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harfbuzz/src/hb-ot-layout-gsub-table.hh

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/*
* Copyright © 2007,2008,2009,2010 Red Hat, Inc.
* Copyright © 2010,2012,2013 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_LAYOUT_GSUB_TABLE_HH
#define HB_OT_LAYOUT_GSUB_TABLE_HH
#include "hb-ot-layout-gsubgpos.hh"
namespace OT {
static inline void SingleSubst_serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const GlyphID> substitutes);
struct SingleSubstFormat1
{
bool intersects (const hb_set_t *glyphs) const
{ return (this+coverage).intersects (glyphs); }
void closure (hb_closure_context_t *c) const
{
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
/* TODO Switch to range-based API to work around malicious fonts.
* https://github.com/harfbuzz/harfbuzz/issues/363 */
hb_codepoint_t glyph_id = iter.get_glyph ();
if (c->glyphs->has (glyph_id))
c->out->add ((glyph_id + deltaGlyphID) & 0xFFFFu);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).add_coverage (c->input))) return;
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
/* TODO Switch to range-based API to work around malicious fonts.
* https://github.com/harfbuzz/harfbuzz/issues/363 */
hb_codepoint_t glyph_id = iter.get_glyph ();
c->output->add ((glyph_id + deltaGlyphID) & 0xFFFFu);
}
}
const Coverage &get_coverage () const { return this+coverage; }
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
}
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
unsigned int index = (this+coverage).get_coverage (glyph_id);
if (likely (index == NOT_COVERED)) return_trace (false);
/* According to the Adobe Annotated OpenType Suite, result is always
* limited to 16bit. */
glyph_id = (glyph_id + deltaGlyphID) & 0xFFFFu;
c->replace_glyph (glyph_id);
return_trace (true);
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
int delta)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs))) return_trace (false);
deltaGlyphID.set (delta); /* TODO(serialize) overflow? */
return_trace (true);
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
const hb_set_t &glyphset = *c->plan->glyphset ();
const hb_map_t &glyph_map = *c->plan->glyph_map;
hb_vector_t<GlyphID> from;
hb_vector_t<GlyphID> to;
hb_codepoint_t delta = deltaGlyphID;
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
if (!glyphset.has (iter.get_glyph ())) continue;
from.push ()->set (glyph_map[iter.get_glyph ()]);
to.push ()->set (glyph_map[(iter.get_glyph () + delta) & 0xFFFF]);
}
c->serializer->propagate_error (from, to);
SingleSubst_serialize (c->serializer, from, to);
return_trace (from.length);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (coverage.sanitize (c, this) && deltaGlyphID.sanitize (c));
}
protected:
HBUINT16 format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of Substitution table */
HBINT16 deltaGlyphID; /* Add to original GlyphID to get
* substitute GlyphID */
public:
DEFINE_SIZE_STATIC (6);
};
struct SingleSubstFormat2
{
bool intersects (const hb_set_t *glyphs) const
{ return (this+coverage).intersects (glyphs); }
void closure (hb_closure_context_t *c) const
{
unsigned int count = substitute.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 ()))
c->out->add (substitute[iter.get_coverage ()]);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).add_coverage (c->input))) return;
unsigned int count = substitute.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 */
c->output->add (substitute[iter.get_coverage ()]);
}
}
const Coverage &get_coverage () const { return this+coverage; }
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
}
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);
if (unlikely (index >= substitute.len)) return_trace (false);
c->replace_glyph (substitute[index]);
return_trace (true);
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const GlyphID> substitutes)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
if (unlikely (!substitute.serialize (c, substitutes))) return_trace (false);
if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs))) return_trace (false);
return_trace (true);
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
const hb_set_t &glyphset = *c->plan->glyphset ();
const hb_map_t &glyph_map = *c->plan->glyph_map;
hb_vector_t<GlyphID> from;
hb_vector_t<GlyphID> to;
for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ())
{
if (!glyphset.has (iter.get_glyph ())) continue;
from.push ()->set (glyph_map[iter.get_glyph ()]);
