/*

 * 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

 */

#ifndef HB_OT_LAYOUT_PRIVATE_HH

#define HB_OT_LAYOUT_PRIVATE_HH

#include "hb-private.hh"

#include "hb-font-private.hh"

#include "hb-buffer-private.hh"

#include "hb-set-digest-private.hh"

#include "hb-open-type-private.hh"

/* Private API corresponding to hb-ot-layout.h: */

HB_INTERNAL 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);

/*

 * GDEF

 */

enum hb_ot_layout_glyph_props_flags_t

{

  /* The following three match LookupFlags::Ignore* numbers. */

  HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH   = 0x02u,

  HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE     = 0x04u,

  HB_OT_LAYOUT_GLYPH_PROPS_MARK         = 0x08u,

  /* The following are used internally; not derived from GDEF. */

  HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED  = 0x10u,

  HB_OT_LAYOUT_GLYPH_PROPS_LIGATED      = 0x20u,

  HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED   = 0x40u,

  HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE     = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |

                                          HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |

                                          HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED

};

HB_MARK_AS_FLAG_T (hb_ot_layout_glyph_props_flags_t);

/*

 * GSUB/GPOS

 */

HB_INTERNAL hb_bool_t

hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,

                                           unsigned int          lookup_index,

                                           const hb_codepoint_t *glyphs,

                                           unsigned int          glyphs_length,

                                           hb_bool_t             zero_context);

/* Should be called before all the substitute_lookup's are done. */

HB_INTERNAL void

hb_ot_layout_substitute_start (hb_font_t    *font,

                               hb_buffer_t  *buffer);

struct hb_ot_layout_lookup_accelerator_t;

namespace OT {

  struct hb_ot_apply_context_t;

  struct SubstLookup;

}

HB_INTERNAL void

hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,

                                const OT::SubstLookup &lookup,

                                const hb_ot_layout_lookup_accelerator_t &accel);

/* Should be called before all the position_lookup's are done. */

HB_INTERNAL void

hb_ot_layout_position_start (hb_font_t    *font,

                             hb_buffer_t  *buffer);

HB_INTERNAL void

hb_ot_layout_position_finish_advances (hb_font_t    *font,

                                       hb_buffer_t  *buffer);

HB_INTERNAL void

hb_ot_layout_position_finish_offsets (hb_font_t    *font,

                                      hb_buffer_t  *buffer);

/*

 * hb_ot_layout_t

 */

namespace OT {

  struct BASE;

  struct COLR;

  struct CPAL;

  struct GDEF;

  struct GSUB;

  struct GPOS;

  struct MATH;

  struct fvar;

  struct avar;

}

namespace AAT {

  struct ankr;

  struct kerx;

  struct morx;

  struct trak;

}

struct hb_ot_layout_lookup_accelerator_t

{

  template <typename TLookup>

  inline void init (const TLookup &lookup)

  {

    digest.init ();

    lookup.add_coverage (&digest);

  }

  inline void fini (void)

  {

  }

  inline bool may_have (hb_codepoint_t g) const {

    return digest.may_have (g);

  }

  private:

  hb_set_digest_t digest;

};

struct hb_ot_layout_t

{

  hb_blob_t *gdef_blob;

  hb_blob_t *gsub_blob;

  hb_blob_t *gpos_blob;

  const struct OT::GDEF *gdef;

  const struct OT::GSUB *gsub;

  const struct OT::GPOS *gpos;

  /* TODO Move the following out of this struct. */

  unsigned int gsub_lookup_count;

  unsigned int gpos_lookup_count;

  hb_ot_layout_lookup_accelerator_t *gsub_accels;

  hb_ot_layout_lookup_accelerator_t *gpos_accels;

};

HB_INTERNAL hb_ot_layout_t *

_hb_ot_layout_create (hb_face_t *face);

HB_INTERNAL void

_hb_ot_layout_destroy (hb_ot_layout_t *layout);

#define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)

/*

 * Buffer var routines.

 */

/* buffer var allocations, used during the entire shaping process */

#define unicode_props()         var2.u16[0]

/* buffer var allocations, used during the GSUB/GPOS processing */

#define glyph_props()           var1.u16[0] /* GDEF glyph properties */

#define lig_props()             var1.u8[2] /* GSUB/GPOS ligature tracking */

#define syllable()              var1.u8[3] /* GSUB/GPOS shaping boundaries */

/* Loop over syllables. Based on foreach_cluster(). */

#define foreach_syllable(buffer, start, end) \

  for (unsigned int \

       _count = buffer->len, \

       start = 0, end = _count ? _next_syllable (buffer, 0) : 0; \

       start < _count; \

       start = end, end = _next_syllable (buffer, start))

static inline unsigned int

_next_syllable (hb_buffer_t *buffer, unsigned int start)

{

  hb_glyph_info_t *info = buffer->info;

  unsigned int count = buffer->len;

  unsigned int syllable = info[start].syllable();

  while (++start < count && syllable == info[start].syllable())

    ;

  return start;

}

/* unicode_props */

/* Design:

 * unicode_props() is a two-byte number.  The low byte includes:

 * - General_Category: 5 bits.

