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harfbuzz/src/hb-aat-layout-morx-table.hh

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/*
* Copyright © 2017 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.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_AAT_LAYOUT_MORX_TABLE_HH
#define HB_AAT_LAYOUT_MORX_TABLE_HH
#include "hb-open-type.hh"
#include "hb-aat-layout-common.hh"
#include "hb-ot-layout-common.hh"
#include "hb-ot-layout-gdef-table.hh"
#include "hb-aat-map.hh"
/*
* morx -- Extended Glyph Metamorphosis
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6morx.html
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6mort.html
*/
#define HB_AAT_TAG_morx HB_TAG('m','o','r','x')
#define HB_AAT_TAG_mort HB_TAG('m','o','r','t')
namespace AAT {
using namespace OT;
template <typename Types>
struct RearrangementSubtable
{
typedef typename Types::HBUINT HBUINT;
typedef void EntryData;
struct driver_context_t
{
static constexpr bool in_place = true;
enum Flags
{
MarkFirst = 0x8000, /* If set, make the current glyph the first
* glyph to be rearranged. */
DontAdvance = 0x4000, /* If set, don't advance to the next glyph
* before going to the new state. This means
* that the glyph index doesn't change, even
* if the glyph at that index has changed. */
MarkLast = 0x2000, /* If set, make the current glyph the last
* glyph to be rearranged. */
Reserved = 0x1FF0, /* These bits are reserved and should be set to 0. */
Verb = 0x000F, /* The type of rearrangement specified. */
};
driver_context_t (const RearrangementSubtable *table HB_UNUSED) :
ret (false),
start (0), end (0) {}
bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED,
const Entry<EntryData> &entry)
{
return (entry.flags & Verb) && start < end;
}
void transition (StateTableDriver<Types, EntryData> *driver,
const Entry<EntryData> &entry)
{
hb_buffer_t *buffer = driver->buffer;
unsigned int flags = entry.flags;
if (flags & MarkFirst)
start = buffer->idx;
if (flags & MarkLast)
end = hb_min (buffer->idx + 1, buffer->len);
if ((flags & Verb) && start < end)
{
/* The following map has two nibbles, for start-side
* and end-side. Values of 0,1,2 mean move that many
* to the other side. Value of 3 means move 2 and
* flip them. */
const unsigned char map[16] =
{
0x00, /* 0 no change */
0x10, /* 1 Ax => xA */
0x01, /* 2 xD => Dx */
0x11, /* 3 AxD => DxA */
0x20, /* 4 ABx => xAB */
0x30, /* 5 ABx => xBA */
0x02, /* 6 xCD => CDx */
0x03, /* 7 xCD => DCx */
0x12, /* 8 AxCD => CDxA */
0x13, /* 9 AxCD => DCxA */
0x21, /* 10 ABxD => DxAB */
0x31, /* 11 ABxD => DxBA */
0x22, /* 12 ABxCD => CDxAB */
0x32, /* 13 ABxCD => CDxBA */
0x23, /* 14 ABxCD => DCxAB */
0x33, /* 15 ABxCD => DCxBA */
};
unsigned int m = map[flags & Verb];
unsigned int l = hb_min (2u, m >> 4);
unsigned int r = hb_min (2u, m & 0x0F);
bool reverse_l = 3 == (m >> 4);
bool reverse_r = 3 == (m & 0x0F);
if (end - start >= l + r && end-start <= HB_MAX_CONTEXT_LENGTH)
{
buffer->merge_clusters (start, hb_min (buffer->idx + 1, buffer->len));
buffer->merge_clusters (start, end);
hb_glyph_info_t *info = buffer->info;
hb_glyph_info_t buf[4];
memcpy (buf, info + start, l * sizeof (buf[0]));
memcpy (buf + 2, info + end - r, r * sizeof (buf[0]));
if (l != r)
memmove (info + start + r, info + start + l, (end - start - l - r) * sizeof (buf[0]));
memcpy (info + start, buf + 2, r * sizeof (buf[0]));
memcpy (info + end - l, buf, l * sizeof (buf[0]));
if (reverse_l)
{
buf[0] = info[end - 1];
info[end - 1] = info[end - 2];
info[end - 2] = buf[0];
}
if (reverse_r)
{
buf[0] = info[start];
info[start] = info[start + 1];
info[start + 1] = buf[0];
}
}
}
}
public:
bool ret;
private:
unsigned int start;
unsigned int end;
};
bool apply (hb_aat_apply_context_t *c) const
{
TRACE_APPLY (this);
driver_context_t dc (this);
StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
driver.drive (&dc);
return_trace (dc.ret);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (machine.sanitize (c));
}
protected:
StateTable<Types, EntryData> machine;
public:
DEFINE_SIZE_STATIC (16);
};
template <typename Types>
struct ContextualSubtable
{
typedef typename Types::HBUINT HBUINT;
