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harfbuzz/src/hb-ot-shape.cc

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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
*/
#define HB_SHAPER ot
#include "hb-shaper-impl.hh"
#include "hb-ot-shape.hh"
#include "hb-ot-shape-complex.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"
/**
* 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);
static bool
_hb_apply_morx (hb_face_t *face)
{
if (hb_options ().aat &&
hb_aat_layout_has_substitution (face))
return true;
return !hb_ot_layout_has_substitution (face) &&
hb_aat_layout_has_substitution (face);
}
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),
aat_map (face, props),
apply_morx (_hb_apply_morx (face)),
shaper (apply_morx ?
&_hb_ot_complex_shaper_default :
hb_ot_shape_complex_categorize (this)) {}
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);
if (apply_morx)
aat_map.compile (plan.aat_map);
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);
plan.rtlm_mask = plan.map.get_1_mask (HB_TAG ('r','t','l','m'));
hb_tag_t kern_tag = HB_DIRECTION_IS_HORIZONTAL (props.direction) ?
HB_TAG ('k','e','r','n') : HB_TAG ('v','k','r','n');
plan.kern_mask = plan.map.get_mask (kern_tag);
plan.trak_mask = plan.map.get_mask (HB_TAG ('t','r','a','k'));
plan.requested_kerning = !!plan.kern_mask;
plan.requested_tracking = !!plan.trak_mask;
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.
*/
plan.apply_morx = apply_morx;
/*
* Decide who does positioning. GPOS, kerx, kern, or fallback.
*/
if (hb_options ().aat && hb_aat_layout_has_positioning (face))
plan.apply_kerx = true;
else if (!disable_gpos && hb_ot_layout_has_positioning (face))
plan.apply_gpos = true;
else if (hb_aat_layout_has_positioning (face))
plan.apply_kerx = true;
if (!plan.apply_kerx && !has_gpos_kern)
{
/* Apparently Apple applies kerx if GPOS kern was not applied. */
if (hb_aat_layout_has_positioning (face))
plan.apply_kerx = true;
else if (hb_ot_layout_has_kerning (face))
plan.apply_kern = true;
}
bool has_kern_mark = plan.apply_kern && hb_ot_layout_has_cross_kerning (face);
plan.zero_marks = !plan.apply_morx && !plan.apply_kerx && !has_kern_mark;
plan.has_gpos_mark = !!plan.map.get_1_mask (HB_TAG ('m','a','r','k'));
plan.fallback_mark_positioning = !plan.apply_gpos && plan.zero_marks;
/* Currently we always apply trak. */
plan.apply_trak = plan.requested_tracking && hb_aat_layout_has_tracking (face);
}
bool
hb_ot_shape_plan_t::init0 (hb_face_t *face,
const hb_shape_plan_key_t *key)
{
map.init ();
aat_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))
return false;
}
return true;
}
void
hb_ot_shape_plan_t::fini (void)
{
if (shaper->data_destroy)
shaper->data_destroy (const_cast<void *> (data));
map.fini ();
aat_map.fini ();
}
static const hb_ot_map_feature_t
common_features[] =
{
{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('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;
}
/* 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'));
/* Random! */
map->enable_feature (HB_TAG ('r','a','n','d'), F_RANDOM, HB_OT_MAP_MAX_VALUE);
/* 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);
map->enable_feature (HB_TAG ('H','A','R','F'));
if (planner->shaper->collect_features)
planner->shaper->collect_features (planner);
map->enable_feature (HB_TAG ('B','U','Z','Z'));
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 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);
}
if (planner->shaper->override_features)
planner->shaper->override_features (planner);
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->apply_morx)
{
hb_aat_map_builder_t *aat_map = &planner->aat_map;
for (unsigned int i = 0; i < num_user_features; i++)
{
const hb_feature_t *feature = &user_features[i];
aat_map->add_feature (feature->tag, feature->value);
}
}
}
/*
* shaper face data
*/
HB_SHAPER_DATA_ENSURE_DEFINE(ot, face);
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
*/
HB_SHAPER_DATA_ENSURE_DEFINE(ot, font);
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]);
}
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]);
}
}
}
}
static void
hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
{
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;
buffer->output_info (info);
while (buffer->idx < buffer->len && buffer->successful)
buffer->next_glyph ();
buffer->swap_buffers ();
}
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);
/* 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))
{
if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