to.push ()->set (glyph_map[substitute[iter.get_coverage ()]]);
}
c->serializer->propagate_error (from, to);
SingleSubst_serialize (c->serializer, from, to);
return_trace (from.length);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (coverage.sanitize (c, this) && substitute.sanitize (c));
}
protected:
HBUINT16 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
{
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const GlyphID> substitutes)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (u.format))) return_trace (false);
unsigned int format = 2;
int delta = 0;
if (glyphs.length)
{
format = 1;
/* TODO(serialize) check for wrap-around */
delta = substitutes[0] - glyphs[0];
for (unsigned int i = 1; i < glyphs.length; i++)
if (delta != (int) (substitutes[i] - glyphs[i])) {
format = 2;
break;
}
}
u.format.set (format);
switch (u.format) {
case 1: return_trace (u.format1.serialize (c, glyphs, delta));
case 2: return_trace (u.format2.serialize (c, glyphs, substitutes));
default:return_trace (false);
}
}
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));
default:return_trace (c->default_return_value ());
}
}
protected:
union {
HBUINT16 format; /* Format identifier */
SingleSubstFormat1 format1;
SingleSubstFormat2 format2;
} u;
};
static inline void
SingleSubst_serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const GlyphID> substitutes)
{ c->start_embed<SingleSubst> ()->serialize (c, glyphs, substitutes); }
struct Sequence
{
void closure (hb_closure_context_t *c) const
{
unsigned int count = substitute.len;
for (unsigned int i = 0; i < count; i++)
c->out->add (substitute[i]);
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{ c->output->add_array (substitute.arrayZ, substitute.len); }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int count = substitute.len;
/* Special-case to make it in-place and not consider this
* as a "multiplied" substitution. */
if (unlikely (count == 1))
{
c->replace_glyph (substitute.arrayZ[0]);
return_trace (true);
}
/* Spec disallows this, but Uniscribe allows it.
* https://github.com/harfbuzz/harfbuzz/issues/253 */
else if (unlikely (count == 0))
{
c->buffer->delete_glyph ();
return_trace (true);
}
unsigned int klass = _hb_glyph_info_is_ligature (&c->buffer->cur()) ?
HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH : 0;
for (unsigned int i = 0; i < count; i++) {
_hb_glyph_info_set_lig_props_for_component (&c->buffer->cur(), i);
c->output_glyph_for_component (substitute.arrayZ[i], klass);
}
c->buffer->skip_glyph ();
return_trace (true);
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs)
{
TRACE_SERIALIZE (this);
return_trace (substitute.serialize (c, glyphs));
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (substitute.sanitize (c));
}
protected:
ArrayOf<GlyphID>
substitute; /* String of GlyphIDs to substitute */
public:
DEFINE_SIZE_ARRAY (2, substitute);
};
struct MultipleSubstFormat1
{
bool intersects (const hb_set_t *glyphs) const
{ return (this+coverage).intersects (glyphs); }
void closure (hb_closure_context_t *c) const
{
unsigned int count = sequence.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+sequence[iter.get_coverage ()]).closure (c);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).add_coverage (c->input))) return;
unsigned int count = sequence.len;
for (unsigned int i = 0; i < count; i++)
(this+sequence[i]).collect_glyphs (c);
}
const Coverage &get_coverage () const { return this+coverage; }
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
}
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);
return_trace ((this+sequence[index]).apply (c));
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const unsigned int> substitute_len_list,
hb_array_t<const GlyphID> substitute_glyphs_list)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
if (unlikely (!sequence.serialize (c, glyphs.length))) return_trace (false);
for (unsigned int i = 0; i < glyphs.length; i++)
{
unsigned int substitute_len = substitute_len_list[i];
if (unlikely (!sequence[i].serialize (c, this)
.serialize (c, substitute_glyphs_list.sub_array (0, substitute_len))))
return_trace (false);
substitute_glyphs_list += substitute_len;
}
return_trace (coverage.serialize (c, this).serialize (c, glyphs));
}
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) && sequence.sanitize (c, this));
}
protected:
HBUINT16 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
{
