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/*
* Copyright © 2007,2008,2009,2010 Red Hat, Inc.
* Copyright © 2010 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_GSUB_TABLE_HH
#define HB_OT_LAYOUT_GSUB_TABLE_HH
#include "hb-ot-layout-gsubgpos-private.hh"
struct SingleSubstFormat1
{
friend struct SingleSubst;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
hb_codepoint_t glyph_id = c->buffer->info[c->buffer->idx].codepoint;
unsigned int index = (this+coverage) (glyph_id);
if (likely (index == NOT_COVERED))
return false;
glyph_id += deltaGlyphID;
c->replace_glyph (glyph_id);
return true;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return coverage.sanitize (c, this)
&& deltaGlyphID.sanitize (c);
}
private:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of Substitution table */
SHORT deltaGlyphID; /* Add to original GlyphID to get
* substitute GlyphID */
public:
DEFINE_SIZE_STATIC (6);
};
struct SingleSubstFormat2
{
friend struct SingleSubst;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
hb_codepoint_t glyph_id = c->buffer->info[c->buffer->idx].codepoint;
unsigned int index = (this+coverage) (glyph_id);
if (likely (index == NOT_COVERED))
return false;
if (unlikely (index >= substitute.len))
return false;
glyph_id = substitute[index];
c->replace_glyph (glyph_id);
return true;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return coverage.sanitize (c, this)
&& substitute.sanitize (c);
}
private:
USHORT format; /* Format identifier--format = 2 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of Substitution table */
ArrayOf<GlyphID>
substitute; /* Array of substitute
* GlyphIDs--ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (6, substitute);
};
struct SingleSubst
{
friend struct SubstLookupSubTable;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
switch (u.format) {
case 1: return u.format1.apply (c);
case 2: return u.format2.apply (c);
default:return false;
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (!u.format.sanitize (c)) return false;
switch (u.format) {
case 1: return u.format1.sanitize (c);
case 2: return u.format2.sanitize (c);
default:return true;
}
}
private:
union {
USHORT format; /* Format identifier */
SingleSubstFormat1 format1;
SingleSubstFormat2 format2;
} u;
};
struct Sequence
{
friend struct MultipleSubstFormat1;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
if (unlikely (!substitute.len))
return false;
if (c->property & HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE)
c->guess_glyph_class (HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH);
c->replace_glyphs_be16 (1, substitute.len, (const uint16_t *) substitute.array);
return true;
}
public:
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return substitute.sanitize (c);
}
private:
ArrayOf<GlyphID>
substitute; /* String of GlyphIDs to substitute */
public:
DEFINE_SIZE_ARRAY (2, substitute);
};
struct MultipleSubstFormat1
{
friend struct MultipleSubst;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
unsigned int index = (this+coverage) (c->buffer->info[c->buffer->idx].codepoint);
if (likely (index == NOT_COVERED))
return false;
return (this+sequence[index]).apply (c);
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return coverage.sanitize (c, this)
&& sequence.sanitize (c, this);
}
private:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of Substitution table */
OffsetArrayOf<Sequence>
sequence; /* Array of Sequence tables
* ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (6, sequence);
};
struct MultipleSubst
{
friend struct SubstLookupSubTable;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
switch (u.format) {
case 1: return u.format1.apply (c);
default:return false;
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (!u.format.sanitize (c)) return false;
switch (u.format) {
case 1: return u.format1.sanitize (c);
