/*

 * 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-open-type-private.hh"

#include "hb-ot-layout-private.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-jstf-table.hh" // Just so we compile it; unused otherwise.

#include "hb-ot-map-private.hh"

hb_ot_layout_t *

_hb_ot_layout_create (hb_face_t *face)

{

  hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));

  if (unlikely (!layout))

    return NULL;

  layout->gdef_blob = OT::Sanitizer<OT::GDEF>::sanitize (face->reference_table (HB_OT_TAG_GDEF));

  layout->gdef = OT::Sanitizer<OT::GDEF>::lock_instance (layout->gdef_blob);

  layout->gsub_blob = OT::Sanitizer<OT::GSUB>::sanitize (face->reference_table (HB_OT_TAG_GSUB));

  layout->gsub = OT::Sanitizer<OT::GSUB>::lock_instance (layout->gsub_blob);

  layout->gpos_blob = OT::Sanitizer<OT::GPOS>::sanitize (face->reference_table (HB_OT_TAG_GPOS));

  layout->gpos = OT::Sanitizer<OT::GPOS>::lock_instance (layout->gpos_blob);

  layout->math.init (face);

  layout->fvar.init (face);

  layout->avar.init (face);

  {

    /*

     * 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

     */

    unsigned int gdef_len = hb_blob_get_length (layout->gdef_blob);

    unsigned int gsub_len = hb_blob_get_length (layout->gsub_blob);

    unsigned int gpos_len = hb_blob_get_length (layout->gpos_blob);

    if (0

      /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */

      || (442 == gdef_len && 42038 == gpos_len && 2874 == gsub_len)

      /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */

      || (430 == gdef_len && 40662 == gpos_len && 2874 == gsub_len)

      /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */

      || (442 == gdef_len && 39116 == gpos_len && 2874 == gsub_len)

      /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */

      || (430 == gdef_len && 39374 == gpos_len && 2874 == gsub_len)

      /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */

      || (490 == gdef_len && 41638 == gpos_len && 3046 == gsub_len)

      /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */

      || (478 == gdef_len && 41902 == gpos_len && 3046 == gsub_len)

    )

    {

      /* In certain versions of Times New Roman Italic and Bold Italic,

       * ASCII double quotation mark U+0022, mapped to glyph 5, has wrong

       * glyph class 3 (mark) in GDEF.  Nuke the GDEF to avoid zero-width

       * double-quote.  See:

       * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html

       */

     if (3 == layout->gdef->get_glyph_class (5))

       layout->gdef = &OT::Null(OT::GDEF);

    }

    else if (0

      /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c  tahoma.ttf from Windows 8 */

      || (898 == gdef_len && 46470 == gpos_len && 12554 == gsub_len)

      /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc  tahomabd.ttf from Windows 8 */

      || (910 == gdef_len && 47732 == gpos_len && 12566 == gsub_len)

      /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e  tahoma.ttf from Windows 8.1 */

      || (928 == gdef_len && 59332 == gpos_len && 23298 == gsub_len)

      /* sha1sum:6d400781948517c3c0441ba42acb309584b73033  tahomabd.ttf from Windows 8.1 */

      || (940 == gdef_len && 60732 == gpos_len && 23310 == gsub_len)

      /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */

      || (964 == gdef_len && 60072 == gpos_len && 23836 == gsub_len)

      /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */

      || (976 == gdef_len && 61456 == gpos_len && 23832 == gsub_len)

      /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846  tahoma.ttf from Windows 10 */

      || (994 == gdef_len && 60336 == gpos_len && 24474 == gsub_len)

      /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343  tahomabd.ttf from Windows 10 */

      || (1006 == gdef_len && 61740 == gpos_len && 24470 == gsub_len)

      /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */

      || (1006 == gdef_len && 61346 == gpos_len && 24576 == gsub_len)

      /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */

      || (1018 == gdef_len && 62828 == gpos_len && 24572 == gsub_len)

      /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5  tahoma.ttf from Windows 10 AU */

      || (1006 == gdef_len && 61352 == gpos_len && 24576 == gsub_len)

