src/hb-ot-layout.cc - platform/external/harfbuzz_ng - Git at Google

 /*
  * Copyright (C) 1998-2004  David Turner and Werner Lemberg
  * Copyright (C) 2006  Behdad Esfahbod
  * Copyright (C) 2007,2008,2009  Red Hat, 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
  */

 #define HB_OT_LAYOUT_CC

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

 #include "hb-ot-layout-gdef-private.hh"
 #include "hb-ot-layout-gsub-private.hh"
 #include "hb-ot-layout-gpos-private.hh"


 #include <stdlib.h>
 #include <string.h>


 hb_ot_layout_t *
 _hb_ot_layout_new (hb_face_t *face)
 {
   /* Remove this object altogether */
   hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));

   layout->gdef_blob = Sanitizer<GDEF>::sanitize (hb_face_get_table (face, HB_OT_TAG_GDEF));
   layout->gdef = Sanitizer<GDEF>::lock_instance (layout->gdef_blob);

   layout->gsub_blob = Sanitizer<GSUB>::sanitize (hb_face_get_table (face, HB_OT_TAG_GSUB));
   layout->gsub = Sanitizer<GSUB>::lock_instance (layout->gsub_blob);

   layout->gpos_blob = Sanitizer<GPOS>::sanitize (hb_face_get_table (face, HB_OT_TAG_GPOS));
   layout->gpos = Sanitizer<GPOS>::lock_instance (layout->gpos_blob);

   return layout;
 }

 void
 _hb_ot_layout_free (hb_ot_layout_t *layout)
 {
   hb_blob_unlock (layout->gdef_blob);
   hb_blob_unlock (layout->gsub_blob);
   hb_blob_unlock (layout->gpos_blob);

   hb_blob_destroy (layout->gdef_blob);
   hb_blob_destroy (layout->gsub_blob);
   hb_blob_destroy (layout->gpos_blob);

   free (layout->new_gdef.klasses);
 }

 static const GDEF&
 _get_gdef (hb_face_t *face)
 {
   return likely (face->ot_layout->gdef) ? *face->ot_layout->gdef : Null(GDEF);
 }

 static const GSUB&
 _get_gsub (hb_face_t *face)
 {
   return likely (face->ot_layout->gsub) ? *face->ot_layout->gsub : Null(GSUB);
 }

 static const GPOS&
 _get_gpos (hb_face_t *face)
 {
   return likely (face->ot_layout->gpos) ? *face->ot_layout->gpos : Null(GPOS);
 }


 /*
  * GDEF
  */

 /* TODO the public class_t is a mess */

 hb_bool_t
 hb_ot_layout_has_glyph_classes (hb_face_t *face)
 {
   return _get_gdef (face).has_glyph_classes ();
 }

 hb_bool_t
 _hb_ot_layout_has_new_glyph_classes (hb_face_t *face)
 {
   return face->ot_layout->new_gdef.len > 0;
 }

 static unsigned int
 _hb_ot_layout_get_glyph_property (hb_face_t      *face,
 				  hb_codepoint_t  glyph)
 {
   hb_ot_layout_class_t klass;
   const GDEF &gdef = _get_gdef (face);

   klass = gdef.get_glyph_class (glyph);

   if (!klass && glyph < face->ot_layout->new_gdef.len)
     klass = face->ot_layout->new_gdef.klasses[glyph];

   switch (klass) {
   default:
   case GDEF::UnclassifiedGlyph:	return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED;
   case GDEF::BaseGlyph:		return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
   case GDEF::LigatureGlyph:	return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
   case GDEF::ComponentGlyph:	return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT;
   case GDEF::MarkGlyph:
 	klass = gdef.get_mark_attachment_type (glyph);
 	return HB_OT_LAYOUT_GLYPH_CLASS_MARK + (klass << 8);
   }
 }

 hb_bool_t
 _hb_ot_layout_check_glyph_property (hb_face_t    *face,
 				    hb_internal_glyph_info_t *ginfo,
 				    unsigned int  lookup_flags,
 				    unsigned int *property_out)
 {
   unsigned int property;

   if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
     ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint);
   property = ginfo->gproperty;
   if (property_out)
     *property_out = property;