default:return true;
}
}
private:
union {
USHORT format; /* Format identifier */
MultipleSubstFormat1 format1;
} u;
};
typedef ArrayOf<GlyphID> AlternateSet; /* Array of alternate GlyphIDs--in
* arbitrary order */
struct AlternateSubstFormat1
{
friend struct AlternateSubst;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
hb_codepoint_t glyph_id = c->buffer->info[c->buffer->idx].codepoint;
hb_mask_t glyph_mask = c->buffer->info[c->buffer->idx].mask;
hb_mask_t lookup_mask = c->lookup_mask;
unsigned int index = (this+coverage) (glyph_id);
if (likely (index == NOT_COVERED))
return false;
const AlternateSet &alt_set = this+alternateSet[index];
if (unlikely (!alt_set.len))
return false;
/* Note: This breaks badly if two features enabled this lookup together. */
unsigned int shift = _hb_ctz (lookup_mask);
unsigned int alt_index = ((lookup_mask & glyph_mask) >> shift);
if (unlikely (alt_index > alt_set.len || alt_index == 0))
return false;
glyph_id = alt_set[alt_index - 1];
c->replace_glyph (glyph_id);
return true;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return coverage.sanitize (c, this)
&& alternateSet.sanitize (c, this);
}
private:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of Substitution table */
OffsetArrayOf<AlternateSet>
alternateSet; /* Array of AlternateSet tables
* ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (6, alternateSet);
};
struct AlternateSubst
{
friend struct SubstLookupSubTable;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
switch (u.format) {
case 1: return u.format1.apply (c);
default:return false;
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (!u.format.sanitize (c)) return false;
switch (u.format) {
case 1: return u.format1.sanitize (c);
default:return true;
}
}
private:
union {
USHORT format; /* Format identifier */
AlternateSubstFormat1 format1;
} u;
};
struct Ligature
{
friend struct LigatureSet;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
unsigned int i, j;
unsigned int count = component.len;
unsigned int end = MIN (c->buffer->len, c->buffer->idx + c->context_length);
if (unlikely (count < 2 || c->buffer->idx + count > end))
return false;
bool first_was_mark = (c->property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
bool found_non_mark = false;
for (i = 1, j = c->buffer->idx + 1; i < count; i++, j++)
{
unsigned int property;
while (_hb_ot_layout_skip_mark (c->face, &c->buffer->info[j], c->lookup_props, &property))
{
if (unlikely (j + count - i == end))
return false;
j++;
}
found_non_mark |= !(property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
if (likely (c->buffer->info[j].codepoint != component[i]))
return false;
}
if (first_was_mark && found_non_mark)
c->guess_glyph_class (HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE);
/* Allocate new ligature id */
unsigned int lig_id = allocate_lig_id (c->buffer);
c->buffer->info[c->buffer->idx].lig_comp() = 0;
c->buffer->info[c->buffer->idx].lig_id() = lig_id;
if (j == c->buffer->idx + i) /* No input glyphs skipped */
{
c->replace_glyphs_be16 (i, 1, (const uint16_t *) &ligGlyph);
}
else
{
c->replace_glyph (ligGlyph);
/* Now we must do a second loop to copy the skipped glyphs to
`out' and assign component values to it. We start with the
glyph after the first component. Glyphs between component
i and i+1 belong to component i. Together with the lig_id
value it is later possible to check whether a specific
component value really belongs to a given ligature. */
for (i = 1; i < count; i++)
{
while (_hb_ot_layout_skip_mark (c->face, &c->buffer->info[c->buffer->idx], c->lookup_props, NULL))
{
c->buffer->info[c->buffer->idx].lig_comp() = i;
c->buffer->info[c->buffer->idx].lig_id() = lig_id;
c->replace_glyph (c->buffer->info[c->buffer->idx].codepoint);
}
/* Skip the base glyph */
c->buffer->idx++;
}
}
return true;
}
public:
