLIST
  return false;
#endif
  return false;
}

static const OT::GSUBGPOS&
get_gsubgpos_table (hb_face_t *face,
		    hb_tag_t   table_tag)
{
  switch (table_tag) {
    case HB_OT_TAG_GSUB: return *face->table.GSUB->table;
    case HB_OT_TAG_GPOS: return *face->table.GPOS->table;
    default:             return Null (OT::GSUBGPOS);
  }
}

/**
 * hb_ot_layout_table_get_script_tags:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @start_offset: offset of the first script tag to retrieve
 * @script_count: (inout) (allow-none): Input = the maximum number of script tags to return;
 *                Output = the actual number of script tags returned (may be zero)
 * @script_tags: (out) (array length=script_count): The array of #hb_tag_t script tags found for the query
 *
 * Fetches a list of all scripts enumerated in the specified face's GSUB table
 * or GPOS table. The list returned will begin at the offset provided.
 *
 **/
unsigned int
hb_ot_layout_table_get_script_tags (hb_face_t    *face,
				    hb_tag_t      table_tag,
				    unsigned int  start_offset,
				    unsigned int *script_count /* IN/OUT */,
				    hb_tag_t     *script_tags  /* OUT */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  return g.get_script_tags (start_offset, script_count, script_tags);
}

#define HB_OT_TAG_LATIN_SCRIPT		HB_TAG ('l', 'a', 't', 'n')

/**
 * hb_ot_layout_table_find_script:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_tag: #hb_tag_t of the script tag requested
 * @script_index: (out): The index of the requested script tag
 *
 * Fetches the index if a given script tag in the specified face's GSUB table
 * or GPOS table.
 *
 * Return value: true if the script is found, false otherwise
 *
 **/
hb_bool_t
hb_ot_layout_table_find_script (hb_face_t    *face,
				hb_tag_t      table_tag,
				hb_tag_t      script_tag,
				unsigned int *script_index /* OUT */)
{
  static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  if (g.find_script_index (script_tag, script_index))
    return true;

  /* try finding 'DFLT' */
  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
    return false;

  /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
   * including many versions of DejaVu Sans Mono! */
  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
    return false;

  /* try with 'latn'; some old fonts put their features there even though
     they're really trying to support Thai, for example :( */
  if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index))
    return false;

  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
  return false;
}

#ifndef HB_DISABLE_DEPRECATED
/**
 * hb_ot_layout_table_choose_script:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_tags: Array of #hb_tag_t script tags
 * @script_index: (out): The index of the requested script tag
 * @chosen_script: (out): #hb_tag_t of the script tag requested
 *
 * Deprecated since 2.0.0
 **/
hb_bool_t
hb_ot_layout_table_choose_script (hb_face_t      *face,
				  hb_tag_t        table_tag,
				  const hb_tag_t *script_tags,
				  unsigned int   *script_index  /* OUT */,
				  hb_tag_t       *chosen_script /* OUT */)
{
  const hb_tag_t *t;
  for (t = script_tags; *t; t++);
  return hb_ot_layout_table_select_script (face, table_tag, t - script_tags, script_tags, script_index, chosen_script);
}
#endif

/**
 * hb_ot_layout_table_select_script:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_count: Number of script tags in the array
 * @script_tags: Array of #hb_tag_t script tags
 * @script_index: (out): The index of the requested script
 * @chosen_script: (out): #hb_tag_t of the requested script
 *
 * Since: 2.0.0
 **/
hb_bool_t
hb_ot_layout_table_select_script (hb_face_t      *face,
				  hb_tag_t        table_tag,
				  unsigned int    script_count,
				  const hb_tag_t *script_tags,
				  unsigned int   *script_index  /* OUT */,
				  hb_tag_t       *chosen_script /* OUT */)
{
  static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
  unsigned int i;

  for (i = 0; i < script_count; i++)
  {
    if (g.find_script_index (script_tags[i], script_index))
    {
      if (chosen_script)
	*chosen_script = script_tags[i];
      return true;
    }
  }

  /* try finding 'DFLT' */
  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
    if (chosen_script)
      *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
    return false;
  }

  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
    if (chosen_script)
      *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
    return false;
  }

  /* try with 'latn'; some old fonts put their features there even though
     they're really trying to support Thai, for example :( */
  if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
    if (chosen_script)
      *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
    return false;
  }

  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
  if (chosen_script)
    *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
  return false;
}

/**
 * hb_ot_layout_table_get_feature_tags:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @start_offset: offset of the first feature tag to retrieve
 * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
 *                 Output = the actual number of feature tags returned (may be zero)
 * @feature_tags: (out) (array length=feature_count): Array of feature tags found in the table
 *
 * Fetches a list of all feature tags in the given face's GSUB or GPOS table.
 *
 **/
unsigned int
hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
				     hb_tag_t      table_tag,
				     unsigned int  start_offset,
				     unsigned int *feature_count /* IN/OUT */,
				     hb_tag_t     *feature_tags  /* OUT */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  return g.get_feature_tags (start_offset, feature_count, feature_tags);
}

/**
 * hb_ot_layout_table_find_feature:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @feature_tag: The #hb_tag_t og the requested feature tag
 * @feature_index: (out): The index of the requested feature
 *
 * Fetches the index for a given feature tag in the specified face's GSUB table
 * or GPOS table.
 *
 * Return value: true if the feature is found, false otherwise
 **/
bool
hb_ot_layout_table_find_feature (hb_face_t    *face,
				 hb_tag_t      table_tag,
				 hb_tag_t      feature_tag,
				 unsigned int *feature_index /* OUT */)
{
  static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  unsigned int num_features = g.get_feature_count ();
  for (unsigned int i = 0; i < num_features; i++)
  {
    if (feature_tag == g.get_feature_tag (i)) {
      if (feature_index) *feature_index = i;
      return true;
    }
  }

  if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
  return false;
}

/**
 * hb_ot_layout_script_get_language_tags:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @start_offset: offset of the first language tag to retrieve
 * @language_count: (inout) (allow-none): Input = the maximum number of language tags to return;
 *                  Output = the actual number of language tags returned (may be zero)
 * @language_tags: (out) (array length=language_count): Array of language tags found in the table
 *
 * Fetches a list of language tags in the given face's GSUB or GPOS table, underneath
 * the specified script index. The list returned will begin at the offset provided.
 *
 **/
unsigned int
hb_ot_layout_script_get_language_tags (hb_face_t    *face,
				       hb_tag_t      table_tag,
				       unsigned int  script_index,
				       unsigned int  start_offset,
				       unsigned int *language_count /* IN/OUT */,
				       hb_tag_t     *language_tags  /* OUT */)
{
  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);

  return s.get_lang_sys_tags (start_offset, language_count, language_tags);
}

#ifndef HB_DISABLE_DEPRECATED
/**
 * hb_ot_layout_script_find_language:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @language_tag: The #hb_tag_t of the requested language
 * @language_index: The index of the requested language
 *
 * Fetches the index of a given language tag in the specified face's GSUB table
 * or GPOS table, underneath the specified script tag.
 *
 * Return value: true if the language tag is found, false otherwise
 *
 * Since: ??
 * Deprecated: ??
 **/
hb_bool_t
hb_ot_layout_script_find_language (hb_face_t    *face,
				   hb_tag_t      table_tag,
				   unsigned int  script_index,
				   hb_tag_t      language_tag,
				   unsigned int *language_index)
{
  return hb_ot_layout_script_select_language (face,
					      table_tag,
					      script_index,
					      1,
					      &language_tag,
					      language_index);
}
#endif

/**
 * hb_ot_layout_script_select_language:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @language_count: The number of languages in the specified script
 * @language_tags: The array of language tags
 * @language_index: (out): The index of the requested language
 *
 * Fetches the index of a given language tag in the specified face's GSUB table
 * or GPOS table, underneath the specified script index.
 *
 * Return value: true if the language tag is found, false otherwise
 *
 * Since: 2.0.0
 **/
hb_bool_t
hb_ot_layout_script_select_language (hb_face_t      *face,
				     hb_tag_t        table_tag,
				     unsigned int    script_index,
				     unsigned int    language_count,
				     const hb_tag_t *language_tags,
				     unsigned int   *language_index /* OUT */)
{
  static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX), "");
  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
  unsigned int i;

  for (i = 0; i < language_count; i++)
  {
    if (s.find_lang_sys_index (language_tags[i], language_index))
      return true;
  }

  /* try finding 'dflt' */
  if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
    return false;

  if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
  return false;
}

/**
 * hb_ot_layout_language_get_required_feature_index:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @language_index: The index of the requested language tag
 * @feature_index: (out): The index of the requested feature
 *
 * Fetches the index of a requested feature in the given face's GSUB or GPOS table,
 * underneath the specified script and language.
 *
 * Return value: true if the feature is found, false otherwise
 *
 **/
hb_bool_t
hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
						  hb_tag_t      table_tag,
						  unsigned int  script_index,
						  unsigned int  language_index,
						  unsigned int *feature_index /* OUT */)
{
  return hb_ot_layout_language_get_required_feature (face,
						     table_tag,
						     script_index,
						     language_index,
						     feature_index,
						     nullptr);
}