   /* Not covered, if, for example, glyph class is ligature and
    * lookup_flags includes LookupFlags::IgnoreLigatures
    */
   if (property & lookup_flags & LookupFlag::IgnoreFlags)
     return false;

   if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
   {
     /* If using mark filtering sets, the high short of
      * lookup_flags has the set index.
      */
     if (lookup_flags & LookupFlag::UseMarkFilteringSet)
       return _get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint);

     /* The second byte of lookup_flags has the meaning
      * "ignore marks of attachment type different than
      * the attachment type specified."
      */
     if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
       return (lookup_flags & LookupFlag::MarkAttachmentType) == (property & LookupFlag::MarkAttachmentType);
   }

   return true;
 }

 hb_bool_t
 _hb_ot_layout_skip_mark (hb_face_t    *face,
 			 hb_internal_glyph_info_t *ginfo,
 			 unsigned int  lookup_flags,
 			 unsigned int *property_out)
 {
   unsigned int property;

   if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
     ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint);
   property = ginfo->gproperty;
   if (property_out)
     *property_out = property;

   if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
   {
     /* Skip mark if lookup_flags includes LookupFlags::IgnoreMarks */
     if (lookup_flags & LookupFlag::IgnoreMarks)
       return true;

     /* If using mark filtering sets, the high short of lookup_flags has the set index. */
     if (lookup_flags & LookupFlag::UseMarkFilteringSet)
       return !_get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint);

     /* The second byte of lookup_flags has the meaning "ignore marks of attachment type
      * different than the attachment type specified." */
     if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
       return (lookup_flags & LookupFlag::MarkAttachmentType) != (property & LookupFlag::MarkAttachmentType);
   }

   return false;
 }

 void
 _hb_ot_layout_set_glyph_class (hb_face_t                  *face,
 			       hb_codepoint_t              glyph,
 			       hb_ot_layout_glyph_class_t  klass)
 {
   if (HB_OBJECT_IS_INERT (face))
     return;

   /* TODO optimize this? similar to old harfbuzz code for example */

   hb_ot_layout_t *layout = face->ot_layout;
   hb_ot_layout_class_t gdef_klass;
   unsigned int len = layout->new_gdef.len;

   if (unlikely (glyph > 65535))
     return;

   /* XXX this is not threadsafe */
   if (glyph >= len) {
     unsigned int new_len;
     unsigned char *new_klasses;

     new_len = len == 0 ? 120 : 2 * len;
     while (new_len <= glyph)
       new_len *= 2;

     if (new_len > 65536)
       new_len = 65536;
     new_klasses = (unsigned char *) realloc (layout->new_gdef.klasses, new_len * sizeof (unsigned char));

     if (unlikely (!new_klasses))
       return;

     memset (new_klasses + len, 0, new_len - len);

     layout->new_gdef.klasses = new_klasses;
     layout->new_gdef.len = new_len;
   }

   switch (klass) {
   default:
   case HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED:	gdef_klass = GDEF::UnclassifiedGlyph;	break;
   case HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH:	gdef_klass = GDEF::BaseGlyph;		break;
   case HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE:	gdef_klass = GDEF::LigatureGlyph;	break;
   case HB_OT_LAYOUT_GLYPH_CLASS_MARK:		gdef_klass = GDEF::MarkGlyph;		break;
   case HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT:	gdef_klass = GDEF::ComponentGlyph;	break;
   }

   layout->new_gdef.klasses[glyph] = gdef_klass;
   return;
 }

 void
 _hb_ot_layout_set_glyph_property (hb_face_t      *face,
 				  hb_codepoint_t  glyph,
 				  unsigned int    property)
 { _hb_ot_layout_set_glyph_class (face, glyph, (hb_ot_layout_glyph_class_t) (property & 0xff)); }


 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) (_hb_ot_layout_get_glyph_property (face, glyph) & 0xff);
 }

 void
 hb_ot_layout_set_glyph_class (hb_face_t                 *face,
 			      hb_codepoint_t             glyph,
 			      hb_ot_layout_glyph_class_t klass)
 {
   _hb_ot_layout_set_glyph_class (face, glyph, klass);
 }

 void
 hb_ot_layout_build_glyph_classes (hb_face_t      *face,
 				  hb_codepoint_t *glyphs,
 				  unsigned char  *klasses,
 				  uint16_t        count)
 {
   if (HB_OBJECT_IS_INERT (face))
     return;

   hb_ot_layout_t *layout = face->ot_layout;

   if (unlikely (!count || !glyphs || !klasses))
     return;

   if (layout->new_gdef.len == 0) {
     layout->new_gdef.klasses = (unsigned char *) calloc (count, sizeof (unsigned char));
     layout->new_gdef.len = count;
   }

   for (unsigned int i = 0; i < count; i++)
     _hb_ot_layout_set_glyph_class (face, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
 }

