Add m-esr52 at 52.6.0

1 files changed, 1237 insertions, 0 deletions

diff --git a/gfx/harfbuzz/src/hb-ot-layout.cc b/gfx/harfbuzz/src/hb-ot-layout.cc
new file mode 100644
index 000000000..f5a4988a6
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-ot-layout.cc
@@ -0,0 +1,1237 @@
+/*
+ * 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"
+
+#include "hb-ot-map-private.hh"
+
+#include <stdlib.h>
+#include <string.h>
+
+
+HB_SHAPER_DATA_ENSURE_DECLARE(ot, face)
+
+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);
+
+  /* The MATH table is rarely used, so only try and load it in _get_math. */
+  layout->math_blob = NULL;
+  layout->math = NULL;
+
+  {
+    /*
+     * 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)
+      /* 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)
+      /* 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)
+      /* 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)
+    )
+    {
+      /* 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);
+  hb_blob_destroy (layout->math_blob);
+
+  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 */,
+				  int            *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);
+}
+
+/**
+ * hb_ot_layout_lookup_would_substitute:
+ *
+ * Since: 0.9.7
+ **/
+hb_bool_t
+hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
+				      unsigned int          lookup_index,
+				      const hb_codepoint_t *glyphs,
+				      unsigned int          glyphs_length,
+				      hb_bool_t             zero_context)
+{
+  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return false;
+  return hb_ot_layout_lookup_would_substitute_fast (face, lookup_index, glyphs, glyphs_length, zero_context);
+}
+
+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)
+{
+  if (unlikely (lookup_index >= hb_ot_layout_from_face (face)->gsub_lookup_count)) return false;
+  OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
+
+  const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
+
+  return l.would_apply (&c, &hb_ot_layout_from_face (face)->gsub_accels[lookup_index]);
+}
+
+void
+hb_ot_layout_substitute_start (hb_font_t *font, hb_buffer_t *buffer)
+{
+  OT::GSUB::substitute_start (font, buffer);
+}
+
+/**
+ * hb_ot_layout_lookup_substitute_closure:
+ *
+ * Since: 0.9.7
+ **/
+void
+hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
+				        unsigned int  lookup_index,
+				        hb_set_t     *glyphs)
+{
+  OT::hb_closure_context_t c (face, glyphs);
+
+  const OT::SubstLookup& l = _get_gsub (face).get_lookup (lookup_index);
+
+  l.closure (&c);
+}
+
+/*
+ * OT::GPOS
+ */
+
+hb_bool_t
+hb_ot_layout_has_positioning (hb_face_t *face)
+{
+  return &_get_gpos (face) != &OT::Null(OT::GPOS);
+}
+
+void
+hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
+{
+  OT::GPOS::position_start (font, buffer);
+}
+
+void
+hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
+{
+  OT::GPOS::position_finish_advances (font, buffer);
+}
+
+void
+hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
+{
+  OT::GPOS::position_finish_offsets (font, buffer);
+}
+
+/**
+ * hb_ot_layout_get_size_params:
+ *
+ * Since: 0.9.10
+ **/
+hb_bool_t
+hb_ot_layout_get_size_params (hb_face_t    *face,
+			      unsigned int *design_size,       /* OUT.  May be NULL */
+			      unsigned int *subfamily_id,      /* OUT.  May be NULL */
+			      unsigned int *subfamily_name_id, /* OUT.  May be NULL */
+			      unsigned int *range_start,       /* OUT.  May be NULL */
+			      unsigned int *range_end          /* OUT.  May be NULL */)
+{
+  const OT::GPOS &gpos = _get_gpos (face);
+  const hb_tag_t tag = HB_TAG ('s','i','z','e');
+
+  unsigned int num_features = gpos.get_feature_count ();
+  for (unsigned int i = 0; i < num_features; i++)
+  {
+    if (tag == gpos.get_feature_tag (i))
+    {
+      const OT::Feature &f = gpos.get_feature (i);
+      const OT::FeatureParamsSize &params = f.get_feature_params ().get_size_params (tag);
+
+      if (params.designSize)
+      {
+#define PARAM(a, A) if (a) *a = params.A
+	PARAM (design_size, designSize);
+	PARAM (subfamily_id, subfamilyID);
+	PARAM (subfamily_name_id, subfamilyNameID);
+	PARAM (range_start, rangeStart);
+	PARAM (range_end, rangeEnd);
+#undef PARAM
+
+	return true;
+      }
+    }
+  }
+
+#define PARAM(a, A) if (a) *a = 0
+  PARAM (design_size, designSize);
+  PARAM (subfamily_id, subfamilyID);
+  PARAM (subfamily_name_id, subfamilyNameID);
+  PARAM (range_start, rangeStart);
+  PARAM (range_end, rangeEnd);
+#undef PARAM
+
+  return false;
+}
+
+
+/*
+ * Parts of different types are implemented here such that they have direct
+ * access to GSUB/GPOS lookups.
