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libfontmanager /
harfbuzz /
hb-ot-layout-gsubgpos.hh
/*
* Copyright 漏 2007,2008,2009,2010 Red Hat, Inc.
* Copyright 漏 2010,2012 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
*/
#ifndef HB_OT_LAYOUT_GSUBGPOS_HH
#define HB_OT_LAYOUT_GSUBGPOS_HH
#include "hb.hh"
#include "hb-buffer.hh"
#include "hb-map.hh"
#include "hb-set.hh"
#include "hb-ot-map.hh"
#include "hb-ot-layout-common.hh"
#include "hb-ot-layout-gdef-table.hh"
namespace OT {
struct hb_intersects_context_t :
hb_dispatch_context_t<hb_intersects_context_t, bool, 0>
{
const char *get_name () { return "INTERSECTS"; }
template <typename T>
return_t dispatch (const T &obj) { return obj.intersects (this->glyphs); }
static return_t default_return_value () { return false; }
bool stop_sublookup_iteration (return_t r) const { return r; }
const hb_set_t *glyphs;
unsigned int debug_depth;
hb_intersects_context_t (const hb_set_t *glyphs_) :
glyphs (glyphs_),
debug_depth (0) {}
};
struct hb_closure_context_t :
hb_dispatch_context_t<hb_closure_context_t, hb_void_t, 0>
{
const char *get_name () { return "CLOSURE"; }
typedef return_t (*recurse_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
template <typename T>
return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; }
static return_t default_return_value () { return HB_VOID; }
void recurse (unsigned int lookup_index)
{
if (unlikely (nesting_level_left == 0 || !recurse_func))
return;
nesting_level_left--;
recurse_func (this, lookup_index);
nesting_level_left++;
}
bool should_visit_lookup (unsigned int lookup_index)
{
if (is_lookup_done (lookup_index))
return false;
done_lookups->set (lookup_index, glyphs->get_population ());
return true;
}
bool is_lookup_done (unsigned int lookup_index)
{
/* Have we visited this lookup with the current set of glyphs? */
return done_lookups->get (lookup_index) == glyphs->get_population ();
}
hb_face_t *face;
hb_set_t *glyphs;
hb_set_t out[1];
recurse_func_t recurse_func;
unsigned int nesting_level_left;
unsigned int debug_depth;
hb_closure_context_t (hb_face_t *face_,
hb_set_t *glyphs_,
hb_map_t *done_lookups_,
unsigned int nesting_level_left_ = HB_MAX_NESTING_LEVEL) :
face (face_),
glyphs (glyphs_),
recurse_func (nullptr),
nesting_level_left (nesting_level_left_),
debug_depth (0),
done_lookups (done_lookups_) {}
~hb_closure_context_t () { flush (); }
void set_recurse_func (recurse_func_t func) { recurse_func = func; }
void flush ()
{
hb_set_union (glyphs, out);
hb_set_clear (out);
}
private:
hb_map_t *done_lookups;
};
struct hb_would_apply_context_t :
hb_dispatch_context_t<hb_would_apply_context_t, bool, HB_DEBUG_WOULD_APPLY>
{
const char *get_name () { return "WOULD_APPLY"; }
template <typename T>
return_t dispatch (const T &obj) { return obj.would_apply (this); }
static return_t default_return_value () { return false; }
bool stop_sublookup_iteration (return_t r) const { return r; }
hb_face_t *face;
const hb_codepoint_t *glyphs;
unsigned int len;
bool zero_context;
unsigned int debug_depth;
hb_would_apply_context_t (hb_face_t *face_,
const hb_codepoint_t *glyphs_,
unsigned int len_,
bool zero_context_) :
face (face_),
glyphs (glyphs_),
len (len_),
zero_context (zero_context_),
debug_depth (0) {}
};
struct hb_collect_glyphs_context_t :
hb_dispatch_context_t<hb_collect_glyphs_context_t, hb_void_t, 0>
{
const char *get_name () { return "COLLECT_GLYPHS"; }
typedef return_t (*recurse_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
template <typename T>
return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
static return_t default_return_value () { return HB_VOID; }
void recurse (unsigned int lookup_index)
{
if (unlikely (nesting_level_left == 0 || !recurse_func))
return;
/* Note that GPOS sets recurse_func to nullptr already, so it doesn't get
* past the previous check. For GSUB, we only want to collect the output
* glyphs in the recursion. If output is not requested, we can go home now.
*
* Note further, that the above is not exactly correct. A recursed lookup
* is allowed to match input that is not matched in the context, but that's
* not how most fonts are built. It's possible to relax that and recurse
* with all sets here if it proves to be an issue.
*/
if (output == hb_set_get_empty ())
return;
/* Return if new lookup was recursed to before. */
if (recursed_lookups->has (lookup_index))
return;
hb_set_t *old_before = before;
hb_set_t *old_input = input;
hb_set_t *old_after = after;
before = input = after = hb_set_get_empty ();
nesting_level_left--;
recurse_func (this, lookup_index);
nesting_level_left++;
before = old_before;
input = old_input;
after = old_after;
recursed_lookups->add (lookup_index);
}
hb_face_t *face;
hb_set_t *before;
hb_set_t *input;
hb_set_t *after;
hb_set_t *output;
recurse_func_t recurse_func;
hb_set_t *recursed_lookups;
unsigned int nesting_level_left;
unsigned int debug_depth;
hb_collect_glyphs_context_t (hb_face_t *face_,
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 */
unsigned int nesting_level_left_ = HB_MAX_NESTING_LEVEL) :
face (face_),
before (glyphs_before ? glyphs_before : hb_set_get_empty ()),
input (glyphs_input ? glyphs_input : hb_set_get_empty ()),
after (glyphs_after ? glyphs_after : hb_set_get_empty ()),
output (glyphs_output ? glyphs_output : hb_set_get_empty ()),
recurse_func (nullptr),
recursed_lookups (hb_set_create ()),
nesting_level_left (nesting_level_left_),
debug_depth (0) {}
~hb_collect_glyphs_context_t () { hb_set_destroy (recursed_lookups); }
void set_recurse_func (recurse_func_t func) { recurse_func = func; }
};
template <typename set_t>
struct hb_add_coverage_context_t :
hb_dispatch_context_t<hb_add_coverage_context_t<set_t>, const Coverage &, HB_DEBUG_GET_COVERAGE>
{
const char *get_name () { return "GET_COVERAGE"; }
typedef const Coverage &return_t;
template <typename T>
return_t dispatch (const T &obj) { return obj.get_coverage (); }
static return_t default_return_value () { return Null(Coverage); }
bool stop_sublookup_iteration (return_t r) const
{
r.add_coverage (set);
return false;
}
hb_add_coverage_context_t (set_t *set_) :
set (set_),
debug_depth (0) {}
set_t *set;
unsigned int debug_depth;
};
struct hb_ot_apply_context_t :
hb_dispatch_context_t<hb_ot_apply_context_t, bool, HB_DEBUG_APPLY>
{
struct matcher_t
{
matcher_t () :
lookup_props (0),
ignore_zwnj (false),
ignore_zwj (false),
mask (-1),
#define arg1(arg) (arg) /* Remove the macro to see why it's needed! */
syllable arg1(0),
#undef arg1
match_func (nullptr),
match_data (nullptr) {}
typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data);
void set_ignore_zwnj (bool ignore_zwnj_) { ignore_zwnj = ignore_zwnj_; }
void set_ignore_zwj (bool ignore_zwj_) { ignore_zwj = ignore_zwj_; }
void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
void set_mask (hb_mask_t mask_) { mask = mask_; }
void set_syllable (uint8_t syllable_) { syllable = syllable_; }
void set_match_func (match_func_t match_func_,
const void *match_data_)
{ match_func = match_func_; match_data = match_data_; }
enum may_match_t {
MATCH_NO,
MATCH_YES,
MATCH_MAYBE
};
may_match_t may_match (const hb_glyph_info_t &info,
const HBUINT16 *glyph_data) const
{
if (!(info.mask & mask) ||
(syllable && syllable != info.syllable ()))
return MATCH_NO;
if (match_func)
