harfbuzz/src/hb-ot-var-common.hh

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/*
* Copyright © 2021 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.
*
*/
#ifndef HB_OT_VAR_COMMON_HH
#define HB_OT_VAR_COMMON_HH
#include "hb-ot-layout-common.hh"
namespace OT {
template <typename MapCountT>
struct DeltaSetIndexMapFormat01
{
friend struct DeltaSetIndexMap;
private:
DeltaSetIndexMapFormat01* copy (hb_serialize_context_t *c) const
{
TRACE_SERIALIZE (this);
auto *out = c->start_embed (this);
if (unlikely (!out)) return_trace (nullptr);
unsigned total_size = min_size + mapCount * get_width ();
HBUINT8 *p = c->allocate_size<HBUINT8> (total_size);
if (unlikely (!p)) return_trace (nullptr);
hb_memcpy (p, this, HBUINT8::static_size * total_size);
return_trace (out);
}
template <typename T>
bool serialize (hb_serialize_context_t *c, const T &plan)
{
unsigned int width = plan.get_width ();
unsigned int inner_bit_count = plan.get_inner_bit_count ();
const hb_array_t<const uint32_t> output_map = plan.get_output_map ();
TRACE_SERIALIZE (this);
if (unlikely (output_map.length && ((((inner_bit_count-1)&~0xF)!=0) || (((width-1)&~0x3)!=0))))
return_trace (false);
if (unlikely (!c->extend_min (this))) return_trace (false);
entryFormat = ((width-1)<<4)|(inner_bit_count-1);
mapCount = output_map.length;
HBUINT8 *p = c->allocate_size<HBUINT8> (width * output_map.length);
if (unlikely (!p)) return_trace (false);
for (unsigned int i = 0; i < output_map.length; i++)
{
unsigned int v = output_map[i];
unsigned int outer = v >> 16;
unsigned int inner = v & 0xFFFF;
unsigned int u = (outer << inner_bit_count) | inner;
for (unsigned int w = width; w > 0;)
{
p[--w] = u;
u >>= 8;
}
p += width;
}
return_trace (true);
}
uint32_t map (unsigned int v) const /* Returns 16.16 outer.inner. */
{
/* If count is zero, pass value unchanged. This takes
* care of direct mapping for advance map. */
if (!mapCount)
return v;
if (v >= mapCount)
v = mapCount - 1;
unsigned int u = 0;
{ /* Fetch it. */
unsigned int w = get_width ();
const HBUINT8 *p = mapDataZ.arrayZ + w * v;
for (; w; w--)
u = (u << 8) + *p++;
}
{ /* Repack it. */
unsigned int n = get_inner_bit_count ();
unsigned int outer = u >> n;
unsigned int inner = u & ((1 << n) - 1);
u = (outer<<16) | inner;
}
return u;
}
unsigned get_map_count () const { return mapCount; }
unsigned get_width () const { return ((entryFormat >> 4) & 3) + 1; }
unsigned get_inner_bit_count () const { return (entryFormat & 0xF) + 1; }
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
c->check_range (mapDataZ.arrayZ,
mapCount,
get_width ()));
}
protected:
HBUINT8 format; /* Format identifier--format = 0 */
HBUINT8 entryFormat; /* A packed field that describes the compressed
* representation of delta-set indices. */
MapCountT mapCount; /* The number of mapping entries. */
UnsizedArrayOf<HBUINT8>
mapDataZ; /* The delta-set index mapping data. */
public:
DEFINE_SIZE_ARRAY (2+MapCountT::static_size, mapDataZ);
};
struct DeltaSetIndexMap
{
template <typename T>
bool serialize (hb_serialize_context_t *c, const T &plan)
{
TRACE_SERIALIZE (this);
unsigned length = plan.get_output_map ().length;
u.format = length <= 0xFFFF ? 0 : 1;
switch (u.format) {
case 0: return_trace (u.format0.serialize (c, plan));
case 1: return_trace (u.format1.serialize (c, plan));
default:return_trace (false);
}
}
uint32_t map (unsigned v) const
{
switch (u.format) {
case 0: return (u.format0.map (v));
case 1: return (u.format1.map (v));
default:return v;
}
}
unsigned get_map_count () const
{
switch (u.format) {
case 0: return u.format0.get_map_count ();
case 1: return u.format1.get_map_count ();
default:return 0;
}
}
unsigned get_width () const
{
switch (u.format) {
case 0: return u.format0.get_width ();
case 1: return u.format1.get_width ();