      /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2  tahomabd.ttf from Windows 10 AU */

      || (1018 == gdef_len && 62834 == gpos_len && 24572 == gsub_len)

      /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7  Tahoma.ttf from Mac OS X 10.9 */

      || (832 == gdef_len && 47162 == gpos_len && 7324 == gsub_len)

      /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba  Tahoma Bold.ttf from Mac OS X 10.9 */

      || (844 == gdef_len && 45474 == gpos_len && 7302 == gsub_len)

      /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc  himalaya.ttf from Windows 7 */

      || (180 == gdef_len && 7254 == gpos_len && 13054 == gsub_len)

      /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0  himalaya.ttf from Windows 8 */

      || (192 == gdef_len && 7254 == gpos_len && 12638 == gsub_len)

      /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427  himalaya.ttf from Windows 8.1 */

      || (192 == gdef_len && 7254 == gpos_len && 12690 == gsub_len)

      /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44  cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */

      /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371  cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */

      || (188 == gdef_len && 3852 == gpos_len && 248 == gsub_len)

      /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f  cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */

      /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b  cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */

      || (188 == gdef_len && 3426 == gpos_len && 264 == gsub_len)

      /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */

      || (1058 == gdef_len && 11818 == gpos_len && 47032 == gsub_len)

      /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/

      || (1046 == gdef_len && 12600 == gpos_len && 47030 == gsub_len)

      /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */

      || (1058 == gdef_len && 16770 == gpos_len && 71796 == gsub_len)

      /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */

      || (1046 == gdef_len && 17862 == gpos_len && 71790 == gsub_len)

      /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */

      || (1046 == gdef_len && 17112 == gpos_len && 71788 == gsub_len)

      /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */

      || (1058 == gdef_len && 17514 == gpos_len && 71794 == gsub_len)

      /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */

      || (1330 == gdef_len && 57938 == gpos_len && 109904 == gsub_len)

      /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */

      || (1330 == gdef_len && 58972 == gpos_len && 109904 == gsub_len)

      /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85  Padauk.ttf

       *  "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */

      || (1004 == gdef_len && 14836 == gpos_len && 59092 == gsub_len)

    )

    {

      /* 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 these fonts 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

       */

      layout->gdef = &OT::Null(OT::GDEF);

    }

  }

  layout->gsub_lookup_count = layout->gsub->get_lookup_count ();

  layout->gpos_lookup_count = layout->gpos->get_lookup_count ();

  layout->gsub_accels = (hb_ot_layout_lookup_accelerator_t *) calloc (layout->gsub->get_lookup_count (), sizeof (hb_ot_layout_lookup_accelerator_t));

  layout->gpos_accels = (hb_ot_layout_lookup_accelerator_t *) calloc (layout->gpos->get_lookup_count (), sizeof (hb_ot_layout_lookup_accelerator_t));

  if (unlikely ((layout->gsub_lookup_count && !layout->gsub_accels) ||

		(layout->gpos_lookup_count && !layout->gpos_accels)))

  {

    _hb_ot_layout_destroy (layout);

    return NULL;

  }

  for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)

    layout->gsub_accels[i].init (layout->gsub->get_lookup (i));

  for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)

    layout->gpos_accels[i].init (layout->gpos->get_lookup (i));

  return layout;

}

void

_hb_ot_layout_destroy (hb_ot_layout_t *layout)

{

  for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)

    layout->gsub_accels[i].fini ();

  for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)

    layout->gpos_accels[i].fini ();

  free (layout->gsub_accels);

  free (layout->gpos_accels);

  hb_blob_destroy (layout->gdef_blob);

  hb_blob_destroy (layout->gsub_blob);

  hb_blob_destroy (layout->gpos_blob);

  layout->math.fini ();

  layout->fvar.fini ();

  layout->avar.fini ();

  free (layout);

}

static inline const OT::GDEF&

_get_gdef (hb_face_t *face)