return match_func (info.codepoint, *glyph_data, match_data) ? MATCH_YES : MATCH_NO;
return MATCH_MAYBE;
}
enum may_skip_t {
SKIP_NO,
SKIP_YES,
SKIP_MAYBE
};
may_skip_t may_skip (const hb_ot_apply_context_t *c,
const hb_glyph_info_t &info) const
{
if (!c->check_glyph_property (&info, lookup_props))
return SKIP_YES;
if (unlikely (_hb_glyph_info_is_default_ignorable_and_not_hidden (&info) &&
(ignore_zwnj || !_hb_glyph_info_is_zwnj (&info)) &&
(ignore_zwj || !_hb_glyph_info_is_zwj (&info))))
return SKIP_MAYBE;
return SKIP_NO;
}
protected:
unsigned int lookup_props;
bool ignore_zwnj;
bool ignore_zwj;
hb_mask_t mask;
uint8_t syllable;
match_func_t match_func;
const void *match_data;
};
struct skipping_iterator_t
{
void init (hb_ot_apply_context_t *c_, bool context_match = false)
{
c = c_;
match_glyph_data = nullptr;
matcher.set_match_func (nullptr, nullptr);
matcher.set_lookup_props (c->lookup_props);
/* Ignore ZWNJ if we are matching GPOS, or matching GSUB context and asked to. */
matcher.set_ignore_zwnj (c->table_index == 1 || (context_match && c->auto_zwnj));
/* Ignore ZWJ if we are matching context, or asked to. */
matcher.set_ignore_zwj (context_match || c->auto_zwj);
matcher.set_mask (context_match ? -1 : c->lookup_mask);
}
void set_lookup_props (unsigned int lookup_props)
{
matcher.set_lookup_props (lookup_props);
}
void set_match_func (matcher_t::match_func_t match_func_,
const void *match_data_,
const HBUINT16 glyph_data[])
{
matcher.set_match_func (match_func_, match_data_);
match_glyph_data = glyph_data;
}
void reset (unsigned int start_index_,
unsigned int num_items_)
{
idx = start_index_;
num_items = num_items_;
end = c->buffer->len;
matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
}
void reject () { num_items++; match_glyph_data--; }
matcher_t::may_skip_t
may_skip (const hb_glyph_info_t &info) const
{ return matcher.may_skip (c, info); }
bool next ()
{
assert (num_items > 0);
while (idx + num_items < end)
{
idx++;
const hb_glyph_info_t &info = c->buffer->info[idx];
matcher_t::may_skip_t skip = matcher.may_skip (c, info);
if (unlikely (skip == matcher_t::SKIP_YES))
continue;
matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
if (match == matcher_t::MATCH_YES ||
(match == matcher_t::MATCH_MAYBE &&
skip == matcher_t::SKIP_NO))
{
num_items--;
match_glyph_data++;
return true;
}
if (skip == matcher_t::SKIP_NO)
return false;
}
return false;
}
bool prev ()
{
assert (num_items > 0);
while (idx > num_items - 1)
{
idx--;
const hb_glyph_info_t &info = c->buffer->out_info[idx];
matcher_t::may_skip_t skip = matcher.may_skip (c, info);
if (unlikely (skip == matcher_t::SKIP_YES))
continue;
matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
if (match == matcher_t::MATCH_YES ||
(match == matcher_t::MATCH_MAYBE &&
skip == matcher_t::SKIP_NO))
{
num_items--;
match_glyph_data++;
return true;
}
if (skip == matcher_t::SKIP_NO)
return false;
}
return false;
}
unsigned int idx;
protected:
hb_ot_apply_context_t *c;
matcher_t matcher;
const HBUINT16 *match_glyph_data;
unsigned int num_items;
unsigned int end;
};
const char *get_name () { return "APPLY"; }
typedef return_t (*recurse_func_t) (hb_ot_apply_context_t *c, unsigned int lookup_index);
template <typename T>
return_t dispatch (const T &obj) { return obj.apply (this); }
static return_t default_return_value () { return false; }
bool stop_sublookup_iteration (return_t r) const { return r; }
return_t recurse (unsigned int sub_lookup_index)
{
if (unlikely (nesting_level_left == 0 || !recurse_func || buffer->max_ops-- <= 0))
return default_return_value ();
nesting_level_left--;
bool ret = recurse_func (this, sub_lookup_index);
nesting_level_left++;
return ret;
}
skipping_iterator_t iter_input, iter_context;
hb_font_t *font;
hb_face_t *face;
hb_buffer_t *buffer;
recurse_func_t recurse_func;
const GDEF &gdef;
const VariationStore &var_store;
hb_direction_t direction;
hb_mask_t lookup_mask;
unsigned int table_index; /* GSUB/GPOS */
unsigned int lookup_index;
unsigned int lookup_props;
unsigned int nesting_level_left;
unsigned int debug_depth;
bool has_glyph_classes;
bool auto_zwnj;
bool auto_zwj;
bool random;
uint32_t random_state;
hb_ot_apply_context_t (unsigned int table_index_,
hb_font_t *font_,
hb_buffer_t *buffer_) :
iter_input (), iter_context (),
font (font_), face (font->face), buffer (buffer_),
recurse_func (nullptr),
gdef (*face->table.GDEF->table),
var_store (gdef.get_var_store ()),
direction (buffer_->props.direction),
lookup_mask (1),
table_index (table_index_),
lookup_index ((unsigned int) -1),
lookup_props (0),
nesting_level_left (HB_MAX_NESTING_LEVEL),
debug_depth (0),
has_glyph_classes (gdef.has_glyph_classes ()),
auto_zwnj (true),
auto_zwj (true),
random (false),
random_state (1) { init_iters (); }
void init_iters ()
{
iter_input.init (this, false);
iter_context.init (this, true);
}
void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; init_iters (); }
void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; init_iters (); }
void set_auto_zwnj (bool auto_zwnj_) { auto_zwnj = auto_zwnj_; init_iters (); }
void set_random (bool random_) { random = random_; }
void set_recurse_func (recurse_func_t func) { recurse_func = func; }
void set_lookup_index (unsigned int lookup_index_) { lookup_index = lookup_index_; }
void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; init_iters (); }
uint32_t random_number ()
{
/* http://www.cplusplus.com/reference/random/minstd_rand/ */
random_state = random_state * 48271 % 2147483647;
return random_state;
}
bool match_properties_mark (hb_codepoint_t glyph,
unsigned int glyph_props,
unsigned int match_props) const
{
/* If using mark filtering sets, the high short of
* match_props has the set index.
*/
if (match_props & LookupFlag::UseMarkFilteringSet)
return gdef.mark_set_covers (match_props >> 16, glyph);
/* The second byte of match_props has the meaning
* "ignore marks of attachment type different than
* the attachment type specified."
*/
if (match_props & LookupFlag::MarkAttachmentType)
return (match_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType);
return true;
}
bool check_glyph_property (const hb_glyph_info_t *info,
unsigned int match_props) const
{
hb_codepoint_t glyph = info->codepoint;
unsigned int glyph_props = _hb_glyph_info_get_glyph_props (info);
/* Not covered, if, for example, glyph class is ligature and
* match_props includes LookupFlags::IgnoreLigatures
*/
if (glyph_props & match_props & LookupFlag::IgnoreFlags)
return false;
if (unlikely (glyph_props & HB_OT_LAYOUT_GLYPH_PROPS_MARK))
return match_properties_mark (glyph, glyph_props, match_props);
return true;
}
void _set_glyph_props (hb_codepoint_t glyph_index,
unsigned int class_guess = 0,
bool ligature = false,
bool component = false) const
{
unsigned int add_in = _hb_glyph_info_get_glyph_props (&buffer->cur()) &
HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE;
add_in |= HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED;
if (ligature)
{
add_in |= HB_OT_LAYOUT_GLYPH_PROPS_LIGATED;
/* In the only place that the MULTIPLIED bit is used, Uniscribe
* seems to only care about the "last" transformation between
* Ligature and Multiple substitutions. Ie. if you ligate, expand,
* and ligate again, it forgives the multiplication and acts as
* if only ligation happened. As such, clear MULTIPLIED bit.