 * - A bit each for:

 *   * Is it Default_Ignorable(); we have a modified Default_Ignorable().

 *   * Whether it's one of the three Mongolian Free Variation Selectors,

 *     CGJ, or other characters that are hidden but should not be ignored

 *     like most other Default_Ignorable()s do during matching.

 *   * One free bit right now.

 *

 * The high-byte has different meanings, switched by the Gen-Cat:

 * - For Mn,Mc,Me: the modified Combining_Class.

 * - For Cf: whether it's ZWJ, ZWNJ, or something else.

 * - For Ws: index of which space character this is, if space fallback

 *   is needed, ie. we don't set this by default, only if asked to.

 */

enum hb_unicode_props_flags_t {

  UPROPS_MASK_GEN_CAT   = 0x001Fu,

  UPROPS_MASK_IGNORABLE = 0x0020u,

  UPROPS_MASK_HIDDEN    = 0x0040u, /* MONGOLIAN FREE VARIATION SELECTOR 1..3,

                                    * or TAG characters */

  /* If GEN_CAT=FORMAT, top byte masks: */

  UPROPS_MASK_Cf_ZWJ    = 0x0100u,

  UPROPS_MASK_Cf_ZWNJ   = 0x0200u

};

HB_MARK_AS_FLAG_T (hb_unicode_props_flags_t);

static inline void

_hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_buffer_t *buffer)

{

  hb_unicode_funcs_t *unicode = buffer->unicode;

  unsigned int u = info->codepoint;

  unsigned int gen_cat = (unsigned int) unicode->general_category (u);

  unsigned int props = gen_cat;

  if (u >= 0x80)

  {

    buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII;

    if (unlikely (unicode->is_default_ignorable (u)))

    {

      buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES;

      props |=  UPROPS_MASK_IGNORABLE;

      if (u == 0x200Cu) props |= UPROPS_MASK_Cf_ZWNJ;

      else if (u == 0x200Du) props |= UPROPS_MASK_Cf_ZWJ;

      /* Mongolian Free Variation Selectors need to be remembered

       * because although we need to hide them like default-ignorables,

       * they need to non-ignorable during shaping.  This is similar to

       * what we do for joiners in Indic-like shapers, but since the

       * FVSes are GC=Mn, we have use a separate bit to remember them.

       * Fixes:

       * https://github.com/harfbuzz/harfbuzz/issues/234 */

      else if (unlikely (hb_in_range (u, 0x180Bu, 0x180Du))) props |= UPROPS_MASK_HIDDEN;

      /* TAG characters need similar treatment. Fixes:

       * https://github.com/harfbuzz/harfbuzz/issues/463 */

      else if (unlikely (hb_in_range (u, 0xE0020u, 0xE007Fu))) props |= UPROPS_MASK_HIDDEN;

      /* COMBINING GRAPHEME JOINER should not be skipped; at least some times.

       * https://github.com/harfbuzz/harfbuzz/issues/554 */

      else if (unlikely (u == 0x034Fu))

      {

        buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_CGJ;

        props |= UPROPS_MASK_HIDDEN;

      }

    }

    else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK_OR_MODIFIER_SYMBOL (gen_cat)))

    {

      /* The above check is just an optimization to let in only things we need further

       * processing on. */

      /* Only Mn and Mc can have non-zero ccc:

       * """

       * Canonical_Combining_Class, General_Category

       * All characters other than those with General_Category property values

       * Spacing_Mark (Mc) and Nonspacing_Mark (Mn) have the Canonical_Combining_Class

       * property value 0.

       * 1.1.5+

       * """

       *

       * Also, all Mn's that are Default_Ignorable, have ccc=0, hence

       * the "else if".

       */

      props |= unicode->modified_combining_class (info->codepoint)<<8;

      /* Recategorize emoji skin-tone modifiers as Unicode mark, so they

       * behave correctly in non-native directionality.  They originally

       * are MODIFIER_SYMBOL.  Fixes:

       * https://github.com/harfbuzz/harfbuzz/issues/169

       */

      if (unlikely (hb_in_range (u, 0x1F3FBu, 0x1F3FFu)))

      {

        props = gen_cat = HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK;

      }

    }

  }

  info->unicode_props() = props;

}

static inline void

_hb_glyph_info_set_general_category (hb_glyph_info_t *info,

                                     hb_unicode_general_category_t gen_cat)

{

  /* Clears top-byte. */

  info->unicode_props() = (unsigned int) gen_cat | (info->unicode_props() & (0xFF & ~UPROPS_MASK_GEN_CAT));

}

static inline hb_unicode_general_category_t

_hb_glyph_info_get_general_category (const hb_glyph_info_t *info)

{

  return (hb_unicode_general_category_t) (info->unicode_props() & UPROPS_MASK_GEN_CAT);

}

static inline bool

_hb_glyph_info_is_unicode_mark (const hb_glyph_info_t *info)

{

  return HB_UNICODE_GENERAL_CATEGORY_IS_MARK (info->unicode_props() & UPROPS_MASK_GEN_CAT);

}

static inline void

_hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,

                                             unsigned int modified_class)