+ */
+
+
+struct GSUBProxy
+{
+  static const unsigned int table_index = 0;
+  static const bool inplace = false;
+  typedef OT::SubstLookup Lookup;
+
+  GSUBProxy (hb_face_t *face) :
+    table (*hb_ot_layout_from_face (face)->gsub),
+    accels (hb_ot_layout_from_face (face)->gsub_accels) {}
+
+  const OT::GSUB &table;
+  const hb_ot_layout_lookup_accelerator_t *accels;
+};
+
+struct GPOSProxy
+{
+  static const unsigned int table_index = 1;
+  static const bool inplace = true;
+  typedef OT::PosLookup Lookup;
+
+  GPOSProxy (hb_face_t *face) :
+    table (*hb_ot_layout_from_face (face)->gpos),
+    accels (hb_ot_layout_from_face (face)->gpos_accels) {}
+
+  const OT::GPOS &table;
+  const hb_ot_layout_lookup_accelerator_t *accels;
+};
+
+
+struct hb_get_subtables_context_t :
+       OT::hb_dispatch_context_t<hb_get_subtables_context_t, hb_void_t, HB_DEBUG_APPLY>
+{
+  template <typename Type>
+  static inline bool apply_to (const void *obj, OT::hb_apply_context_t *c)
+  {
+    const Type *typed_obj = (const Type *) obj;
+    return typed_obj->apply (c);
+  }
+
+  typedef bool (*hb_apply_func_t) (const void *obj, OT::hb_apply_context_t *c);
+
+  struct hb_applicable_t
+  {
+    inline void init (const void *obj_, hb_apply_func_t apply_func_)
+    {
+      obj = obj_;
+      apply_func = apply_func_;
+    }
+
+    inline bool apply (OT::hb_apply_context_t *c) const { return apply_func (obj, c); }
+
+    private:
+    const void *obj;
+    hb_apply_func_t apply_func;
+  };
+
+  typedef hb_auto_array_t<hb_applicable_t> array_t;
+
+  /* Dispatch interface. */
+  inline const char *get_name (void) { return "GET_SUBTABLES"; }
+  template <typename T>
+  inline return_t dispatch (const T &obj)
+  {
+    hb_applicable_t *entry = array.push();
+    if (likely (entry))
+      entry->init (&obj, apply_to<T>);
+    return HB_VOID;
+  }
+  static return_t default_return_value (void) { return HB_VOID; }
+  bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
+
+  hb_get_subtables_context_t (array_t &array_) :
+			      array (array_),
+			      debug_depth (0) {}
+
+  array_t &array;
+  unsigned int debug_depth;
+};
+
+static inline bool
+apply_forward (OT::hb_apply_context_t *c,
+	       const hb_ot_layout_lookup_accelerator_t &accel,
+	       const hb_get_subtables_context_t::array_t &subtables)
+{
+  bool ret = false;
+  hb_buffer_t *buffer = c->buffer;
+  while (buffer->idx < buffer->len && !buffer->in_error)
+  {
+    bool applied = false;
+    if (accel.may_have (buffer->cur().codepoint) &&
+	(buffer->cur().mask & c->lookup_mask) &&
+	c->check_glyph_property (&buffer->cur(), c->lookup_props))
+     {
+       for (unsigned int i = 0; i < subtables.len; i++)
+         if (subtables[i].apply (c))
+	 {
+	   applied = true;
+	   break;
+	 }
+     }
+
+    if (applied)
+      ret = true;
+    else
+      buffer->next_glyph ();
+  }
+  return ret;
+}
+
+static inline bool
+apply_backward (OT::hb_apply_context_t *c,
+	       const hb_ot_layout_lookup_accelerator_t &accel,
+	       const hb_get_subtables_context_t::array_t &subtables)
+{
+  bool ret = false;
+  hb_buffer_t *buffer = c->buffer;
+  do
+  {