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return ligGlyph.sanitize (c)
&& component.sanitize (c);
}
private:
GlyphID ligGlyph; /* GlyphID of ligature to substitute */
HeadlessArrayOf<GlyphID>
component; /* Array of component GlyphIDs--start
* with the second component--ordered
* in writing direction */
public:
DEFINE_SIZE_ARRAY (4, component);
};
struct LigatureSet
{
friend struct LigatureSubstFormat1;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
unsigned int num_ligs = ligature.len;
for (unsigned int i = 0; i < num_ligs; i++)
{
const Ligature &lig = this+ligature[i];
if (lig.apply (c))
return true;
}
return false;
}
public:
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return ligature.sanitize (c, this);
}
private:
OffsetArrayOf<Ligature>
ligature; /* Array LigatureSet tables
* ordered by preference */
public:
DEFINE_SIZE_ARRAY (2, ligature);
};
struct LigatureSubstFormat1
{
friend struct LigatureSubst;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
hb_codepoint_t glyph_id = c->buffer->info[c->buffer->idx].codepoint;
unsigned int index = (this+coverage) (glyph_id);
if (likely (index == NOT_COVERED))
return false;
const LigatureSet &lig_set = this+ligatureSet[index];
return lig_set.apply (c);
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return coverage.sanitize (c, this)
&& ligatureSet.sanitize (c, this);
}
private:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of Substitution table */
OffsetArrayOf<LigatureSet>
ligatureSet; /* Array LigatureSet tables
* ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (6, ligatureSet);
};
struct LigatureSubst
{
friend struct SubstLookupSubTable;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
switch (u.format) {
case 1: return u.format1.apply (c);
default:return false;
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (!u.format.sanitize (c)) return false;
switch (u.format) {
case 1: return u.format1.sanitize (c);
default:return true;
}
}
private:
union {
USHORT format; /* Format identifier */
LigatureSubstFormat1 format1;
} u;
};
static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index);
struct ContextSubst : Context
{
friend struct SubstLookupSubTable;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
return Context::apply (c, substitute_lookup);
}
};
struct ChainContextSubst : ChainContext
{
friend struct SubstLookupSubTable;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
return ChainContext::apply (c, substitute_lookup);
}
};
struct ExtensionSubst : Extension
{
friend struct SubstLookupSubTable;
friend struct SubstLookup;
private:
inline const struct SubstLookupSubTable& get_subtable (void) const
{
unsigned int offset = get_offset ();
if (unlikely (!offset)) return Null(SubstLookupSubTable);
return StructAtOffset<SubstLookupSubTable> (this, offset);
}
inline bool apply (hb_apply_context_t *c) const;
inline bool sanitize (hb_sanitize_context_t *c);
inline bool is_reverse (void) const;
};
struct ReverseChainSingleSubstFormat1
{
friend struct ReverseChainSingleSubst;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
if (unlikely (c->context_length != NO_CONTEXT))
return false; /* No chaining to this type */
unsigned int index = (this+coverage) (c->buffer->info[c->buffer->idx].codepoint);
if (likely (index == NOT_COVERED))
return false;
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
if (match_backtrack (c,
backtrack.len, (USHORT *) backtrack.array,
match_coverage, this) &&
match_lookahead (c,
lookahead.len, (USHORT *) lookahead.array,
match_coverage, this,
1))
{
c->buffer->info[c->buffer->idx].codepoint = substitute[index];
c->buffer->idx--; /* Reverse! */
return true;
}
return false;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (!(coverage.sanitize (c, this)
&& backtrack.sanitize (c, this)))
return false;
OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
if (!lookahead.sanitize (c, this))
return false;
ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
return substitute.sanitize (c);
}
private:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of table */
OffsetArrayOf<Coverage>
backtrack; /* Array of coverage tables
* in backtracking sequence, in glyph
* sequence order */
OffsetArrayOf<Coverage>
lookaheadX; /* Array of coverage tables
* in lookahead sequence, in glyph
* sequence order */
ArrayOf<GlyphID>
substituteX; /* Array of substitute
* GlyphIDs--ordered by Coverage Index */
public:
DEFINE_SIZE_MIN (10);
};
struct ReverseChainSingleSubst
{
friend struct SubstLookupSubTable;
private:
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
switch (u.format) {
case 1: return u.format1.apply (c);
default:return false;
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (!u.format.sanitize (c)) return false;
switch (u.format) {
case 1: return u.format1.sanitize (c);
default:return true;
}
}
private:
union {
USHORT format; /* Format identifier */
ReverseChainSingleSubstFormat1 format1;
} u;
};
/*
* SubstLookup
*/
struct SubstLookupSubTable
{
friend struct SubstLookup;
enum {
Single = 1,
Multiple = 2,
Alternate = 3,
Ligature = 4,
Context = 5,
ChainContext = 6,
Extension = 7,
ReverseChainSingle = 8
};
inline bool apply (hb_apply_context_t *c, unsigned int lookup_type) const
{
TRACE_APPLY ();
switch (lookup_type) {
case Single: return u.single.apply (c);
case Multiple: return u.multiple.apply (c);
case Alternate: return u.alternate.apply (c);
case Ligature: return u.ligature.apply (c);
case Context: return u.c.apply (c);
case ChainContext: return u.chainContext.apply (c);
case Extension: return u.extension.apply (c);
case ReverseChainSingle: return u.reverseChainContextSingle.apply (c);
default:return false;
}
}
inline bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) {
TRACE_SANITIZE ();
switch (lookup_type) {
case Single: return u.single.sanitize (c);
case Multiple: return u.multiple.sanitize (c);
case Alternate: return u.alternate.sanitize (c);
case Ligature: return u.ligature.sanitize (c);
case Context: return u.c.sanitize (c);
case ChainContext: return u.chainContext.sanitize (c);
case Extension: return u.extension.sanitize (c);
case ReverseChainSingle: return u.reverseChainContextSingle.sanitize (c);
default:return true;
}
}
private:
union {
USHORT sub_format;
SingleSubst single;
MultipleSubst multiple;
AlternateSubst alternate;
LigatureSubst ligature;
ContextSubst c;
ChainContextSubst chainContext;
ExtensionSubst extension;
ReverseChainSingleSubst reverseChainContextSingle;
} u;
public:
DEFINE_SIZE_UNION (2, sub_format);
};
struct SubstLookup : Lookup
{
inline const SubstLookupSubTable& get_subtable (unsigned int i) const
{ return this+CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i]; }
inline static bool lookup_type_is_reverse (unsigned int lookup_type)
{ return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
inline bool is_reverse (void) const
{
unsigned int type = get_type ();
if (unlikely (type == SubstLookupSubTable::Extension))
return CastR<ExtensionSubst> (get_subtable(0)).is_reverse ();
return lookup_type_is_reverse (type);
}
inline bool apply_once (hb_face_t *face,
hb_buffer_t *buffer,
hb_mask_t lookup_mask,
unsigned int context_length,
unsigned int nesting_level_left) const
{
unsigned int lookup_type = get_type ();
hb_apply_context_t c[1] = {{0}};
c->face = face;
c->buffer = buffer;
c->direction = buffer->props.direction;
c->lookup_mask = lookup_mask;
c->context_length = context_length;
c->nesting_level_left = nesting_level_left;
c->lookup_props = get_props ();
if (!_hb_ot_layout_check_glyph_property (c->face, &c->buffer->info[c->buffer->idx], c->lookup_props, &c->property))
return false;
if (unlikely (lookup_type == SubstLookupSubTable::Extension))
{
/* The spec says all subtables should have the same type.
* This is specially important if one has a reverse type!