default:return 0;
}
}
unsigned get_inner_bit_count () const
{
switch (u.format) {
case 0: return u.format0.get_inner_bit_count ();
case 1: return u.format1.get_inner_bit_count ();
default:return 0;
}
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!u.format.sanitize (c)) return_trace (false);
switch (u.format) {
case 0: return_trace (u.format0.sanitize (c));
case 1: return_trace (u.format1.sanitize (c));
default:return_trace (true);
}
}
DeltaSetIndexMap* copy (hb_serialize_context_t *c) const
{
TRACE_SERIALIZE (this);
switch (u.format) {
case 0: return_trace (reinterpret_cast<DeltaSetIndexMap *> (u.format0.copy (c)));
case 1: return_trace (reinterpret_cast<DeltaSetIndexMap *> (u.format1.copy (c)));
default:return_trace (nullptr);
}
}
protected:
union {
HBUINT8 format; /* Format identifier */
DeltaSetIndexMapFormat01<HBUINT16> format0;
DeltaSetIndexMapFormat01<HBUINT32> format1;
} u;
public:
DEFINE_SIZE_UNION (1, format);
};
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struct VarStoreInstancer
{
VarStoreInstancer (const VariationStore *varStore,
const DeltaSetIndexMap *varIdxMap,
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hb_array_t<int> coords) :
varStore (varStore), varIdxMap (varIdxMap), coords (coords) {}
operator bool () const { return varStore && bool (coords); }
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/* according to the spec, if colr table has varStore but does not have
* varIdxMap, then an implicit identity mapping is used */
float operator() (uint32_t varIdx, unsigned short offset = 0) const
{ return varStore->get_delta (varIdxMap ? varIdxMap->map (VarIdx::add (varIdx, offset)) : varIdx + offset, coords); }
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const VariationStore *varStore;
const DeltaSetIndexMap *varIdxMap;
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hb_array_t<int> coords;
};
/* https://docs.microsoft.com/en-us/typography/opentype/spec/otvarcommonformats#tuplevariationheader */
struct TupleVariationHeader
{
unsigned get_size (unsigned axis_count) const
{ return min_size + get_all_tuples (axis_count).get_size (); }
unsigned get_data_size () const { return varDataSize; }
const TupleVariationHeader &get_next (unsigned axis_count) const
{ return StructAtOffset<TupleVariationHeader> (this, get_size (axis_count)); }
float calculate_scalar (hb_array_t<int> coords, unsigned int coord_count,
const hb_array_t<const F2DOT14> shared_tuples) const
{
hb_array_t<const F2DOT14> peak_tuple;
if (has_peak ())
peak_tuple = get_peak_tuple (coord_count);
else
{
unsigned int index = get_index ();
if (unlikely (index * coord_count >= shared_tuples.length))
return 0.f;
peak_tuple = shared_tuples.sub_array (coord_count * index, coord_count);
}
hb_array_t<const F2DOT14> start_tuple;
hb_array_t<const F2DOT14> end_tuple;
if (has_intermediate ())
{
start_tuple = get_start_tuple (coord_count);
end_tuple = get_end_tuple (coord_count);
}
float scalar = 1.f;
for (unsigned int i = 0; i < coord_count; i++)
{
int v = coords[i];
int peak = peak_tuple[i].to_int ();
if (!peak || v == peak) continue;
if (has_intermediate ())
{
int start = start_tuple[i].to_int ();
int end = end_tuple[i].to_int ();
if (unlikely (start > peak || peak > end ||
(start < 0 && end > 0 && peak))) continue;
if (v < start || v > end) return 0.f;
if (v < peak)
{ if (peak != start) scalar *= (float) (v - start) / (peak - start); }
else
{ if (peak != end) scalar *= (float) (end - v) / (end - peak); }
}
else if (!v || v < hb_min (0, peak) || v > hb_max (0, peak)) return 0.f;
else
scalar *= (float) v / peak;
}
return scalar;
}
bool has_peak () const { return tupleIndex & TuppleIndex::EmbeddedPeakTuple; }
bool has_intermediate () const { return tupleIndex & TuppleIndex::IntermediateRegion; }