*/
add_in &= ~HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
}
if (component)
add_in |= HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
if (likely (has_glyph_classes))
_hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | gdef.get_glyph_props (glyph_index));
else if (class_guess)
_hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | class_guess);
}
void replace_glyph (hb_codepoint_t glyph_index) const
{
_set_glyph_props (glyph_index);
buffer->replace_glyph (glyph_index);
}
void replace_glyph_inplace (hb_codepoint_t glyph_index) const
{
_set_glyph_props (glyph_index);
buffer->cur().codepoint = glyph_index;
}
void replace_glyph_with_ligature (hb_codepoint_t glyph_index,
unsigned int class_guess) const
{
_set_glyph_props (glyph_index, class_guess, true);
buffer->replace_glyph (glyph_index);
}
void output_glyph_for_component (hb_codepoint_t glyph_index,
unsigned int class_guess) const
{
_set_glyph_props (glyph_index, class_guess, false, true);
buffer->output_glyph (glyph_index);
}
};
struct hb_get_subtables_context_t :
hb_dispatch_context_t<hb_get_subtables_context_t, hb_void_t, HB_DEBUG_APPLY>
{
template <typename Type>
static bool apply_to (const void *obj, OT::hb_ot_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_ot_apply_context_t *c);
struct hb_applicable_t
{
template <typename T>
void init (const T &obj_, hb_apply_func_t apply_func_)
{
obj = &obj_;
apply_func = apply_func_;
digest.init ();
obj_.get_coverage ().add_coverage (&digest);
}
bool apply (OT::hb_ot_apply_context_t *c) const
{
return digest.may_have (c->buffer->cur().codepoint) && apply_func (obj, c);
}
private:
const void *obj;
hb_apply_func_t apply_func;
hb_set_digest_t digest;
};
typedef hb_vector_t<hb_applicable_t> array_t;
/* Dispatch interface. */
const char *get_name () { return "GET_SUBTABLES"; }
template <typename T>
return_t dispatch (const T &obj)
{
hb_applicable_t *entry = array.push();
entry->init (obj, apply_to<T>);
return HB_VOID;
}
static return_t default_return_value () { return HB_VOID; }
hb_get_subtables_context_t (array_t &array_) :
array (array_),
debug_depth (0) {}
array_t &array;
unsigned int debug_depth;
};
typedef bool (*intersects_func_t) (const hb_set_t *glyphs, const HBUINT16 &value, const void *data);
typedef void (*collect_glyphs_func_t) (hb_set_t *glyphs, const HBUINT16 &value, const void *data);
typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data);
struct ContextClosureFuncs
{
intersects_func_t intersects;
};
struct ContextCollectGlyphsFuncs
{
collect_glyphs_func_t collect;
};
struct ContextApplyFuncs
{
match_func_t match;
};
static inline bool intersects_glyph (const hb_set_t *glyphs, const HBUINT16 &value, const void *data HB_UNUSED)
{
return glyphs->has (value);
}
static inline bool intersects_class (const hb_set_t *glyphs, const HBUINT16 &value, const void *data)
{
const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
return class_def.intersects_class (glyphs, value);
}
static inline bool intersects_coverage (const hb_set_t *glyphs, const HBUINT16 &value, const void *data)
{
const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
return (data+coverage).intersects (glyphs);
}
static inline bool intersects_array (const hb_set_t *glyphs,
unsigned int count,
const HBUINT16 values[],
intersects_func_t intersects_func,
const void *intersects_data)
{
for (unsigned int i = 0; i < count; i++)
if (likely (!intersects_func (glyphs, values[i], intersects_data)))
return false;
return true;
}
static inline void collect_glyph (hb_set_t *glyphs, const HBUINT16 &value, const void *data HB_UNUSED)
{
glyphs->add (value);
}
static inline void collect_class (hb_set_t *glyphs, const HBUINT16 &value, const void *data)
{
const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
class_def.add_class (glyphs, value);
}
static inline void collect_coverage (hb_set_t *glyphs, const HBUINT16 &value, const void *data)
{
const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
(data+coverage).add_coverage (glyphs);
}
static inline void collect_array (hb_collect_glyphs_context_t *c HB_UNUSED,
hb_set_t *glyphs,
unsigned int count,
const HBUINT16 values[],
collect_glyphs_func_t collect_func,
const void *collect_data)
{
for (unsigned int i = 0; i < count; i++)
collect_func (glyphs, values[i], collect_data);
}
static inline bool match_glyph (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data HB_UNUSED)
{
return glyph_id == value;
}
static inline bool match_class (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data)
{
const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
return class_def.get_class (glyph_id) == value;
}
static inline bool match_coverage (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data)
{
const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
return (data+coverage).get_coverage (glyph_id) != NOT_COVERED;
}
static inline bool would_match_input (hb_would_apply_context_t *c,
unsigned int count, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
match_func_t match_func,
const void *match_data)
{
if (count != c->len)
return false;
for (unsigned int i = 1; i < count; i++)
if (likely (!match_func (c->glyphs[i], input[i - 1], match_data)))
return false;
return true;
}
static inline bool match_input (hb_ot_apply_context_t *c,
unsigned int count, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
match_func_t match_func,
const void *match_data,
unsigned int *end_offset,
unsigned int match_positions[HB_MAX_CONTEXT_LENGTH],
unsigned int *p_total_component_count = nullptr)
{
TRACE_APPLY (nullptr);
if (unlikely (count > HB_MAX_CONTEXT_LENGTH)) return_trace (false);
hb_buffer_t *buffer = c->buffer;
hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
skippy_iter.reset (buffer->idx, count - 1);
skippy_iter.set_match_func (match_func, match_data, input);
/*
* This is perhaps the trickiest part of OpenType... Remarks:
*
* - If all components of the ligature were marks, we call this a mark ligature.
*
* - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize
* it as a ligature glyph.
*
* - Ligatures cannot be formed across glyphs attached to different components
* of previous ligatures. Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and
* LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother.
* However, it would be wrong to ligate that SHADDA,FATHA sequence.
* There are a couple of exceptions to this:
*
* o If a ligature tries ligating with marks that belong to it itself, go ahead,
* assuming that the font designer knows what they are doing (otherwise it can
* break Indic stuff when a matra wants to ligate with a conjunct,
*
* o If two marks want to ligate and they belong to different components of the
* same ligature glyph, and said ligature glyph is to be ignored according to
* mark-filtering rules, then allow.
