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harfbuzz/src/hb-ot-var-gvar-table.hh

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/*
* Copyright © 2019 Adobe 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.
*
* Adobe Author(s): Michiharu Ariza
*/
#ifndef HB_OT_VAR_GVAR_TABLE_HH
#define HB_OT_VAR_GVAR_TABLE_HH
#include "hb-open-type.hh"
#include "hb-ot-glyf-table.hh"
#include "hb-ot-var-fvar-table.hh"
/*
* gvar -- Glyph Variation Table
* https://docs.microsoft.com/en-us/typography/opentype/spec/gvar
*/
#define HB_OT_TAG_gvar HB_TAG('g','v','a','r')
namespace OT {
struct contour_point_t
{
void init (float x_=0.f, float y_=0.f) { flag = 0; x = x_; y = y_; }
void translate (const contour_point_t &p) { x += p.x; y += p.y; }
uint8_t flag;
float x, y;
};
struct contour_point_vector_t : hb_vector_t<contour_point_t>
{
void extend (const hb_array_t<contour_point_t> &a)
{
unsigned int old_len = length;
resize (old_len + a.length);
for (unsigned int i = 0; i < a.length; i++)
(*this)[old_len + i] = a[i];
}
void transform (const float (&matrix)[4])
{
for (unsigned int i = 0; i < length; i++)
{
contour_point_t &p = (*this)[i];
float x_ = p.x * matrix[0] + p.y * matrix[1];
p.y = p.x * matrix[2] + p.y * matrix[3];
p.x = x_;
}
}
void translate (const contour_point_t& delta)
{
for (unsigned int i = 0; i < length; i++)
(*this)[i].translate (delta);
}
};
struct range_checker_t
{
range_checker_t (const void *table_, unsigned int start_offset_, unsigned int end_offset_)
: table ((const char*)table_), start_offset (start_offset_), end_offset (end_offset_) {}
template <typename T>
bool in_range (const T *p) const
{
return ((const char *) p) >= table + start_offset
&& ((const char *) p + T::static_size) <= table + end_offset;
}
protected:
const char *table;
const unsigned int start_offset;
const unsigned int end_offset;
};
struct Tuple : UnsizedArrayOf<F2DOT14> {};
struct TuppleIndex : HBUINT16
{
enum Flags {
EmbeddedPeakTuple = 0x8000u,
IntermediateRegion = 0x4000u,
PrivatePointNumbers = 0x2000u,
TupleIndexMask = 0x0FFFu
};
DEFINE_SIZE_STATIC (2);
};
struct TupleVarHeader
{
unsigned int get_size (unsigned int axis_count) const
{
return min_size +
(has_peak ()? get_peak_tuple ().get_size (axis_count): 0) +
(has_intermediate ()? (get_start_tuple (axis_count).get_size (axis_count) +
get_end_tuple (axis_count).get_size (axis_count)): 0);
}
const TupleVarHeader &get_next (unsigned int axis_count) const
{ return StructAtOffset<TupleVarHeader> (this, get_size (axis_count)); }
float calculate_scalar (const int *coords, unsigned int coord_count,
const hb_array_t<const F2DOT14> shared_tuples) const
{
const F2DOT14 *peak_tuple;
if (has_peak ())
peak_tuple = &(get_peak_tuple ()[0]);
else
{
unsigned int index = get_index ();
if (unlikely (index * coord_count >= shared_tuples.length))
return 0.f;
peak_tuple = &shared_tuples[coord_count * index];
}
const F2DOT14 *start_tuple = nullptr;
const F2DOT14 *end_tuple = nullptr;
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];
if (!peak || v == peak) continue;
if (has_intermediate ())
{
int start = start_tuple[i];
int end = end_tuple[i];
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 < MIN (0, peak) || v > MAX (0, peak)) return 0.f;
else
scalar *= (float)v / peak;
}
return scalar;
}
unsigned int get_data_size () const { return varDataSize; }
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 int get_index () const { return (tupleIndex & TuppleIndex::TupleIndexMask); }
protected:
const Tuple &get_peak_tuple () const
{ return StructAfter<Tuple> (tupleIndex); }
const Tuple &get_start_tuple (unsigned int axis_count) const
{ return StructAfter<Tuple> (get_peak_tuple ()[has_peak ()? axis_count: 0]); }
const Tuple &get_end_tuple (unsigned int axis_count) const
{ return StructAfter<Tuple> (get_peak_tuple ()[has_peak ()? (axis_count * 2): 0]); }
HBUINT16 varDataSize;
TuppleIndex tupleIndex;
/* UnsizedArrayOf<F2DOT14> peakTuple - optional */