bool has_private_points () const { return tupleIndex & TuppleIndex::PrivatePointNumbers; }
unsigned get_index () const { return tupleIndex & TuppleIndex::TupleIndexMask; }
protected:
struct TuppleIndex : HBUINT16
{
enum Flags {
EmbeddedPeakTuple = 0x8000u,
IntermediateRegion = 0x4000u,
PrivatePointNumbers = 0x2000u,
TupleIndexMask = 0x0FFFu
};
DEFINE_SIZE_STATIC (2);
};
hb_array_t<const F2DOT14> get_all_tuples (unsigned axis_count) const
{ return StructAfter<UnsizedArrayOf<F2DOT14>> (tupleIndex).as_array ((has_peak () + has_intermediate () * 2) * axis_count); }
hb_array_t<const F2DOT14> get_peak_tuple (unsigned axis_count) const
{ return get_all_tuples (axis_count).sub_array (0, axis_count); }
hb_array_t<const F2DOT14> get_start_tuple (unsigned axis_count) const
{ return get_all_tuples (axis_count).sub_array (has_peak () * axis_count, axis_count); }
hb_array_t<const F2DOT14> get_end_tuple (unsigned axis_count) const
{ return get_all_tuples (axis_count).sub_array (has_peak () * axis_count + axis_count, axis_count); }
HBUINT16 varDataSize; /* The size in bytes of the serialized
* data for this tuple variation table. */
TuppleIndex tupleIndex; /* A packed field. The high 4 bits are flags (see below).
The low 12 bits are an index into a shared tuple
records array. */
/* UnsizedArrayOf<F2DOT14> peakTuple - optional */
/* Peak tuple record for this tuple variation table — optional,
* determined by flags in the tupleIndex value.
*
* Note that this must always be included in the 'cvar' table. */
/* UnsizedArrayOf<F2DOT14> intermediateStartTuple - optional */
/* Intermediate start tuple record for this tuple variation table — optional,
determined by flags in the tupleIndex value. */
/* UnsizedArrayOf<F2DOT14> intermediateEndTuple - optional */
/* Intermediate end tuple record for this tuple variation table — optional,
* determined by flags in the tupleIndex value. */
public:
DEFINE_SIZE_MIN (4);
};
struct TupleVariationData
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
// here check on min_size only, TupleVariationHeader and var data will be
// checked while accessing through iterator.
return_trace (c->check_struct (this));
}
unsigned get_size (unsigned axis_count) const
{
unsigned total_size = min_size;
unsigned count = tupleVarCount;
const TupleVariationHeader *tuple_var_header = &(get_tuple_var_header());
for (unsigned i = 0; i < count; i++)
{
total_size += tuple_var_header->get_size (axis_count) + tuple_var_header->get_data_size ();
tuple_var_header = &tuple_var_header->get_next (axis_count);
}
return total_size;
}
const TupleVariationHeader &get_tuple_var_header (void) const
{ return StructAfter<TupleVariationHeader> (data); }
struct tuple_iterator_t
{
void init (hb_bytes_t var_data_bytes_, unsigned int axis_count_, const void *table_base_)
{
var_data_bytes = var_data_bytes_;
var_data = var_data_bytes_.as<TupleVariationData> ();
index = 0;
axis_count = axis_count_;
current_tuple = &var_data->get_tuple_var_header ();
data_offset = 0;
table_base = table_base_;
}
bool get_shared_indices (hb_vector_t<unsigned int> &shared_indices /* OUT */)
{
if (var_data->has_shared_point_numbers ())
{
const HBUINT8 *base = &(table_base+var_data->data);
const HBUINT8 *p = base;
if (!unpack_points (p, shared_indices, (const HBUINT8 *) (var_data_bytes.arrayZ + var_data_bytes.length))) return false;
data_offset = p - base;
}
return true;
}
bool is_valid () const
{
return (index < var_data->tupleVarCount.get_count ()) &&
var_data_bytes.check_range (current_tuple, TupleVariationHeader::min_size) &&
var_data_bytes.check_range (current_tuple, hb_max (current_tuple->get_data_size (),
current_tuple->get_size (axis_count)));
}
bool move_to_next ()
{
data_offset += current_tuple->get_data_size ();
current_tuple = &current_tuple->get_next (axis_count);