* https://github.com/harfbuzz/harfbuzz/issues/545
*/
unsigned int total_component_count = 0;
total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->cur());
unsigned int first_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
unsigned int first_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
enum {
LIGBASE_NOT_CHECKED,
LIGBASE_MAY_NOT_SKIP,
LIGBASE_MAY_SKIP
} ligbase = LIGBASE_NOT_CHECKED;
match_positions[0] = buffer->idx;
for (unsigned int i = 1; i < count; i++)
{
if (!skippy_iter.next ()) return_trace (false);
match_positions[i] = skippy_iter.idx;
unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx]);
unsigned int this_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]);
if (first_lig_id && first_lig_comp)
{
/* If first component was attached to a previous ligature component,
* all subsequent components should be attached to the same ligature
* component, otherwise we shouldn't ligate them... */
if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp)
{
/* ...unless, we are attached to a base ligature and that base
* ligature is ignorable. */
if (ligbase == LIGBASE_NOT_CHECKED)
{
bool found = false;
const hb_glyph_info_t *out = buffer->out_info;
unsigned int j = buffer->out_len;
while (j && _hb_glyph_info_get_lig_id (&out[j - 1]) == first_lig_id)
{
if (_hb_glyph_info_get_lig_comp (&out[j - 1]) == 0)
{
j--;
found = true;
break;
}
j--;
}
if (found && skippy_iter.may_skip (out[j]) == hb_ot_apply_context_t::matcher_t::SKIP_YES)
ligbase = LIGBASE_MAY_SKIP;
else
ligbase = LIGBASE_MAY_NOT_SKIP;
}
if (ligbase == LIGBASE_MAY_NOT_SKIP)
return_trace (false);
}
}
else
{
/* If first component was NOT attached to a previous ligature component,
* all subsequent components should also NOT be attached to any ligature
* component, unless they are attached to the first component itself! */
if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id))
return_trace (false);
}
total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->info[skippy_iter.idx]);
}
*end_offset = skippy_iter.idx - buffer->idx + 1;
if (p_total_component_count)
*p_total_component_count = total_component_count;
return_trace (true);
}
static inline bool ligate_input (hb_ot_apply_context_t *c,
unsigned int count, /* Including the first glyph */
const unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */
unsigned int match_length,
hb_codepoint_t lig_glyph,
unsigned int total_component_count)
{
TRACE_APPLY (nullptr);
hb_buffer_t *buffer = c->buffer;
buffer->merge_clusters (buffer->idx, buffer->idx + match_length);
/* - If a base and one or more marks ligate, consider that as a base, NOT
* ligature, such that all following marks can still attach to it.
* https://github.com/harfbuzz/harfbuzz/issues/1109
*
* - If all components of the ligature were marks, we call this a mark ligature.
* If it *is* a mark ligature, we don't allocate a new ligature id, and leave
* the ligature to keep its old ligature id. This will allow it to attach to
* a base ligature in GPOS. Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH,
* and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA with a
* ligature id and component value of 2. Then if SHADDA,FATHA form a ligature
* later, we don't want them to lose their ligature id/component, otherwise
* GPOS will fail to correctly position the mark ligature on top of the
* LAM,LAM,HEH ligature. See:
* https://bugzilla.gnome.org/show_bug.cgi?id=676343
*
* - If a ligature is formed of components that some of which are also ligatures
* themselves, and those ligature components had marks attached to *their*
* components, we have to attach the marks to the new ligature component
* positions! Now *that*'s tricky! And these marks may be following the
* last component of the whole sequence, so we should loop forward looking
* for them and update them.
*
* Eg. the sequence is LAM,LAM,SHADDA,FATHA,HEH, and the font first forms a
* 'calt' ligature of LAM,HEH, leaving the SHADDA and FATHA with a ligature
* id and component == 1. Now, during 'liga', the LAM and the LAM-HEH ligature
* form a LAM-LAM-HEH ligature. We need to reassign the SHADDA and FATHA to
* the new ligature with a component value of 2.
*
* This in fact happened to a font... See:
* https://bugzilla.gnome.org/show_bug.cgi?id=437633
*/
bool is_base_ligature = _hb_glyph_info_is_base_glyph (&buffer->info[match_positions[0]]);
bool is_mark_ligature = _hb_glyph_info_is_mark (&buffer->info[match_positions[0]]);
for (unsigned int i = 1; i < count; i++)
if (!_hb_glyph_info_is_mark (&buffer->info[match_positions[i]]))
{
is_base_ligature = false;
is_mark_ligature = false;
break;
}
bool is_ligature = !is_base_ligature && !is_mark_ligature;
unsigned int klass = is_ligature ? HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE : 0;
unsigned int lig_id = is_ligature ? _hb_allocate_lig_id (buffer) : 0;
unsigned int last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
unsigned int last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
unsigned int components_so_far = last_num_components;
if (is_ligature)
{
_hb_glyph_info_set_lig_props_for_ligature (&buffer->cur(), lig_id, total_component_count);
if (_hb_glyph_info_get_general_category (&buffer->cur()) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
{
_hb_glyph_info_set_general_category (&buffer->cur(), HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER);
}
}
c->replace_glyph_with_ligature (lig_glyph, klass);
for (unsigned int i = 1; i < count; i++)
{
while (buffer->idx < match_positions[i] && buffer->successful)
{
if (is_ligature)
{
unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
if (this_comp == 0)
this_comp = last_num_components;
unsigned int new_lig_comp = components_so_far - last_num_components +
MIN (this_comp, last_num_components);
_hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp);
}
buffer->next_glyph ();
}
last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
components_so_far += last_num_components;
/* Skip the base glyph */
buffer->idx++;
}
if (!is_mark_ligature && last_lig_id) {
/* Re-adjust components for any marks following. */
for (unsigned int i = buffer->idx; i < buffer->len; i++) {
if (last_lig_id == _hb_glyph_info_get_lig_id (&buffer->info[i])) {
unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->info[i]);
if (!this_comp)
break;
unsigned int new_lig_comp = components_so_far - last_num_components +
MIN (this_comp, last_num_components);
_hb_glyph_info_set_lig_props_for_mark (&buffer->info[i], lig_id, new_lig_comp);
} else
break;
}
}
return_trace (true);
}
static inline bool match_backtrack (hb_ot_apply_context_t *c,
unsigned int count,
const HBUINT16 backtrack[],
match_func_t match_func,
const void *match_data,
unsigned int *match_start)
{
TRACE_APPLY (nullptr);
hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
skippy_iter.reset (c->buffer->backtrack_len (), count);
skippy_iter.set_match_func (match_func, match_data, backtrack);
for (unsigned int i = 0; i < count; i++)
if (!skippy_iter.prev ())
return_trace (false);
*match_start = skippy_iter.idx;
return_trace (true);
}
static inline bool match_lookahead (hb_ot_apply_context_t *c,
unsigned int count,
const HBUINT16 lookahead[],
match_func_t match_func,
const void *match_data,
unsigned int offset,
unsigned int *end_index)
{
TRACE_APPLY (nullptr);
hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
skippy_iter.reset (c->buffer->idx + offset - 1, count);
skippy_iter.set_match_func (match_func, match_data, lookahead);
for (unsigned int i = 0; i < count; i++)
if (!skippy_iter.next ())
return_trace (false);
*end_index = skippy_iter.idx + 1;
return_trace (true);
}
struct LookupRecord
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
HBUINT16 sequenceIndex; /* Index into current glyph
* sequence--first glyph = 0 */
HBUINT16 lookupListIndex; /* Lookup to apply to that
* position--zero--based */
public:
DEFINE_SIZE_STATIC (4);
};
template <typename context_t>
static inline void recurse_lookups (context_t *c,
unsigned int lookupCount,
const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
{
for (unsigned int i = 0; i < lookupCount; i++)
c->recurse (lookupRecord[i].lookupListIndex);
}
static inline bool apply_lookup (hb_ot_apply_context_t *c,
unsigned int count, /* Including the first glyph */
unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */
unsigned int lookupCount,
const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */
unsigned int match_length)
{
TRACE_APPLY (nullptr);
hb_buffer_t *buffer = c->buffer;
int end;
/* All positions are distance from beginning of *output* buffer.
* Adjust. */
{
unsigned int bl = buffer->backtrack_len ();
end = bl + match_length;
int delta = bl - buffer->idx;
/* Convert positions to new indexing. */
for (unsigned int j = 0; j < count; j++)
match_positions[j] += delta;
}
for (unsigned int i = 0; i < lookupCount && buffer->successful; i++)
{
unsigned int idx = lookupRecord[i].sequenceIndex;
if (idx >= count)
continue;
/* Don't recurse to ourself at same position.
* Note that this test is too naive, it doesn't catch longer loops. */
if (idx == 0 && lookupRecord[i].lookupListIndex == c->lookup_index)
continue;
if (unlikely (!buffer->move_to (match_positions[idx])))
break;
if (unlikely (buffer->max_ops <= 0))
break;
unsigned int orig_len = buffer->backtrack_len () + buffer->lookahead_len ();
if (!c->recurse (lookupRecord[i].lookupListIndex))
continue;
unsigned int new_len = buffer->backtrack_len () + buffer->lookahead_len ();
int delta = new_len - orig_len;
if (!delta)
continue;
/* Recursed lookup changed buffer len. Adjust.
