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+/*
+ * Copyright © 2009,2010 Red Hat, Inc.
+ * Copyright © 2010,2011,2012 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.hh"
+
+#ifndef HB_NO_OT_SHAPE
+
+#ifdef HB_NO_OT_LAYOUT
+#error "Cannot compile 'ot' shaper with HB_NO_OT_LAYOUT."
+#endif
+
+#include "hb-shaper-impl.hh"
+
+#include "hb-ot-shape.hh"
+#include "hb-ot-shaper.hh"
+#include "hb-ot-shape-fallback.hh"
+#include "hb-ot-shape-normalize.hh"
+
+#include "hb-ot-face.hh"
+
+#include "hb-set.hh"
+
+#include "hb-aat-layout.hh"
+
+static inline bool
+_hb_codepoint_is_regional_indicator (hb_codepoint_t u)
+{ return hb_in_range<hb_codepoint_t> (u, 0x1F1E6u, 0x1F1FFu); }
+
+#ifndef HB_NO_AAT_SHAPE
+static inline bool
+_hb_apply_morx (hb_face_t *face, const hb_segment_properties_t &props)
+{
+ /* https://github.com/harfbuzz/harfbuzz/issues/2124 */
+ return hb_aat_layout_has_substitution (face) &&
+ (HB_DIRECTION_IS_HORIZONTAL (props.direction) || !hb_ot_layout_has_substitution (face));
+}
+#endif
+
+/**
+ * SECTION:hb-ot-shape
+ * @title: hb-ot-shape
+ * @short_description: OpenType shaping support
+ * @include: hb-ot.h
+ *
+ * Support functions for OpenType shaping related queries.
+ **/
+
+
+static void
+hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
+ const hb_feature_t *user_features,
+ unsigned int num_user_features);
+
+hb_ot_shape_planner_t::hb_ot_shape_planner_t (hb_face_t *face,
+ const hb_segment_properties_t &props) :
+ face (face),
+ props (props),
+ map (face, props)
+#ifndef HB_NO_AAT_SHAPE
+ , apply_morx (_hb_apply_morx (face, props))
+#endif
+{
+ shaper = hb_ot_shaper_categorize (this);
+
+ script_zero_marks = shaper->zero_width_marks != HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE;
+ script_fallback_mark_positioning = shaper->fallback_position;
+
+#ifndef HB_NO_AAT_SHAPE
+ /* https://github.com/harfbuzz/harfbuzz/issues/1528 */
+ if (apply_morx && shaper != &_hb_ot_shaper_default)
+ shaper = &_hb_ot_shaper_dumber;
+#endif
+}
+
+void
+hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t &plan,
+ const hb_ot_shape_plan_key_t &key)
+{
+ plan.props = props;
+ plan.shaper = shaper;
+ map.compile (plan.map, key);
+
+#ifndef HB_NO_OT_SHAPE_FRACTIONS
+ plan.frac_mask = plan.map.get_1_mask (HB_TAG ('f','r','a','c'));
+ plan.numr_mask = plan.map.get_1_mask (HB_TAG ('n','u','m','r'));
+ plan.dnom_mask = plan.map.get_1_mask (HB_TAG ('d','n','o','m'));
+ plan.has_frac = plan.frac_mask || (plan.numr_mask && plan.dnom_mask);
+#endif
+
+ plan.rtlm_mask = plan.map.get_1_mask (HB_TAG ('r','t','l','m'));
+ plan.has_vert = !!plan.map.get_1_mask (HB_TAG ('v','e','r','t'));
+
+ hb_tag_t kern_tag = HB_DIRECTION_IS_HORIZONTAL (props.direction) ?
+ HB_TAG ('k','e','r','n') : HB_TAG ('v','k','r','n');
+#ifndef HB_NO_OT_KERN
+ plan.kern_mask = plan.map.get_mask (kern_tag);
+ plan.requested_kerning = !!plan.kern_mask;
+#endif
+#ifndef HB_NO_AAT_SHAPE
+ plan.trak_mask = plan.map.get_mask (HB_TAG ('t','r','a','k'));
+ plan.requested_tracking = !!plan.trak_mask;
+#endif
+
+ bool has_gpos_kern = plan.map.get_feature_index (1, kern_tag) != HB_OT_LAYOUT_NO_FEATURE_INDEX;
+ bool disable_gpos = plan.shaper->gpos_tag &&
+ plan.shaper->gpos_tag != plan.map.chosen_script[1];
+
+ /*
+ * Decide who provides glyph classes. GDEF or Unicode.
+ */
+
+ if (!hb_ot_layout_has_glyph_classes (face))
+ plan.fallback_glyph_classes = true;
+
+ /*
+ * Decide who does substitutions. GSUB, morx, or fallback.
+ */
+
+#ifndef HB_NO_AAT_SHAPE
+ plan.apply_morx = apply_morx;
+#endif
+
+ /*
+ * Decide who does positioning. GPOS, kerx, kern, or fallback.