struct EntryData
{
HBUINT16 markIndex; /* Index of the substitution table for the
* marked glyph (use 0xFFFF for none). */
HBUINT16 currentIndex; /* Index of the substitution table for the
* current glyph (use 0xFFFF for none). */
public:
DEFINE_SIZE_STATIC (4);
};
struct driver_context_t
{
static constexpr bool in_place = true;
enum Flags
{
SetMark = 0x8000, /* If set, make the current glyph the marked glyph. */
DontAdvance = 0x4000, /* If set, don't advance to the next glyph before
* going to the new state. */
Reserved = 0x3FFF, /* These bits are reserved and should be set to 0. */
};
driver_context_t (const ContextualSubtable *table_,
hb_aat_apply_context_t *c_) :
ret (false),
c (c_),
gdef (*c->gdef_table),
mark_set (false),
has_glyph_classes (gdef.has_glyph_classes ()),
mark (0),
table (table_),
subs (table+table->substitutionTables) {}
bool is_actionable (StateTableDriver<Types, EntryData> *driver,
const Entry<EntryData> &entry)
{
hb_buffer_t *buffer = driver->buffer;
if (buffer->idx == buffer->len && !mark_set)
return false;
return entry.data.markIndex != 0xFFFF || entry.data.currentIndex != 0xFFFF;
}
void transition (StateTableDriver<Types, EntryData> *driver,
const Entry<EntryData> &entry)
{
hb_buffer_t *buffer = driver->buffer;
/* Looks like CoreText applies neither mark nor current substitution for
* end-of-text if mark was not explicitly set. */
if (buffer->idx == buffer->len && !mark_set)
return;
const HBGlyphID16 *replacement;
replacement = nullptr;
if (Types::extended)
{
if (entry.data.markIndex != 0xFFFF)
{
const Lookup<HBGlyphID16> &lookup = subs[entry.data.markIndex];
replacement = lookup.get_value (buffer->info[mark].codepoint, driver->num_glyphs);
}
}
else
{
unsigned int offset = entry.data.markIndex + buffer->info[mark].codepoint;
const UnsizedArrayOf<HBGlyphID16> &subs_old = (const UnsizedArrayOf<HBGlyphID16> &) subs;
replacement = &subs_old[Types::wordOffsetToIndex (offset, table, subs_old.arrayZ)];
if (!replacement->sanitize (&c->sanitizer) || !*replacement)
replacement = nullptr;
}
if (replacement)
{
buffer->unsafe_to_break (mark, hb_min (buffer->idx + 1, buffer->len));
buffer->info[mark].codepoint = *replacement;
if (has_glyph_classes)
_hb_glyph_info_set_glyph_props (&buffer->info[mark],
gdef.get_glyph_props (*replacement));
ret = true;
}
replacement = nullptr;
unsigned int idx = hb_min (buffer->idx, buffer->len - 1);
if (Types::extended)
{
if (entry.data.currentIndex != 0xFFFF)
{
const Lookup<HBGlyphID16> &lookup = subs[entry.data.currentIndex];
replacement = lookup.get_value (buffer->info[idx].codepoint, driver->num_glyphs);
}
}
else
{
unsigned int offset = entry.data.currentIndex + buffer->info[idx].codepoint;
const UnsizedArrayOf<HBGlyphID16> &subs_old = (const UnsizedArrayOf<HBGlyphID16> &) subs;
replacement = &subs_old[Types::wordOffsetToIndex (offset, table, subs_old.arrayZ)];
if (!replacement->sanitize (&c->sanitizer) || !*replacement)
replacement = nullptr;
}
if (replacement)
{
buffer->info[idx].codepoint = *replacement;
if (has_glyph_classes)
_hb_glyph_info_set_glyph_props (&buffer->info[idx],
gdef.get_glyph_props (*replacement));
ret = true;
}
if (entry.flags & SetMark)
{
mark_set = true;
mark = buffer->idx;
}
}
public:
bool ret;
private:
hb_aat_apply_context_t *c;
const OT::GDEF &gdef;
bool mark_set;
bool has_glyph_classes;
unsigned int mark;
const ContextualSubtable *table;
const UnsizedListOfOffset16To<Lookup<HBGlyphID16>, HBUINT, false> &subs;
};
bool apply (hb_aat_apply_context_t *c) const
{
TRACE_APPLY (this);
driver_context_t dc (this, c);
StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
driver.drive (&dc);
return_trace (dc.ret);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
unsigned int num_entries = 0;
if (unlikely (!machine.sanitize (c, &num_entries))) return_trace (false);
if (!Types::extended)
return_trace (substitutionTables.sanitize (c, this, 0));
unsigned int num_lookups = 0;
const Entry<EntryData> *entries = machine.get_entries ();
for (unsigned int i = 0; i < num_entries; i++)
{
const EntryData &data = entries[i].data;
if (data.markIndex != 0xFFFF)
num_lookups = hb_max (num_lookups, 1u + data.markIndex);