/**
 * hb_ot_layout_language_get_required_feature:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @language_index: The index of the requested language tag
 * @feature_index: (out): The index of the requested feature
 * @feature_tag: (out): The #hb_tag_t of the requested feature
 *
 * Fetches the tag of a requested feature index in the given face's GSUB or GPOS table,
 * underneath the specified script and language.
 *
 * Return value: true if the feature is found, false otherwise
 *
 * Since: 0.9.30
 **/
hb_bool_t
hb_ot_layout_language_get_required_feature (hb_face_t    *face,
					    hb_tag_t      table_tag,
					    unsigned int  script_index,
					    unsigned int  language_index,
					    unsigned int *feature_index /* OUT */,
					    hb_tag_t     *feature_tag   /* OUT */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);

  unsigned int index = l.get_required_feature_index ();
  if (feature_index) *feature_index = index;
  if (feature_tag) *feature_tag = g.get_feature_tag (index);

  return l.has_required_feature ();
}

/**
 * hb_ot_layout_language_get_feature_indexes:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @language_index: The index of the requested language tag
 * @start_offset: offset of the first feature tag to retrieve
 * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
 *                 Output: the actual number of feature tags returned (may be zero)
 * @feature_indexes: (out) (array length=feature_count): The array of feature indexes found for the query
 *
 * Fetches a list of all features in the specified face's GSUB table
 * or GPOS table, underneath the specified script and language. The list
 * returned will begin at the offset provided.
 **/
unsigned int
hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
					   hb_tag_t      table_tag,
					   unsigned int  script_index,
					   unsigned int  language_index,
					   unsigned int  start_offset,
					   unsigned int *feature_count   /* IN/OUT */,
					   unsigned int *feature_indexes /* OUT */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);

  return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
}

/**
 * hb_ot_layout_language_get_feature_tags:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @language_index: The index of the requested language tag
 * @start_offset: offset of the first feature tag to retrieve
 * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
 *                 Output = the actual number of feature tags returned (may be zero)
 * @feature_tags: (out) (array length=feature_count): The array of #hb_tag_t feature tags found for the query
 *
 * Fetches a list of all features in the specified face's GSUB table
 * or GPOS table, underneath the specified script and language. The list
 * returned will begin at the offset provided.
 *
 **/
unsigned int
hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
					hb_tag_t      table_tag,
					unsigned int  script_index,
					unsigned int  language_index,
					unsigned int  start_offset,
					unsigned int *feature_count /* IN/OUT */,
					hb_tag_t     *feature_tags  /* OUT */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);

  static_assert ((sizeof (unsigned int) == sizeof (hb_tag_t)), "");
  unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);

  if (feature_tags) {
    unsigned int count = *feature_count;
    for (unsigned int i = 0; i < count; i++)
      feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
  }

  return ret;
}

/**
 * hb_ot_layout_language_find_feature:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @script_index: The index of the requested script tag
 * @language_index: The index of the requested language tag
 * @feature_tag: #hb_tag_t of the feature tag requested
 * @feature_index: (out): The index of the requested feature
 *
 * Fetches the index of a given feature tag in the specified face's GSUB table
 * or GPOS table, underneath the specified script and language.
 *
 * Return value: true if the feature is found, false otherwise
 *
 **/
hb_bool_t
hb_ot_layout_language_find_feature (hb_face_t    *face,
				    hb_tag_t      table_tag,
				    unsigned int  script_index,
				    unsigned int  language_index,
				    hb_tag_t      feature_tag,
				    unsigned int *feature_index /* OUT */)
{
  static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);

  unsigned int num_features = l.get_feature_count ();
  for (unsigned int i = 0; i < num_features; i++) {
    unsigned int f_index = l.get_feature_index (i);

    if (feature_tag == g.get_feature_tag (f_index)) {
      if (feature_index) *feature_index = f_index;
      return true;
    }
  }

  if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
  return false;
}

/**
 * hb_ot_layout_feature_get_lookups:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @feature_index: The index of the requested feature
 * @start_offset: offset of the first lookup to retrieve
 * @lookup_count: (inout) (allow-none): Input = the maximum number of lookups to return;
 *                Output = the actual number of lookups returned (may be zero)
 * @lookup_indexes: (out) (array length=lookup_count): The array of lookup indexes found for the query
 *
 * Fetches a list of all lookups enumerated for the specified feature, in
 * the specified face's GSUB table or GPOS table. The list returned will
 * begin at the offset provided.
 *
 * Since: 0.9.7
 **/
unsigned int
hb_ot_layout_feature_get_lookups (hb_face_t    *face,
				  hb_tag_t      table_tag,
				  unsigned int  feature_index,
				  unsigned int  start_offset,
				  unsigned int *lookup_count   /* IN/OUT */,
				  unsigned int *lookup_indexes /* OUT */)
{
  return hb_ot_layout_feature_with_variations_get_lookups (face,
							   table_tag,
							   feature_index,
							   HB_OT_LAYOUT_NO_VARIATIONS_INDEX,
							   start_offset,
							   lookup_count,
							   lookup_indexes);
}

/**
 * hb_ot_layout_table_get_lookup_count:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 *
 * Fetches the total number of lookups enumerated in the specified
 * face's GSUB table or GPOS table.
 *
 * Since: 0.9.22
 **/
unsigned int
hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
				     hb_tag_t      table_tag)
{
  return get_gsubgpos_table (face, table_tag).get_lookup_count ();
}

struct hb_collect_features_context_t
{
  hb_collect_features_context_t (hb_face_t *face,
				 hb_tag_t   table_tag,
				 hb_set_t  *feature_indexes_)
    : g (get_gsubgpos_table (face, table_tag)),
      feature_indexes (feature_indexes_),
      script_count (0),langsys_count (0), feature_index_count (0) {}

  bool visited (const OT::Script &s)
  {
    /* We might have Null() object here.  Don't want to involve
     * that in the memoize.  So, detect empty objects and return. */
    if (unlikely (!s.has_default_lang_sys () &&
		  !s.get_lang_sys_count ()))
      return true;

    if (script_count++ > HB_MAX_SCRIPTS)
      return true;

    return visited (s, visited_script);
  }
  bool visited (const OT::LangSys &l)
  {
    /* We might have Null() object here.  Don't want to involve
     * that in the memoize.  So, detect empty objects and return. */
    if (unlikely (!l.has_required_feature () &&
		  !l.get_feature_count ()))
      return true;

    if (langsys_count++ > HB_MAX_LANGSYS)
      return true;

    return visited (l, visited_langsys);
  }

  bool visited_feature_indices (unsigned count)
  {
    feature_index_count += count;
    return feature_index_count > HB_MAX_FEATURE_INDICES;
  }

  private:
  template <typename T>
  bool visited (const T &p, hb_set_t &visited_set)
  {
    hb_codepoint_t delta = (hb_codepoint_t) ((uintptr_t) &p - (uintptr_t) &g);
     if (visited_set.has (delta))
      return true;

    visited_set.add (delta);
    return false;
  }

  public:
  const OT::GSUBGPOS &g;
  hb_set_t           *feature_indexes;

  private:
  hb_set_t visited_script;
  hb_set_t visited_langsys;
  unsigned int script_count;
  unsigned int langsys_count;
  unsigned int feature_index_count;
};

static void
langsys_collect_features (hb_collect_features_context_t *c,
			  const OT::LangSys  &l,
			  const hb_tag_t     *features)
{
  if (c->visited (l)) return;

  if (!features)
  {
    /* All features. */
    if (l.has_required_feature () && !c->visited_feature_indices (1))
      c->feature_indexes->add (l.get_required_feature_index ());

    if (!c->visited_feature_indices (l.featureIndex.len))
      l.add_feature_indexes_to (c->feature_indexes);
  }
  else
  {
    /* Ugh. Any faster way? */
    for (; *features; features++)
    {
      hb_tag_t feature_tag = *features;
      unsigned int num_features = l.get_feature_count ();
      for (unsigned int i = 0; i < num_features; i++)
      {
	unsigned int feature_index = l.get_feature_index (i);

	if (feature_tag == c->g.get_feature_tag (feature_index))
	{
	  c->feature_indexes->add (feature_index);
	  break;
	}
      }
    }
  }
}

static void
script_collect_features (hb_collect_features_context_t *c,
			 const OT::Script   &s,
			 const hb_tag_t *languages,
			 const hb_tag_t *features)
{
  if (c->visited (s)) return;

  if (!languages)
  {
    /* All languages. */
    if (s.has_default_lang_sys ())
      langsys_collect_features (c,
				s.get_default_lang_sys (),
				features);

    unsigned int count = s.get_lang_sys_count ();
    for (unsigned int language_index = 0; language_index < count; language_index++)
      langsys_collect_features (c,
				s.get_lang_sys (language_index),
				features);
  }
  else
  {
    for (; *languages; languages++)
    {
      unsigned int language_index;
      if (s.find_lang_sys_index (*languages, &language_index))
	langsys_collect_features (c,
				  s.get_lang_sys (language_index),
				  features);
    }
  }
}

/**
 * hb_ot_layout_collect_features:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @scripts: The array of scripts to collect features for
 * @languages: The array of languages to collect features for
 * @features: The array of features to collect
 * @feature_indexes: (out): The array of feature indexes found for the query
 *
 * Fetches a list of all feature indexes in the specified face's GSUB table
 * or GPOS table, underneath the specified scripts, languages, and features.
 * If no list of scripts is provided, all scripts will be queried. If no list
 * of languages is provided, all languages will be queried. If no list of
 * features is provided, all features will be queried.
 *
 * Since: 1.8.5
 **/
void
hb_ot_layout_collect_features (hb_face_t      *face,
			       hb_tag_t        table_tag,
			       const hb_tag_t *scripts,
			       const hb_tag_t *languages,
			       const hb_tag_t *features,
			       hb_set_t       *feature_indexes /* OUT */)
{
  hb_collect_features_context_t c (face, table_tag, feature_indexes);
  if (!scripts)
  {
    /* All scripts. */
    unsigned int count = c.g.get_script_count ();
    for (unsigned int script_index = 0; script_index < count; script_index++)
      script_collect_features (&c,
			       c.g.get_script (script_index),
			       languages,
			       features);
  }
  else
  {
    for (; *scripts; scripts++)
    {
      unsigned int script_index;
      if (c.g.find_script_index (*scripts, &script_index))
	script_collect_features (&c,
				 c.g.get_script (script_index),
				 languages,
				 features);
    }
  }
}