+ */
+
+#ifndef HB_NO_AAT_SHAPE
+ bool has_kerx = hb_aat_layout_has_positioning (face);
+ bool has_gsub = !apply_morx && hb_ot_layout_has_substitution (face);
+#endif
+ bool has_gpos = !disable_gpos && hb_ot_layout_has_positioning (face);
+ if (false)
+ ;
+#ifndef HB_NO_AAT_SHAPE
+ /* Prefer GPOS over kerx if GSUB is present;
+ * https://github.com/harfbuzz/harfbuzz/issues/3008 */
+ else if (has_kerx && !(has_gsub && has_gpos))
+ plan.apply_kerx = true;
+#endif
+ else if (has_gpos)
+ plan.apply_gpos = true;
+
+ if (!plan.apply_kerx && (!has_gpos_kern || !plan.apply_gpos))
+ {
+#ifndef HB_NO_AAT_SHAPE
+ if (has_kerx)
+ plan.apply_kerx = true;
+ else
+#endif
+#ifndef HB_NO_OT_KERN
+ if (hb_ot_layout_has_kerning (face))
+ plan.apply_kern = true;
+#endif
+ }
+
+ plan.apply_fallback_kern = !(plan.apply_gpos || plan.apply_kerx || plan.apply_kern);
+
+ plan.zero_marks = script_zero_marks &&
+ !plan.apply_kerx &&
+ (!plan.apply_kern
+#ifndef HB_NO_OT_KERN
+ || !hb_ot_layout_has_machine_kerning (face)
+#endif
+ );
+ plan.has_gpos_mark = !!plan.map.get_1_mask (HB_TAG ('m','a','r','k'));
+
+ plan.adjust_mark_positioning_when_zeroing = !plan.apply_gpos &&
+ !plan.apply_kerx &&
+ (!plan.apply_kern
+#ifndef HB_NO_OT_KERN
+ || !hb_ot_layout_has_cross_kerning (face)
+#endif
+ );
+
+ plan.fallback_mark_positioning = plan.adjust_mark_positioning_when_zeroing &&
+ script_fallback_mark_positioning;
+
+#ifndef HB_NO_AAT_SHAPE
+ /* If we're using morx shaping, we cancel mark position adjustment because
+ Apple Color Emoji assumes this will NOT be done when forming emoji sequences;
+ https://github.com/harfbuzz/harfbuzz/issues/2967. */
+ if (plan.apply_morx)
+ plan.adjust_mark_positioning_when_zeroing = false;
+
+ /* Currently we always apply trak. */
+ plan.apply_trak = plan.requested_tracking && hb_aat_layout_has_tracking (face);
+#endif
+}
+
+bool
+hb_ot_shape_plan_t::init0 (hb_face_t *face,
+ const hb_shape_plan_key_t *key)
+{
+ map.init ();
+
+ hb_ot_shape_planner_t planner (face,
+ key->props);
+
+ hb_ot_shape_collect_features (&planner,
+ key->user_features,
+ key->num_user_features);
+
+ planner.compile (*this, key->ot);
+
+ if (shaper->data_create)
+ {
+ data = shaper->data_create (this);
+ if (unlikely (!data))
+ {
+ map.fini ();
+ return false;
+ }
+ }
+
+ return true;
+}
+
+void
+hb_ot_shape_plan_t::fini ()
+{
+ if (shaper->data_destroy)
+ shaper->data_destroy (const_cast<void *> (data));
+
+ map.fini ();
+}
+
+void
+hb_ot_shape_plan_t::substitute (hb_font_t *font,
+ hb_buffer_t *buffer) const
+{
+ map.substitute (this, font, buffer);
+}
+
+void
+hb_ot_shape_plan_t::position (hb_font_t *font,
+ hb_buffer_t *buffer) const
+{
+ if (this->apply_gpos)
+ map.position (this, font, buffer);
+#ifndef HB_NO_AAT_SHAPE
+ else if (this->apply_kerx)
+ hb_aat_layout_position (this, font, buffer);
+#endif
+
+#ifndef HB_NO_OT_KERN
+ if (this->apply_kern)
+ hb_ot_layout_kern (this, font, buffer);
+#endif
+ else if (this->apply_fallback_kern)
+ _hb_ot_shape_fallback_kern (this, font, buffer);
+
+#ifndef HB_NO_AAT_SHAPE
+ if (this->apply_trak)
+ hb_aat_layout_track (this, font, buffer);
+#endif
+}
+
+
+static const hb_ot_map_feature_t
+common_features[] =
+{
+ {HB_TAG('a','b','v','m'), F_GLOBAL},
+ {HB_TAG('b','l','w','m'), F_GLOBAL},
+ {HB_TAG('c','c','m','p'), F_GLOBAL},
+ {HB_TAG('l','o','c','l'), F_GLOBAL},
+ {HB_TAG('m','a','r','k'), F_GLOBAL_MANUAL_JOINERS},
+ {HB_TAG('m','k','m','k'), F_GLOBAL_MANUAL_JOINERS},
+ {HB_TAG('r','l','i','g'), F_GLOBAL},
+};
+
+
+static const hb_ot_map_feature_t
+horizontal_features[] =
+{
+ {HB_TAG('c','a','l','t'), F_GLOBAL},
+ {HB_TAG('c','l','i','g'), F_GLOBAL},
+ {HB_TAG('c','u','r','s'), F_GLOBAL},
+ {HB_TAG('d','i','s','t'), F_GLOBAL},
+ {HB_TAG('k','e','r','n'), F_GLOBAL_HAS_FALLBACK},
+ {HB_TAG('l','i','g','a'), F_GLOBAL},
+ {HB_TAG('r','c','l','t'), F_GLOBAL},
+};
+
+static void
+hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
+ const hb_feature_t *user_features,
+ unsigned int num_user_features)
+{
+ hb_ot_map_builder_t *map = &planner->map;
+
+ map->enable_feature (HB_TAG('r','v','r','n'));
+ map->add_gsub_pause (nullptr);
+
+ switch (planner->props.direction)
+ {
+ case HB_DIRECTION_LTR:
+ map->enable_feature (HB_TAG ('l','t','r','a'));
+ map->enable_feature (HB_TAG ('l','t','r','m'));
+ break;
+ case HB_DIRECTION_RTL:
+ map->enable_feature (HB_TAG ('r','t','l','a'));
+ map->add_feature (HB_TAG ('r','t','l','m'));
+ break;
+ case HB_DIRECTION_TTB:
+ case HB_DIRECTION_BTT:
+ case HB_DIRECTION_INVALID:
+ default:
+ break;
+ }
+
+#ifndef HB_NO_OT_SHAPE_FRACTIONS
+ /* Automatic fractions. */
+ map->add_feature (HB_TAG ('f','r','a','c'));
+ map->add_feature (HB_TAG ('n','u','m','r'));
+ map->add_feature (HB_TAG ('d','n','o','m'));
+#endif
+
+ /* Random! */
+ map->enable_feature (HB_TAG ('r','a','n','d'), F_RANDOM, HB_OT_MAP_MAX_VALUE);
+
+#ifndef HB_NO_AAT_SHAPE
+ /* Tracking. We enable dummy feature here just to allow disabling
+ * AAT 'trak' table using features.