*
* TODO:
*
* Right now, if buffer length increased by n, we assume n new glyphs
* were added right after the current position, and if buffer length
* was decreased by n, we assume n match positions after the current
* one where removed. The former (buffer length increased) case is
* fine, but the decrease case can be improved in at least two ways,
* both of which are significant:
*
* - If recursed-to lookup is MultipleSubst and buffer length
* decreased, then it's current match position that was deleted,
* NOT the one after it.
*
* - If buffer length was decreased by n, it does not necessarily
* mean that n match positions where removed, as there might
* have been marks and default-ignorables in the sequence. We
* should instead drop match positions between current-position
* and current-position + n instead.
*
* It should be possible to construct tests for both of these cases.
*/
end += delta;
if (end <= int (match_positions[idx]))
{
/* End might end up being smaller than match_positions[idx] if the recursed
* lookup ended up removing many items, more than we have had matched.
* Just never rewind end back and get out of here.
* https://bugs.chromium.org/p/chromium/issues/detail?id=659496 */
end = match_positions[idx];
/* There can't be any further changes. */
break;
}
unsigned int next = idx + 1; /* next now is the position after the recursed lookup. */
if (delta > 0)
{
if (unlikely (delta + count > HB_MAX_CONTEXT_LENGTH))
break;
}
else
{
/* NOTE: delta is negative. */
delta = MAX (delta, (int) next - (int) count);
next -= delta;
}
/* Shift! */
memmove (match_positions + next + delta, match_positions + next,
(count - next) * sizeof (match_positions[0]));
next += delta;
count += delta;
/* Fill in new entries. */
for (unsigned int j = idx + 1; j < next; j++)
match_positions[j] = match_positions[j - 1] + 1;
/* And fixup the rest. */
for (; next < count; next++)
match_positions[next] += delta;
}
buffer->move_to (end);
return_trace (true);
}
/* Contextual lookups */
struct ContextClosureLookupContext
{
ContextClosureFuncs funcs;
const void *intersects_data;
};
struct ContextCollectGlyphsLookupContext
{
ContextCollectGlyphsFuncs funcs;
const void *collect_data;
};
struct ContextApplyLookupContext
{
ContextApplyFuncs funcs;
const void *match_data;
};
static inline bool context_intersects (const hb_set_t *glyphs,
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
ContextClosureLookupContext &lookup_context)
{
return intersects_array (glyphs,
inputCount ? inputCount - 1 : 0, input,
lookup_context.funcs.intersects, lookup_context.intersects_data);
}
static inline void context_closure_lookup (hb_closure_context_t *c,
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookupCount,
const LookupRecord lookupRecord[],
ContextClosureLookupContext &lookup_context)
{
if (context_intersects (c->glyphs,
inputCount, input,
lookup_context))
recurse_lookups (c,
lookupCount, lookupRecord);
}
static inline void context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookupCount,
const LookupRecord lookupRecord[],
ContextCollectGlyphsLookupContext &lookup_context)
{
collect_array (c, c->input,
inputCount ? inputCount - 1 : 0, input,
lookup_context.funcs.collect, lookup_context.collect_data);
recurse_lookups (c,
lookupCount, lookupRecord);
}
static inline bool context_would_apply_lookup (hb_would_apply_context_t *c,
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookupCount HB_UNUSED,
const LookupRecord lookupRecord[] HB_UNUSED,
ContextApplyLookupContext &lookup_context)
{
return would_match_input (c,
inputCount, input,
lookup_context.funcs.match, lookup_context.match_data);
}
static inline bool context_apply_lookup (hb_ot_apply_context_t *c,
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookupCount,
const LookupRecord lookupRecord[],
ContextApplyLookupContext &lookup_context)
{
unsigned int match_length = 0;
unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
return match_input (c,
inputCount, input,
lookup_context.funcs.match, lookup_context.match_data,
&match_length, match_positions)
&& (c->buffer->unsafe_to_break (c->buffer->idx, c->buffer->idx + match_length),
apply_lookup (c,
inputCount, match_positions,
lookupCount, lookupRecord,
match_length));
}
struct Rule
{
bool intersects (const hb_set_t *glyphs, ContextClosureLookupContext &lookup_context) const
{
return context_intersects (glyphs,
inputCount, inputZ.arrayZ,
lookup_context);
}
void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
{
const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> >
(inputZ.as_array ((inputCount ? inputCount - 1 : 0)));
context_closure_lookup (c,
inputCount, inputZ.arrayZ,
lookupCount, lookupRecord.arrayZ,
lookup_context);
}
void collect_glyphs (hb_collect_glyphs_context_t *c,
ContextCollectGlyphsLookupContext &lookup_context) const
{
const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> >
(inputZ.as_array (inputCount ? inputCount - 1 : 0));
context_collect_glyphs_lookup (c,
inputCount, inputZ.arrayZ,
lookupCount, lookupRecord.arrayZ,
lookup_context);
}
bool would_apply (hb_would_apply_context_t *c,
ContextApplyLookupContext &lookup_context) const
{
TRACE_WOULD_APPLY (this);
const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> >
(inputZ.as_array (inputCount ? inputCount - 1 : 0));
return_trace (context_would_apply_lookup (c, inputCount, inputZ.arrayZ, lookupCount, lookupRecord.arrayZ, lookup_context));
}
bool apply (hb_ot_apply_context_t *c,
ContextApplyLookupContext &lookup_context) const
{
TRACE_APPLY (this);
const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> >
(inputZ.as_array (inputCount ? inputCount - 1 : 0));
return_trace (context_apply_lookup (c, inputCount, inputZ.arrayZ, lookupCount, lookupRecord.arrayZ, lookup_context));
}
public:
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (inputCount.sanitize (c) &&
lookupCount.sanitize (c) &&
c->check_range (inputZ.arrayZ,
inputZ.item_size * (inputCount ? inputCount - 1 : 0) +
LookupRecord::static_size * lookupCount));
}
protected:
HBUINT16 inputCount; /* Total number of glyphs in input
* glyph sequence--includes the first
* glyph */
HBUINT16 lookupCount; /* Number of LookupRecords */
UnsizedArrayOf<HBUINT16>
inputZ; /* Array of match inputs--start with
* second glyph */
/*UnsizedArrayOf<LookupRecord>
lookupRecordX;*/ /* Array of LookupRecords--in
* design order */
public:
DEFINE_SIZE_ARRAY (4, inputZ);
};
struct RuleSet
{
bool intersects (const hb_set_t *glyphs,
ContextClosureLookupContext &lookup_context) const
{
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
if ((this+rule[i]).intersects (glyphs, lookup_context))
return true;
return false;
}
void closure (hb_closure_context_t *c,
ContextClosureLookupContext &lookup_context) const
{
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
(this+rule[i]).closure (c, lookup_context);
}
void collect_glyphs (hb_collect_glyphs_context_t *c,
ContextCollectGlyphsLookupContext &lookup_context) const
{
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
(this+rule[i]).collect_glyphs (c, lookup_context);
}
bool would_apply (hb_would_apply_context_t *c,
ContextApplyLookupContext &lookup_context) const
{
TRACE_WOULD_APPLY (this);
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
{
if ((this+rule[i]).would_apply (c, lookup_context))
return_trace (true);
}
return_trace (false);
}
bool apply (hb_ot_apply_context_t *c,
ContextApplyLookupContext &lookup_context) const
{
TRACE_APPLY (this);
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
{
if ((this+rule[i]).apply (c, lookup_context))
return_trace (true);
}
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (rule.sanitize (c, this));
}
protected:
OffsetArrayOf<Rule>
rule; /* Array of Rule tables
* ordered by preference */
public:
DEFINE_SIZE_ARRAY (2, rule);
};
struct ContextFormat1
{
bool intersects (const hb_set_t *glyphs) const
{
struct ContextClosureLookupContext lookup_context = {
{intersects_glyph},
nullptr
};
unsigned int count = ruleSet.len;
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
if (unlikely (iter.get_coverage () >= count))
break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */
if (glyphs->has (iter.get_glyph ()) &&
(this+ruleSet[iter.get_coverage ()]).intersects (glyphs, lookup_context))
return true;
}
return false;
}
void closure (hb_closure_context_t *c) const
{
struct ContextClosureLookupContext lookup_context = {
{intersects_glyph},
nullptr
};