/**
 * hb_ot_layout_collect_lookups:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @scripts: The array of scripts to collect lookups for
 * @languages: The array of languages to collect lookups for
 * @features: The array of features to collect lookups for
 * @lookup_indexes: (out): The array of lookup indexes found for the query
 *
 * Fetches a list of all feature-lookup indexes in the specified face's GSUB
 * table or GPOS table, underneath the specified scripts, languages, and
 * features. If no list of scripts is provided, all scripts will be queried.
 * If no list of languages is provided, all languages will be queried. If no
 * list of features is provided, all features will be queried.
 *
 * Since: 0.9.8
 **/
void
hb_ot_layout_collect_lookups (hb_face_t      *face,
			      hb_tag_t        table_tag,
			      const hb_tag_t *scripts,
			      const hb_tag_t *languages,
			      const hb_tag_t *features,
			      hb_set_t       *lookup_indexes /* OUT */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  hb_set_t feature_indexes;
  hb_ot_layout_collect_features (face, table_tag, scripts, languages, features, &feature_indexes);

  for (hb_codepoint_t feature_index = HB_SET_VALUE_INVALID;
       hb_set_next (&feature_indexes, &feature_index);)
    g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes);

  g.feature_variation_collect_lookups (&feature_indexes, lookup_indexes);
}

#ifdef HB_EXPERIMENTAL_API
/**
 * hb_ot_layout_closure_lookups:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @lookup_indexes: (inout): lookup_indices collected from feature
 * list
 *
 * Returns all inactive lookups reachable from lookup_indices
 *
 * Since: EXPERIMENTAL
 **/
void
hb_ot_layout_closure_lookups (hb_face_t      *face,
			      hb_tag_t        table_tag,
			      const hb_set_t *glyphs,
			      hb_set_t       *lookup_indexes /* IN/OUT */)
{
  hb_set_t visited_lookups, inactive_lookups;
  OT::hb_closure_lookups_context_t c (face, glyphs, &visited_lookups, &inactive_lookups);

  for (unsigned lookup_index : + hb_iter (lookup_indexes))
  {
    switch (table_tag)
    {
      case HB_OT_TAG_GSUB:
      {
	const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
	l.closure_lookups (&c, lookup_index);
	break;
      }
      case HB_OT_TAG_GPOS:
      {
	const OT::PosLookup& l = face->table.GPOS->table->get_lookup (lookup_index);
	l.closure_lookups (&c, lookup_index);
	break;
      }
    }
  }

  hb_set_union (lookup_indexes, &visited_lookups);
  hb_set_subtract (lookup_indexes, &inactive_lookups);
}

/**
 * hb_ot_layout_closure_features:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @lookup_indexes: (in): collected active lookup_indices
 * @feature_indexes: (out): all active feature indexes collected
 *
 * Returns all active feature indexes
 *
 * Since: EXPERIMENTAL
 **/
void
hb_ot_layout_closure_features (hb_face_t      *face,
			       hb_tag_t        table_tag,
			       const hb_map_t *lookup_indexes, /* IN */
			       hb_set_t       *feature_indexes /* OUT */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
  g.closure_features (lookup_indexes, feature_indexes);
}
#endif

#ifndef HB_NO_LAYOUT_COLLECT_GLYPHS
/**
 * hb_ot_layout_lookup_collect_glyphs:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @lookup_index: The index of the feature lookup to query
 * @glyphs_before: (out): Array of glyphs preceding the substitution range
 * @glyphs_input: (out): Array of input glyphs that would be substituted by the lookup
 * @glyphs_after: (out): Array of glyphs following the substitution range
 * @glyphs_output: (out): Array of glyphs that would be the substitued output of the lookup
 *
 * Fetches a list of all glyphs affected by the specified lookup in the
 * specified face's GSUB table or GPOS table.
 *
 * Since: 0.9.7
 **/
void
hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
				    hb_tag_t      table_tag,
				    unsigned int  lookup_index,
				    hb_set_t     *glyphs_before, /* OUT.  May be NULL */
				    hb_set_t     *glyphs_input,  /* OUT.  May be NULL */
				    hb_set_t     *glyphs_after,  /* OUT.  May be NULL */
				    hb_set_t     *glyphs_output  /* OUT.  May be NULL */)
{
  OT::hb_collect_glyphs_context_t c (face,
				     glyphs_before,
				     glyphs_input,
				     glyphs_after,
				     glyphs_output);

  switch (table_tag)
  {
    case HB_OT_TAG_GSUB:
    {
      const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
      l.collect_glyphs (&c);
      return;
    }
    case HB_OT_TAG_GPOS:
    {
      const OT::PosLookup& l = face->table.GPOS->table->get_lookup (lookup_index);
      l.collect_glyphs (&c);
      return;
    }
  }
}
#endif

/* Variations support */

/**
 * hb_ot_layout_table_find_feature_variations:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @coords: The variation coordinates to query
 * @num_coords: The number of variation coorinates
 * @variations_index: (out): The array of feature variations found for the query
 *
 * Fetches a list of feature variations in the specified face's GSUB table
 * or GPOS table, at the specified variation coordinates.
 *
 **/
hb_bool_t
hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
					    hb_tag_t      table_tag,
					    const int    *coords,
					    unsigned int  num_coords,
					    unsigned int *variations_index /* out */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  return g.find_variations_index (coords, num_coords, variations_index);
}

/**
 * hb_ot_layout_feature_with_variations_get_lookups:
 * @face: #hb_face_t to work upon
 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
 * @feature_index: The index of the feature to query
 * @variations_index: The index of the feature variation to query
 * @start_offset: offset of the first lookup to retrieve
 * @lookup_count: (inout) (allow-none): Input = the maximum number of lookups to return;
 *                Output = the actual number of lookups returned (may be zero)
 * @lookup_indexes: (out) (array length=lookup_count): The array of lookups found for the query
 *
 * Fetches a list of all lookups enumerated for the specified feature, in
 * the specified face's GSUB table or GPOS table, enabled at the specified
 * variations index. The list returned will begin at the offset provided.
 *
 **/
unsigned int
hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
						  hb_tag_t      table_tag,
						  unsigned int  feature_index,
						  unsigned int  variations_index,
						  unsigned int  start_offset,
						  unsigned int *lookup_count /* IN/OUT */,
						  unsigned int *lookup_indexes /* OUT */)
{
  static_assert ((OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX), "");
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  const OT::Feature &f = g.get_feature_variation (feature_index, variations_index);

  return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
}

/*
 * OT::GSUB
 */

/**
 * hb_ot_layout_has_substitution:
 * @face: #hb_face_t to work upon
 *
 * Tests whether the specified face includes any GSUB substitutions.
 *
 * Return value: true if data found, false otherwise
 *
 **/
hb_bool_t
hb_ot_layout_has_substitution (hb_face_t *face)
{
  return face->table.GSUB->table->has_data ();
}

/**
 * hb_ot_layout_lookup_would_substitute:
 * @face: #hb_face_t to work upon
 * @lookup_index: The index of the lookup to query
 * @glyphs: The sequence of glyphs to query for substitution
 * @glyphs_length: The length of the glyph sequence
 * @zero_context: #hb_bool_t indicating whether substitutions should be context-free
 *
 * Tests whether a specified lookup in the specified face would
 * trigger a substitution on the given glyph sequence.
 *
 * Return value: true if a substitution would be triggered, false otherwise
 *
 * Since: 0.9.7
 **/
hb_bool_t
hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
				      unsigned int          lookup_index,
				      const hb_codepoint_t *glyphs,
				      unsigned int          glyphs_length,
				      hb_bool_t             zero_context)
{
  if (unlikely (lookup_index >= face->table.GSUB->lookup_count)) return false;
  OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);

  const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);

  return l.would_apply (&c, &face->table.GSUB->accels[lookup_index]);
}

/**
 * hb_ot_layout_substitute_start:
 * @font: #hb_font_t to use
 * @buffer: #hb_buffer_t buffer to work upon
 *
 * Called before substitution lookups are performed, to ensure that glyph
 * class and other properties are set on the glyphs in the buffer.
 *
 **/
void
hb_ot_layout_substitute_start (hb_font_t    *font,
			       hb_buffer_t  *buffer)
{
_hb_ot_layout_set_glyph_props (font, buffer);
}

void
hb_ot_layout_delete_glyphs_inplace (hb_buffer_t *buffer,
				    bool (*filter) (const hb_glyph_info_t *info))
{
  /* Merge clusters and delete filtered glyphs.
   * NOTE! We can't use out-buffer as we have positioning data. */
  unsigned int j = 0;
  unsigned int count = buffer->len;
  hb_glyph_info_t *info = buffer->info;
  hb_glyph_position_t *pos = buffer->pos;
  for (unsigned int i = 0; i < count; i++)
  {
    if (filter (&info[i]))
    {
      /* Merge clusters.
       * Same logic as buffer->delete_glyph(), but for in-place removal. */

      unsigned int cluster = info[i].cluster;
      if (i + 1 < count && cluster == info[i + 1].cluster)
	continue; /* Cluster survives; do nothing. */

      if (j)
      {
	/* Merge cluster backward. */
	if (cluster < info[j - 1].cluster)
	{
	  unsigned int mask = info[i].mask;
	  unsigned int old_cluster = info[j - 1].cluster;
	  for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
	    buffer->set_cluster (info[k - 1], cluster, mask);
	}
	continue;
      }

      if (i + 1 < count)
	buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */

      continue;
    }

    if (j != i)
    {
      info[j] = info[i];
      pos[j] = pos[i];
    }
    j++;
  }
  buffer->len = j;
}