+ * https://github.com/harfbuzz/harfbuzz/issues/1303 */
+ map->enable_feature (HB_TAG ('t','r','a','k'), F_HAS_FALLBACK);
+#endif
+
+ map->enable_feature (HB_TAG ('H','a','r','f')); /* Considered required. */
+ map->enable_feature (HB_TAG ('H','A','R','F')); /* Considered discretionary. */
+
+ if (planner->shaper->collect_features)
+ planner->shaper->collect_features (planner);
+
+ map->enable_feature (HB_TAG ('B','u','z','z')); /* Considered required. */
+ map->enable_feature (HB_TAG ('B','U','Z','Z')); /* Considered discretionary. */
+
+ for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
+ map->add_feature (common_features[i]);
+
+ if (HB_DIRECTION_IS_HORIZONTAL (planner->props.direction))
+ for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
+ map->add_feature (horizontal_features[i]);
+ else
+ {
+ /* We only apply `vert` feature. See:
+ * https://github.com/harfbuzz/harfbuzz/commit/d71c0df2d17f4590d5611239577a6cb532c26528
+ * https://lists.freedesktop.org/archives/harfbuzz/2013-August/003490.html */
+
+ /* We really want to find a 'vert' feature if there's any in the font, no
+ * matter which script/langsys it is listed (or not) under.
+ * See various bugs referenced from:
+ * https://github.com/harfbuzz/harfbuzz/issues/63 */
+ map->enable_feature (HB_TAG ('v','e','r','t'), F_GLOBAL_SEARCH);
+ }
+
+ for (unsigned int i = 0; i < num_user_features; i++)
+ {
+ const hb_feature_t *feature = &user_features[i];
+ map->add_feature (feature->tag,
+ (feature->start == HB_FEATURE_GLOBAL_START &&
+ feature->end == HB_FEATURE_GLOBAL_END) ? F_GLOBAL : F_NONE,
+ feature->value);
+ }
+
+ if (planner->shaper->override_features)
+ planner->shaper->override_features (planner);
+}
+
+
+/*
+ * shaper face data
+ */
+
+struct hb_ot_face_data_t {};
+
+hb_ot_face_data_t *
+_hb_ot_shaper_face_data_create (hb_face_t *face)
+{
+ return (hb_ot_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
+}
+
+void
+_hb_ot_shaper_face_data_destroy (hb_ot_face_data_t *data)
+{
+}
+
+
+/*
+ * shaper font data
+ */
+
+struct hb_ot_font_data_t {};
+
+hb_ot_font_data_t *
+_hb_ot_shaper_font_data_create (hb_font_t *font HB_UNUSED)
+{
+ return (hb_ot_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
+}
+
+void
+_hb_ot_shaper_font_data_destroy (hb_ot_font_data_t *data HB_UNUSED)
+{
+}
+
+
+/*
+ * shaper
+ */
+
+struct hb_ot_shape_context_t
+{
+ hb_ot_shape_plan_t *plan;
+ hb_font_t *font;
+ hb_face_t *face;
+ hb_buffer_t *buffer;
+ const hb_feature_t *user_features;
+ unsigned int num_user_features;
+
+ /* Transient stuff */
+ hb_direction_t target_direction;
+};
+
+
+
+/* Main shaper */
+
+
+/* Prepare */
+
+static void
+hb_set_unicode_props (hb_buffer_t *buffer)
+{
+ /* Implement enough of Unicode Graphemes here that shaping
+ * in reverse-direction wouldn't break graphemes. Namely,
+ * we mark all marks and ZWJ and ZWJ,Extended_Pictographic
+ * sequences as continuations. The foreach_grapheme()
+ * macro uses this bit.
+ *
+ * https://www.unicode.org/reports/tr29/#Regex_Definitions
+ */
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ for (unsigned int i = 0; i < count; i++)
+ {
+ _hb_glyph_info_set_unicode_props (&info[i], buffer);
+
+ /* Marks are already set as continuation by the above line.
+ * Handle Emoji_Modifier and ZWJ-continuation. */
+ if (unlikely (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL &&
+ hb_in_range<hb_codepoint_t> (info[i].codepoint, 0x1F3FBu, 0x1F3FFu)))
+ {
+ _hb_glyph_info_set_continuation (&info[i]);
+ }
+ /* Regional_Indicators are hairy as hell...
+ * https://github.com/harfbuzz/harfbuzz/issues/2265 */
+ else if (unlikely (i && _hb_codepoint_is_regional_indicator (info[i].codepoint)))
+ {
+ if (_hb_codepoint_is_regional_indicator (info[i - 1].codepoint) &&
+ !_hb_glyph_info_is_continuation (&info[i - 1]))
+ _hb_glyph_info_set_continuation (&info[i]);
+ }
+#ifndef HB_NO_EMOJI_SEQUENCES
+ else if (unlikely (_hb_glyph_info_is_zwj (&info[i])))
+ {
+ _hb_glyph_info_set_continuation (&info[i]);
+ if (i + 1 < count &&
+ _hb_unicode_is_emoji_Extended_Pictographic (info[i + 1].codepoint))
+ {
+ i++;
+ _hb_glyph_info_set_unicode_props (&info[i], buffer);
+ _hb_glyph_info_set_continuation (&info[i]);
+ }
+ }
+#endif
+ /* Or part of the Other_Grapheme_Extend that is not marks.