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const unsigned int> substitute_len_list,
hb_array_t<const GlyphID> substitute_glyphs_list)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (u.format))) return_trace (false);
unsigned int format = 1;
u.format.set (format);
switch (u.format) {
case 1: return_trace (u.format1.serialize (c, glyphs, substitute_len_list, substitute_glyphs_list));
default:return_trace (false);
}
}
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));
default:return_trace (c->default_return_value ());
}
}
protected:
union {
HBUINT16 format; /* Format identifier */
MultipleSubstFormat1 format1;
} u;
};
struct AlternateSet
{
void closure (hb_closure_context_t *c) const
{
unsigned int count = alternates.len;
for (unsigned int i = 0; i < count; i++)
c->out->add (alternates[i]);
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{ c->output->add_array (alternates.arrayZ, alternates.len); }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int count = alternates.len;
if (unlikely (!count)) return_trace (false);
hb_mask_t glyph_mask = c->buffer->cur().mask;
hb_mask_t lookup_mask = c->lookup_mask;
/* 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 alt_index is MAX, randomize feature if it is the rand feature. */
if (alt_index == HB_OT_MAP_MAX_VALUE && c->random)
alt_index = c->random_number () % count + 1;
if (unlikely (alt_index > count || alt_index == 0)) return_trace (false);
c->replace_glyph (alternates[alt_index - 1]);
return_trace (true);
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs)
{
TRACE_SERIALIZE (this);
return_trace (alternates.serialize (c, glyphs));
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (alternates.sanitize (c));
}
protected:
ArrayOf<GlyphID>
alternates; /* Array of alternate GlyphIDs--in
* arbitrary order */
public:
DEFINE_SIZE_ARRAY (2, alternates);
};
struct AlternateSubstFormat1
{
bool intersects (const hb_set_t *glyphs) const
{ return (this+coverage).intersects (glyphs); }
void closure (hb_closure_context_t *c) const
{
unsigned int count = alternateSet.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+alternateSet[iter.get_coverage ()]).closure (c);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).add_coverage (c->input))) return;
unsigned int count = alternateSet.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 */
(this+alternateSet[iter.get_coverage ()]).collect_glyphs (c);
}
}
const Coverage &get_coverage () const { return this+coverage; }
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
}
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);
return_trace ((this+alternateSet[index]).apply (c));
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const unsigned int> alternate_len_list,
hb_array_t<const GlyphID> alternate_glyphs_list)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
if (unlikely (!alternateSet.serialize (c, glyphs.length))) return_trace (false);
for (unsigned int i = 0; i < glyphs.length; i++)
{
unsigned int alternate_len = alternate_len_list[i];
if (unlikely (!alternateSet[i].serialize (c, this)
.serialize (c, alternate_glyphs_list.sub_array (0, alternate_len))))
return_trace (false);
alternate_glyphs_list += alternate_len;
}
return_trace (coverage.serialize (c, this).serialize (c, glyphs));
}
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) && alternateSet.sanitize (c, this));
}
protected:
HBUINT16 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
{
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const unsigned int> alternate_len_list,
hb_array_t<const GlyphID> alternate_glyphs_list)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (u.format))) return_trace (false);
unsigned int format = 1;
u.format.set (format);
switch (u.format) {
case 1: return_trace (u.format1.serialize (c, glyphs, alternate_len_list, alternate_glyphs_list));
default:return_trace (false);
}
}
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));
default:return_trace (c->default_return_value ());
}
}
protected:
union {
HBUINT16 format; /* Format identifier */
AlternateSubstFormat1 format1;
} u;
};
struct Ligature
{
bool intersects (const hb_set_t *glyphs) const
{
unsigned int count = component.lenP1;
for (unsigned int i = 1; i < count; i++)
if (!glyphs->has (component[i]))
return false;
return true;
}
void closure (hb_closure_context_t *c) const
{
unsigned int count = component.lenP1;
for (unsigned int i = 1; i < count; i++)
if (!c->glyphs->has (component[i]))
return;
c->out->add (ligGlyph);