/**
 * hb_ot_layout_lookup_substitute_closure:
 * @face: #hb_face_t to work upon
 * @lookup_index: index of the feature lookup to query
 * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookup
 *
 * Compute the transitive closure of glyphs needed for a
 * specified lookup.
 *
 * Since: 0.9.7
 **/
void
hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
					unsigned int  lookup_index,
					hb_set_t     *glyphs /* OUT */)
{
  hb_map_t done_lookups;
  OT::hb_closure_context_t c (face, glyphs, &done_lookups);

  const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);

  l.closure (&c, lookup_index);
}

/**
 * hb_ot_layout_lookups_substitute_closure:
 * @face: #hb_face_t to work upon
 * @lookups: The set of lookups to query
 * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookups
 *
 * Compute the transitive closure of glyphs needed for all of the
 * provided lookups.
 *
 * Since: 1.8.1
 **/
void
hb_ot_layout_lookups_substitute_closure (hb_face_t      *face,
					 const hb_set_t *lookups,
					 hb_set_t       *glyphs /* OUT */)
{
  hb_map_t done_lookups;
  OT::hb_closure_context_t c (face, glyphs, &done_lookups);
  const OT::GSUB& gsub = *face->table.GSUB->table;

  unsigned int iteration_count = 0;
  unsigned int glyphs_length;
  do
  {
    glyphs_length = glyphs->get_population ();
    if (lookups)
    {
      for (hb_codepoint_t lookup_index = HB_SET_VALUE_INVALID; hb_set_next (lookups, &lookup_index);)
	gsub.get_lookup (lookup_index).closure (&c, lookup_index);
    }
    else
    {
      for (unsigned int i = 0; i < gsub.get_lookup_count (); i++)
	gsub.get_lookup (i).closure (&c, i);
    }
  } while (iteration_count++ <= HB_CLOSURE_MAX_STAGES &&
	   glyphs_length != glyphs->get_population ());
}

/*
 * OT::GPOS
 */

/**
 * hb_ot_layout_has_positioning:
 * @face: #hb_face_t to work upon
 *
 * Return value: true if the face has GPOS data, false otherwise
 *
 **/
hb_bool_t
hb_ot_layout_has_positioning (hb_face_t *face)
{
  return face->table.GPOS->table->has_data ();
}

/**
 * hb_ot_layout_position_start:
 * @font: #hb_font_t to use
 * @buffer: #hb_buffer_t buffer to work upon
 *
 * Called before positioning lookups are performed, to ensure that glyph
 * attachment types and glyph-attachment chains are set for the glyphs in the buffer.
 *
 **/
void
hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
{
  OT::GPOS::position_start (font, buffer);
}

/**
 * hb_ot_layout_position_finish_advances:
 * @font: #hb_font_t to use
 * @buffer: #hb_buffer_t buffer to work upon
 *
 * Called after positioning lookups are performed, to finish glyph advances.
 *
 **/
void
hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
{
  OT::GPOS::position_finish_advances (font, buffer);
}

/**
 * hb_ot_layout_position_finish_offsets:
 * @font: #hb_font_t to use
 * @buffer: #hb_buffer_t buffer to work upon
 *
 * Called after positioning lookups are performed, to finish glyph offsets.
 *
 **/
void
hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
{
  OT::GPOS::position_finish_offsets (font, buffer);
}

#ifndef HB_NO_LAYOUT_FEATURE_PARAMS
/**
 * hb_ot_layout_get_size_params:
 * @face: #hb_face_t to work upon
 * @design_size: (out): The design size of the face
 * @subfamily_id: (out): The identifier of the face within the font subfamily
 * @subfamily_name_id: (out): The ‘name’ table name ID of the face within the font subfamily
 * @range_start: (out): The minimum size of the recommended size range for the face
 * @range_end: (out): The maximum size of the recommended size range for the face
 *
 * Fetches optical-size feature data (i.e., the `size` feature from GPOS). Note that
 * the subfamily_id and the subfamily name string (accessible via the subfamily_name_id)
 * as used here are defined as pertaining only to fonts within a font family that differ
 * specifically in their respective size ranges; other ways to differentiate fonts within
 * a subfamily are not covered by the `size` feature.
 *
 * For more information on this distinction, see the [`size` feature documentation](
 * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-size).
 *
 * Return value: true if data found, false otherwise
 *
 * Since: 0.9.10
 **/
hb_bool_t
hb_ot_layout_get_size_params (hb_face_t       *face,
			      unsigned int    *design_size,       /* OUT.  May be NULL */
			      unsigned int    *subfamily_id,      /* OUT.  May be NULL */
			      hb_ot_name_id_t *subfamily_name_id, /* OUT.  May be NULL */
			      unsigned int    *range_start,       /* OUT.  May be NULL */
			      unsigned int    *range_end          /* OUT.  May be NULL */)
{
  const OT::GPOS &gpos = *face->table.GPOS->table;
  const hb_tag_t tag = HB_TAG ('s','i','z','e');

  unsigned int num_features = gpos.get_feature_count ();
  for (unsigned int i = 0; i < num_features; i++)
  {
    if (tag == gpos.get_feature_tag (i))
    {
      const OT::Feature &f = gpos.get_feature (i);
      const OT::FeatureParamsSize &params = f.get_feature_params ().get_size_params (tag);

      if (params.designSize)
      {
	if (design_size) *design_size = params.designSize;
	if (subfamily_id) *subfamily_id = params.subfamilyID;
	if (subfamily_name_id) *subfamily_name_id = params.subfamilyNameID;
	if (range_start) *range_start = params.rangeStart;
	if (range_end) *range_end = params.rangeEnd;

	return true;
      }
    }
  }

  if (design_size) *design_size = 0;
  if (subfamily_id) *subfamily_id = 0;
  if (subfamily_name_id) *subfamily_name_id = HB_OT_NAME_ID_INVALID;
  if (range_start) *range_start = 0;
  if (range_end) *range_end = 0;

  return false;
}
/**
 * hb_ot_layout_feature_get_name_ids:
 * @face: #hb_face_t to work upon
 * @table_tag: table tag to query, "GSUB" or "GPOS".
 * @feature_index: index of feature to query.
 * @label_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
 *            for a user-interface label for this feature. (May be NULL.)
 * @tooltip_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
 *              that an application can use for tooltip text for this
 *              feature. (May be NULL.)
 * @sample_id: (out) (allow-none): The ‘name’ table name ID that specifies sample text
 *             that illustrates the effect of this feature. (May be NULL.)
 * @num_named_parameters: (out) (allow-none):  Number of named parameters. (May be zero.)
 * @first_param_id: (out) (allow-none): The first ‘name’ table name ID used to specify
 *                  strings for user-interface labels for the feature
 *                  parameters. (Must be zero if numParameters is zero.)
 *
 * Fetches name indices from feature parameters for "Stylistic Set" ('ssXX') or
 * "Character Variant" ('cvXX') features.
 *
 * Return value: true if data found, false otherwise
 *
 * Since: 2.0.0
 **/
hb_bool_t
hb_ot_layout_feature_get_name_ids (hb_face_t       *face,
				   hb_tag_t         table_tag,
				   unsigned int     feature_index,
				   hb_ot_name_id_t *label_id,             /* OUT.  May be NULL */
				   hb_ot_name_id_t *tooltip_id,           /* OUT.  May be NULL */
				   hb_ot_name_id_t *sample_id,            /* OUT.  May be NULL */
				   unsigned int    *num_named_parameters, /* OUT.  May be NULL */
				   hb_ot_name_id_t *first_param_id        /* OUT.  May be NULL */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  hb_tag_t feature_tag = g.get_feature_tag (feature_index);
  const OT::Feature &f = g.get_feature (feature_index);

  const OT::FeatureParams &feature_params = f.get_feature_params ();
  if (&feature_params != &Null (OT::FeatureParams))
  {
    const OT::FeatureParamsStylisticSet& ss_params =
      feature_params.get_stylistic_set_params (feature_tag);
    if (&ss_params != &Null (OT::FeatureParamsStylisticSet)) /* ssXX */
    {
      if (label_id) *label_id = ss_params.uiNameID;
      // ssXX features don't have the rest
      if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
      if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
      if (num_named_parameters) *num_named_parameters = 0;
      if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
      return true;
    }
    const OT::FeatureParamsCharacterVariants& cv_params =
      feature_params.get_character_variants_params (feature_tag);
    if (&cv_params != &Null (OT::FeatureParamsCharacterVariants)) /* cvXX */
    {
      if (label_id) *label_id = cv_params.featUILableNameID;
      if (tooltip_id) *tooltip_id = cv_params.featUITooltipTextNameID;
      if (sample_id) *sample_id = cv_params.sampleTextNameID;
      if (num_named_parameters) *num_named_parameters = cv_params.numNamedParameters;
      if (first_param_id) *first_param_id = cv_params.firstParamUILabelNameID;
      return true;
    }
  }

  if (label_id) *label_id = HB_OT_NAME_ID_INVALID;
  if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
  if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
  if (num_named_parameters) *num_named_parameters = 0;
  if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
  return false;
}
/**
 * hb_ot_layout_feature_get_characters:
 * @face: #hb_face_t to work upon
 * @table_tag: table tag to query, "GSUB" or "GPOS".
 * @feature_index: index of feature to query.
 * @start_offset: offset of the first character to retrieve
 * @char_count: (inout) (allow-none): Input = the maximum number of characters to return;
 *              Output = the actual number of characters returned (may be zero)
 * @characters: (out caller-allocates) (array length=char_count): A buffer pointer.
 *              The Unicode codepoints of the characters for which this feature provides
 *               glyph variants.
 *
 * Fetches a list of the characters defined as having a variant under the specified
 * "Character Variant" ("cvXX") feature tag.
 *
 * <note>Note: If the char_count output value is equal to its input value, then there
 *       is a chance there were more characters defined under the feature tag than were
 *       returned. This function can be called with incrementally larger start_offset
 *       until the char_count output value is lower than its input value, or the size
 *       of the characters array can be increased.</note>
 *
 * Return value: Number of total sample characters in the cvXX feature.
 *
 * Since: 2.0.0
 **/
unsigned int
hb_ot_layout_feature_get_characters (hb_face_t      *face,
				     hb_tag_t        table_tag,
				     unsigned int    feature_index,
				     unsigned int    start_offset,
				     unsigned int   *char_count, /* IN/OUT.  May be NULL */
				     hb_codepoint_t *characters  /* OUT.     May be NULL */)
{
  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  hb_tag_t feature_tag = g.get_feature_tag (feature_index);
  const OT::Feature &f = g.get_feature (feature_index);

  const OT::FeatureParams &feature_params = f.get_feature_params ();

  const OT::FeatureParamsCharacterVariants& cv_params =
    feature_params.get_character_variants_params(feature_tag);

  unsigned int len = 0;
  if (char_count && characters && start_offset < cv_params.characters.len)
  {
    len = hb_min (cv_params.characters.len - start_offset, *char_count);
    for (unsigned int i = 0; i < len; ++i)
      characters[i] = cv_params.characters[start_offset + i];
  }
  if (char_count) *char_count = len;
  return cv_params.characters.len;
}
#endif