+ * As of Unicode 15 that is just:
+ *
+ * 200C ; Other_Grapheme_Extend # Cf ZERO WIDTH NON-JOINER
+ * FF9E..FF9F ; Other_Grapheme_Extend # Lm [2] HALFWIDTH KATAKANA VOICED SOUND MARK..HALFWIDTH KATAKANA SEMI-VOICED SOUND MARK
+ * E0020..E007F ; Other_Grapheme_Extend # Cf [96] TAG SPACE..CANCEL TAG
+ *
+ * ZWNJ is special, we don't want to merge it as there's no need, and keeping
+ * it separate results in more granular clusters.
+ * Tags are used for Emoji sub-region flag sequences:
+ * https://github.com/harfbuzz/harfbuzz/issues/1556
+ * Katakana ones were requested:
+ * https://github.com/harfbuzz/harfbuzz/issues/3844
+ */
+ else if (unlikely (hb_in_ranges<hb_codepoint_t> (info[i].codepoint, 0xFF9Eu, 0xFF9Fu, 0xE0020u, 0xE007Fu)))
+ _hb_glyph_info_set_continuation (&info[i]);
+ }
+}
+
+static void
+hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
+{
+ if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
+ return;
+
+ if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
+ buffer->context_len[0] ||
+ !_hb_glyph_info_is_unicode_mark (&buffer->info[0]))
+ return;
+
+ if (!font->has_glyph (0x25CCu))
+ return;
+
+ hb_glyph_info_t dottedcircle = {0};
+ dottedcircle.codepoint = 0x25CCu;
+ _hb_glyph_info_set_unicode_props (&dottedcircle, buffer);
+
+ buffer->clear_output ();
+
+ buffer->idx = 0;
+ hb_glyph_info_t info = dottedcircle;
+ info.cluster = buffer->cur().cluster;
+ info.mask = buffer->cur().mask;
+ (void) buffer->output_info (info);
+
+ buffer->sync ();
+}
+
+static void
+hb_form_clusters (hb_buffer_t *buffer)
+{
+ if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII))
+ return;
+
+ if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
+ foreach_grapheme (buffer, start, end)
+ buffer->merge_clusters (start, end);
+ else
+ foreach_grapheme (buffer, start, end)
+ buffer->unsafe_to_break (start, end);
+}
+
+static void
+hb_ensure_native_direction (hb_buffer_t *buffer)
+{
+ hb_direction_t direction = buffer->props.direction;
+ hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
+
+ /* Numeric runs in natively-RTL scripts are actually native-LTR, so we reset
+ * the horiz_dir if the run contains at least one decimal-number char, and no
+ * letter chars (ideally we should be checking for chars with strong
+ * directionality but hb-unicode currently lacks bidi categories).
+ *
+ * This allows digit sequences in Arabic etc to be shaped in "native"
+ * direction, so that features like ligatures will work as intended.
+ *
+ * https://github.com/harfbuzz/harfbuzz/issues/501
+ *
+ * Similar thing about Regional_Indicators; They are bidi=L, but Script=Common.
+ * If they are present in a run of natively-RTL text, they get assigned a script
+ * with natively RTL direction, which would result in wrong shaping if we
+ * assign such native RTL direction to them then. Detect that as well.
+ *
+ * https://github.com/harfbuzz/harfbuzz/issues/3314
+ */
+ if (unlikely (horiz_dir == HB_DIRECTION_RTL && direction == HB_DIRECTION_LTR))
+ {
+ bool found_number = false, found_letter = false, found_ri = false;
+ const auto* info = buffer->info;
+ const auto count = buffer->len;
+ for (unsigned i = 0; i < count; i++)
+ {
+ auto gc = _hb_glyph_info_get_general_category (&info[i]);
+ if (gc == HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
+ found_number = true;
+ else if (HB_UNICODE_GENERAL_CATEGORY_IS_LETTER (gc))
+ {
+ found_letter = true;
+ break;
+ }
+ else if (_hb_codepoint_is_regional_indicator (info[i].codepoint))
+ found_ri = true;
+ }
+ if ((found_number || found_ri) && !found_letter)
+ horiz_dir = HB_DIRECTION_LTR;
+ }
+
+ /* TODO vertical:
+ * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
+ * Ogham fonts are supposed to be implemented BTT or not. Need to research that
+ * first. */
+ if ((HB_DIRECTION_IS_HORIZONTAL (direction) &&
+ direction != horiz_dir && horiz_dir != HB_DIRECTION_INVALID) ||
+ (HB_DIRECTION_IS_VERTICAL (direction) &&
+ direction != HB_DIRECTION_TTB))
+ {
+ _hb_ot_layout_reverse_graphemes (buffer);
+ buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
+ }
+}
+
+
+/*
+ * Substitute
+ */
+
+#ifndef HB_NO_VERTICAL
+static hb_codepoint_t
+hb_vert_char_for (hb_codepoint_t u)
+{
+ switch (u >> 8)
+ {
+ case 0x20: switch (u) {
+ case 0x2013u: return 0xfe32u; // EN DASH
+ case 0x2014u: return 0xfe31u; // EM DASH
+ case 0x2025u: return 0xfe30u; // TWO DOT LEADER
+ case 0x2026u: return 0xfe19u; // HORIZONTAL ELLIPSIS
+ } break;
+ case 0x30: switch (u) {
+ case 0x3001u: return 0xfe11u; // IDEOGRAPHIC COMMA
+ case 0x3002u: return 0xfe12u; // IDEOGRAPHIC FULL STOP
+ case 0x3008u: return 0xfe3fu; // LEFT ANGLE BRACKET
+ case 0x3009u: return 0xfe40u; // RIGHT ANGLE BRACKET
+ case 0x300au: return 0xfe3du; // LEFT DOUBLE ANGLE BRACKET
+ case 0x300bu: return 0xfe3eu; // RIGHT DOUBLE ANGLE BRACKET