 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_lig_carets (hb_font_t      *font,
 			     hb_face_t      *face,
 			     hb_codepoint_t  glyph,
 			     unsigned int    start_offset,
 			     unsigned int   *caret_count /* IN/OUT */,
 			     int            *caret_array /* OUT */)
 {
   hb_ot_layout_context_t c;
   c.font = font;
   c.face = face;
   return _get_gdef (face).get_lig_carets (&c, glyph, start_offset, caret_count, caret_array);
 }

 /*
  * GSUB/GPOS
  */

 static const 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 Null(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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

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

 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 (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
   const 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 :( */
   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, 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)
 {
   ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

   while (*script_tags)
   {
     if (g.find_script_index (*script_tags, script_index))
       return TRUE;
     script_tags++;
   }

   /* 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 :( */
   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
     return FALSE;

   if (script_index) *script_index = 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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

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


 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 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 (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
   const 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)
 {
   const LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);

   if (feature_index) *feature_index = l.get_required_feature_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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
   const 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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
   const 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 (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
   const 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;
 }

 unsigned int
 hb_ot_layout_feature_get_lookup_indexes (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 */)
 {
   const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
   const Feature &f = g.get_feature (feature_index);

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


 /*
  * GSUB
  */

 hb_bool_t
 hb_ot_layout_has_substitution (hb_face_t *face)
 {
   return &_get_gsub (face) != &Null(GSUB);
 }

 hb_bool_t
 hb_ot_layout_substitute_lookup (hb_face_t    *face,
 				hb_buffer_t  *buffer,
 				unsigned int  lookup_index,
 				hb_mask_t     mask)
 {
   hb_ot_layout_context_t c;
   c.font = NULL;
   c.face = face;
   return _get_gsub (face).substitute_lookup (&c, buffer, lookup_index, mask);
 }


 /*
  * GPOS
  */

 hb_bool_t
 hb_ot_layout_has_positioning (hb_face_t *face)
 {
   return &_get_gpos (face) != &Null(GPOS);
 }

 hb_bool_t
 hb_ot_layout_position_lookup   (hb_font_t    *font,
 				hb_face_t    *face,
 				hb_buffer_t  *buffer,
 				unsigned int  lookup_index,
 				hb_mask_t     mask)
 {
   hb_ot_layout_context_t c;
   c.font = font;
   c.face = face;
   return _get_gpos (face).position_lookup (&c, buffer, lookup_index, mask);
 }

 void
 hb_ot_layout_position_finish (hb_font_t    *font HB_UNUSED,
 			      hb_face_t    *face HB_UNUSED,
 			      hb_buffer_t  *buffer)
 {
   unsigned int i, j;
   unsigned int len = hb_buffer_get_length (buffer);
   hb_internal_glyph_position_t *pos = (hb_internal_glyph_position_t *) hb_buffer_get_glyph_positions (buffer);

   /* TODO: Vertical */

   /* Handle cursive connections */
   /* First handle all left-to-right connections */
   for (j = 0; j < len; j++) {
     if (pos[j].cursive_chain > 0)
     {
       pos[j].y_offset += pos[j - pos[j].cursive_chain].y_offset;
       pos[j].cursive_chain = 0;
     }
   }
   /* Then handle all right-to-left connections */
   for (i = len; i > 0; i--) {
     j = i - 1;
     if (pos[j].cursive_chain < 0)
     {
       pos[j].y_offset += pos[j - pos[j].cursive_chain].y_offset;
       pos[j].cursive_chain = 0;
     }
   }

   /* Handle attachments */
   for (i = 0; i < len; i++)
     if (pos[i].back)
     {
       unsigned int back = i - pos[i].back;
       pos[i].back = 0;
       pos[i].x_offset += pos[back].x_offset;
       pos[i].y_offset += pos[back].y_offset;

       if (buffer->direction == HB_DIRECTION_RTL)
 	for (j = back + 1; j < i + 1; j++) {
 	  pos[i].x_offset += pos[j].x_advance;
 	  pos[i].y_offset += pos[j].y_advance;
 	}
       else
 	for (j = back; j < i; j++) {
 	  pos[i].x_offset -= pos[j].x_advance;
 	  pos[i].y_offset -= pos[j].y_advance;
 	}
     }
 }
	/*
	* Copyright (C) 1998-2004 David Turner and Werner Lemberg
	* Copyright (C) 2006 Behdad Esfahbod
	* Copyright (C) 2007,2008,2009 Red Hat, 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
	*/