/*
 * Parts of different types are implemented here such that they have direct
 * access to GSUB/GPOS lookups.
 */

struct GSUBProxy
{
  static constexpr unsigned table_index = 0u;
  static constexpr bool inplace = false;
  typedef OT::SubstLookup Lookup;

  GSUBProxy (hb_face_t *face) :
    table (*face->table.GSUB->table),
    accels (face->table.GSUB->accels) {}

  const OT::GSUB &table;
  const OT::hb_ot_layout_lookup_accelerator_t *accels;
};

struct GPOSProxy
{
  static constexpr unsigned table_index = 1u;
  static constexpr bool inplace = true;
  typedef OT::PosLookup Lookup;

  GPOSProxy (hb_face_t *face) :
    table (*face->table.GPOS->table),
    accels (face->table.GPOS->accels) {}

  const OT::GPOS &table;
  const OT::hb_ot_layout_lookup_accelerator_t *accels;
};

static inline bool
apply_forward (OT::hb_ot_apply_context_t *c,
	       const OT::hb_ot_layout_lookup_accelerator_t &accel)
{
  bool ret = false;
  hb_buffer_t *buffer = c->buffer;
  while (buffer->idx < buffer->len && buffer->successful)
  {
    bool applied = false;
    if (accel.may_have (buffer->cur().codepoint) &&
	(buffer->cur().mask & c->lookup_mask) &&
	c->check_glyph_property (&buffer->cur(), c->lookup_props))
     {
       applied = accel.apply (c);
     }

    if (applied)
      ret = true;
    else
      buffer->next_glyph ();
  }
  return ret;
}

static inline bool
apply_backward (OT::hb_ot_apply_context_t *c,
	       const OT::hb_ot_layout_lookup_accelerator_t &accel)
{
  bool ret = false;
  hb_buffer_t *buffer = c->buffer;
  do
  {
    if (accel.may_have (buffer->cur().codepoint) &&
	(buffer->cur().mask & c->lookup_mask) &&
	c->check_glyph_property (&buffer->cur(), c->lookup_props))
     ret |= accel.apply (c);

    /* The reverse lookup doesn't "advance" cursor (for good reason). */
    buffer->idx--;

  }
  while ((int) buffer->idx >= 0);
  return ret;
}

template <typename Proxy>
static inline void
apply_string (OT::hb_ot_apply_context_t *c,
	      const typename Proxy::Lookup &lookup,
	      const OT::hb_ot_layout_lookup_accelerator_t &accel)
{
  hb_buffer_t *buffer = c->buffer;

  if (unlikely (!buffer->len || !c->lookup_mask))
    return;

  c->set_lookup_props (lookup.get_props ());

  if (likely (!lookup.is_reverse ()))
  {
    /* in/out forward substitution/positioning */
    if (Proxy::table_index == 0u)
      buffer->clear_output ();
    buffer->idx = 0;

    bool ret;
    ret = apply_forward (c, accel);
    if (ret)
    {
      if (!Proxy::inplace)
	buffer->swap_buffers ();
      else
	assert (!buffer->has_separate_output ());
    }
  }
  else
  {
    /* in-place backward substitution/positioning */
    if (Proxy::table_index == 0u)
      buffer->remove_output ();
    buffer->idx = buffer->len - 1;

    apply_backward (c, accel);
  }
}

template <typename Proxy>
inline void hb_ot_map_t::apply (const Proxy &proxy,
				const hb_ot_shape_plan_t *plan,
				hb_font_t *font,
				hb_buffer_t *buffer) const
{
  const unsigned int table_index = proxy.table_index;
  unsigned int i = 0;
  OT::hb_ot_apply_context_t c (table_index, font, buffer);
  c.set_recurse_func (Proxy::Lookup::apply_recurse_func);

  for (unsigned int stage_index = 0; stage_index < stages[table_index].length; stage_index++) {
    const stage_map_t *stage = &stages[table_index][stage_index];
    for (; i < stage->last_lookup; i++)
    {
      unsigned int lookup_index = lookups[table_index][i].index;
      if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
      c.set_lookup_index (lookup_index);
      c.set_lookup_mask (lookups[table_index][i].mask);
      c.set_auto_zwj (lookups[table_index][i].auto_zwj);
      c.set_auto_zwnj (lookups[table_index][i].auto_zwnj);
      if (lookups[table_index][i].random)
      {
	c.set_random (true);
	buffer->unsafe_to_break_all ();
      }
      apply_string<Proxy> (&c,
			   proxy.table.get_lookup (lookup_index),
			   proxy.accels[lookup_index]);
      (void) buffer->message (font, "end lookup %d", lookup_index);
    }

    if (stage->pause_func)
    {
      buffer->clear_output ();
      stage->pause_func (plan, font, buffer);
    }
  }
}

void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
{
  GSUBProxy proxy (font->face);
  apply (proxy, plan, font, buffer);
}

void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
{
  GPOSProxy proxy (font->face);
  apply (proxy, plan, font, buffer);
}

void
hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
				const OT::SubstLookup &lookup,
				const OT::hb_ot_layout_lookup_accelerator_t &accel)
{
  apply_string<GSUBProxy> (c, lookup, accel);
}

#ifndef HB_NO_BASE
/**
 * hb_ot_layout_get_baseline:
 * @font: a font
 * @baseline_tag: a baseline tag
 * @direction: text direction.
 * @script_tag:  script tag.
 * @language_tag: language tag.
 * @coord: (out): baseline value if found.
 *
 * Fetches a baseline value from the face.
 *
 * Return value: if found baseline value in the font.
 *
 * Since: 2.6.0
 **/
hb_bool_t
hb_ot_layout_get_baseline (hb_font_t                   *font,
			   hb_ot_layout_baseline_tag_t  baseline_tag,
			   hb_direction_t               direction,
			   hb_tag_t                     script_tag,
			   hb_tag_t                     language_tag,
			   hb_position_t               *coord        /* OUT.  May be NULL. */)
{
  bool result = font->face->table.BASE->get_baseline (font, baseline_tag, direction, script_tag, language_tag, coord);

  if (result && coord)
    *coord = HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_y (*coord) : font->em_scale_x (*coord);

  return result;
}
#endif
#endif


text:
/*
 * 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_CFF_INTERP_COMMON_HH
#define HB_CFF_INTERP_COMMON_HH

namespace CFF {

using namespace OT;

typedef unsigned int op_code_t;

/* === Dict operators === */

/* One byte operators (0-31) */
#define OpCode_version		  0 /* CFF Top */
#define OpCode_Notice		  1 /* CFF Top */
#define OpCode_FullName		  2 /* CFF Top */
#define OpCode_FamilyName	  3 /* CFF Top */
#define OpCode_Weight		  4 /* CFF Top */
#define OpCode_FontBBox		  5 /* CFF Top */
#define OpCode_BlueValues	  6 /* CFF Private, CFF2 Private */
#define OpCode_OtherBlues	  7 /* CFF Private, CFF2 Private */
#define OpCode_FamilyBlues	  8 /* CFF Private, CFF2 Private */
#define OpCode_FamilyOtherBlues	  9 /* CFF Private, CFF2 Private */
#define OpCode_StdHW		 10 /* CFF Private, CFF2 Private */
#define OpCode_StdVW		 11 /* CFF Private, CFF2 Private */
#define OpCode_escape		 12 /* All. Shared with CS */
#define OpCode_UniqueID		 13 /* CFF Top */
#define OpCode_XUID		 14 /* CFF Top */
#define OpCode_charset		 15 /* CFF Top (0) */
#define OpCode_Encoding		 16 /* CFF Top (0) */
#define OpCode_CharStrings	 17 /* CFF Top, CFF2 Top */
#define OpCode_Private		 18 /* CFF Top, CFF2 FD */
#define OpCode_Subrs		 19 /* CFF Private, CFF2 Private */
#define OpCode_defaultWidthX	 20 /* CFF Private (0) */
#define OpCode_nominalWidthX	 21 /* CFF Private (0) */
#define OpCode_vsindexdict	 22 /* CFF2 Private/CS */
#define OpCode_blenddict	 23 /* CFF2 Private/CS */
#define OpCode_vstore		 24 /* CFF2 Top */
#define OpCode_reserved25	 25
#define OpCode_reserved26	 26
#define OpCode_reserved27	 27

/* Numbers */
#define OpCode_shortint		 28 /* 16-bit integer, All */
#define OpCode_longintdict	 29 /* 32-bit integer, All */
#define OpCode_BCD		 30 /* Real number, CFF2 Top/FD */
#define OpCode_reserved31	 31

/* 1-byte integers */
#define OpCode_OneByteIntFirst	 32 /* All. beginning of the range of first byte ints */
#define OpCode_OneByteIntLast	246 /* All. ending of the range of first byte int */

/* 2-byte integers */
#define OpCode_TwoBytePosInt0	247 /* All. first byte of two byte positive int (+108 to +1131) */
#define OpCode_TwoBytePosInt1	248
#define OpCode_TwoBytePosInt2	249
#define OpCode_TwoBytePosInt3	250

#define OpCode_TwoByteNegInt0	251 /* All. first byte of two byte negative int (-1131 to -108) */
#define OpCode_TwoByteNegInt1	252
#define OpCode_TwoByteNegInt2	253
#define OpCode_TwoByteNegInt3	254