unsigned int count = ruleSet.len;
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
if (unlikely (iter.get_coverage () >= count))
break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */
if (c->glyphs->has (iter.get_glyph ()))
(this+ruleSet[iter.get_coverage ()]).closure (c, lookup_context);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
(this+coverage).add_coverage (c->input);
struct ContextCollectGlyphsLookupContext lookup_context = {
{collect_glyph},
nullptr
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
(this+ruleSet[i]).collect_glyphs (c, lookup_context);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
const RuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
struct ContextApplyLookupContext lookup_context = {
{match_glyph},
nullptr
};
return_trace (rule_set.would_apply (c, lookup_context));
}
const Coverage &get_coverage () const { return this+coverage; }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
if (likely (index == NOT_COVERED))
return_trace (false);
const RuleSet &rule_set = this+ruleSet[index];
struct ContextApplyLookupContext lookup_context = {
{match_glyph},
nullptr
};
return_trace (rule_set.apply (c, lookup_context));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
// TODO(subset)
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
}
protected:
HBUINT16 format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of table */
OffsetArrayOf<RuleSet>
ruleSet; /* Array of RuleSet tables
* ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (6, ruleSet);
};
struct ContextFormat2
{
bool intersects (const hb_set_t *glyphs) const
{
if (!(this+coverage).intersects (glyphs))
return false;
const ClassDef &class_def = this+classDef;
struct ContextClosureLookupContext lookup_context = {
{intersects_class},
&class_def
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
if (class_def.intersects_class (glyphs, i) &&
(this+ruleSet[i]).intersects (glyphs, lookup_context))
return true;
return false;
}
void closure (hb_closure_context_t *c) const
{
if (!(this+coverage).intersects (c->glyphs))
return;
const ClassDef &class_def = this+classDef;
struct ContextClosureLookupContext lookup_context = {
{intersects_class},
&class_def
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
if (class_def.intersects_class (c->glyphs, i)) {
const RuleSet &rule_set = this+ruleSet[i];
rule_set.closure (c, lookup_context);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
(this+coverage).add_coverage (c->input);
const ClassDef &class_def = this+classDef;
struct ContextCollectGlyphsLookupContext lookup_context = {
{collect_class},
&class_def
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
(this+ruleSet[i]).collect_glyphs (c, lookup_context);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
const ClassDef &class_def = this+classDef;
unsigned int index = class_def.get_class (c->glyphs[0]);
const RuleSet &rule_set = this+ruleSet[index];
struct ContextApplyLookupContext lookup_context = {
{match_class},
&class_def
};
return_trace (rule_set.would_apply (c, lookup_context));
}
const Coverage &get_coverage () const { return this+coverage; }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return_trace (false);
const ClassDef &class_def = this+classDef;
index = class_def.get_class (c->buffer->cur().codepoint);
const RuleSet &rule_set = this+ruleSet[index];
struct ContextApplyLookupContext lookup_context = {
{match_class},
&class_def
};
return_trace (rule_set.apply (c, lookup_context));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
// TODO(subset)
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this));
}
protected:
HBUINT16 format; /* Format identifier--format = 2 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of table */
OffsetTo<ClassDef>
classDef; /* Offset to glyph ClassDef table--from
* beginning of table */
OffsetArrayOf<RuleSet>
ruleSet; /* Array of RuleSet tables
* ordered by class */
public:
DEFINE_SIZE_ARRAY (8, ruleSet);
};
struct ContextFormat3
{
bool intersects (const hb_set_t *glyphs) const
{
if (!(this+coverageZ[0]).intersects (glyphs))
return false;
struct ContextClosureLookupContext lookup_context = {
{intersects_coverage},
this
};
return context_intersects (glyphs,
glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1),
lookup_context);
}
void closure (hb_closure_context_t *c) const
{
if (!(this+coverageZ[0]).intersects (c->glyphs))
return;
const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount));
struct ContextClosureLookupContext lookup_context = {
{intersects_coverage},
this
};
context_closure_lookup (c,
glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1),
lookupCount, lookupRecord,
lookup_context);
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
(this+coverageZ[0]).add_coverage (c->input);
const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount));
struct ContextCollectGlyphsLookupContext lookup_context = {
{collect_coverage},
this
};
context_collect_glyphs_lookup (c,
glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1),
lookupCount, lookupRecord,
lookup_context);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount));
struct ContextApplyLookupContext lookup_context = {
{match_coverage},
this
};
return_trace (context_would_apply_lookup (c, glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1), lookupCount, lookupRecord, lookup_context));
}
const Coverage &get_coverage () const { return this+coverageZ[0]; }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return_trace (false);
const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount));
struct ContextApplyLookupContext lookup_context = {
{match_coverage},
this
};
return_trace (context_apply_lookup (c, glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1), lookupCount, lookupRecord, lookup_context));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
// TODO(subset)
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!c->check_struct (this)) return_trace (false);
unsigned int count = glyphCount;
if (!count) return_trace (false); /* We want to access coverageZ[0] freely. */
if (!c->check_array (coverageZ.arrayZ, count)) return_trace (false);
for (unsigned int i = 0; i < count; i++)
if (!coverageZ[i].sanitize (c, this)) return_trace (false);
const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount));
return_trace (c->check_array (lookupRecord, lookupCount));
}
protected:
HBUINT16 format; /* Format identifier--format = 3 */
HBUINT16 glyphCount; /* Number of glyphs in the input glyph
* sequence */
HBUINT16 lookupCount; /* Number of LookupRecords */
UnsizedArrayOf<OffsetTo<Coverage> >
coverageZ; /* Array of offsets to Coverage
* table in glyph sequence order */
/*UnsizedArrayOf<LookupRecord>
lookupRecordX;*/ /* Array of LookupRecords--in
* design order */
public:
DEFINE_SIZE_ARRAY (6, coverageZ);
};
struct Context
{
template <typename context_t>
typename context_t::return_t dispatch (context_t *c) const
{
TRACE_DISPATCH (this, u.format);
if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
switch (u.format) {
case 1: return_trace (c->dispatch (u.format1));
case 2: return_trace (c->dispatch (u.format2));
case 3: return_trace (c->dispatch (u.format3));
default:return_trace (c->default_return_value ());
}
}
protected:
union {
HBUINT16 format; /* Format identifier */
ContextFormat1 format1;
ContextFormat2 format2;
ContextFormat3 format3;
} u;
};
/* Chaining Contextual lookups */
struct ChainContextClosureLookupContext
{
ContextClosureFuncs funcs;
const void *intersects_data[3];
};
struct ChainContextCollectGlyphsLookupContext
{
ContextCollectGlyphsFuncs funcs;
const void *collect_data[3];
};
struct ChainContextApplyLookupContext
{
ContextApplyFuncs funcs;
const void *match_data[3];
};
static inline bool chain_context_intersects (const hb_set_t *glyphs,
unsigned int backtrackCount,
const HBUINT16 backtrack[],
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookaheadCount,
const HBUINT16 lookahead[],
ChainContextClosureLookupContext &lookup_context)
{
return intersects_array (glyphs,
backtrackCount, backtrack,
lookup_context.funcs.intersects, lookup_context.intersects_data[0])
&& intersects_array (glyphs,
inputCount ? inputCount - 1 : 0, input,
lookup_context.funcs.intersects, lookup_context.intersects_data[1])
&& intersects_array (glyphs,
lookaheadCount, lookahead,
lookup_context.funcs.intersects, lookup_context.intersects_data[2]);
}
static inline void chain_context_closure_lookup (hb_closure_context_t *c,