{

  if (unlikely (!_hb_glyph_info_is_unicode_mark (info)))

    return;

  info->unicode_props() = (modified_class<<8) | (info->unicode_props() & 0xFF);

}

static inline unsigned int

_hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)

{

  return _hb_glyph_info_is_unicode_mark (info) ? info->unicode_props()>>8 : 0;

}

/* Loop over grapheme. Based on foreach_cluster(). */

#define foreach_grapheme(buffer, start, end) \

  for (unsigned int \

       _count = buffer->len, \

       start = 0, end = _count ? _next_grapheme (buffer, 0) : 0; \

       start < _count; \

       start = end, end = _next_grapheme (buffer, start))

static inline unsigned int

_next_grapheme (hb_buffer_t *buffer, unsigned int start)

{

  hb_glyph_info_t *info = buffer->info;

  unsigned int count = buffer->len;

  while (++start < count && _hb_glyph_info_is_unicode_mark (&info[start]))

    ;

  return start;

}

#define info_cc(info) (_hb_glyph_info_get_modified_combining_class (&(info)))

static inline bool

_hb_glyph_info_is_unicode_space (const hb_glyph_info_t *info)

{

  return _hb_glyph_info_get_general_category (info) ==

         HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR;

}

static inline void

_hb_glyph_info_set_unicode_space_fallback_type (hb_glyph_info_t *info, hb_unicode_funcs_t::space_t s)

{

  if (unlikely (!_hb_glyph_info_is_unicode_space (info)))

    return;

  info->unicode_props() = (((unsigned int) s)<<8) | (info->unicode_props() & 0xFF);

}

static inline hb_unicode_funcs_t::space_t

_hb_glyph_info_get_unicode_space_fallback_type (const hb_glyph_info_t *info)

{

  return _hb_glyph_info_is_unicode_space (info) ?

         (hb_unicode_funcs_t::space_t) (info->unicode_props()>>8) :

         hb_unicode_funcs_t::NOT_SPACE;

}

static inline bool _hb_glyph_info_ligated (const hb_glyph_info_t *info);

static inline hb_bool_t

_hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)

{

  return (info->unicode_props() & UPROPS_MASK_IGNORABLE) &&

         !_hb_glyph_info_ligated (info);

}

static inline hb_bool_t

_hb_glyph_info_is_default_ignorable_and_not_hidden (const hb_glyph_info_t *info)

{

  return ((info->unicode_props() & (UPROPS_MASK_IGNORABLE|UPROPS_MASK_HIDDEN))

          == UPROPS_MASK_IGNORABLE) &&

         !_hb_glyph_info_ligated (info);

}

static inline void

_hb_glyph_info_unhide (hb_glyph_info_t *info)

{

  info->unicode_props() &= ~ UPROPS_MASK_HIDDEN;

}

static inline bool

_hb_glyph_info_is_unicode_format (const hb_glyph_info_t *info)

{

  return _hb_glyph_info_get_general_category (info) ==

         HB_UNICODE_GENERAL_CATEGORY_FORMAT;

}

static inline hb_bool_t

_hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)

{

  return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & UPROPS_MASK_Cf_ZWNJ);

}

static inline hb_bool_t

_hb_glyph_info_is_zwj (const hb_glyph_info_t *info)

{

  return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & UPROPS_MASK_Cf_ZWJ);

}

static inline hb_bool_t

_hb_glyph_info_is_joiner (const hb_glyph_info_t *info)

{

  return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & (UPROPS_MASK_Cf_ZWNJ|UPROPS_MASK_Cf_ZWJ));

}

static inline void

_hb_glyph_info_flip_joiners (hb_glyph_info_t *info)

{

  if (!_hb_glyph_info_is_unicode_format (info))

    return;

  info->unicode_props() ^= UPROPS_MASK_Cf_ZWNJ | UPROPS_MASK_Cf_ZWJ;

}

/* lig_props: aka lig_id / lig_comp

 *

 * When a ligature is formed:

 *

 *   - The ligature glyph and any marks in between all the same newly allocated

 *     lig_id,

 *   - The ligature glyph will get lig_num_comps set to the number of components

 *   - The marks get lig_comp > 0, reflecting which component of the ligature

 *     they were applied to.

 *   - This is used in GPOS to attach marks to the right component of a ligature

 *     in MarkLigPos,

 *   - Note that when marks are ligated together, much of the above is skipped

 *     and the current lig_id reused.

 *

 * When a multiple-substitution is done:

 *

 *   - All resulting glyphs will have lig_id = 0,

 *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.

 *   - This is used in GPOS to attach marks to the first component of a

 *     multiple substitution in MarkBasePos.

 *

 * The numbers are also used in GPOS to do mark-to-mark positioning only

 * to marks that belong to the same component of the same ligature.

 */

static inline void

_hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)

{

  info->lig_props() = 0;

}

#define IS_LIG_BASE 0x10

static inline void

_hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,

                                           unsigned int lig_id,

                                           unsigned int lig_num_comps)

{

  info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);

}

static inline void

_hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,

                                       unsigned int lig_id,

                                       unsigned int lig_comp)

{