foreach_grapheme (buffer, start, end)
{
buffer->merge_clusters (start, end);
buffer->reverse_range (start, end);
}
else
foreach_grapheme (buffer, start, end)
/* form_clusters() merged clusters already, we don't merge. */
buffer->reverse_range (start, end);
buffer->reverse ();
buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
}
}
/*
* Substitute
*/
static inline void
hb_ot_mirror_chars (const hb_ot_shape_context_t *c)
{
if (HB_DIRECTION_IS_FORWARD (c->target_direction))
return;
hb_buffer_t *buffer = c->buffer;
hb_unicode_funcs_t *unicode = buffer->unicode;
hb_mask_t rtlm_mask = c->plan->rtlm_mask;
unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info;
for (unsigned int i = 0; i < count; i++) {
hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
if (likely (codepoint == info[i].codepoint || !c->font->has_glyph (codepoint)))
info[i].mask |= rtlm_mask;
else
info[i].codepoint = codepoint;
}
}
static inline void
hb_ot_shape_setup_masks_fraction (const hb_ot_shape_context_t *c)
{
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 == 0 && feature->end == (unsigned int)-1)) {
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
hb_ot_layout_delete_glyphs_inplace (buffer, _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_mirror_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_complex (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);
if (unlikely (c->plan->apply_morx))
hb_aat_layout_substitute (c->plan, c->font, c->buffer);
else
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_complex (c);
}
static inline void
hb_ot_substitute_post (const hb_ot_shape_context_t *c)
{
hb_ot_hide_default_ignorables (c->buffer, c->font);
if (c->plan->apply_morx)
hb_aat_layout_remove_deleted_glyphs (c->buffer);
if (c->plan->shaper->postprocess_glyphs)
c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
}
/*
* 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_complex (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, no fallback positioning will
* happen, 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.
* If fallback positinoing happens or GPOS is present, we don't
* care.
*/
bool adjust_offsets_when_zeroing = c->plan->fallback_mark_positioning &&
!c->plan->shaper->fallback_position &&
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;
}
if (c->plan->apply_gpos)
c->plan->position (c->font, c->buffer);
else if (c->plan->apply_kerx)
hb_aat_layout_position (c->plan, c->font, c->buffer);
else if (c->plan->apply_kern)
hb_ot_layout_kern (c->plan, c->font, c->buffer);
else
_hb_ot_shape_fallback_kern (c->plan, c->font, c->buffer);
if (c->plan->apply_trak)
hb_aat_layout_track (c->plan, 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);
if (c->plan->apply_morx)
hb_aat_layout_zero_width_deleted_glyphs (c->buffer);
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 && c->plan->shaper->fallback_position)
_hb_ot_shape_fallback_mark_position (c->plan, c->font, c->buffer);
}
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_complex (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_UNSAFE_TO_BREAK))
return;
hb_glyph_info_t *info = buffer->info;
foreach_cluster (buffer, start, end)
{
unsigned int mask = 0;
for (unsigned int i = start; i < end; i++)
if (info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
{
mask = HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
break;
}
if (mask)
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)
{
c->buffer->deallocate_var_all ();
c->buffer->scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_LEN_FACTOR)))
{
c->buffer->max_len = MAX (c->buffer->len * HB_BUFFER_MAX_LEN_FACTOR,
(unsigned) HB_BUFFER_MAX_LEN_MIN);
}
if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_OPS_FACTOR)))
{
c->buffer->max_ops = MAX (c->buffer->len * HB_BUFFER_MAX_OPS_FACTOR,
(unsigned) HB_BUFFER_MAX_OPS_MIN);
}
/* Save the original direction, we use it later. */
c->target_direction = c->buffer->props.direction;
_hb_buffer_allocate_unicode_vars (c->buffer);
c->buffer->clear_output ();
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->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
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->max_len = HB_BUFFER_MAX_LEN_DEFAULT;
c->buffer->max_ops = HB_BUFFER_MAX_OPS_DEFAULT;
c->buffer->deallocate_var_all ();
}
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:
*
* 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:
*
* 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);
}
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