if (data.currentIndex != 0xFFFF)
num_lookups = hb_max (num_lookups, 1u + data.currentIndex);
}
return_trace (substitutionTables.sanitize (c, this, num_lookups));
}
protected:
StateTable<Types, EntryData>
machine;
NNOffsetTo<UnsizedListOfOffset16To<Lookup<HBGlyphID16>, HBUINT, false>, HBUINT>
substitutionTables;
public:
DEFINE_SIZE_STATIC (20);
};
template <bool extended>
struct LigatureEntry;
template <>
struct LigatureEntry<true>
{
enum Flags
{
SetComponent = 0x8000, /* Push this glyph onto the component stack for
* eventual processing. */
DontAdvance = 0x4000, /* Leave the glyph pointer at this glyph for the
next iteration. */
PerformAction = 0x2000, /* Use the ligActionIndex to process a ligature
* group. */
Reserved = 0x1FFF, /* These bits are reserved and should be set to 0. */
};
struct EntryData
{
HBUINT16 ligActionIndex; /* Index to the first ligActionTable entry
* for processing this group, if indicated
* by the flags. */
public:
DEFINE_SIZE_STATIC (2);
};
static bool performAction (const Entry<EntryData> &entry)
{ return entry.flags & PerformAction; }
static unsigned int ligActionIndex (const Entry<EntryData> &entry)
{ return entry.data.ligActionIndex; }
};
template <>
struct LigatureEntry<false>
{
enum Flags
{
SetComponent = 0x8000, /* Push this glyph onto the component stack for
* eventual processing. */
DontAdvance = 0x4000, /* Leave the glyph pointer at this glyph for the
next iteration. */
Offset = 0x3FFF, /* Byte offset from beginning of subtable to the
* ligature action list. This value must be a
* multiple of 4. */
};
typedef void EntryData;
static bool performAction (const Entry<EntryData> &entry)
{ return entry.flags & Offset; }
static unsigned int ligActionIndex (const Entry<EntryData> &entry)
{ return entry.flags & Offset; }
};
template <typename Types>
struct LigatureSubtable
{
typedef typename Types::HBUINT HBUINT;
typedef LigatureEntry<Types::extended> LigatureEntryT;
typedef typename LigatureEntryT::EntryData EntryData;
struct driver_context_t
{
static constexpr bool in_place = false;
enum
{
DontAdvance = LigatureEntryT::DontAdvance,
};
enum LigActionFlags
{
LigActionLast = 0x80000000, /* This is the last action in the list. This also
* implies storage. */
LigActionStore = 0x40000000, /* Store the ligature at the current cumulated index
* in the ligature table in place of the marked
* (i.e. currently-popped) glyph. */
LigActionOffset = 0x3FFFFFFF, /* A 30-bit value which is sign-extended to 32-bits
* and added to the glyph ID, resulting in an index
* into the component table. */
};
driver_context_t (const LigatureSubtable *table_,
hb_aat_apply_context_t *c_) :
ret (false),
c (c_),
table (table_),
ligAction (table+table->ligAction),
component (table+table->component),
ligature (table+table->ligature),
match_length (0) {}
bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED,
const Entry<EntryData> &entry)
{
return LigatureEntryT::performAction (entry);
}
void transition (StateTableDriver<Types, EntryData> *driver,
const Entry<EntryData> &entry)
{
hb_buffer_t *buffer = driver->buffer;
DEBUG_MSG (APPLY, nullptr, "Ligature transition at %u", buffer->idx);
if (entry.flags & LigatureEntryT::SetComponent)
{
/* Never mark same index twice, in case DontAdvance was used... */
if (match_length && match_positions[(match_length - 1u) % ARRAY_LENGTH (match_positions)] == buffer->out_len)
match_length--;
match_positions[match_length++ % ARRAY_LENGTH (match_positions)] = buffer->out_len;
DEBUG_MSG (APPLY, nullptr, "Set component at %u", buffer->out_len);
}
if (LigatureEntryT::performAction (entry))
{
DEBUG_MSG (APPLY, nullptr, "Perform action with %u", match_length);
unsigned int end = buffer->out_len;
if (unlikely (!match_length))
return;
if (buffer->idx >= buffer->len)
return; /* TODO Work on previous instead? */
unsigned int cursor = match_length;
unsigned int action_idx = LigatureEntryT::ligActionIndex (entry);
action_idx = Types::offsetToIndex (action_idx, table, ligAction.arrayZ);
const HBUINT32 *actionData = &ligAction[action_idx];
unsigned int ligature_idx = 0;
unsigned int action;
do
{
if (unlikely (!cursor))