+    if (accel.may_have (buffer->cur().codepoint) &&
+	(buffer->cur().mask & c->lookup_mask) &&
+	c->check_glyph_property (&buffer->cur(), c->lookup_props))
+    {
+     for (unsigned int i = 0; i < subtables.len; i++)
+       if (subtables[i].apply (c))
+       {
+	 ret = true;
+	 break;
+       }
+    }
+    /* The reverse lookup doesn't "advance" cursor (for good reason). */
+    buffer->idx--;
+
+  }
+  while ((int) buffer->idx >= 0);
+  return ret;
+}
+
+template <typename Proxy>
+static inline void
+apply_string (OT::hb_apply_context_t *c,
+	      const typename Proxy::Lookup &lookup,
+	      const hb_ot_layout_lookup_accelerator_t &accel)
+{
+  hb_buffer_t *buffer = c->buffer;
+
+  if (unlikely (!buffer->len || !c->lookup_mask))
+    return;
+
+  c->set_lookup_props (lookup.get_props ());
+
+  hb_get_subtables_context_t::array_t subtables;
+  hb_get_subtables_context_t c_get_subtables (subtables);
+  lookup.dispatch (&c_get_subtables);
+
+  if (likely (!lookup.is_reverse ()))
+  {
+    /* in/out forward substitution/positioning */
+    if (Proxy::table_index == 0)
+      buffer->clear_output ();
+    buffer->idx = 0;
+
+    bool ret;
+    ret = apply_forward (c, accel, subtables);
+    if (ret)
+    {
+      if (!Proxy::inplace)
+	buffer->swap_buffers ();
+      else
+	assert (!buffer->has_separate_output ());
+    }
+  }
+  else
+  {
+    /* in-place backward substitution/positioning */
+    if (Proxy::table_index == 0)
+      buffer->remove_output ();
+    buffer->idx = buffer->len - 1;
+
+    apply_backward (c, accel, subtables);
+  }
+}
+
+template <typename Proxy>
+inline void hb_ot_map_t::apply (const Proxy &proxy,
+				const hb_ot_shape_plan_t *plan,
+				hb_font_t *font,
+				hb_buffer_t *buffer) const
+{
+  const unsigned int table_index = proxy.table_index;
+  unsigned int i = 0;
+  OT::hb_apply_context_t c (table_index, font, buffer);
+  c.set_recurse_func (Proxy::Lookup::apply_recurse_func);
+
+  for (unsigned int stage_index = 0; stage_index < stages[table_index].len; stage_index++) {
+    const stage_map_t *stage = &stages[table_index][stage_index];
+    for (; i < stage->last_lookup; i++)
+    {
+      unsigned int lookup_index = lookups[table_index][i].index;
+      if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
+      c.set_lookup_index (lookup_index);
+      c.set_lookup_mask (lookups[table_index][i].mask);
+      c.set_auto_zwj (lookups[table_index][i].auto_zwj);
+      apply_string<Proxy> (&c,
+			   proxy.table.get_lookup (lookup_index),
+			   proxy.accels[lookup_index]);
+      (void) buffer->message (font, "end lookup %d", lookup_index);
+    }
+
+    if (stage->pause_func)
+    {
+      buffer->clear_output ();
+      stage->pause_func (plan, font, buffer);
+    }
+  }
+}
+
+void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
+{
+  GSUBProxy proxy (font->face);
+  apply (proxy, plan, font, buffer);
+}
+
+void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
+{
+  GPOSProxy proxy (font->face);
+  apply (proxy, plan, font, buffer);
+}
+
+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)
+{
+  apply_string<GSUBProxy> (c, lookup, accel);
+}