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
c->input->add_array (component.arrayZ, component.lenP1 ? component.lenP1 - 1 : 0);
c->output->add (ligGlyph);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
if (c->len != component.lenP1)
return_trace (false);
for (unsigned int i = 1; i < c->len; i++)
if (likely (c->glyphs[i] != component[i]))
return_trace (false);
return_trace (true);
}
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
unsigned int count = component.lenP1;
if (unlikely (!count)) return_trace (false);
/* Special-case to make it in-place and not consider this
* as a "ligated" substitution. */
if (unlikely (count == 1))
{
c->replace_glyph (ligGlyph);
return_trace (true);
}
unsigned int total_component_count = 0;
unsigned int match_length = 0;
unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
if (likely (!match_input (c, count,
&component[1],
match_glyph,
nullptr,
&match_length,
match_positions,
&total_component_count)))
return_trace (false);
ligate_input (c,
count,
match_positions,
match_length,
ligGlyph,
total_component_count);
return_trace (true);
}
bool serialize (hb_serialize_context_t *c,
GlyphID ligature,
hb_array_t<const GlyphID> components /* Starting from second */)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
ligGlyph = ligature;
if (unlikely (!component.serialize (c, components))) return_trace (false);
return_trace (true);
}
public:
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (ligGlyph.sanitize (c) && component.sanitize (c));
}
protected:
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
{
bool intersects (const hb_set_t *glyphs) const
{
unsigned int num_ligs = ligature.len;
for (unsigned int i = 0; i < num_ligs; i++)
if ((this+ligature[i]).intersects (glyphs))
return true;
return false;
}
void closure (hb_closure_context_t *c) const
{
unsigned int num_ligs = ligature.len;
for (unsigned int i = 0; i < num_ligs; i++)
(this+ligature[i]).closure (c);
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
unsigned int num_ligs = ligature.len;
for (unsigned int i = 0; i < num_ligs; i++)
(this+ligature[i]).collect_glyphs (c);
}
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
unsigned int num_ligs = ligature.len;
for (unsigned int i = 0; i < num_ligs; i++)
{
const Ligature &lig = this+ligature[i];
if (lig.would_apply (c))
return_trace (true);
}
return_trace (false);
}
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
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_trace (true);
}
return_trace (false);
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> ligatures,
hb_array_t<const unsigned int> component_count_list,
hb_array_t<const GlyphID> &component_list /* Starting from second for each ligature */)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
if (unlikely (!ligature.serialize (c, ligatures.length))) return_trace (false);
for (unsigned int i = 0; i < ligatures.length; i++)
{
unsigned int component_count = MAX<int> (component_count_list[i] - 1, 0);
if (unlikely (!ligature[i].serialize (c, this)
.serialize (c,
ligatures[i],
component_list.sub_array (0, component_count))))
return_trace (false);
component_list += component_count;
}
return_trace (true);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (ligature.sanitize (c, this));
}
protected:
OffsetArrayOf<Ligature>
ligature; /* Array LigatureSet tables
* ordered by preference */
public:
DEFINE_SIZE_ARRAY (2, ligature);
};
struct LigatureSubstFormat1
{
bool intersects (const hb_set_t *glyphs) const
{
unsigned int count = ligatureSet.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+ligatureSet[iter.get_coverage ()]).intersects (glyphs))
return true;
}
return false;
}
void closure (hb_closure_context_t *c) const
{
unsigned int count = ligatureSet.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+ligatureSet[iter.get_coverage ()]).closure (c);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).add_coverage (c->input))) return;
unsigned int count = ligatureSet.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 */
(this+ligatureSet[iter.get_coverage ()]).collect_glyphs (c);
}
}
const Coverage &get_coverage () const { return this+coverage; }
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
unsigned int index = (this+coverage).get_coverage (c->glyphs[0]);
if (likely (index == NOT_COVERED)) return_trace (false);
const LigatureSet &lig_set = this+ligatureSet[index];
return_trace (lig_set.would_apply (c));
}