{
/* Stack underflow. Clear the stack. */
DEBUG_MSG (APPLY, nullptr, "Stack underflow");
match_length = 0;
break;
}
DEBUG_MSG (APPLY, nullptr, "Moving to stack position %u", cursor - 1);
if (unlikely (!buffer->move_to (match_positions[--cursor % ARRAY_LENGTH (match_positions)]))) return;
if (unlikely (!actionData->sanitize (&c->sanitizer))) break;
action = *actionData;
uint32_t uoffset = action & LigActionOffset;
if (uoffset & 0x20000000)
uoffset |= 0xC0000000; /* Sign-extend. */
int32_t offset = (int32_t) uoffset;
unsigned int component_idx = buffer->cur().codepoint + offset;
component_idx = Types::wordOffsetToIndex (component_idx, table, component.arrayZ);
const HBUINT16 &componentData = component[component_idx];
if (unlikely (!componentData.sanitize (&c->sanitizer))) break;
ligature_idx += componentData;
DEBUG_MSG (APPLY, nullptr, "Action store %u last %u",
bool (action & LigActionStore),
bool (action & LigActionLast));
if (action & (LigActionStore | LigActionLast))
{
ligature_idx = Types::offsetToIndex (ligature_idx, table, ligature.arrayZ);
const HBGlyphID16 &ligatureData = ligature[ligature_idx];
if (unlikely (!ligatureData.sanitize (&c->sanitizer))) break;
hb_codepoint_t lig = ligatureData;
DEBUG_MSG (APPLY, nullptr, "Produced ligature %u", lig);
if (unlikely (!buffer->replace_glyph (lig))) return;
unsigned int lig_end = match_positions[(match_length - 1u) % ARRAY_LENGTH (match_positions)] + 1u;
/* Now go and delete all subsequent components. */
while (match_length - 1u > cursor)
{
DEBUG_MSG (APPLY, nullptr, "Skipping ligature component");
if (unlikely (!buffer->move_to (match_positions[--match_length % ARRAY_LENGTH (match_positions)]))) return;
if (unlikely (!buffer->replace_glyph (DELETED_GLYPH))) return;
}
if (unlikely (!buffer->move_to (lig_end))) return;
buffer->merge_out_clusters (match_positions[cursor % ARRAY_LENGTH (match_positions)], buffer->out_len);
}
actionData++;
}
while (!(action & LigActionLast));
if (unlikely (!buffer->move_to (end))) return;
}
}
public:
bool ret;
private:
hb_aat_apply_context_t *c;
const LigatureSubtable *table;
const UnsizedArrayOf<HBUINT32> &ligAction;
const UnsizedArrayOf<HBUINT16> &component;
const UnsizedArrayOf<HBGlyphID16> &ligature;
unsigned int match_length;
unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
};
bool apply (hb_aat_apply_context_t *c) const
{
TRACE_APPLY (this);
driver_context_t dc (this, c);
StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
driver.drive (&dc);
return_trace (dc.ret);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
/* The rest of array sanitizations are done at run-time. */
return_trace (c->check_struct (this) && machine.sanitize (c) &&
ligAction && component && ligature);
}
protected:
StateTable<Types, EntryData>
machine;
NNOffsetTo<UnsizedArrayOf<HBUINT32>, HBUINT>
ligAction; /* Offset to the ligature action table. */
NNOffsetTo<UnsizedArrayOf<HBUINT16>, HBUINT>
component; /* Offset to the component table. */
NNOffsetTo<UnsizedArrayOf<HBGlyphID16>, HBUINT>
ligature; /* Offset to the actual ligature lists. */
public:
DEFINE_SIZE_STATIC (28);
};
template <typename Types>
struct NoncontextualSubtable
{
bool apply (hb_aat_apply_context_t *c) const
{
TRACE_APPLY (this);
const OT::GDEF &gdef (*c->gdef_table);
bool has_glyph_classes = gdef.has_glyph_classes ();
bool ret = false;
unsigned int num_glyphs = c->face->get_num_glyphs ();
hb_glyph_info_t *info = c->buffer->info;
unsigned int count = c->buffer->len;
for (unsigned int i = 0; i < count; i++)
{
const HBGlyphID16 *replacement = substitute.get_value (info[i].codepoint, num_glyphs);
if (replacement)
{
info[i].codepoint = *replacement;
if (has_glyph_classes)
_hb_glyph_info_set_glyph_props (&info[i],
gdef.get_glyph_props (*replacement));
ret = true;
}
}
return_trace (ret);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (substitute.sanitize (c));
}
protected:
Lookup<HBGlyphID16> substitute;
public:
DEFINE_SIZE_MIN (2);
};
template <typename Types>
struct InsertionSubtable
{
typedef typename Types::HBUINT HBUINT;
struct EntryData
{
HBUINT16 currentInsertIndex; /* Zero-based index into the insertion glyph table.