+ case 0x300cu: return 0xfe41u; // LEFT CORNER BRACKET
+ case 0x300du: return 0xfe42u; // RIGHT CORNER BRACKET
+ case 0x300eu: return 0xfe43u; // LEFT WHITE CORNER BRACKET
+ case 0x300fu: return 0xfe44u; // RIGHT WHITE CORNER BRACKET
+ case 0x3010u: return 0xfe3bu; // LEFT BLACK LENTICULAR BRACKET
+ case 0x3011u: return 0xfe3cu; // RIGHT BLACK LENTICULAR BRACKET
+ case 0x3014u: return 0xfe39u; // LEFT TORTOISE SHELL BRACKET
+ case 0x3015u: return 0xfe3au; // RIGHT TORTOISE SHELL BRACKET
+ case 0x3016u: return 0xfe17u; // LEFT WHITE LENTICULAR BRACKET
+ case 0x3017u: return 0xfe18u; // RIGHT WHITE LENTICULAR BRACKET
+ } break;
+ case 0xfe: switch (u) {
+ case 0xfe4fu: return 0xfe34u; // WAVY LOW LINE
+ } break;
+ case 0xff: switch (u) {
+ case 0xff01u: return 0xfe15u; // FULLWIDTH EXCLAMATION MARK
+ case 0xff08u: return 0xfe35u; // FULLWIDTH LEFT PARENTHESIS
+ case 0xff09u: return 0xfe36u; // FULLWIDTH RIGHT PARENTHESIS
+ case 0xff0cu: return 0xfe10u; // FULLWIDTH COMMA
+ case 0xff1au: return 0xfe13u; // FULLWIDTH COLON
+ case 0xff1bu: return 0xfe14u; // FULLWIDTH SEMICOLON
+ case 0xff1fu: return 0xfe16u; // FULLWIDTH QUESTION MARK
+ case 0xff3bu: return 0xfe47u; // FULLWIDTH LEFT SQUARE BRACKET
+ case 0xff3du: return 0xfe48u; // FULLWIDTH RIGHT SQUARE BRACKET
+ case 0xff3fu: return 0xfe33u; // FULLWIDTH LOW LINE
+ case 0xff5bu: return 0xfe37u; // FULLWIDTH LEFT CURLY BRACKET
+ case 0xff5du: return 0xfe38u; // FULLWIDTH RIGHT CURLY BRACKET
+ } break;
+ }
+
+ return u;
+}
+#endif
+
+static inline void
+hb_ot_rotate_chars (const hb_ot_shape_context_t *c)
+{
+ hb_buffer_t *buffer = c->buffer;
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+
+ if (HB_DIRECTION_IS_BACKWARD (c->target_direction))
+ {
+ hb_unicode_funcs_t *unicode = buffer->unicode;
+ hb_mask_t rtlm_mask = c->plan->rtlm_mask;
+
+ for (unsigned int i = 0; i < count; i++) {
+ hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
+ if (unlikely (codepoint != info[i].codepoint && c->font->has_glyph (codepoint)))
+ info[i].codepoint = codepoint;
+ else
+ info[i].mask |= rtlm_mask;
+ }
+ }
+
+#ifndef HB_NO_VERTICAL
+ if (HB_DIRECTION_IS_VERTICAL (c->target_direction) && !c->plan->has_vert)
+ {
+ for (unsigned int i = 0; i < count; i++) {
+ hb_codepoint_t codepoint = hb_vert_char_for (info[i].codepoint);
+ if (unlikely (codepoint != info[i].codepoint && c->font->has_glyph (codepoint)))
+ info[i].codepoint = codepoint;
+ }
+ }
+#endif
+}
+
+static inline void
+hb_ot_shape_setup_masks_fraction (const hb_ot_shape_context_t *c)
+{
+#ifdef HB_NO_OT_SHAPE_FRACTIONS
+ return;
+#endif
+
+ if (!(c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII) ||
+ !c->plan->has_frac)
+ return;
+
+ hb_buffer_t *buffer = c->buffer;
+
+ hb_mask_t pre_mask, post_mask;
+ if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
+ {
+ pre_mask = c->plan->numr_mask | c->plan->frac_mask;
+ post_mask = c->plan->frac_mask | c->plan->dnom_mask;
+ }
+ else
+ {
+ pre_mask = c->plan->frac_mask | c->plan->dnom_mask;
+ post_mask = c->plan->numr_mask | c->plan->frac_mask;
+ }
+
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ for (unsigned int i = 0; i < count; i++)
+ {
+ if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
+ {
+ unsigned int start = i, end = i + 1;
+ while (start &&
+ _hb_glyph_info_get_general_category (&info[start - 1]) ==
+ HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
+ start--;
+ while (end < count &&
+ _hb_glyph_info_get_general_category (&info[end]) ==
+ HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
+ end++;
+
+ buffer->unsafe_to_break (start, end);
+
+ for (unsigned int j = start; j < i; j++)
+ info[j].mask |= pre_mask;
+ info[i].mask |= c->plan->frac_mask;
+ for (unsigned int j = i + 1; j < end; j++)
+ info[j].mask |= post_mask;
+
+ i = end - 1;
+ }
+ }
+}
+
+static inline void
+hb_ot_shape_initialize_masks (const hb_ot_shape_context_t *c)
+{
+ hb_ot_map_t *map = &c->plan->map;
+ hb_buffer_t *buffer = c->buffer;
+
+ hb_mask_t global_mask = map->get_global_mask ();
+ buffer->reset_masks (global_mask);
+}
+
+static inline void
+hb_ot_shape_setup_masks (const hb_ot_shape_context_t *c)
+{
+ hb_ot_map_t *map = &c->plan->map;
+ hb_buffer_t *buffer = c->buffer;
+
+ hb_ot_shape_setup_masks_fraction (c);
+
+ if (c->plan->shaper->setup_masks)
+ c->plan->shaper->setup_masks (c->plan, buffer, c->font);
+
+ for (unsigned int i = 0; i < c->num_user_features; i++)
+ {
+ const hb_feature_t *feature = &c->user_features[i];
+ if (!(feature->start == HB_FEATURE_GLOBAL_START && feature->end == HB_FEATURE_GLOBAL_END)) {
+ unsigned int shift;
+ hb_mask_t mask = map->get_mask (feature->tag, &shift);
+ buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
+ }
+ }
+}
+
+static void
+hb_ot_zero_width_default_ignorables (const hb_buffer_t *buffer)
+{