*
* This is rather slow to do this here for every glyph,
* but it's easiest, and who uses extension lookups anyway?!*/
unsigned int count = get_subtable_count ();
unsigned int type = get_subtable(0).u.extension.get_type ();
for (unsigned int i = 1; i < count; i++)
if (get_subtable(i).u.extension.get_type () != type)
return false;
}
unsigned int count = get_subtable_count ();
for (unsigned int i = 0; i < count; i++)
if (get_subtable (i).apply (c, lookup_type))
return true;
return false;
}
inline bool apply_string (hb_face_t *face,
hb_buffer_t *buffer,
hb_mask_t mask) const
{
bool ret = false;
if (unlikely (!buffer->len))
return false;
if (likely (!is_reverse ()))
{
/* in/out forward substitution */
buffer->clear_output ();
buffer->idx = 0;
while (buffer->idx < buffer->len)
{
if ((buffer->info[buffer->idx].mask & mask) &&
apply_once (face, buffer, mask, NO_CONTEXT, MAX_NESTING_LEVEL))
ret = true;
else
buffer->next_glyph ();
}
if (ret)
buffer->swap_buffers ();
}
else
{
/* in-place backward substitution */
buffer->idx = buffer->len - 1;
do
{
if ((buffer->info[buffer->idx].mask & mask) &&
apply_once (face, buffer, mask, NO_CONTEXT, MAX_NESTING_LEVEL))
ret = true;
else
buffer->idx--;
}
while ((int) buffer->idx >= 0);
}
return ret;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (unlikely (!Lookup::sanitize (c))) return false;
OffsetArrayOf<SubstLookupSubTable> &list = CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable);
return list.sanitize (c, this, get_type ());
}
};
typedef OffsetListOf<SubstLookup> SubstLookupList;
/*
* GSUB
*/
struct GSUB : GSUBGPOS
{
static const hb_tag_t Tag = HB_OT_TAG_GSUB;
inline const SubstLookup& get_lookup (unsigned int i) const
{ return CastR<SubstLookup> (GSUBGPOS::get_lookup (i)); }
inline bool substitute_lookup (hb_face_t *face,
hb_buffer_t *buffer,
unsigned int lookup_index,
hb_mask_t mask) const
{ return get_lookup (lookup_index).apply_string (face, buffer, mask); }
static inline void substitute_start (hb_buffer_t *buffer);
static inline void substitute_finish (hb_buffer_t *buffer);
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (unlikely (!GSUBGPOS::sanitize (c))) return false;
OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
return list.sanitize (c, this);
}
public:
DEFINE_SIZE_STATIC (10);
};
void
GSUB::substitute_start (hb_buffer_t *buffer)
{
HB_BUFFER_ALLOCATE_VAR (buffer, props_cache);
HB_BUFFER_ALLOCATE_VAR (buffer, lig_id);
HB_BUFFER_ALLOCATE_VAR (buffer, lig_comp);
unsigned int count = buffer->len;
for (unsigned int i = 0; i < count; i++)
buffer->info[i].props_cache() = buffer->info[i].lig_id() = buffer->info[i].lig_comp() = 0;
}
void
GSUB::substitute_finish (hb_buffer_t *buffer)
{
}
/* Out-of-class implementation for methods recursing */
inline bool ExtensionSubst::apply (hb_apply_context_t *c) const
{
TRACE_APPLY ();
return get_subtable ().apply (c, get_type ());
}
inline bool ExtensionSubst::sanitize (hb_sanitize_context_t *c)
{
TRACE_SANITIZE ();
if (unlikely (!Extension::sanitize (c))) return false;
unsigned int offset = get_offset ();
if (unlikely (!offset)) return true;
return StructAtOffset<SubstLookupSubTable> (this, offset).sanitize (c, get_type ());
}
inline bool ExtensionSubst::is_reverse (void) const
{
unsigned int type = get_type ();
if (unlikely (type == SubstLookupSubTable::Extension))
return CastR<ExtensionSubst> (get_subtable()).is_reverse ();
return SubstLookup::lookup_type_is_reverse (type);
}
static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index)
{
const GSUB &gsub = *(c->face->ot_layout->gsub);
const SubstLookup &l = gsub.get_lookup (lookup_index);
if (unlikely (c->nesting_level_left == 0))
return false;
if (unlikely (c->context_length < 1))
return false;
return l.apply_once (c->face, c->buffer, c->lookup_mask, c->context_length, c->nesting_level_left - 1);
}
#endif /* HB_OT_LAYOUT_GSUB_TABLE_HH */
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