/* Two byte escape operators 12, (0-41) */
#define OpCode_ESC_Base		256
#define Make_OpCode_ESC(byte2)	((op_code_t)(OpCode_ESC_Base + (byte2)))

inline op_code_t Unmake_OpCode_ESC (op_code_t op)  { return (op_code_t)(op - OpCode_ESC_Base); }
inline bool Is_OpCode_ESC (op_code_t op) { return op >= OpCode_ESC_Base; }
inline unsigned int OpCode_Size (op_code_t op) { return Is_OpCode_ESC (op) ? 2: 1; }

#define OpCode_Copyright	Make_OpCode_ESC(0) /* CFF Top */
#define OpCode_isFixedPitch	Make_OpCode_ESC(1) /* CFF Top (false) */
#define OpCode_ItalicAngle	Make_OpCode_ESC(2) /* CFF Top (0) */
#define OpCode_UnderlinePosition Make_OpCode_ESC(3) /* CFF Top (-100) */
#define OpCode_UnderlineThickness Make_OpCode_ESC(4) /* CFF Top (50) */
#define OpCode_PaintType	Make_OpCode_ESC(5) /* CFF Top (0) */
#define OpCode_CharstringType	Make_OpCode_ESC(6) /* CFF Top (2) */
#define OpCode_FontMatrix	Make_OpCode_ESC(7) /* CFF Top, CFF2 Top (.001 0 0 .001 0 0)*/
#define OpCode_StrokeWidth	Make_OpCode_ESC(8) /* CFF Top (0) */
#define OpCode_BlueScale	Make_OpCode_ESC(9) /* CFF Private, CFF2 Private (0.039625) */
#define OpCode_BlueShift	Make_OpCode_ESC(10) /* CFF Private, CFF2 Private (7) */
#define OpCode_BlueFuzz		Make_OpCode_ESC(11) /* CFF Private, CFF2 Private (1) */
#define OpCode_StemSnapH	Make_OpCode_ESC(12) /* CFF Private, CFF2 Private */
#define OpCode_StemSnapV	Make_OpCode_ESC(13) /* CFF Private, CFF2 Private */
#define OpCode_ForceBold	Make_OpCode_ESC(14) /* CFF Private (false) */
#define OpCode_reservedESC15	Make_OpCode_ESC(15)
#define OpCode_reservedESC16	Make_OpCode_ESC(16)
#define OpCode_LanguageGroup	Make_OpCode_ESC(17) /* CFF Private, CFF2 Private (0) */
#define OpCode_ExpansionFactor	Make_OpCode_ESC(18) /* CFF Private, CFF2 Private (0.06) */
#define OpCode_initialRandomSeed Make_OpCode_ESC(19) /* CFF Private (0) */
#define OpCode_SyntheticBase	Make_OpCode_ESC(20) /* CFF Top */
#define OpCode_PostScript	Make_OpCode_ESC(21) /* CFF Top */
#define OpCode_BaseFontName	Make_OpCode_ESC(22) /* CFF Top */
#define OpCode_BaseFontBlend	Make_OpCode_ESC(23) /* CFF Top */
#define OpCode_reservedESC24	Make_OpCode_ESC(24)
#define OpCode_reservedESC25	Make_OpCode_ESC(25)
#define OpCode_reservedESC26	Make_OpCode_ESC(26)
#define OpCode_reservedESC27	Make_OpCode_ESC(27)
#define OpCode_reservedESC28	Make_OpCode_ESC(28)
#define OpCode_reservedESC29	Make_OpCode_ESC(29)
#define OpCode_ROS		Make_OpCode_ESC(30) /* CFF Top_CID */
#define OpCode_CIDFontVersion	Make_OpCode_ESC(31) /* CFF Top_CID (0) */
#define OpCode_CIDFontRevision	Make_OpCode_ESC(32) /* CFF Top_CID (0) */
#define OpCode_CIDFontType	Make_OpCode_ESC(33) /* CFF Top_CID (0) */
#define OpCode_CIDCount		Make_OpCode_ESC(34) /* CFF Top_CID (8720) */
#define OpCode_UIDBase		Make_OpCode_ESC(35) /* CFF Top_CID */
#define OpCode_FDArray		Make_OpCode_ESC(36) /* CFF Top_CID, CFF2 Top */
#define OpCode_FDSelect		Make_OpCode_ESC(37) /* CFF Top_CID, CFF2 Top */
#define OpCode_FontName		Make_OpCode_ESC(38) /* CFF Top_CID */

/* === CharString operators === */

#define OpCode_hstem		  1 /* CFF, CFF2 */
#define OpCode_Reserved2	  2
#define OpCode_vstem		  3 /* CFF, CFF2 */
#define OpCode_vmoveto		  4 /* CFF, CFF2 */
#define OpCode_rlineto		  5 /* CFF, CFF2 */
#define OpCode_hlineto		  6 /* CFF, CFF2 */
#define OpCode_vlineto		  7 /* CFF, CFF2 */
#define OpCode_rrcurveto	  8 /* CFF, CFF2 */
#define OpCode_Reserved9	  9
#define OpCode_callsubr		 10 /* CFF, CFF2 */
#define OpCode_return		 11 /* CFF */
//#define OpCode_escape		 12 /* CFF, CFF2 */
#define OpCode_Reserved13	 13
#define OpCode_endchar		 14 /* CFF */
#define OpCode_vsindexcs	 15 /* CFF2 */
#define OpCode_blendcs		 16 /* CFF2 */
#define OpCode_Reserved17	 17
#define OpCode_hstemhm		 18 /* CFF, CFF2 */
#define OpCode_hintmask		 19 /* CFF, CFF2 */
#define OpCode_cntrmask		 20 /* CFF, CFF2 */
#define OpCode_rmoveto		 21 /* CFF, CFF2 */
#define OpCode_hmoveto		 22 /* CFF, CFF2 */
#define OpCode_vstemhm		 23 /* CFF, CFF2 */
#define OpCode_rcurveline	 24 /* CFF, CFF2 */
#define OpCode_rlinecurve	 25 /* CFF, CFF2 */
#define OpCode_vvcurveto	 26 /* CFF, CFF2 */
#define OpCode_hhcurveto	 27 /* CFF, CFF2 */
//#define OpCode_shortint	 28 /* CFF, CFF2 */
#define OpCode_callgsubr	 29 /* CFF, CFF2 */
#define OpCode_vhcurveto	 30 /* CFF, CFF2 */
#define OpCode_hvcurveto	 31 /* CFF, CFF2 */

#define OpCode_fixedcs		255 /* 32-bit fixed */

/* Two byte escape operators 12, (0-41) */
#define OpCode_dotsection	Make_OpCode_ESC(0) /* CFF (obsoleted) */
#define OpCode_ReservedESC1	Make_OpCode_ESC(1)
#define OpCode_ReservedESC2	Make_OpCode_ESC(2)
#define OpCode_and		Make_OpCode_ESC(3) /* CFF */
#define OpCode_or		Make_OpCode_ESC(4) /* CFF */
#define OpCode_not		Make_OpCode_ESC(5) /* CFF */
#define OpCode_ReservedESC6	Make_OpCode_ESC(6)
#define OpCode_ReservedESC7	Make_OpCode_ESC(7)
#define OpCode_ReservedESC8	Make_OpCode_ESC(8)
#define OpCode_abs		Make_OpCode_ESC(9) /* CFF */
#define OpCode_add		Make_OpCode_ESC(10) /* CFF */
#define OpCode_sub		Make_OpCode_ESC(11) /* CFF */
#define OpCode_div		Make_OpCode_ESC(12) /* CFF */
#define OpCode_ReservedESC13	Make_OpCode_ESC(13)
#define OpCode_neg		Make_OpCode_ESC(14) /* CFF */
#define OpCode_eq		Make_OpCode_ESC(15) /* CFF */
#define OpCode_ReservedESC16	Make_OpCode_ESC(16)
#define OpCode_ReservedESC17	Make_OpCode_ESC(17)
#define OpCode_drop		Make_OpCode_ESC(18) /* CFF */
#define OpCode_ReservedESC19	Make_OpCode_ESC(19)
#define OpCode_put		Make_OpCode_ESC(20) /* CFF */
#define OpCode_get		Make_OpCode_ESC(21) /* CFF */
#define OpCode_ifelse		Make_OpCode_ESC(22) /* CFF */
#define OpCode_random		Make_OpCode_ESC(23) /* CFF */
#define OpCode_mul		Make_OpCode_ESC(24) /* CFF */
//#define OpCode_reservedESC25	Make_OpCode_ESC(25)
#define OpCode_sqrt		Make_OpCode_ESC(26) /* CFF */
#define OpCode_dup		Make_OpCode_ESC(27) /* CFF */
#define OpCode_exch		Make_OpCode_ESC(28) /* CFF */
#define OpCode_index		Make_OpCode_ESC(29) /* CFF */
#define OpCode_roll		Make_OpCode_ESC(30) /* CFF */
#define OpCode_reservedESC31	Make_OpCode_ESC(31)
#define OpCode_reservedESC32	Make_OpCode_ESC(32)
#define OpCode_reservedESC33	Make_OpCode_ESC(33)
#define OpCode_hflex		Make_OpCode_ESC(34) /* CFF, CFF2 */
#define OpCode_flex		Make_OpCode_ESC(35) /* CFF, CFF2 */
#define OpCode_hflex1		Make_OpCode_ESC(36) /* CFF, CFF2 */
#define OpCode_flex1		Make_OpCode_ESC(37) /* CFF, CFF2 */

#define OpCode_Invalid		0xFFFFu

struct number_t
{
  void init () { set_real (0.0); }
  void fini () {}

  void set_int (int v)       { value = v; }
  int to_int () const        { return value; }

  void set_fixed (int32_t v) { value = v / 65536.0; }
  int32_t to_fixed () const  { return value * 65536.0; }

  void set_real (double v)   { value = v; }
  double to_real () const    { return value; }

  bool in_int_range () const
  { return ((double) (int16_t) to_int () == value); }

  bool operator >  (const number_t &n) const { return value > n.to_real (); }
  bool operator <  (const number_t &n) const { return n > *this; }
  bool operator >= (const number_t &n) const { return !(*this < n); }
  bool operator <= (const number_t &n) const { return !(*this > n); }

  const number_t &operator += (const number_t &n)
  {
    set_real (to_real () + n.to_real ());

    return *this;
  }

  protected:
  double value;
};