* The number of glyphs to be inserted is contained
* in the currentInsertCount field in the flags.
* A value of 0xFFFF indicates no insertion is to
* be done. */
HBUINT16 markedInsertIndex; /* Zero-based index into the insertion glyph table.
* The number of glyphs to be inserted is contained
* in the markedInsertCount field in the flags.
* A value of 0xFFFF indicates no insertion is to
* be done. */
public:
DEFINE_SIZE_STATIC (4);
};
struct driver_context_t
{
static constexpr bool in_place = false;
enum Flags
{
SetMark = 0x8000, /* If set, mark the current glyph. */
DontAdvance = 0x4000, /* If set, don't advance to the next glyph before
* going to the new state. This does not mean
* that the glyph pointed to is the same one as
* before. If you've made insertions immediately
* downstream of the current glyph, the next glyph
* processed would in fact be the first one
* inserted. */
CurrentIsKashidaLike= 0x2000, /* If set, and the currentInsertList is nonzero,
* then the specified glyph list will be inserted
* as a kashida-like insertion, either before or
* after the current glyph (depending on the state
* of the currentInsertBefore flag). If clear, and
* the currentInsertList is nonzero, then the
* specified glyph list will be inserted as a
* split-vowel-like insertion, either before or
* after the current glyph (depending on the state
* of the currentInsertBefore flag). */
MarkedIsKashidaLike= 0x1000, /* If set, and the markedInsertList is nonzero,
* then the specified glyph list will be inserted
* as a kashida-like insertion, either before or
* after the marked glyph (depending on the state
* of the markedInsertBefore flag). If clear, and
* the markedInsertList is nonzero, then the
* specified glyph list will be inserted as a
* split-vowel-like insertion, either before or
* after the marked glyph (depending on the state
* of the markedInsertBefore flag). */
CurrentInsertBefore= 0x0800, /* If set, specifies that insertions are to be made
* to the left of the current glyph. If clear,
* they're made to the right of the current glyph. */
MarkedInsertBefore= 0x0400, /* If set, specifies that insertions are to be
* made to the left of the marked glyph. If clear,
* they're made to the right of the marked glyph. */
CurrentInsertCount= 0x3E0, /* This 5-bit field is treated as a count of the
* number of glyphs to insert at the current
* position. Since zero means no insertions, the
* largest number of insertions at any given
* current location is 31 glyphs. */
MarkedInsertCount= 0x001F, /* This 5-bit field is treated as a count of the
* number of glyphs to insert at the marked
* position. Since zero means no insertions, the
* largest number of insertions at any given
* marked location is 31 glyphs. */
};
driver_context_t (const InsertionSubtable *table,
hb_aat_apply_context_t *c_) :
ret (false),
c (c_),
mark (0),
insertionAction (table+table->insertionAction) {}
bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED,
const Entry<EntryData> &entry)
{
return (entry.flags & (CurrentInsertCount | MarkedInsertCount)) &&
(entry.data.currentInsertIndex != 0xFFFF ||entry.data.markedInsertIndex != 0xFFFF);
}
void transition (StateTableDriver<Types, EntryData> *driver,
const Entry<EntryData> &entry)
{
hb_buffer_t *buffer = driver->buffer;
unsigned int flags = entry.flags;
unsigned mark_loc = buffer->out_len;
if (entry.data.markedInsertIndex != 0xFFFF)
{
unsigned int count = (flags & MarkedInsertCount);
if (unlikely ((buffer->max_ops -= count) <= 0)) return;
unsigned int start = entry.data.markedInsertIndex;
const HBGlyphID16 *glyphs = &insertionAction[start];
if (unlikely (!c->sanitizer.check_array (glyphs, count))) count = 0;
bool before = flags & MarkedInsertBefore;
unsigned int end = buffer->out_len;
if (unlikely (!buffer->move_to (mark))) return;