+ if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
+ (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) ||
+ (buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES))
+ return;
+
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ hb_glyph_position_t *pos = buffer->pos;
+ unsigned int i = 0;
+ for (i = 0; i < count; i++)
+ if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
+ pos[i].x_advance = pos[i].y_advance = pos[i].x_offset = pos[i].y_offset = 0;
+}
+
+static void
+hb_ot_hide_default_ignorables (hb_buffer_t *buffer,
+ hb_font_t *font)
+{
+ if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
+ (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES))
+ return;
+
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+
+ hb_codepoint_t invisible = buffer->invisible;
+ if (!(buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES) &&
+ (invisible || font->get_nominal_glyph (' ', &invisible)))
+ {
+ /* Replace default-ignorables with a zero-advance invisible glyph. */
+ for (unsigned int i = 0; i < count; i++)
+ {
+ if (_hb_glyph_info_is_default_ignorable (&info[i]))
+ info[i].codepoint = invisible;
+ }
+ }
+ else
+ buffer->delete_glyphs_inplace (_hb_glyph_info_is_default_ignorable);
+}
+
+
+static inline void
+hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
+{
+ /* Normalization process sets up glyph_index(), we just copy it. */
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ for (unsigned int i = 0; i < count; i++)
+ info[i].codepoint = info[i].glyph_index();
+
+ buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
+}
+
+static inline void
+hb_synthesize_glyph_classes (hb_buffer_t *buffer)
+{
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ for (unsigned int i = 0; i < count; i++)
+ {
+ hb_ot_layout_glyph_props_flags_t klass;
+
+ /* Never mark default-ignorables as marks.
+ * They won't get in the way of lookups anyway,
+ * but having them as mark will cause them to be skipped
+ * over if the lookup-flag says so, but at least for the
+ * Mongolian variation selectors, looks like Uniscribe
+ * marks them as non-mark. Some Mongolian fonts without
+ * GDEF rely on this. Another notable character that
+ * this applies to is COMBINING GRAPHEME JOINER. */
+ klass = (_hb_glyph_info_get_general_category (&info[i]) !=
+ HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
+ _hb_glyph_info_is_default_ignorable (&info[i])) ?
+ HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
+ HB_OT_LAYOUT_GLYPH_PROPS_MARK;
+ _hb_glyph_info_set_glyph_props (&info[i], klass);
+ }
+}
+
+static inline void
+hb_ot_substitute_default (const hb_ot_shape_context_t *c)
+{
+ hb_buffer_t *buffer = c->buffer;
+
+ hb_ot_rotate_chars (c);
+
+ HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
+
+ _hb_ot_shape_normalize (c->plan, buffer, c->font);
+
+ hb_ot_shape_setup_masks (c);
+
+ /* This is unfortunate to go here, but necessary... */
+ if (c->plan->fallback_mark_positioning)
+ _hb_ot_shape_fallback_mark_position_recategorize_marks (c->plan, c->font, buffer);
+
+ hb_ot_map_glyphs_fast (buffer);
+
+ HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
+}
+
+static inline void
+hb_ot_substitute_plan (const hb_ot_shape_context_t *c)
+{
+ hb_buffer_t *buffer = c->buffer;
+
+ hb_ot_layout_substitute_start (c->font, buffer);
+
+ if (c->plan->fallback_glyph_classes)
+ hb_synthesize_glyph_classes (c->buffer);
+
+#ifndef HB_NO_AAT_SHAPE
+ if (unlikely (c->plan->apply_morx))
+ hb_aat_layout_substitute (c->plan, c->font, c->buffer,
+ c->user_features, c->num_user_features);
+ else
+#endif
+ c->plan->substitute (c->font, buffer);
+}
+
+static inline void
+hb_ot_substitute_pre (const hb_ot_shape_context_t *c)
+{
+ hb_ot_substitute_default (c);
+
+ _hb_buffer_allocate_gsubgpos_vars (c->buffer);
+
+ hb_ot_substitute_plan (c);
+
+#ifndef HB_NO_AAT_SHAPE
+ if (c->plan->apply_morx && c->plan->apply_gpos)
+ hb_aat_layout_remove_deleted_glyphs (c->buffer);
+#endif
+}
+
+static inline void
+hb_ot_substitute_post (const hb_ot_shape_context_t *c)
+{
+#ifndef HB_NO_AAT_SHAPE
+ if (c->plan->apply_morx && !c->plan->apply_gpos)
+ hb_aat_layout_remove_deleted_glyphs (c->buffer);
+#endif
+
+ hb_ot_hide_default_ignorables (c->buffer, c->font);
+
+ if (c->plan->shaper->postprocess_glyphs &&
+ c->buffer->message(c->font, "start postprocess-glyphs")) {
+ c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
+ (void) c->buffer->message(c->font, "end postprocess-glyphs");
+ }
+}
+
+
+/*
+ * Position
+ */
+
+static inline void
+adjust_mark_offsets (hb_glyph_position_t *pos)
+{
+ pos->x_offset -= pos->x_advance;
+ pos->y_offset -= pos->y_advance;
+}
+
+static inline void
+zero_mark_width (hb_glyph_position_t *pos)
+{
+ pos->x_advance = 0;
+ pos->y_advance = 0;
+}
+
+static inline void
+zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