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 LigatureSet &lig_set = this+ligatureSet[index];
return_trace (lig_set.apply (c));
}
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> first_glyphs,
hb_array_t<const unsigned int> ligature_per_first_glyph_count_list,
hb_array_t<const GlyphID> ligatures_list,
hb_array_t<const unsigned int> component_count_list,
hb_array_t<const GlyphID> component_list /* Starting from second for each ligature */)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
if (unlikely (!ligatureSet.serialize (c, first_glyphs.length))) return_trace (false);
for (unsigned int i = 0; i < first_glyphs.length; i++)
{
unsigned int ligature_count = ligature_per_first_glyph_count_list[i];
if (unlikely (!ligatureSet[i].serialize (c, this)
.serialize (c,
ligatures_list.sub_array (0, ligature_count),
component_count_list.sub_array (0, ligature_count),
component_list))) return_trace (false);
ligatures_list += ligature_count;
component_count_list += ligature_count;
}
return_trace (coverage.serialize (c, this).serialize (c, first_glyphs));
}
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) && ligatureSet.sanitize (c, this));
}
protected:
HBUINT16 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
{
bool serialize (hb_serialize_context_t *c,
hb_array_t<const GlyphID> first_glyphs,
hb_array_t<const unsigned int> ligature_per_first_glyph_count_list,
hb_array_t<const GlyphID> ligatures_list,
hb_array_t<const unsigned int> component_count_list,
hb_array_t<const GlyphID> component_list /* Starting from second for each ligature */)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (u.format))) return_trace (false);
unsigned int format = 1;
u.format.set (format);
switch (u.format) {
case 1: return_trace (u.format1.serialize (c,
first_glyphs,
ligature_per_first_glyph_count_list,
ligatures_list,
component_count_list,
component_list));
default:return_trace (false);
}
}
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));
default:return_trace (c->default_return_value ());
}
}
protected:
union {
HBUINT16 format; /* Format identifier */
LigatureSubstFormat1 format1;
} u;
};
struct ContextSubst : Context {};
struct ChainContextSubst : ChainContext {};
struct ExtensionSubst : Extension<ExtensionSubst>
{
typedef struct SubstLookupSubTable SubTable;
bool is_reverse () const;
};
struct ReverseChainSingleSubstFormat1
{
bool intersects (const hb_set_t *glyphs) const
{
if (!(this+coverage).intersects (glyphs))
return false;
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
unsigned int count;
count = backtrack.len;
for (unsigned int i = 0; i < count; i++)
if (!(this+backtrack[i]).intersects (glyphs))
return false;
count = lookahead.len;
for (unsigned int i = 0; i < count; i++)
if (!(this+lookahead[i]).intersects (glyphs))
return false;
return true;
}
void closure (hb_closure_context_t *c) const
{
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
unsigned int count;
count = backtrack.len;
for (unsigned int i = 0; i < count; i++)
if (!(this+backtrack[i]).intersects (c->glyphs))
return;
count = lookahead.len;
for (unsigned int i = 0; i < count; i++)
if (!(this+lookahead[i]).intersects (c->glyphs))
return;
const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
count = substitute.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 ()))
c->out->add (substitute[iter.get_coverage ()]);
}
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).add_coverage (c->input))) return;
unsigned int count;
count = backtrack.len;
for (unsigned int i = 0; i < count; i++)
if (unlikely (!(this+backtrack[i]).add_coverage (c->before))) return;
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
count = lookahead.len;
for (unsigned int i = 0; i < count; i++)
if (unlikely (!(this+lookahead[i]).add_coverage (c->after))) return;
const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
count = substitute.len;
c->output->add_array (substitute.arrayZ, substitute.len);
}
const Coverage &get_coverage () const { return this+coverage; }
bool would_apply (hb_would_apply_context_t *c) const
{
TRACE_WOULD_APPLY (this);
return_trace (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
}
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
if (unlikely (c->nesting_level_left != HB_MAX_NESTING_LEVEL))
return_trace (false); /* No chaining to this type */
unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return_trace (false);
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
unsigned int start_index = 0, end_index = 0;