	#define HB_OT_LAYOUT_CC

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

	#include "hb-ot-layout-gdef-private.hh"
	#include "hb-ot-layout-gsub-private.hh"
	#include "hb-ot-layout-gpos-private.hh"


	#include <stdlib.h>
	#include <string.h>


	hb_ot_layout_t *
	_hb_ot_layout_new (hb_face_t *face)
	{
	/* Remove this object altogether */
	hb_ot_layout_t layout = (hb_ot_layout_t ) calloc (1, sizeof (hb_ot_layout_t));

	layout->gdef_blob = Sanitizer<GDEF>::sanitize (hb_face_get_table (face, HB_OT_TAG_GDEF));
	layout->gdef = Sanitizer<GDEF>::lock_instance (layout->gdef_blob);

	layout->gsub_blob = Sanitizer<GSUB>::sanitize (hb_face_get_table (face, HB_OT_TAG_GSUB));
	layout->gsub = Sanitizer<GSUB>::lock_instance (layout->gsub_blob);

	layout->gpos_blob = Sanitizer<GPOS>::sanitize (hb_face_get_table (face, HB_OT_TAG_GPOS));
	layout->gpos = Sanitizer<GPOS>::lock_instance (layout->gpos_blob);

	return layout;
	}

	void
	_hb_ot_layout_free (hb_ot_layout_t *layout)
	{
	hb_blob_unlock (layout->gdef_blob);
	hb_blob_unlock (layout->gsub_blob);
	hb_blob_unlock (layout->gpos_blob);

	hb_blob_destroy (layout->gdef_blob);
	hb_blob_destroy (layout->gsub_blob);
	hb_blob_destroy (layout->gpos_blob);

	free (layout->new_gdef.klasses);
	}

	static const GDEF&
	_get_gdef (hb_face_t *face)
	{
	return likely (face->ot_layout->gdef) ? *face->ot_layout->gdef : Null(GDEF);
	}

	static const GSUB&
	_get_gsub (hb_face_t *face)
	{
	return likely (face->ot_layout->gsub) ? *face->ot_layout->gsub : Null(GSUB);
	}

	static const GPOS&
	_get_gpos (hb_face_t *face)
	{
	return likely (face->ot_layout->gpos) ? *face->ot_layout->gpos : Null(GPOS);
	}


	/*
	* GDEF
	*/

	/* TODO the public class_t is a mess */

	hb_bool_t
	hb_ot_layout_has_glyph_classes (hb_face_t *face)
	{
	return _get_gdef (face).has_glyph_classes ();
	}

	hb_bool_t
	_hb_ot_layout_has_new_glyph_classes (hb_face_t *face)
	{
	return face->ot_layout->new_gdef.len > 0;
	}

	static unsigned int
	_hb_ot_layout_get_glyph_property (hb_face_t *face,
	hb_codepoint_t glyph)
	{
	hb_ot_layout_class_t klass;
	const GDEF &gdef = _get_gdef (face);

	klass = gdef.get_glyph_class (glyph);

	if (!klass && glyph < face->ot_layout->new_gdef.len)
	klass = face->ot_layout->new_gdef.klasses[glyph];

	switch (klass) {
	default:
	case GDEF::UnclassifiedGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED;
	case GDEF::BaseGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
	case GDEF::LigatureGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
	case GDEF::ComponentGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT;
	case GDEF::MarkGlyph:
	klass = gdef.get_mark_attachment_type (glyph);
	return HB_OT_LAYOUT_GLYPH_CLASS_MARK + (klass << 8);
	}
	}

	hb_bool_t
	_hb_ot_layout_check_glyph_property (hb_face_t *face,
	hb_internal_glyph_info_t *ginfo,
	unsigned int lookup_flags,
	unsigned int *property_out)
	{
	unsigned int property;

	if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
	ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint);
	property = ginfo->gproperty;
	if (property_out)
	*property_out = property;