if (buffer->idx < buffer->len && !before)
if (unlikely (!buffer->copy_glyph ())) return;
/* TODO We ignore KashidaLike setting. */
if (unlikely (!buffer->replace_glyphs (0, count, glyphs))) return;
if (buffer->idx < buffer->len && !before)
buffer->skip_glyph ();
if (unlikely (!buffer->move_to (end + count))) return;
buffer->unsafe_to_break_from_outbuffer (mark, hb_min (buffer->idx + 1, buffer->len));
}
if (flags & SetMark)
mark = mark_loc;
if (entry.data.currentInsertIndex != 0xFFFF)
{
unsigned int count = (flags & CurrentInsertCount) >> 5;
if (unlikely ((buffer->max_ops -= count) <= 0)) return;
unsigned int start = entry.data.currentInsertIndex;
const HBGlyphID16 *glyphs = &insertionAction[start];
if (unlikely (!c->sanitizer.check_array (glyphs, count))) count = 0;
bool before = flags & CurrentInsertBefore;
unsigned int end = buffer->out_len;
if (buffer->idx < buffer->len && !before)
if (unlikely (!buffer->copy_glyph ())) return;
/* TODO We ignore KashidaLike setting. */
if (unlikely (!buffer->replace_glyphs (0, count, glyphs))) return;
if (buffer->idx < buffer->len && !before)
buffer->skip_glyph ();
/* Humm. Not sure where to move to. There's this wording under
* DontAdvance flag:
*
* "If set, don't update the glyph index before going to the new state.
* This does not mean that the glyph pointed to is the same one as
* before. If you've made insertions immediately downstream of the
* current glyph, the next glyph processed would in fact be the first
* one inserted."
*
* This suggests that if DontAdvance is NOT set, we should move to
* end+count. If it *was*, then move to end, such that newly inserted
* glyphs are now visible.
*
* https://github.com/harfbuzz/harfbuzz/issues/1224#issuecomment-427691417
*/
if (unlikely (!buffer->move_to ((flags & DontAdvance) ? end : end + count))) return;
}
}
public:
bool ret;
private:
hb_aat_apply_context_t *c;
unsigned int mark;
const UnsizedArrayOf<HBGlyphID16> &insertionAction;
};
bool apply (hb_aat_apply_context_t *c) const
{
TRACE_APPLY (this);
driver_context_t dc (this, c);
StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
driver.drive (&dc);
return_trace (dc.ret);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
/* The rest of array sanitizations are done at run-time. */
return_trace (c->check_struct (this) && machine.sanitize (c) &&
insertionAction);
}
protected:
StateTable<Types, EntryData>
machine;
NNOffsetTo<UnsizedArrayOf<HBGlyphID16>, HBUINT>
insertionAction; /* Byte offset from stateHeader to the start of
* the insertion glyph table. */
public:
DEFINE_SIZE_STATIC (20);
};
struct Feature
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
public:
HBUINT16 featureType; /* The type of feature. */
HBUINT16 featureSetting; /* The feature's setting (aka selector). */
HBUINT32 enableFlags; /* Flags for the settings that this feature
* and setting enables. */
HBUINT32 disableFlags; /* Complement of flags for the settings that this
* feature and setting disable. */
public:
DEFINE_SIZE_STATIC (12);
};
template <typename Types>
struct ChainSubtable
{
typedef typename Types::HBUINT HBUINT;
template <typename T>
friend struct Chain;
unsigned int get_size () const { return length; }
unsigned int get_type () const { return coverage & 0xFF; }
unsigned int get_coverage () const { return coverage >> (sizeof (HBUINT) * 8 - 8); }
enum Coverage
{
Vertical = 0x80, /* If set, this subtable will only be applied
* to vertical text. If clear, this subtable
* will only be applied to horizontal text. */
Backwards = 0x40, /* If set, this subtable will process glyphs
* in descending order. If clear, it will
* process the glyphs in ascending order. */
AllDirections = 0x20, /* If set, this subtable will be applied to
* both horizontal and vertical text (i.e.