if (match_backtrack (c,
backtrack.len, (HBUINT16 *) backtrack.arrayZ,
match_coverage, this,
&start_index) &&
match_lookahead (c,
lookahead.len, (HBUINT16 *) lookahead.arrayZ,
match_coverage, this,
1, &end_index))
{
c->buffer->unsafe_to_break_from_outbuffer (start_index, end_index);
c->replace_glyph_inplace (substitute[index]);
/* Note: We DON'T decrease buffer->idx. The main loop does it
* for us. This is useful for preventing surprises if someone
* calls us through a Context lookup. */
return_trace (true);
}
return_trace (false);
}
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 (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this)))
return_trace (false);
const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
if (!lookahead.sanitize (c, this))
return_trace (false);
const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
return_trace (substitute.sanitize (c));
}
protected:
HBUINT16 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
{
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));
default:return_trace (c->default_return_value ());
}
}
protected:
union {
HBUINT16 format; /* Format identifier */
ReverseChainSingleSubstFormat1 format1;
} u;
};
/*
* SubstLookup
*/
struct SubstLookupSubTable
{
friend struct Lookup;
friend struct SubstLookup;
enum Type {
Single = 1,
Multiple = 2,
Alternate = 3,
Ligature = 4,
Context = 5,
ChainContext = 6,
Extension = 7,
ReverseChainSingle = 8
};
template <typename context_t>
typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
{
TRACE_DISPATCH (this, lookup_type);
switch (lookup_type) {
case Single: return_trace (u.single.dispatch (c));
case Multiple: return_trace (u.multiple.dispatch (c));
case Alternate: return_trace (u.alternate.dispatch (c));
case Ligature: return_trace (u.ligature.dispatch (c));
case Context: return_trace (u.context.dispatch (c));
case ChainContext: return_trace (u.chainContext.dispatch (c));
case Extension: return_trace (u.extension.dispatch (c));
case ReverseChainSingle: return_trace (u.reverseChainContextSingle.dispatch (c));
default: return_trace (c->default_return_value ());
}
}
protected:
union {
SingleSubst single;
MultipleSubst multiple;
AlternateSubst alternate;
LigatureSubst ligature;
ContextSubst context;
ChainContextSubst chainContext;
ExtensionSubst extension;
ReverseChainSingleSubst reverseChainContextSingle;
} u;
public:
DEFINE_SIZE_MIN (0);
};
struct SubstLookup : Lookup
{
typedef SubstLookupSubTable SubTable;
const SubTable& get_subtable (unsigned int i) const
{ return Lookup::get_subtable<SubTable> (i); }
static bool lookup_type_is_reverse (unsigned int lookup_type)
{ return lookup_type == SubTable::ReverseChainSingle; }
bool is_reverse () const
{
unsigned int type = get_type ();
if (unlikely (type == SubTable::Extension))
return CastR<ExtensionSubst> (get_subtable(0)).is_reverse ();
return lookup_type_is_reverse (type);
}
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
return_trace (dispatch (c));
}
bool intersects (const hb_set_t *glyphs) const
{
hb_intersects_context_t c (glyphs);
return dispatch (&c);
}
hb_closure_context_t::return_t closure (hb_closure_context_t *c, unsigned int this_index) const
{
if (!c->should_visit_lookup (this_index))
return hb_closure_context_t::default_return_value ();
c->set_recurse_func (dispatch_closure_recurse_func);
hb_closure_context_t::return_t ret = dispatch (c);
c->flush ();
return ret;
}
hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
{
c->set_recurse_func (dispatch_recurse_func<hb_collect_glyphs_context_t>);
return dispatch (c);
}
template <typename set_t>
void add_coverage (set_t *glyphs) const
{
hb_add_coverage_context_t<set_t> c (glyphs);
dispatch (&c);
}
bool would_apply (hb_would_apply_context_t *c,
const hb_ot_layout_lookup_accelerator_t *accel) const
{
TRACE_WOULD_APPLY (this);
if (unlikely (!c->len)) return_trace (false);
if (!accel->may_have (c->glyphs[0])) return_trace (false);
return_trace (dispatch (c));
}
static bool apply_recurse_func (hb_ot_apply_context_t *c, unsigned int lookup_index);
SubTable& serialize_subtable (hb_serialize_context_t *c,
unsigned int i)
{ return get_subtables<SubTable> ()[i].serialize (c, this); }
bool serialize_single (hb_serialize_context_t *c,
uint32_t lookup_props,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const GlyphID> substitutes)
{
TRACE_SERIALIZE (this);
if (unlikely (!Lookup::serialize (c, SubTable::Single, lookup_props, 1))) return_trace (false);