{

  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GDEF);

  return *hb_ot_layout_from_face (face)->gdef;

}

static inline const OT::GSUB&

_get_gsub (hb_face_t *face)

{

  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GSUB);

  return *hb_ot_layout_from_face (face)->gsub;

}

static inline const OT::GPOS&

_get_gpos (hb_face_t *face)

{

  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GPOS);

  return *hb_ot_layout_from_face (face)->gpos;

}

/*

 * GDEF

 */

hb_bool_t

hb_ot_layout_has_glyph_classes (hb_face_t *face)

{

  return _get_gdef (face).has_glyph_classes ();

}

/**

 * hb_ot_layout_get_glyph_class:

 *

 * 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) _get_gdef (face).get_glyph_class (glyph);

}

/**

 * hb_ot_layout_get_glyphs_in_class:

 *

 * 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 _get_gdef (face).get_glyphs_in_class (klass, glyphs);

}

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 _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);

}

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 */)

{

  return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);

}

/*

 * GSUB/GPOS

 */

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 _get_gsub (face);

    case HB_OT_TAG_GPOS: return _get_gpos (face);

    default:             return OT::Null(OT::GSUBGPOS);

  }

}

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_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)

{

  ASSERT_STATIC (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;

}

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,

				  hb_tag_t       *chosen_script)

{

  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);

  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

  while (*script_tags)

  {

    if (g.find_script_index (*script_tags, script_index)) {

      if (chosen_script)

        *chosen_script = *script_tags;

      return true;

    }

    script_tags++;

  }

  /* 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;

}

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_bool_t

hb_ot_layout_table_find_feature (hb_face_t    *face,

				 hb_tag_t      table_tag,

				 hb_tag_t      feature_tag,

				 unsigned int *feature_index)

{

  ASSERT_STATIC (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;

}

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);

}

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)

{

  ASSERT_STATIC (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);

  if (s.find_lang_sys_index (language_tag, language_index))

    return true;

  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */

  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_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)

{

  return hb_ot_layout_language_get_required_feature (face,

						     table_tag,

						     script_index,

						     language_index,

						     feature_index,

						     NULL);

}

/**

 * hb_ot_layout_language_get_required_feature:

 *

 * 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,

					    hb_tag_t     *feature_tag)

{

  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 ();

}

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);

}

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);

  ASSERT_STATIC (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_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)

{

  ASSERT_STATIC (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:

 *

 * 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:

 *

 * Since: 0.9.22

 **/

unsigned int

hb_ot_layout_table_get_lookup_count (hb_face_t    *face,

				     hb_tag_t      table_tag)

{

  switch (table_tag)

  {

    case HB_OT_TAG_GSUB:

    {

      return hb_ot_layout_from_face (face)->gsub_lookup_count;

    }

    case HB_OT_TAG_GPOS:

    {

      return hb_ot_layout_from_face (face)->gpos_lookup_count;

    }

  }

  return 0;

}

static void

_hb_ot_layout_collect_lookups_lookups (hb_face_t      *face,

				       hb_tag_t        table_tag,

				       unsigned int    feature_index,

				       hb_set_t       *lookup_indexes /* OUT */)

{

  unsigned int lookup_indices[32];

  unsigned int offset, len;

  offset = 0;

  do {

    len = ARRAY_LENGTH (lookup_indices);

    hb_ot_layout_feature_get_lookups (face,

				      table_tag,

				      feature_index,

				      offset, &len,

				      lookup_indices);

    for (unsigned int i = 0; i < len; i++)

      lookup_indexes->add (lookup_indices[i]);

    offset += len;

  } while (len == ARRAY_LENGTH (lookup_indices));

}

static void

_hb_ot_layout_collect_lookups_features (hb_face_t      *face,

					hb_tag_t        table_tag,

					unsigned int    script_index,

					unsigned int    language_index,

					const hb_tag_t *features,

					hb_set_t       *lookup_indexes /* OUT */)

{

  if (!features)