/* byte string */
struct UnsizedByteStr : UnsizedArrayOf <HBUINT8>
{
  // encode 2-byte int (Dict/CharString) or 4-byte int (Dict)
  template <typename T, typename V>
  static bool serialize_int (hb_serialize_context_t *c, op_code_t intOp, V value)
  {
    TRACE_SERIALIZE (this);

    HBUINT8 *p = c->allocate_size<HBUINT8> (1);
    if (unlikely (!p)) return_trace (false);
    *p = intOp;

    T *ip = c->allocate_size<T> (T::static_size);
    if (unlikely (!ip)) return_trace (false);
    return_trace (c->check_assign (*ip, value));
  }

  template <typename V>
  static bool serialize_int4 (hb_serialize_context_t *c, V value)
  { return serialize_int<HBINT32> (c, OpCode_longintdict, value); }

  template <typename V>
  static bool serialize_int2 (hb_serialize_context_t *c, V value)
  { return serialize_int<HBINT16> (c, OpCode_shortint, value); }

  /* Defining null_size allows a Null object may be created. Should be safe because:
   * A descendent struct Dict uses a Null pointer to indicate a missing table,
   * checked before access.
   * byte_str_t, a wrapper struct pairing a byte pointer along with its length, always
   * checks the length before access. A Null pointer is used as the initial pointer
   * along with zero length by the default ctor.
   */
  DEFINE_SIZE_MIN(0);
};

/* Holder of a section of byte string within a CFFIndex entry */
struct byte_str_t : hb_ubytes_t
{
  byte_str_t ()
    : hb_ubytes_t () {}
  byte_str_t (const UnsizedByteStr& s, unsigned int l)
    : hb_ubytes_t ((const unsigned char*)&s, l) {}
  byte_str_t (const unsigned char *s, unsigned int l)
    : hb_ubytes_t (s, l) {}
  byte_str_t (const hb_ubytes_t &ub)	/* conversion from hb_ubytes_t */
    : hb_ubytes_t (ub) {}

  /* sub-string */
  byte_str_t sub_str (unsigned int offset, unsigned int len_) const
  { return byte_str_t (hb_ubytes_t::sub_array (offset, len_)); }

  bool check_limit (unsigned int offset, unsigned int count) const
  { return (offset + count <= length); }
};

/* A byte string associated with the current offset and an error condition */
struct byte_str_ref_t
{
  byte_str_ref_t () { init (); }

  void init ()
  {
    str = byte_str_t ();
    offset = 0;
    error = false;
  }

  void fini () {}

  byte_str_ref_t (const byte_str_t &str_, unsigned int offset_ = 0)
    : str (str_), offset (offset_), error (false) {}

  void reset (const byte_str_t &str_, unsigned int offset_ = 0)
  {
    str = str_;
    offset = offset_;
    error = false;
  }

  const unsigned char& operator [] (int i) {
    if (unlikely ((unsigned int) (offset + i) >= str.length))
    {
      set_error ();
      return Null (unsigned char);
    }
    return str[offset + i];
  }

  /* Conversion to byte_str_t */
  operator byte_str_t () const { return str.sub_str (offset, str.length - offset); }

  byte_str_t sub_str (unsigned int offset_, unsigned int len_) const
  { return str.sub_str (offset_, len_); }

  bool avail (unsigned int count=1) const
  { return (!in_error () && str.check_limit (offset, count)); }
  void inc (unsigned int count=1)
  {
    if (likely (!in_error () && (offset <= str.length) && (offset + count <= str.length)))
    {
      offset += count;
    }
    else
    {
      offset = str.length;
      set_error ();
    }
  }

  void set_error ()      { error = true; }
  bool in_error () const { return error; }

  byte_str_t       str;
  unsigned int  offset; /* beginning of the sub-string within str */

  protected:
  bool	  error;
};

typedef hb_vector_t<byte_str_t> byte_str_array_t;

/* stack */
template <typename ELEM, int LIMIT>
struct cff_stack_t
{
  void init ()
  {
    error = false;
    count = 0;
    elements.init ();
    elements.resize (kSizeLimit);
    for (unsigned int i = 0; i < elements.length; i++)
      elements[i].init ();
  }
  void fini () { elements.fini_deep (); }

  ELEM& operator [] (unsigned int i)
  {
    if (unlikely (i >= count)) set_error ();
    return elements[i];
  }

  void push (const ELEM &v)
  {
    if (likely (count < elements.length))
      elements[count++] = v;
    else
      set_error ();
  }
  ELEM &push ()
  {
    if (likely (count < elements.length))
      return elements[count++];
    else
    {
      set_error ();
      return Crap (ELEM);
    }
  }

  ELEM& pop ()
  {
    if (likely (count > 0))
      return elements[--count];
    else
    {
      set_error ();
      return Crap (ELEM);
    }
  }
  void pop (unsigned int n)
  {
    if (likely (count >= n))
      count -= n;
    else
      set_error ();
  }

  const ELEM& peek ()
  {
    if (unlikely (count < 0))
    {
      set_error ();
      return Null (ELEM);
    }
    return elements[count - 1];
  }

  void unpop ()
  {
    if (likely (count < elements.length))
      count++;
    else
      set_error ();
  }

  void clear () { count = 0; }

  bool in_error () const { return (error || elements.in_error ()); }
  void set_error ()      { error = true; }

  unsigned int get_count () const { return count; }
  bool is_empty () const          { return !count; }

  static constexpr unsigned kSizeLimit = LIMIT;

  protected:
  bool error;
  unsigned int count;
  hb_vector_t<ELEM> elements;
};

/* argument stack */
template <typename ARG=number_t>
struct arg_stack_t : cff_stack_t<ARG, 513>
{
  void push_int (int v)
  {
    ARG &n = S::push ();
    n.set_int (v);
  }

  void push_fixed (int32_t v)
  {
    ARG &n = S::push ();
    n.set_fixed (v);
  }

  void push_real (double v)
  {
    ARG &n = S::push ();
    n.set_real (v);
  }

  ARG& pop_num () { return this->pop (); }

  int pop_int ()  { return this->pop ().to_int (); }

  unsigned int pop_uint ()
  {
    int i = pop_int ();
    if (unlikely (i < 0))
    {
      i = 0;
      S::set_error ();
    }
    return (unsigned) i;
  }

  void push_longint_from_substr (byte_str_ref_t& str_ref)
  {
    push_int ((str_ref[0] << 24) | (str_ref[1] << 16) | (str_ref[2] << 8) | (str_ref[3]));
    str_ref.inc (4);
  }

  bool push_fixed_from_substr (byte_str_ref_t& str_ref)
  {
    if (unlikely (!str_ref.avail (4)))
      return false;
    push_fixed ((int32_t)*(const HBUINT32*)&str_ref[0]);
    str_ref.inc (4);
    return true;
  }

  hb_array_t<const ARG> get_subarray (unsigned int start) const
  { return S::elements.sub_array (start); }

  private:
  typedef cff_stack_t<ARG, 513> S;
};

/* an operator prefixed by its operands in a byte string */
struct op_str_t
{
  void init () {}
  void fini () {}

  op_code_t  op;
  byte_str_t str;
};

/* base of OP_SERIALIZER */
struct op_serializer_t
{
  protected:
  bool copy_opstr (hb_serialize_context_t *c, const op_str_t& opstr) const
  {
    TRACE_SERIALIZE (this);

    HBUINT8 *d = c->allocate_size<HBUINT8> (opstr.str.length);
    if (unlikely (!d)) return_trace (false);
    memcpy (d, &opstr.str[0], opstr.str.length);
    return_trace (true);
  }
};

template <typename VAL>
struct parsed_values_t
{
  void init ()
  {
    opStart = 0;
    values.init ();
  }
  void fini () { values.fini_deep (); }

  void add_op (op_code_t op, const byte_str_ref_t& str_ref = byte_str_ref_t ())
  {
    VAL *val = values.push ();
    val->op = op;
    val->str = str_ref.str.sub_str (opStart, str_ref.offset - opStart);
    opStart = str_ref.offset;
  }

  void add_op (op_code_t op, const byte_str_ref_t& str_ref, const VAL &v)
  {
    VAL *val = values.push (v);
    val->op = op;
    val->str = str_ref.sub_str ( opStart, str_ref.offset - opStart);
    opStart = str_ref.offset;
  }

  bool has_op (op_code_t op) const
  {
    for (unsigned int i = 0; i < get_count (); i++)
      if (get_value (i).op == op) return true;
    return false;
  }

  unsigned get_count () const { return values.length; }
  const VAL &get_value (unsigned int i)   const { return values[i]; }
  const VAL &operator [] (unsigned int i) const { return get_value (i); }

  unsigned int       opStart;
  hb_vector_t<VAL>   values;
};

template <typename ARG=number_t>
struct interp_env_t
{
  void init (const byte_str_t &str_)
  {
    str_ref.reset (str_);
    argStack.init ();
    error = false;
  }
  void fini () { argStack.fini (); }

  bool in_error () const
  { return error || str_ref.in_error () || argStack.in_error (); }

  void set_error () { error = true; }

  op_code_t fetch_op ()
  {
    op_code_t  op = OpCode_Invalid;
    if (unlikely (!str_ref.avail ()))
      return OpCode_Invalid;
    op = (op_code_t)(unsigned char)str_ref[0];
    if (op == OpCode_escape) {
      if (unlikely (!str_ref.avail ()))
	return OpCode_Invalid;
      op = Make_OpCode_ESC(str_ref[1]);
      str_ref.inc ();
    }
    str_ref.inc ();
    return op;
  }