	/* Not covered, if, for example, glyph class is ligature and
	* lookup_flags includes LookupFlags::IgnoreLigatures
	*/
	if (property & lookup_flags & LookupFlag::IgnoreFlags)
	return false;

	if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
	{
	/* If using mark filtering sets, the high short of
	* lookup_flags has the set index.
	*/
	if (lookup_flags & LookupFlag::UseMarkFilteringSet)
	return _get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint);

	/* The second byte of lookup_flags has the meaning
	* "ignore marks of attachment type different than
	* the attachment type specified."
	*/
	if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
	return (lookup_flags & LookupFlag::MarkAttachmentType) == (property & LookupFlag::MarkAttachmentType);
	}

	return true;
	}

	hb_bool_t
	_hb_ot_layout_skip_mark (hb_face_t *face,
	hb_internal_glyph_info_t *ginfo,
	unsigned int lookup_flags,
	unsigned int *property_out)
	{
	unsigned int property;

	if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
	ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint);
	property = ginfo->gproperty;
	if (property_out)
	*property_out = property;

	if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
	{
	/* Skip mark if lookup_flags includes LookupFlags::IgnoreMarks */
	if (lookup_flags & LookupFlag::IgnoreMarks)
	return true;

	/* If using mark filtering sets, the high short of lookup_flags has the set index. */
	if (lookup_flags & LookupFlag::UseMarkFilteringSet)
	return !_get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint);

	/* The second byte of lookup_flags has the meaning "ignore marks of attachment type
	* different than the attachment type specified." */
	if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
	return (lookup_flags & LookupFlag::MarkAttachmentType) != (property & LookupFlag::MarkAttachmentType);
	}

	return false;
	}

	void
	_hb_ot_layout_set_glyph_class (hb_face_t *face,
	hb_codepoint_t glyph,
	hb_ot_layout_glyph_class_t klass)
	{
	if (HB_OBJECT_IS_INERT (face))
	return;

	/* TODO optimize this? similar to old harfbuzz code for example */

	hb_ot_layout_t *layout = face->ot_layout;
	hb_ot_layout_class_t gdef_klass;
	unsigned int len = layout->new_gdef.len;

	if (unlikely (glyph > 65535))
	return;

	/* XXX this is not threadsafe */
	if (glyph >= len) {
	unsigned int new_len;
	unsigned char *new_klasses;

	new_len = len == 0 ? 120 : 2 * len;
	while (new_len <= glyph)
	new_len *= 2;

	if (new_len > 65536)
	new_len = 65536;
	new_klasses = (unsigned char ) realloc (layout->new_gdef.klasses, new_len sizeof (unsigned char));

	if (unlikely (!new_klasses))
	return;

	memset (new_klasses + len, 0, new_len - len);

	layout->new_gdef.klasses = new_klasses;
	layout->new_gdef.len = new_len;
	}

	switch (klass) {
	default:
	case HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED: gdef_klass = GDEF::UnclassifiedGlyph; break;
	case HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH: gdef_klass = GDEF::BaseGlyph; break;
	case HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE: gdef_klass = GDEF::LigatureGlyph; break;
	case HB_OT_LAYOUT_GLYPH_CLASS_MARK: gdef_klass = GDEF::MarkGlyph; break;
	case HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT: gdef_klass = GDEF::ComponentGlyph; break;
	}

	layout->new_gdef.klasses[glyph] = gdef_klass;
	return;
	}

	void
	_hb_ot_layout_set_glyph_property (hb_face_t *face,
	hb_codepoint_t glyph,
	unsigned int property)
	{ _hb_ot_layout_set_glyph_class (face, glyph, (hb_ot_layout_glyph_class_t) (property & 0xff)); }


	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) (_hb_ot_layout_get_glyph_property (face, glyph) & 0xff);
	}

	void
	hb_ot_layout_set_glyph_class (hb_face_t *face,
	hb_codepoint_t glyph,
	hb_ot_layout_glyph_class_t klass)
	{
	_hb_ot_layout_set_glyph_class (face, glyph, klass);
	}

	void
	hb_ot_layout_build_glyph_classes (hb_face_t *face,
	hb_codepoint_t *glyphs,
	unsigned char *klasses,
	uint16_t count)
	{
	if (HB_OBJECT_IS_INERT (face))
	return;

	hb_ot_layout_t *layout = face->ot_layout;

	if (unlikely (!count \|\| !glyphs \|\| !klasses))
	return;

	if (layout->new_gdef.len == 0) {
	layout->new_gdef.klasses = (unsigned char *) calloc (count, sizeof (unsigned char));
	layout->new_gdef.len = count;
	}

	for (unsigned int i = 0; i < count; i++)
	_hb_ot_layout_set_glyph_class (face, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
	}