unsigned int backtrackCount,
const HBUINT16 backtrack[],
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookaheadCount,
const HBUINT16 lookahead[],
unsigned int lookupCount,
const LookupRecord lookupRecord[],
ChainContextClosureLookupContext &lookup_context)
{
if (chain_context_intersects (c->glyphs,
backtrackCount, backtrack,
inputCount, input,
lookaheadCount, lookahead,
lookup_context))
recurse_lookups (c,
lookupCount, lookupRecord);
}
static inline void chain_context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
unsigned int backtrackCount,
const HBUINT16 backtrack[],
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookaheadCount,
const HBUINT16 lookahead[],
unsigned int lookupCount,
const LookupRecord lookupRecord[],
ChainContextCollectGlyphsLookupContext &lookup_context)
{
collect_array (c, c->before,
backtrackCount, backtrack,
lookup_context.funcs.collect, lookup_context.collect_data[0]);
collect_array (c, c->input,
inputCount ? inputCount - 1 : 0, input,
lookup_context.funcs.collect, lookup_context.collect_data[1]);
collect_array (c, c->after,
lookaheadCount, lookahead,
lookup_context.funcs.collect, lookup_context.collect_data[2]);
recurse_lookups (c,
lookupCount, lookupRecord);
}
static inline bool chain_context_would_apply_lookup (hb_would_apply_context_t *c,
unsigned int backtrackCount,
const HBUINT16 backtrack[] HB_UNUSED,
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookaheadCount,
const HBUINT16 lookahead[] HB_UNUSED,
unsigned int lookupCount HB_UNUSED,
const LookupRecord lookupRecord[] HB_UNUSED,
ChainContextApplyLookupContext &lookup_context)
{
return (c->zero_context ? !backtrackCount && !lookaheadCount : true)
&& would_match_input (c,
inputCount, input,
lookup_context.funcs.match, lookup_context.match_data[1]);
}
static inline bool chain_context_apply_lookup (hb_ot_apply_context_t *c,
unsigned int backtrackCount,
const HBUINT16 backtrack[],
unsigned int inputCount, /* Including the first glyph (not matched) */
const HBUINT16 input[], /* Array of input values--start with second glyph */
unsigned int lookaheadCount,
const HBUINT16 lookahead[],
unsigned int lookupCount,
const LookupRecord lookupRecord[],
ChainContextApplyLookupContext &lookup_context)
{
unsigned int start_index = 0, match_length = 0, end_index = 0;
unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
return match_input (c,
inputCount, input,
lookup_context.funcs.match, lookup_context.match_data[1],
&match_length, match_positions)
&& match_backtrack (c,
backtrackCount, backtrack,
lookup_context.funcs.match, lookup_context.match_data[0],
&start_index)
&& match_lookahead (c,
lookaheadCount, lookahead,
lookup_context.funcs.match, lookup_context.match_data[2],
match_length, &end_index)
&& (c->buffer->unsafe_to_break_from_outbuffer (start_index, end_index),
apply_lookup (c,
inputCount, match_positions,
lookupCount, lookupRecord,
match_length));
}
struct ChainRule
{
bool intersects (const hb_set_t *glyphs, ChainContextClosureLookupContext &lookup_context) const
{
const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack);
const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input);
return chain_context_intersects (glyphs,
backtrack.len, backtrack.arrayZ,
input.lenP1, input.arrayZ,
lookahead.len, lookahead.arrayZ,
lookup_context);
}
void closure (hb_closure_context_t *c,
ChainContextClosureLookupContext &lookup_context) const
{
const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack);
const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
chain_context_closure_lookup (c,
backtrack.len, backtrack.arrayZ,
input.lenP1, input.arrayZ,
lookahead.len, lookahead.arrayZ,
lookup.len, lookup.arrayZ,
lookup_context);
}
void collect_glyphs (hb_collect_glyphs_context_t *c,
ChainContextCollectGlyphsLookupContext &lookup_context) const
{
const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack);
const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
chain_context_collect_glyphs_lookup (c,
backtrack.len, backtrack.arrayZ,
input.lenP1, input.arrayZ,
lookahead.len, lookahead.arrayZ,
lookup.len, lookup.arrayZ,
lookup_context);
}
bool would_apply (hb_would_apply_context_t *c,
ChainContextApplyLookupContext &lookup_context) const
{
TRACE_WOULD_APPLY (this);
const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack);
const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
return_trace (chain_context_would_apply_lookup (c,
backtrack.len, backtrack.arrayZ,
input.lenP1, input.arrayZ,
lookahead.len, lookahead.arrayZ, lookup.len,
lookup.arrayZ, lookup_context));
}
bool apply (hb_ot_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
{
TRACE_APPLY (this);
const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack);
const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
return_trace (chain_context_apply_lookup (c,
backtrack.len, backtrack.arrayZ,
input.lenP1, input.arrayZ,
lookahead.len, lookahead.arrayZ, lookup.len,
lookup.arrayZ, lookup_context));
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!backtrack.sanitize (c)) return_trace (false);
const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack);
if (!input.sanitize (c)) return_trace (false);
const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input);
if (!lookahead.sanitize (c)) return_trace (false);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
return_trace (lookup.sanitize (c));
}
protected:
ArrayOf<HBUINT16>
backtrack; /* Array of backtracking values
* (to be matched before the input
* sequence) */
HeadlessArrayOf<HBUINT16>
inputX; /* Array of input values (start with
* second glyph) */
ArrayOf<HBUINT16>
lookaheadX; /* Array of lookahead values's (to be
* matched after the input sequence) */
ArrayOf<LookupRecord>
lookupX; /* Array of LookupRecords--in
* design order) */
public:
DEFINE_SIZE_MIN (8);
};
struct ChainRuleSet
{
bool intersects (const hb_set_t *glyphs, ChainContextClosureLookupContext &lookup_context) const
{
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
if ((this+rule[i]).intersects (glyphs, lookup_context))
return true;
return false;
}
void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
{
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
(this+rule[i]).closure (c, lookup_context);
}
void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
{
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
(this+rule[i]).collect_glyphs (c, lookup_context);
}
bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
{
TRACE_WOULD_APPLY (this);
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
if ((this+rule[i]).would_apply (c, lookup_context))
return_trace (true);
return_trace (false);
}
bool apply (hb_ot_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
{
TRACE_APPLY (this);
unsigned int num_rules = rule.len;
for (unsigned int i = 0; i < num_rules; i++)
if ((this+rule[i]).apply (c, lookup_context))
return_trace (true);
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (rule.sanitize (c, this));
}
protected:
OffsetArrayOf<ChainRule>
rule; /* Array of ChainRule tables
* ordered by preference */
public:
DEFINE_SIZE_ARRAY (2, rule);
};
struct ChainContextFormat1
{
bool intersects (const hb_set_t *glyphs) const
{
struct ChainContextClosureLookupContext lookup_context = {
{intersects_glyph},
{nullptr, nullptr, nullptr}
};
unsigned int count = ruleSet.len;
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
if (unlikely (iter.get_coverage () >= count))
break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */
if (glyphs->has (iter.get_glyph ()) &&
(this+ruleSet[iter.get_coverage ()]).intersects (glyphs, lookup_context))
return true;
}
return false;
}
void closure (hb_closure_context_t *c) const
{
struct ChainContextClosureLookupContext lookup_context = {
{intersects_glyph},
{nullptr, nullptr, nullptr}
};
unsigned int count = ruleSet.len;
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
if (unlikely (iter.get_coverage () >= count))
break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */
if (c->glyphs->has (iter.get_glyph ()))
(this+ruleSet[iter.get_coverage ()]).closure (c, lookup_context);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
(this+coverage).add_coverage (c->input);
struct ChainContextCollectGlyphsLookupContext lookup_context = {
{collect_glyph},
{nullptr, nullptr, nullptr}
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