+{
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ for (unsigned int i = 0; i < count; i++)
+ if (_hb_glyph_info_is_mark (&info[i]))
+ {
+ if (adjust_offsets)
+ adjust_mark_offsets (&buffer->pos[i]);
+ zero_mark_width (&buffer->pos[i]);
+ }
+}
+
+static inline void
+hb_ot_position_default (const hb_ot_shape_context_t *c)
+{
+ hb_direction_t direction = c->buffer->props.direction;
+ unsigned int count = c->buffer->len;
+ hb_glyph_info_t *info = c->buffer->info;
+ hb_glyph_position_t *pos = c->buffer->pos;
+
+ if (HB_DIRECTION_IS_HORIZONTAL (direction))
+ {
+ c->font->get_glyph_h_advances (count, &info[0].codepoint, sizeof(info[0]),
+ &pos[0].x_advance, sizeof(pos[0]));
+ /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
+ if (c->font->has_glyph_h_origin_func ())
+ for (unsigned int i = 0; i < count; i++)
+ c->font->subtract_glyph_h_origin (info[i].codepoint,
+ &pos[i].x_offset,
+ &pos[i].y_offset);
+ }
+ else
+ {
+ c->font->get_glyph_v_advances (count, &info[0].codepoint, sizeof(info[0]),
+ &pos[0].y_advance, sizeof(pos[0]));
+ for (unsigned int i = 0; i < count; i++)
+ {
+ c->font->subtract_glyph_v_origin (info[i].codepoint,
+ &pos[i].x_offset,
+ &pos[i].y_offset);
+ }
+ }
+ if (c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK)
+ _hb_ot_shape_fallback_spaces (c->plan, c->font, c->buffer);
+}
+
+static inline void
+hb_ot_position_plan (const hb_ot_shape_context_t *c)
+{
+ unsigned int count = c->buffer->len;
+ hb_glyph_info_t *info = c->buffer->info;
+ hb_glyph_position_t *pos = c->buffer->pos;
+
+ /* If the font has no GPOS and direction is forward, then when
+ * zeroing mark widths, we shift the mark with it, such that the
+ * mark is positioned hanging over the previous glyph. When
+ * direction is backward we don't shift and it will end up
+ * hanging over the next glyph after the final reordering.
+ *
+ * Note: If fallback positinoing happens, we don't care about
+ * this as it will be overridden.
+ */
+ bool adjust_offsets_when_zeroing = c->plan->adjust_mark_positioning_when_zeroing &&
+ HB_DIRECTION_IS_FORWARD (c->buffer->props.direction);
+
+ /* We change glyph origin to what GPOS expects (horizontal), apply GPOS, change it back. */
+
+ /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
+ if (c->font->has_glyph_h_origin_func ())
+ for (unsigned int i = 0; i < count; i++)
+ c->font->add_glyph_h_origin (info[i].codepoint,
+ &pos[i].x_offset,
+ &pos[i].y_offset);
+
+ hb_ot_layout_position_start (c->font, c->buffer);
+
+ if (c->plan->zero_marks)
+ switch (c->plan->shaper->zero_width_marks)
+ {
+ case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
+ zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
+ break;
+
+ default:
+ case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
+ case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
+ break;
+ }
+
+ c->plan->position (c->font, c->buffer);
+
+ if (c->plan->zero_marks)
+ switch (c->plan->shaper->zero_width_marks)
+ {
+ case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
+ zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
+ break;
+
+ default:
+ case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
+ case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
+ break;
+ }
+
+ /* Finish off. Has to follow a certain order. */
+ hb_ot_layout_position_finish_advances (c->font, c->buffer);
+ hb_ot_zero_width_default_ignorables (c->buffer);
+#ifndef HB_NO_AAT_SHAPE
+ if (c->plan->apply_morx)
+ hb_aat_layout_zero_width_deleted_glyphs (c->buffer);
+#endif
+ hb_ot_layout_position_finish_offsets (c->font, c->buffer);
+
+ /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
+ if (c->font->has_glyph_h_origin_func ())
+ for (unsigned int i = 0; i < count; i++)
+ c->font->subtract_glyph_h_origin (info[i].codepoint,
+ &pos[i].x_offset,
+ &pos[i].y_offset);
+
+ if (c->plan->fallback_mark_positioning)
+ _hb_ot_shape_fallback_mark_position (c->plan, c->font, c->buffer,
+ adjust_offsets_when_zeroing);
+}
+
+static inline void
+hb_ot_position (const hb_ot_shape_context_t *c)
+{
+ c->buffer->clear_positions ();
+
+ hb_ot_position_default (c);
+
+ hb_ot_position_plan (c);
+
+ if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
+ hb_buffer_reverse (c->buffer);
+
+ _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
+}
+
+static inline void
+hb_propagate_flags (hb_buffer_t *buffer)
+{
+ /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
+ * Simplifies using them. */
+
+ if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS))
+ return;
+
+ /* If we are producing SAFE_TO_INSERT_TATWEEL, then do two things:
+ *
+ * - If the places that the Arabic shaper marked as SAFE_TO_INSERT_TATWEEL,
+ * are UNSAFE_TO_BREAK, then clear the SAFE_TO_INSERT_TATWEEL,
+ * - Any place that is SAFE_TO_INSERT_TATWEEL, is also now UNSAFE_TO_BREAK.