* the state of bit 0x80000000 is ignored). */
Logical = 0x10, /* If set, this subtable will process glyphs
* in logical order (or reverse logical order,
* depending on the value of bit 0x80000000). */
};
enum Type
{
Rearrangement = 0,
Contextual = 1,
Ligature = 2,
Noncontextual = 4,
Insertion = 5
};
template <typename context_t, typename ...Ts>
typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
{
unsigned int subtable_type = get_type ();
TRACE_DISPATCH (this, subtable_type);
switch (subtable_type) {
case Rearrangement: return_trace (c->dispatch (u.rearrangement, std::forward<Ts> (ds)...));
case Contextual: return_trace (c->dispatch (u.contextual, std::forward<Ts> (ds)...));
case Ligature: return_trace (c->dispatch (u.ligature, std::forward<Ts> (ds)...));
case Noncontextual: return_trace (c->dispatch (u.noncontextual, std::forward<Ts> (ds)...));
case Insertion: return_trace (c->dispatch (u.insertion, std::forward<Ts> (ds)...));
default: return_trace (c->default_return_value ());
}
}
bool apply (hb_aat_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_sanitize_with_object_t with (&c->sanitizer, this);
return_trace (dispatch (c));
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!length.sanitize (c) ||
length <= min_size ||
!c->check_range (this, length))
return_trace (false);
hb_sanitize_with_object_t with (c, this);
return_trace (dispatch (c));
}
protected:
HBUINT length; /* Total subtable length, including this header. */
HBUINT coverage; /* Coverage flags and subtable type. */
HBUINT32 subFeatureFlags;/* The 32-bit mask identifying which subtable this is. */
union {
RearrangementSubtable<Types> rearrangement;
ContextualSubtable<Types> contextual;
LigatureSubtable<Types> ligature;
NoncontextualSubtable<Types> noncontextual;
InsertionSubtable<Types> insertion;
} u;
public:
DEFINE_SIZE_MIN (2 * sizeof (HBUINT) + 4);
};
template <typename Types>
struct Chain
{
typedef typename Types::HBUINT HBUINT;
hb_mask_t compile_flags (const hb_aat_map_builder_t *map) const
{
hb_mask_t flags = defaultFlags;
{
unsigned int count = featureCount;
for (unsigned i = 0; i < count; i++)
{
const Feature &feature = featureZ[i];
hb_aat_layout_feature_type_t type = (hb_aat_layout_feature_type_t) (unsigned int) feature.featureType;
hb_aat_layout_feature_selector_t setting = (hb_aat_layout_feature_selector_t) (unsigned int) feature.featureSetting;
retry:
// Check whether this type/setting pair was requested in the map, and if so, apply its flags.
// (The search here only looks at the type and setting fields of feature_info_t.)
hb_aat_map_builder_t::feature_info_t info = { type, setting, false, 0 };
if (map->features.bsearch (info))
{
flags &= feature.disableFlags;
flags |= feature.enableFlags;
}
else if (type == HB_AAT_LAYOUT_FEATURE_TYPE_LETTER_CASE && setting == HB_AAT_LAYOUT_FEATURE_SELECTOR_SMALL_CAPS)
{
/* Deprecated. https://github.com/harfbuzz/harfbuzz/issues/1342 */
type = HB_AAT_LAYOUT_FEATURE_TYPE_LOWER_CASE;
setting = HB_AAT_LAYOUT_FEATURE_SELECTOR_LOWER_CASE_SMALL_CAPS;
goto retry;
}
#ifndef HB_NO_AAT
else if (type == HB_AAT_LAYOUT_FEATURE_TYPE_LANGUAGE_TAG_TYPE && setting &&
/* TODO: Rudimentary language matching. */
hb_language_matches (map->face->table.ltag->get_language (setting - 1), map->props.language))
{
flags &= feature.disableFlags;
flags |= feature.enableFlags;
}
#endif
}
}
return flags;
}
void apply (hb_aat_apply_context_t *c,
hb_mask_t flags) const
{
const ChainSubtable<Types> *subtable = &StructAfter<ChainSubtable<Types>> (featureZ.as_array (featureCount));
unsigned int count = subtableCount;
for (unsigned int i = 0; i < count; i++)
{
bool reverse;
if (!(subtable->subFeatureFlags & flags))
goto skip;
if (!(subtable->get_coverage() & ChainSubtable<Types>::AllDirections) &&
HB_DIRECTION_IS_VERTICAL (c->buffer->props.direction) !=
bool (subtable->get_coverage() & ChainSubtable<Types>::Vertical))
goto skip;
/* Buffer contents is always in logical direction. Determine if
* we need to reverse before applying this subtable. We reverse
* back after if we did reverse indeed.
*
* Quoting the spac:
* """
* Bits 28 and 30 of the coverage field control the order in which
* glyphs are processed when the subtable is run by the layout engine.
* Bit 28 is used to indicate if the glyph processing direction is
* the same as logical order or layout order. Bit 30 is used to
* indicate whether glyphs are processed forwards or backwards within
* that order.
Bit 30 Bit 28 Interpretation for Horizontal Text
0 0 The subtable is processed in layout order
(the same order as the glyphs, which is
always left-to-right).
