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 /*

  * 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-private.hh"

 /*

  * GDEF

  */

 typedef enum

 {

   /* 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_PRESERVE     = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |

 					  HB_OT_LAYOUT_GLYPH_PROPS_LIGATED

 } hb_ot_layout_glyph_class_mask_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_apply_context_t;

   struct SubstLookup;

 }

 HB_INTERNAL void

 hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,

 				const OT::SubstLookup &lookup,

 				const hb_ot_layout_lookup_accelerator_t &accel);

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

 HB_INTERNAL void

 hb_ot_layout_substitute_finish (hb_font_t    *font,

 				hb_buffer_t  *buffer);

 /* Should be called before all the position_lookup's are done.  Resets positions to zero. */

 HB_INTERNAL void

 hb_ot_layout_position_start (hb_font_t    *font,

 			     hb_buffer_t  *buffer);

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

 HB_INTERNAL void

 hb_ot_layout_position_finish (hb_font_t    *font,

 			      hb_buffer_t  *buffer);

 /*

  * hb_ot_layout_t

  */

 namespace OT {

   struct GDEF;

   struct GSUB;

   struct GPOS;

 }

 struct hb_ot_layout_lookup_accelerator_t

 {

   template <typename TLookup>

   inline void init (const TLookup &lookup)

   {

     digest.init ();

     lookup.add_coverage (&digest);

   }

   template <typename TLookup>

   inline void fini (const TLookup &lookup)

   {

   }

   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;

   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_props0()	var2.u8[0]

 #define unicode_props1()	var2.u8[1]

 /* 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 */

 /* unicode_props */

 enum {

   MASK0_ZWJ       = 0x20u,

   MASK0_ZWNJ      = 0x40u,

   MASK0_IGNORABLE = 0x80u,

   MASK0_GEN_CAT   = 0x1Fu

 };

 inline void

 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)

 {

   /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */

   info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |

 			   (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) |

 			   (info->codepoint == 0x200C ? MASK0_ZWNJ : 0) |

 			   (info->codepoint == 0x200D ? MASK0_ZWJ : 0);

   info->unicode_props1() = unicode->modified_combining_class (info->codepoint);

 }

 inline void

 _hb_glyph_info_set_general_category (hb_glyph_info_t *info,

 				     hb_unicode_general_category_t gen_cat)

 {

   info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT);

 }

 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_props0() & MASK0_GEN_CAT);

 }

 inline void

 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,

 					     unsigned int modified_class)

 {

   info->unicode_props1() = modified_class;

 }

 inline unsigned int

 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)

 {

   return info->unicode_props1();

 }

 inline hb_bool_t

 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)

 {

   return !!(info->unicode_props0() & MASK0_IGNORABLE);

 }

 inline hb_bool_t

 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)

 {

   return !!(info->unicode_props0() & MASK0_ZWNJ);

 }

 inline hb_bool_t

 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info)

 {

   return !!(info->unicode_props0() & MASK0_ZWJ);

 }

 inline void

 _hb_glyph_info_flip_joiners (hb_glyph_info_t *info)

 {

   info->unicode_props0() ^= MASK0_ZWNJ | MASK0_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)

 {

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

 }

 static inline void

 _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)

 {

   _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);

 }

 static inline unsigned int

 _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)

 {

   return info->lig_props() >> 5;

 }

 static inline bool

 _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)

 {

   return !!(info->lig_props() & IS_LIG_BASE);

 }

 static inline unsigned int

 _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)

 {

   if (_hb_glyph_info_ligated_internal (info))

     return 0;

   else

     return info->lig_props() & 0x0F;

 }

 static inline unsigned int

 _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)

 {

   if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&

       _hb_glyph_info_ligated_internal (info))

     return info->lig_props() & 0x0F;

   else

     return 1;

 }

 static inline uint8_t

 _hb_allocate_lig_id (hb_buffer_t *buffer) {

   uint8_t lig_id = buffer->next_serial () & 0x07;

   if (unlikely (!lig_id))

     lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */

   return lig_id;

 }

 /* glyph_props: */

 inline void

 _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)

 {

   info->glyph_props() = props;

 }

 inline unsigned int

 _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)

 {

   return info->glyph_props();

 }

 inline bool

 _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)

 {

   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);

 }

 inline bool

 _hb_glyph_info_is_ligature (const hb_glyph_info_t *info)

 {

   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);

 }

 inline bool

 _hb_glyph_info_is_mark (const hb_glyph_info_t *info)

 {

   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);

 }

 static inline bool

 _hb_glyph_info_substituted (const hb_glyph_info_t *info)

 {

   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);

 }

 static inline bool

 _hb_glyph_info_ligated (const hb_glyph_info_t *info)

 {

   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);

 }

 /* Allocation / deallocation. */

 inline void

 _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)

 {

   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0);

   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1);

 }

 inline void

 _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)

 {

   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0);

   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1);

 }

 inline void

 _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)

 {

   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);

   HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);

   HB_BUFFER_ALLOCATE_VAR (buffer, syllable);

 }

 inline void

 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)

 {

   HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);

   HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);

   HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);

 }

 /* Make sure no one directly touches our props... */

 #undef unicode_props0

 #undef unicode_props1

 #undef lig_props

 #undef glyph_props

 #endif /* HB_OT_LAYOUT_PRIVATE_HH */