+ *
+ * We couldn't make this interaction earlier. It has to be done here.
+ */
+ bool flip_tatweel = buffer->flags & HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL;
+
+ bool clear_concat = (buffer->flags & HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT) == 0;
+
+ hb_glyph_info_t *info = buffer->info;
+
+ foreach_cluster (buffer, start, end)
+ {
+ unsigned int mask = 0;
+ for (unsigned int i = start; i < end; i++)
+ mask |= info[i].mask & HB_GLYPH_FLAG_DEFINED;
+
+ if (flip_tatweel)
+ {
+ if (mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
+ mask &= ~HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL;
+ if (mask & HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL)
+ mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK | HB_GLYPH_FLAG_UNSAFE_TO_CONCAT;
+ }
+
+ if (clear_concat)
+ mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_CONCAT;
+
+ for (unsigned int i = start; i < end; i++)
+ info[i].mask = mask;
+ }
+}
+
+/* Pull it all together! */
+
+static void
+hb_ot_shape_internal (hb_ot_shape_context_t *c)
+{
+ /* Save the original direction, we use it later. */
+ c->target_direction = c->buffer->props.direction;
+
+ _hb_buffer_allocate_unicode_vars (c->buffer);
+
+ hb_ot_shape_initialize_masks (c);
+ hb_set_unicode_props (c->buffer);
+ hb_insert_dotted_circle (c->buffer, c->font);
+
+ hb_form_clusters (c->buffer);
+
+ hb_ensure_native_direction (c->buffer);
+
+ if (c->plan->shaper->preprocess_text &&
+ c->buffer->message(c->font, "start preprocess-text"))
+ {
+ c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
+ (void) c->buffer->message(c->font, "end preprocess-text");
+ }
+
+ hb_ot_substitute_pre (c);
+ hb_ot_position (c);
+ hb_ot_substitute_post (c);
+
+ hb_propagate_flags (c->buffer);
+
+ _hb_buffer_deallocate_unicode_vars (c->buffer);
+
+ c->buffer->props.direction = c->target_direction;
+
+ c->buffer->leave ();
+}
+
+
+hb_bool_t
+_hb_ot_shape (hb_shape_plan_t *shape_plan,
+ hb_font_t *font,
+ hb_buffer_t *buffer,
+ const hb_feature_t *features,
+ unsigned int num_features)
+{
+ hb_ot_shape_context_t c = {&shape_plan->ot, font, font->face, buffer, features, num_features};
+ hb_ot_shape_internal (&c);
+
+ return true;
+}
+
+
+/**
+ * hb_ot_shape_plan_collect_lookups:
+ * @shape_plan: #hb_shape_plan_t to query
+ * @table_tag: GSUB or GPOS
+ * @lookup_indexes: (out): The #hb_set_t set of lookups returned
+ *
+ * Computes the complete set of GSUB or GPOS lookups that are applicable
+ * under a given @shape_plan.
+ *
+ * Since: 0.9.7
+ **/
+void
+hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
+ hb_tag_t table_tag,
+ hb_set_t *lookup_indexes /* OUT */)
+{
+ shape_plan->ot.collect_lookups (table_tag, lookup_indexes);
+}
+
+
+/* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
+static void
+add_char (hb_font_t *font,
+ hb_unicode_funcs_t *unicode,
+ hb_bool_t mirror,
+ hb_codepoint_t u,
+ hb_set_t *glyphs)
+{
+ hb_codepoint_t glyph;
+ if (font->get_nominal_glyph (u, &glyph))
+ glyphs->add (glyph);
+ if (mirror)
+ {
+ hb_codepoint_t m = unicode->mirroring (u);
+ if (m != u && font->get_nominal_glyph (m, &glyph))
+ glyphs->add (glyph);
+ }
+}
+
+
+/**
+ * hb_ot_shape_glyphs_closure:
+ * @font: #hb_font_t to work upon
+ * @buffer: The input buffer to compute from
+ * @features: (array length=num_features): The features enabled on the buffer
+ * @num_features: The number of features enabled on the buffer
+ * @glyphs: (out): The #hb_set_t set of glyphs comprising the transitive closure of the query
+ *
+ * Computes the transitive closure of glyphs needed for a specified
+ * input buffer under the given font and feature list. The closure is
+ * computed as a set, not as a list.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_ot_shape_glyphs_closure (hb_font_t *font,
+ hb_buffer_t *buffer,
+ const hb_feature_t *features,
+ unsigned int num_features,
+ hb_set_t *glyphs)
+{
+ const char *shapers[] = {"ot", nullptr};
+ hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
+ features, num_features, shapers);
+
+ bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
+
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ for (unsigned int i = 0; i < count; i++)
+ add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
+
+ hb_set_t *lookups = hb_set_create ();
+ hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, lookups);
+ hb_ot_layout_lookups_substitute_closure (font->face, lookups, glyphs);
+
+ hb_set_destroy (lookups);
+
+ hb_shape_plan_destroy (shape_plan);
+}
+
+
+#endif