1 0 The subtable is processed in reverse layout order
(the order opposite that of the glyphs, which is
always right-to-left).
0 1 The subtable is processed in logical order
(the same order as the characters, which may be
left-to-right or right-to-left).
1 1 The subtable is processed in reverse logical order
(the order opposite that of the characters, which
may be right-to-left or left-to-right).
*/
reverse = subtable->get_coverage () & ChainSubtable<Types>::Logical ?
bool (subtable->get_coverage () & ChainSubtable<Types>::Backwards) :
bool (subtable->get_coverage () & ChainSubtable<Types>::Backwards) !=
HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction);
if (!c->buffer->message (c->font, "start chainsubtable %d", c->lookup_index))
goto skip;
if (reverse)
c->buffer->reverse ();
subtable->apply (c);
if (reverse)
c->buffer->reverse ();
(void) c->buffer->message (c->font, "end chainsubtable %d", c->lookup_index);
if (unlikely (!c->buffer->successful)) return;
skip:
subtable = &StructAfter<ChainSubtable<Types>> (*subtable);
c->set_lookup_index (c->lookup_index + 1);
}
}
unsigned int get_size () const { return length; }
bool sanitize (hb_sanitize_context_t *c, unsigned int version HB_UNUSED) const
{
TRACE_SANITIZE (this);
if (!length.sanitize (c) ||
length < min_size ||
!c->check_range (this, length))
return_trace (false);
if (!c->check_array (featureZ.arrayZ, featureCount))
return_trace (false);
const ChainSubtable<Types> *subtable = &StructAfter<ChainSubtable<Types>> (featureZ.as_array (featureCount));
unsigned int count = subtableCount;
for (unsigned int i = 0; i < count; i++)
{
if (!subtable->sanitize (c))
return_trace (false);
subtable = &StructAfter<ChainSubtable<Types>> (*subtable);
}
return_trace (true);
}
protected:
HBUINT32 defaultFlags; /* The default specification for subtables. */
HBUINT32 length; /* Total byte count, including this header. */
HBUINT featureCount; /* Number of feature subtable entries. */
HBUINT subtableCount; /* The number of subtables in the chain. */
UnsizedArrayOf<Feature> featureZ; /* Features. */
/*ChainSubtable firstSubtable;*//* Subtables. */
/*subtableGlyphCoverageArray*/ /* Only if version >= 3. We don't use. */
public:
DEFINE_SIZE_MIN (8 + 2 * sizeof (HBUINT));
};
/*
* The 'mort'/'morx' Table
*/
template <typename Types, hb_tag_t TAG>
struct mortmorx
{
static constexpr hb_tag_t tableTag = TAG;
bool has_data () const { return version != 0; }
void compile_flags (const hb_aat_map_builder_t *mapper,
hb_aat_map_t *map) const
{
const Chain<Types> *chain = &firstChain;
unsigned int count = chainCount;
for (unsigned int i = 0; i < count; i++)
{
map->chain_flags.push (chain->compile_flags (mapper));
chain = &StructAfter<Chain<Types>> (*chain);
}
}
void apply (hb_aat_apply_context_t *c) const
{
if (unlikely (!c->buffer->successful)) return;
c->set_lookup_index (0);
const Chain<Types> *chain = &firstChain;
unsigned int count = chainCount;
for (unsigned int i = 0; i < count; i++)
{
chain->apply (c, c->plan->aat_map.chain_flags[i]);
if (unlikely (!c->buffer->successful)) return;
chain = &StructAfter<Chain<Types>> (*chain);
}
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!version.sanitize (c) || !version || !chainCount.sanitize (c))
return_trace (false);
const Chain<Types> *chain = &firstChain;
unsigned int count = chainCount;
for (unsigned int i = 0; i < count; i++)
{
if (!chain->sanitize (c, version))
return_trace (false);
chain = &StructAfter<Chain<Types>> (*chain);
}
return_trace (true);
}
protected:
HBUINT16 version; /* Version number of the glyph metamorphosis table.
* 1, 2, or 3. */
HBUINT16 unused; /* Set to 0. */
HBUINT32 chainCount; /* Number of metamorphosis chains contained in this
* table. */
Chain<Types> firstChain; /* Chains. */
public:
DEFINE_SIZE_MIN (8);
};
struct morx : mortmorx<ExtendedTypes, HB_AAT_TAG_morx> {};
struct mort : mortmorx<ObsoleteTypes, HB_AAT_TAG_mort> {};
} /* namespace AAT */
#endif /* HB_AAT_LAYOUT_MORX_TABLE_HH */
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