index++;
return is_valid ();
}
const HBUINT8 *get_serialized_data () const
{ return &(table_base+var_data->data) + data_offset; }
private:
const TupleVariationData *var_data;
unsigned int index;
unsigned int axis_count;
unsigned int data_offset;
const void *table_base;
public:
hb_bytes_t var_data_bytes;
const TupleVariationHeader *current_tuple;
};
static bool get_tuple_iterator (hb_bytes_t var_data_bytes, unsigned axis_count,
const void *table_base,
hb_vector_t<unsigned int> &shared_indices /* OUT */,
tuple_iterator_t *iterator /* OUT */)
{
iterator->init (var_data_bytes, axis_count, table_base);
if (!iterator->get_shared_indices (shared_indices))
return false;
return iterator->is_valid ();
}
bool has_shared_point_numbers () const { return tupleVarCount.has_shared_point_numbers (); }
static bool unpack_points (const HBUINT8 *&p /* IN/OUT */,
hb_vector_t<unsigned int> &points /* OUT */,
const HBUINT8 *end)
{
enum packed_point_flag_t
{
POINTS_ARE_WORDS = 0x80,
POINT_RUN_COUNT_MASK = 0x7F
};
if (unlikely (p + 1 > end)) return false;
unsigned count = *p++;
if (count & POINTS_ARE_WORDS)
{
if (unlikely (p + 1 > end)) return false;
count = ((count & POINT_RUN_COUNT_MASK) << 8) | *p++;
}
if (unlikely (!points.resize (count, false))) return false;
unsigned n = 0;
unsigned i = 0;
while (i < count)
{
if (unlikely (p + 1 > end)) return false;
unsigned control = *p++;
unsigned run_count = (control & POINT_RUN_COUNT_MASK) + 1;
if (unlikely (i + run_count > count)) return false;
unsigned j;
if (control & POINTS_ARE_WORDS)
{
if (unlikely (p + run_count * HBUINT16::static_size > end)) return false;
for (j = 0; j < run_count; j++, i++)
{
n += *(const HBUINT16 *)p;
points.arrayZ[i] = n;
p += HBUINT16::static_size;
}
}
else
{
if (unlikely (p + run_count > end)) return false;
for (j = 0; j < run_count; j++, i++)
{
n += *p++;
points.arrayZ[i] = n;
}
}
}
return true;
}
static bool unpack_deltas (const HBUINT8 *&p /* IN/OUT */,
hb_vector_t<int> &deltas /* IN/OUT */,
const HBUINT8 *end)
{
enum packed_delta_flag_t
{
DELTAS_ARE_ZERO = 0x80,
DELTAS_ARE_WORDS = 0x40,
DELTA_RUN_COUNT_MASK = 0x3F
};
unsigned i = 0;
unsigned count = deltas.length;
while (i < count)
{
if (unlikely (p + 1 > end)) return false;
unsigned control = *p++;
unsigned run_count = (control & DELTA_RUN_COUNT_MASK) + 1;
if (unlikely (i + run_count > count)) return false;
unsigned j;
if (control & DELTAS_ARE_ZERO)
{
for (j = 0; j < run_count; j++, i++)
deltas.arrayZ[i] = 0;
}
else if (control & DELTAS_ARE_WORDS)
{
if (unlikely (p + run_count * HBUINT16::static_size > end)) return false;
for (j = 0; j < run_count; j++, i++)
{
deltas.arrayZ[i] = * (const HBINT16 *) p;
p += HBUINT16::static_size;
}
}
else
{
if (unlikely (p + run_count > end)) return false;
for (j = 0; j < run_count; j++, i++)
{
deltas.arrayZ[i] = * (const HBINT8 *) p++;
}
}
}
return true;
}
bool has_data () const { return tupleVarCount; }
protected:
struct TupleVarCount : HBUINT16
{
bool has_shared_point_numbers () const { return ((*this) & SharedPointNumbers); }
unsigned int get_count () const { return (*this) & CountMask; }
protected:
enum Flags
{
SharedPointNumbers= 0x8000u,
CountMask = 0x0FFFu
};
public:
DEFINE_SIZE_STATIC (2);
};
TupleVarCount tupleVarCount; /* A packed field. The high 4 bits are flags, and the
* low 12 bits are the number of tuple variation tables
* for this glyph. The number of tuple variation tables
* can be any number between 1 and 4095. */
Offset16To<HBUINT8>
data; /* Offset from the start of the base table
* to the serialized data. */
/* TupleVariationHeader tupleVariationHeaders[] *//* Array of tuple variation headers. */
public:
DEFINE_SIZE_MIN (4);
};
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} /* namespace OT */
#endif /* HB_OT_VAR_COMMON_HH */