  {

    unsigned int required_feature_index;

    if (hb_ot_layout_language_get_required_feature (face,

						    table_tag,

						    script_index,

						    language_index,

						    &required_feature_index,

						    NULL))

      _hb_ot_layout_collect_lookups_lookups (face,

					     table_tag,

					     required_feature_index,

					     lookup_indexes);

    /* All features */

    unsigned int feature_indices[32];

    unsigned int offset, len;

    offset = 0;

    do {

      len = ARRAY_LENGTH (feature_indices);

      hb_ot_layout_language_get_feature_indexes (face,

						 table_tag,

						 script_index,

						 language_index,

						 offset, &len,

						 feature_indices);

      for (unsigned int i = 0; i < len; i++)

	_hb_ot_layout_collect_lookups_lookups (face,

					       table_tag,

					       feature_indices[i],

					       lookup_indexes);

      offset += len;

    } while (len == ARRAY_LENGTH (feature_indices));

  }

  else

  {

    for (; *features; features++)

    {

      unsigned int feature_index;

      if (hb_ot_layout_language_find_feature (face,

					      table_tag,

					      script_index,

					      language_index,

					      *features,

					      &feature_index))

        _hb_ot_layout_collect_lookups_lookups (face,

					       table_tag,

					       feature_index,

					       lookup_indexes);

    }

  }

}

static void

_hb_ot_layout_collect_lookups_languages (hb_face_t      *face,

					 hb_tag_t        table_tag,

					 unsigned int    script_index,

					 const hb_tag_t *languages,

					 const hb_tag_t *features,

					 hb_set_t       *lookup_indexes /* OUT */)

{

  _hb_ot_layout_collect_lookups_features (face,

					  table_tag,

					  script_index,

					  HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,

					  features,

					  lookup_indexes);

  if (!languages)

  {

    /* All languages */

    unsigned int count = hb_ot_layout_script_get_language_tags (face,

								table_tag,

								script_index,

								0, NULL, NULL);

    for (unsigned int language_index = 0; language_index < count; language_index++)

      _hb_ot_layout_collect_lookups_features (face,

					      table_tag,

					      script_index,

					      language_index,

					      features,

					      lookup_indexes);

  }

  else

  {

    for (; *languages; languages++)

    {

      unsigned int language_index;

      if (hb_ot_layout_script_find_language (face,

					     table_tag,

					     script_index,

					     *languages,

					     &language_index))

        _hb_ot_layout_collect_lookups_features (face,

						table_tag,

						script_index,

						language_index,

						features,

						lookup_indexes);

    }

  }

}

/**

 * hb_ot_layout_collect_lookups:

 *

 * 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 */)

{

  if (!scripts)

  {

    /* All scripts */

    unsigned int count = hb_ot_layout_table_get_script_tags (face,

							     table_tag,

							     0, NULL, NULL);

    for (unsigned int script_index = 0; script_index < count; script_index++)

      _hb_ot_layout_collect_lookups_languages (face,

					       table_tag,

					       script_index,

					       languages,

					       features,

					       lookup_indexes);

  }

  else

  {

    for (; *scripts; scripts++)

    {

      unsigned int script_index;

      if (hb_ot_layout_table_find_script (face,

					  table_tag,

					  *scripts,

					  &script_index))

        _hb_ot_layout_collect_lookups_languages (face,

						 table_tag,

						 script_index,

						 languages,

						 features,

						 lookup_indexes);

    }

  }

}

/**

 * hb_ot_layout_lookup_collect_glyphs:

 *

 * 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 */)

{

  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return;

  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 = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);

      l.collect_glyphs (&c);

      return;

    }

    case HB_OT_TAG_GPOS:

    {

      const OT::PosLookup& l = hb_ot_layout_from_face (face)->gpos->get_lookup (lookup_index);

      l.collect_glyphs (&c);

      return;

    }

  }

}

/* Variations support */

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);

}

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 */)

{

  ASSERT_STATIC (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_bool_t

hb_ot_layout_has_substitution (hb_face_t *face)

{

  return &_get_gsub (face) != &OT::Null(OT::GSUB);

}