(this+ruleSet[i]).collect_glyphs (c, lookup_context);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
const ChainRuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
struct ChainContextApplyLookupContext lookup_context = {
{match_glyph},
{nullptr, nullptr, nullptr}
};
return_trace (rule_set.would_apply (c, lookup_context));
}
const Coverage &get_coverage () const { return this+coverage; }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return_trace (false);
const ChainRuleSet &rule_set = this+ruleSet[index];
struct ChainContextApplyLookupContext lookup_context = {
{match_glyph},
{nullptr, nullptr, nullptr}
};
return_trace (rule_set.apply (c, lookup_context));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
// TODO(subset)
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
}
protected:
HBUINT16 format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of table */
OffsetArrayOf<ChainRuleSet>
ruleSet; /* Array of ChainRuleSet tables
* ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (6, ruleSet);
};
struct ChainContextFormat2
{
bool intersects (const hb_set_t *glyphs) const
{
if (!(this+coverage).intersects (glyphs))
return false;
const ClassDef &backtrack_class_def = this+backtrackClassDef;
const ClassDef &input_class_def = this+inputClassDef;
const ClassDef &lookahead_class_def = this+lookaheadClassDef;
struct ChainContextClosureLookupContext lookup_context = {
{intersects_class},
{&backtrack_class_def,
&input_class_def,
&lookahead_class_def}
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
if (input_class_def.intersects_class (glyphs, i) &&
(this+ruleSet[i]).intersects (glyphs, lookup_context))
return true;
return false;
}
void closure (hb_closure_context_t *c) const
{
if (!(this+coverage).intersects (c->glyphs))
return;
const ClassDef &backtrack_class_def = this+backtrackClassDef;
const ClassDef &input_class_def = this+inputClassDef;
const ClassDef &lookahead_class_def = this+lookaheadClassDef;
struct ChainContextClosureLookupContext lookup_context = {
{intersects_class},
{&backtrack_class_def,
&input_class_def,
&lookahead_class_def}
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
if (input_class_def.intersects_class (c->glyphs, i)) {
const ChainRuleSet &rule_set = this+ruleSet[i];
rule_set.closure (c, lookup_context);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
(this+coverage).add_coverage (c->input);
const ClassDef &backtrack_class_def = this+backtrackClassDef;
const ClassDef &input_class_def = this+inputClassDef;
const ClassDef &lookahead_class_def = this+lookaheadClassDef;
struct ChainContextCollectGlyphsLookupContext lookup_context = {
{collect_class},
{&backtrack_class_def,
&input_class_def,
&lookahead_class_def}
};
unsigned int count = ruleSet.len;
for (unsigned int i = 0; i < count; i++)
(this+ruleSet[i]).collect_glyphs (c, lookup_context);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
const ClassDef &backtrack_class_def = this+backtrackClassDef;
const ClassDef &input_class_def = this+inputClassDef;
const ClassDef &lookahead_class_def = this+lookaheadClassDef;
unsigned int index = input_class_def.get_class (c->glyphs[0]);
const ChainRuleSet &rule_set = this+ruleSet[index];
struct ChainContextApplyLookupContext lookup_context = {
{match_class},
{&backtrack_class_def,
&input_class_def,
&lookahead_class_def}
};
return_trace (rule_set.would_apply (c, lookup_context));
}
const Coverage &get_coverage () const { return this+coverage; }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return_trace (false);
const ClassDef &backtrack_class_def = this+backtrackClassDef;
const ClassDef &input_class_def = this+inputClassDef;
const ClassDef &lookahead_class_def = this+lookaheadClassDef;
index = input_class_def.get_class (c->buffer->cur().codepoint);
const ChainRuleSet &rule_set = this+ruleSet[index];
struct ChainContextApplyLookupContext lookup_context = {
{match_class},
{&backtrack_class_def,
&input_class_def,
&lookahead_class_def}
};
return_trace (rule_set.apply (c, lookup_context));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
// TODO(subset)
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (coverage.sanitize (c, this) &&
backtrackClassDef.sanitize (c, this) &&
inputClassDef.sanitize (c, this) &&
lookaheadClassDef.sanitize (c, this) &&
ruleSet.sanitize (c, this));
}
protected:
HBUINT16 format; /* Format identifier--format = 2 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of table */
OffsetTo<ClassDef>
backtrackClassDef; /* Offset to glyph ClassDef table
* containing backtrack sequence
* data--from beginning of table */
OffsetTo<ClassDef>
inputClassDef; /* Offset to glyph ClassDef
* table containing input sequence
* data--from beginning of table */
OffsetTo<ClassDef>
lookaheadClassDef; /* Offset to glyph ClassDef table
* containing lookahead sequence
* data--from beginning of table */
OffsetArrayOf<ChainRuleSet>
ruleSet; /* Array of ChainRuleSet tables
* ordered by class */
public:
DEFINE_SIZE_ARRAY (12, ruleSet);
};
struct ChainContextFormat3
{
bool intersects (const hb_set_t *glyphs) const
{
const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
if (!(this+input[0]).intersects (glyphs))
return false;
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
struct ChainContextClosureLookupContext lookup_context = {
{intersects_coverage},
{this, this, this}
};
return chain_context_intersects (glyphs,
backtrack.len, (const HBUINT16 *) backtrack.arrayZ,
input.len, (const HBUINT16 *) input.arrayZ + 1,
lookahead.len, (const HBUINT16 *) lookahead.arrayZ,
lookup_context);
}
void closure (hb_closure_context_t *c) const
{
const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
if (!(this+input[0]).intersects (c->glyphs))
return;
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
struct ChainContextClosureLookupContext lookup_context = {
{intersects_coverage},
{this, this, this}
};
chain_context_closure_lookup (c,
backtrack.len, (const HBUINT16 *) backtrack.arrayZ,
input.len, (const HBUINT16 *) input.arrayZ + 1,
lookahead.len, (const HBUINT16 *) lookahead.arrayZ,
lookup.len, lookup.arrayZ,
lookup_context);
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
(this+input[0]).add_coverage (c->input);
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
struct ChainContextCollectGlyphsLookupContext lookup_context = {
{collect_coverage},
{this, this, this}
};
chain_context_collect_glyphs_lookup (c,
backtrack.len, (const HBUINT16 *) backtrack.arrayZ,
input.len, (const HBUINT16 *) input.arrayZ + 1,
lookahead.len, (const HBUINT16 *) lookahead.arrayZ,
lookup.len, lookup.arrayZ,
lookup_context);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
struct ChainContextApplyLookupContext lookup_context = {
{match_coverage},
{this, this, this}
};
return_trace (chain_context_would_apply_lookup (c,
backtrack.len, (const HBUINT16 *) backtrack.arrayZ,
input.len, (const HBUINT16 *) input.arrayZ + 1,
lookahead.len, (const HBUINT16 *) lookahead.arrayZ,
lookup.len, lookup.arrayZ, lookup_context));
}
const Coverage &get_coverage () const
{
const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
return this+input[0];
}
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
unsigned int index = (this+input[0]).get_coverage (c->buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return_trace (false);
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
struct ChainContextApplyLookupContext lookup_context = {
{match_coverage},
{this, this, this}
};
return_trace (chain_context_apply_lookup (c,
backtrack.len, (const HBUINT16 *) backtrack.arrayZ,
input.len, (const HBUINT16 *) input.arrayZ + 1,
lookahead.len, (const HBUINT16 *) lookahead.arrayZ,
lookup.len, lookup.arrayZ, lookup_context));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
// TODO(subset)
return_trace (false);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!backtrack.sanitize (c, this)) return_trace (false);
const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
if (!input.sanitize (c, this)) return_trace (false);
if (!input.len) return_trace (false); /* To be consistent with Context. */
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
if (!lookahead.sanitize (c, this)) return_trace (false);
const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
return_trace (lookup.sanitize (c));
}
protected:
HBUINT16 format; /* Format identifier--format = 3 */
OffsetArrayOf<Coverage>
backtrack; /* Array of coverage tables
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