	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_lig_carets (hb_font_t *font,
	hb_face_t *face,
	hb_codepoint_t glyph,
	unsigned int start_offset,
	unsigned int caret_count / IN/OUT */,
	int caret_array / OUT */)
	{
	hb_ot_layout_context_t c;
	c.font = font;
	c.face = face;
	return _get_gdef (face).get_lig_carets (&c, glyph, start_offset, caret_count, caret_array);
	}

	/*
	* GSUB/GPOS
	*/

	static const 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 Null(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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

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

	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 (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
	const 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 :( */
	if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, 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)
	{
	ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
	const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

	while (*script_tags)
	{
	if (g.find_script_index (*script_tags, script_index))
	return TRUE;
	script_tags++;
	}

	/* 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 :( */
	if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
	return FALSE;

	if (script_index) *script_index = 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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);

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


	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 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 (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
	const 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)
	{
	const LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);

	if (feature_index) *feature_index = l.get_required_feature_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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
	const 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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
	const 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 (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
	const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
	const 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;
	}

	unsigned int
	hb_ot_layout_feature_get_lookup_indexes (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 */)
	{
	const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
	const Feature &f = g.get_feature (feature_index);

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


	/*
	* GSUB
	*/

	hb_bool_t
	hb_ot_layout_has_substitution (hb_face_t *face)
	{
	return &_get_gsub (face) != &Null(GSUB);
	}

	hb_bool_t
	hb_ot_layout_substitute_lookup (hb_face_t *face,
	hb_buffer_t *buffer,
	unsigned int lookup_index,
	hb_mask_t mask)
	{
	hb_ot_layout_context_t c;
	c.font = NULL;
	c.face = face;
	return _get_gsub (face).substitute_lookup (&c, buffer, lookup_index, mask);
	}


	/*
	* GPOS
	*/

	hb_bool_t
	hb_ot_layout_has_positioning (hb_face_t *face)
	{
	return &_get_gpos (face) != &Null(GPOS);
	}

	hb_bool_t
	hb_ot_layout_position_lookup (hb_font_t *font,
	hb_face_t *face,
	hb_buffer_t *buffer,
	unsigned int lookup_index,
	hb_mask_t mask)
	{
	hb_ot_layout_context_t c;
	c.font = font;
	c.face = face;
	return _get_gpos (face).position_lookup (&c, buffer, lookup_index, mask);
	}

	void
	hb_ot_layout_position_finish (hb_font_t *font HB_UNUSED,
	hb_face_t *face HB_UNUSED,
	hb_buffer_t *buffer)
	{
	unsigned int i, j;
	unsigned int len = hb_buffer_get_length (buffer);
	hb_internal_glyph_position_t pos = (hb_internal_glyph_position_t ) hb_buffer_get_glyph_positions (buffer);

	/* TODO: Vertical */

	/* Handle cursive connections */
	/* First handle all left-to-right connections */
	for (j = 0; j < len; j++) {
	if (pos[j].cursive_chain > 0)
	{
	pos[j].y_offset += pos[j - pos[j].cursive_chain].y_offset;
	pos[j].cursive_chain = 0;
	}
	}
	/* Then handle all right-to-left connections */
	for (i = len; i > 0; i--) {
	j = i - 1;
	if (pos[j].cursive_chain < 0)
	{
	pos[j].y_offset += pos[j - pos[j].cursive_chain].y_offset;
	pos[j].cursive_chain = 0;
	}
	}

	/* Handle attachments */
	for (i = 0; i < len; i++)
	if (pos[i].back)
	{
	unsigned int back = i - pos[i].back;
	pos[i].back = 0;
	pos[i].x_offset += pos[back].x_offset;
	pos[i].y_offset += pos[back].y_offset;

	if (buffer->direction == HB_DIRECTION_RTL)
	for (j = back + 1; j < i + 1; j++) {
	pos[i].x_offset += pos[j].x_advance;
	pos[i].y_offset += pos[j].y_advance;
	}
	else
	for (j = back; j < i; j++) {
	pos[i].x_offset -= pos[j].x_advance;
	pos[i].y_offset -= pos[j].y_advance;
	}
	}
	}