return_trace (serialize_subtable (c, 0).u.single.serialize (c, glyphs, substitutes));
}
bool serialize_multiple (hb_serialize_context_t *c,
uint32_t lookup_props,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const unsigned int> substitute_len_list,
hb_array_t<const GlyphID> substitute_glyphs_list)
{
TRACE_SERIALIZE (this);
if (unlikely (!Lookup::serialize (c, SubTable::Multiple, lookup_props, 1))) return_trace (false);
return_trace (serialize_subtable (c, 0).u.multiple.serialize (c,
glyphs,
substitute_len_list,
substitute_glyphs_list));
}
bool serialize_alternate (hb_serialize_context_t *c,
uint32_t lookup_props,
hb_array_t<const GlyphID> glyphs,
hb_array_t<const unsigned int> alternate_len_list,
hb_array_t<const GlyphID> alternate_glyphs_list)
{
TRACE_SERIALIZE (this);
if (unlikely (!Lookup::serialize (c, SubTable::Alternate, lookup_props, 1))) return_trace (false);
return_trace (serialize_subtable (c, 0).u.alternate.serialize (c,
glyphs,
alternate_len_list,
alternate_glyphs_list));
}
bool serialize_ligature (hb_serialize_context_t *c,
uint32_t lookup_props,
hb_array_t<const GlyphID> first_glyphs,
hb_array_t<const unsigned int> ligature_per_first_glyph_count_list,
hb_array_t<const GlyphID> ligatures_list,
hb_array_t<const unsigned int> component_count_list,
hb_array_t<const GlyphID> component_list /* Starting from second for each ligature */)
{
TRACE_SERIALIZE (this);
if (unlikely (!Lookup::serialize (c, SubTable::Ligature, lookup_props, 1))) return_trace (false);
return_trace (serialize_subtable (c, 0).u.ligature.serialize (c,
first_glyphs,
ligature_per_first_glyph_count_list,
ligatures_list,
component_count_list,
component_list));
}
template <typename context_t>
static typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
static hb_closure_context_t::return_t dispatch_closure_recurse_func (hb_closure_context_t *c, unsigned int lookup_index)
{
if (!c->should_visit_lookup (lookup_index))
return HB_VOID;
hb_closure_context_t::return_t ret = dispatch_recurse_func (c, lookup_index);
/* While in theory we should flush here, it will cause timeouts because a recursive
* lookup can keep growing the glyph set. Skip, and outer loop will retry up to
* HB_CLOSURE_MAX_STAGES time, which should be enough for every realistic font. */
//c->flush ();
return ret;
}
template <typename context_t>
typename context_t::return_t dispatch (context_t *c) const
{ return Lookup::dispatch<SubTable> (c); }
bool subset (hb_subset_context_t *c) const
{ return Lookup::subset<SubTable> (c); }
bool sanitize (hb_sanitize_context_t *c) const
{ return Lookup::sanitize<SubTable> (c); }
};
/*
* GSUB -- Glyph Substitution
* https://docs.microsoft.com/en-us/typography/opentype/spec/gsub
*/
struct GSUB : GSUBGPOS
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_GSUB;
const SubstLookup& get_lookup (unsigned int i) const
{ return CastR<SubstLookup> (GSUBGPOS::get_lookup (i)); }
bool subset (hb_subset_context_t *c) const
{ return GSUBGPOS::subset<SubstLookup> (c); }
bool sanitize (hb_sanitize_context_t *c) const
{ return GSUBGPOS::sanitize<SubstLookup> (c); }
HB_INTERNAL bool is_blacklisted (hb_blob_t *blob,
hb_face_t *face) const;
typedef GSUBGPOS::accelerator_t<GSUB> accelerator_t;
};
struct GSUB_accelerator_t : GSUB::accelerator_t {};
/* Out-of-class implementation for methods recursing */
/*static*/ inline bool ExtensionSubst::is_reverse () const
{
unsigned int type = get_type ();
if (unlikely (type == SubTable::Extension))
return CastR<ExtensionSubst> (get_subtable<SubTable>()).is_reverse ();
return SubstLookup::lookup_type_is_reverse (type);
}
template <typename context_t>
/*static*/ inline typename context_t::return_t SubstLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
{
const SubstLookup &l = c->face->table.GSUB.get_relaxed ()->table->get_lookup (lookup_index);
return l.dispatch (c);
}
/*static*/ inline bool SubstLookup::apply_recurse_func (hb_ot_apply_context_t *c, unsigned int lookup_index)
{
const SubstLookup &l = c->face->table.GSUB.get_relaxed ()->table->get_lookup (lookup_index);
unsigned int saved_lookup_props = c->lookup_props;
unsigned int saved_lookup_index = c->lookup_index;
c->set_lookup_index (lookup_index);
c->set_lookup_props (l.get_props ());
bool ret = l.dispatch (c);
c->set_lookup_index (saved_lookup_index);
c->set_lookup_props (saved_lookup_props);
return ret;
}
} /* namespace OT */
#endif /* HB_OT_LAYOUT_GSUB_TABLE_HH */
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