  const ARG& eval_arg (unsigned int i) { return argStack[i]; }

  ARG& pop_arg () { return argStack.pop (); }
  void pop_n_args (unsigned int n) { argStack.pop (n); }

  void clear_args () { pop_n_args (argStack.get_count ()); }

  byte_str_ref_t
		str_ref;
  arg_stack_t<ARG>
		argStack;
  protected:
  bool		error;
};

typedef interp_env_t<> num_interp_env_t;

template <typename ARG=number_t>
struct opset_t
{
  static void process_op (op_code_t op, interp_env_t<ARG>& env)
  {
    switch (op) {
      case OpCode_shortint:
	env.argStack.push_int ((int16_t)((env.str_ref[0] << 8) | env.str_ref[1]));
	env.str_ref.inc (2);
	break;

      case OpCode_TwoBytePosInt0: case OpCode_TwoBytePosInt1:
      case OpCode_TwoBytePosInt2: case OpCode_TwoBytePosInt3:
	env.argStack.push_int ((int16_t)((op - OpCode_TwoBytePosInt0) * 256 + env.str_ref[0] + 108));
	env.str_ref.inc ();
	break;

      case OpCode_TwoByteNegInt0: case OpCode_TwoByteNegInt1:
      case OpCode_TwoByteNegInt2: case OpCode_TwoByteNegInt3:
	env.argStack.push_int ((-(int16_t)(op - OpCode_TwoByteNegInt0) * 256 - env.str_ref[0] - 108));
	env.str_ref.inc ();
	break;

      default:
	/* 1-byte integer */
	if (likely ((OpCode_OneByteIntFirst <= op) && (op <= OpCode_OneByteIntLast)))
	{
	  env.argStack.push_int ((int)op - 139);
	} else {
	  /* invalid unknown operator */
	  env.clear_args ();
	  env.set_error ();
	}
	break;
    }
  }
};

template <typename ENV>
struct interpreter_t
{
  ~interpreter_t() { fini (); }

  void fini () { env.fini (); }

  ENV env;
};

} /* namespace CFF */

#endif /* HB_CFF_INTERP_COMMON_HH */

repo_language: C

mime_type: text/x-c


text:
#!/usr/bin/env python3

import sys
import os.path
from collections import OrderedDict
import packTab

if len (sys.argv) != 2:
	print("""usage: ./gen-emoji-table.py emoji-data.txt

Input file, as of Unicode 12:
* https://www.unicode.org/Public/emoji/12.0/emoji-data.txt""", file=sys.stderr)
	sys.exit (1)

f = open(sys.argv[1])
header = [f.readline () for _ in range(10)]

ranges = OrderedDict()
for line in f.readlines():
	line = line.strip()
	if not line or line[0] == '#':
		continue
	rang, typ = [s.strip() for s in line.split('#')[0].split(';')[:2]]

	rang = [int(s, 16) for s in rang.split('..')]
	if len(rang) > 1:
		start, end = rang
	else:
		start = end = rang[0]

	if typ not in ranges:
		ranges[typ] = []
	if ranges[typ] and ranges[typ][-1][1] == start - 1:
		ranges[typ][-1] = (ranges[typ][-1][0], end)
	else:
		ranges[typ].append((start, end))

print ("/* == Start of generated table == */")
print ("/*")
print (" * The following tables are generated by running:")
print (" *")
print (" *   ./gen-emoji-table.py emoji-data.txt")
print (" *")
print (" * on file with this header:")
print (" *")
for l in header:
	print (" * %s" % (l.strip()))
print (" */")
print ()
print ("#ifndef HB_UNICODE_EMOJI_TABLE_HH")
print ("#define HB_UNICODE_EMOJI_TABLE_HH")
print ()
print ('#include "hb-unicode.hh"')
print ()

for typ, s in ranges.items():
	if typ != "Extended_Pictographic": continue

	arr = dict()
	for start,end in s:
		for i in range(start,end):
			arr[i] = 1

	sol = packTab.pack_table(arr, 0, compression=3)
	code = packTab.Code('_hb_emoji')
	sol.genCode(code, 'is_'+typ)
	code.print_c(linkage='static inline')
	print()

print ()
print ("#endif /* HB_UNICODE_EMOJI_TABLE_HH */")
print ()
print ("/* == End of generated table == */")


text:
/*
 * Copyright © 2018  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_NULL_HH
#define HB_NULL_HH

#include "hb.hh"
#include "hb-meta.hh"

/*
 * Static pools
 */

/* Global nul-content Null pool.  Enlarge as necessary. */

#define HB_NULL_POOL_SIZE 384

/* Use SFINAE to sniff whether T has min_size; in which case return T::null_size,
 * otherwise return sizeof(T). */

/* The hard way...
 * https://stackoverflow.com/questions/7776448/sfinae-tried-with-bool-gives-compiler-error-template-argument-tvalue-invol
 */

template <typename T, typename>
struct _hb_null_size : hb_integral_constant<unsigned, sizeof (T)> {};
template <typename T>
struct _hb_null_size<T, hb_void_t<decltype (T::min_size)>> : hb_integral_constant<unsigned, T::null_size> {};

template <typename T>
using hb_null_size = _hb_null_size<T, void>;
#define hb_null_size(T) hb_null_size<T>::value

/* These doesn't belong here, but since is copy/paste from above, put it here. */

/* hb_static_size (T)
 * Returns T::static_size if T::min_size is defined, or sizeof (T) otherwise. */

template <typename T, typename>
struct _hb_static_size : hb_integral_constant<unsigned, sizeof (T)> {};
template <typename T>
struct _hb_static_size<T, hb_void_t<decltype (T::min_size)>> : hb_integral_constant<unsigned, T::static_size> {};
template <typename T>
using hb_static_size = _hb_static_size<T, void>;
#define hb_static_size(T) hb_static_size<T>::value

/*
 * Null()
 */

extern HB_INTERNAL
uint64_t const _hb_NullPool[(HB_NULL_POOL_SIZE + sizeof (uint64_t) - 1) / sizeof (uint64_t)];

/* Generic nul-content Null objects. */
template <typename Type>
struct Null {
  static Type const & get_null ()
  {
    static_assert (hb_null_size (Type) <= HB_NULL_POOL_SIZE, "Increase HB_NULL_POOL_SIZE.");
    return *reinterpret_cast<Type const *> (_hb_NullPool);
  }
};
template <typename QType>
struct NullHelper
{
  typedef hb_remove_const<hb_remove_reference<QType>> Type;
  static const Type & get_null () { return Null<Type>::get_null (); }
};
#define Null(Type) NullHelper<Type>::get_null ()

/* Specializations for arbitrary-content Null objects expressed in bytes. */
#define DECLARE_NULL_NAMESPACE_BYTES(Namespace, Type) \
	} /* Close namespace. */ \
	extern HB_INTERNAL const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::null_size]; \
	template <> \
	struct Null<Namespace::Type> { \
	  static Namespace::Type const & get_null () { \
	    return *reinterpret_cast<const Namespace::Type *> (_hb_Null_##Namespace##_##Type); \
	  } \
	}; \
	namespace Namespace { \
	static_assert (true, "") /* Require semicolon after. */
#define DEFINE_NULL_NAMESPACE_BYTES(Namespace, Type) \
	const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::null_size]

/* Specializations for arbitrary-content Null objects expressed as struct initializer. */
#define DECLARE_NULL_INSTANCE(Type) \
	extern HB_INTERNAL const Type _hb_Null_##Type; \
	template <> \
	struct Null<Type> { \
	  static Type const & get_null () { \
	    return _hb_Null_##Type; \
	  } \
	}; \
	static_assert (true, "") /* Require semicolon after. */
#define DEFINE_NULL_INSTANCE(Type) \
	const Type _hb_Null_##Type

/* Global writable pool.  Enlarge as necessary. */

/* To be fully correct, CrapPool must be thread_local. However, we do not rely on CrapPool
 * for correct operation. It only exist to catch and divert program logic bugs instead of
 * causing bad memory access. So, races there are not actually introducing incorrectness
 * in the code. Has ~12kb binary size overhead to have it, also clang build fails with it. */
extern HB_INTERNAL
/*thread_local*/ uint64_t _hb_CrapPool[(HB_NULL_POOL_SIZE + sizeof (uint64_t) - 1) / sizeof (uint64_t)];

/* CRAP pool: Common Region for Access Protection. */
template <typename Type>
static inline Type& Crap () {
  static_assert (hb_null_size (Type) <= HB_NULL_POOL_SIZE, "Increase HB_NULL_POOL_SIZE.");
  Type *obj = reinterpret_cast<Type *> (_hb_CrapPool);
  memcpy (obj, &Null (Type), sizeof (*obj));
  return *obj;
}
template <typename QType>
struct CrapHelper
{
  typedef hb_remove_const<hb_remove_reference<QType>> Type;
  static Type & get_crap () { return Crap<Type> (); }
};
#define Crap(Type) CrapHelper<Type>::get_crap ()

template <typename Type>
struct CrapOrNullHelper {
  static Type & get () { return Crap (Type); }
};
template <typename Type>
struct CrapOrNullHelper<const Type> {
  static const Type & get () { return Null (Type); }
};
#define CrapOrNull(Type) CrapOrNullHelper<Type>::get ()

/*
 * hb_nonnull_ptr_t
 */

template <typename P>
struct hb_nonnull_ptr_t
{
  typedef hb_remove_pointer<P> T;

  hb_nonnull_ptr_t (T *v_ = nullptr) : v (v_) {}
  T * operator = (T *v_)   { return v = v_; }
  T * operator -> () const { return get (); }
  T & operator * () const  { return *get (); }
  T ** operator & () const { return &v; }
  /* Only auto-cast to const types. */
  template <typename C> operator const C * () const { return get (); }
  operator const char * () const { return (const char *) get (); }
  T * get () const { return v ? v : const_cast<T *> (&Null (T)); }
  T * get_raw () const { return v; }

  T *v;
};

#endif /* HB_NULL_HH */