/* UnsizedArrayOf<F2DOT14> intermediateStartTuple - optional */
/* UnsizedArrayOf<F2DOT14> intermediateEndTuple - optional */
public:
DEFINE_SIZE_MIN (4);
};
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);
};
struct GlyphVarData
{
const TupleVarHeader &get_tuple_var_header (void) const
{ return StructAfter<TupleVarHeader>(data); }
struct tuple_iterator_t
{
void init (const GlyphVarData *var_data_, unsigned int length_, unsigned int axis_count_)
{
var_data = var_data_;
length = length_;
index = 0;
axis_count = axis_count_;
current_tuple = &var_data->get_tuple_var_header ();
data_offset = 0;
}
bool get_shared_indices (hb_vector_t<unsigned int> &shared_indices /* OUT */)
{
if (var_data->has_shared_point_numbers ())
{
range_checker_t checker (var_data, 0, length);
const HBUINT8 *base = &(var_data+var_data->data);
const HBUINT8 *p = base;
if (!unpack_points (p, shared_indices, checker)) return false;
data_offset = p - base;
}
return true;
}
bool is_valid () const
{
return (index < var_data->tupleVarCount.get_count ()) &&
in_range (current_tuple) &&
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 ();
}
bool in_range (const void *p, unsigned int l) const
{ return (const char*)p >= (const char*)var_data && (const char*)p+l <= (const char*)var_data + length; }
template <typename T> bool in_range (const T *p) const { return in_range (p, sizeof (*p)); }
const HBUINT8 *get_serialized_data () const
{ return &(var_data+var_data->data) + data_offset; }
private:
const GlyphVarData *var_data;
unsigned int length;
unsigned int index;
unsigned int axis_count;
unsigned int data_offset;
public:
const TupleVarHeader *current_tuple;
};
static bool get_tuple_iterator (const GlyphVarData *var_data,
unsigned int length,
unsigned int axis_count,
hb_vector_t<unsigned int> &shared_indices /* OUT */,
tuple_iterator_t *iterator /* OUT */)
{
iterator->init (var_data, length, axis_count);
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 range_checker_t &check)
{
enum packed_point_flag_t
{
POINTS_ARE_WORDS = 0x80,
POINT_RUN_COUNT_MASK = 0x7F
};
if (!check.in_range (p)) return false;
uint16_t count = *p++;
if (count & POINTS_ARE_WORDS)
{
if (!check.in_range (p)) return false;
count = ((count & POINT_RUN_COUNT_MASK) << 8) | *p++;
}
points.resize (count);
unsigned int n = 0;
uint16_t i = 0;
while (i < count)
{
if (!check.in_range (p)) return false;
uint16_t j;
uint8_t control = *p++;
uint16_t run_count = (control & POINT_RUN_COUNT_MASK) + 1;
if (control & POINTS_ARE_WORDS)
{
for (j = 0; j < run_count && i < count; j++, i++)
{
if (!check.in_range ((const HBUINT16 *)p)) return false;
n += *(const HBUINT16 *)p;
points[i] = n;
p += HBUINT16::static_size;
}
}
else
{
for (j = 0; j < run_count && i < count; j++, i++)
{
if (!check.in_range (p)) return false;
n += *p++;
points[i] = n;
}
}
if (j < run_count) return false;
}
return true;
}
static bool unpack_deltas (const HBUINT8 *&p /* IN/OUT */,
hb_vector_t<int> &deltas /* IN/OUT */,
const range_checker_t &check)
{
enum packed_delta_flag_t
{
DELTAS_ARE_ZERO = 0x80,
DELTAS_ARE_WORDS = 0x40,
DELTA_RUN_COUNT_MASK = 0x3F
};
unsigned int i = 0;
unsigned int count = deltas.length;
while (i < count)
{
if (!check.in_range (p)) return false;
uint16_t j;
uint8_t control = *p++;
uint16_t run_count = (control & DELTA_RUN_COUNT_MASK) + 1;
if (control & DELTAS_ARE_ZERO)
{
for (j = 0; j < run_count && i < count; j++, i++)
deltas[i] = 0;
}
else if (control & DELTAS_ARE_WORDS)
{
for (j = 0; j < run_count && i < count; j++, i++)
{
if (!check.in_range ((const HBUINT16 *)p))
return false;
deltas[i] = *(const HBINT16 *)p;
p += HBUINT16::static_size;
}
}
else
{
for (j = 0; j < run_count && i < count; j++, i++)
{
if (!check.in_range (p))
return false;
deltas[i] = *(const HBINT8 *)p++;
}
}
if (j < run_count)
return false;
}
return true;
}
protected:
TupleVarCount tupleVarCount;
OffsetTo<HBUINT8> data;
/* TupleVarHeader tupleVarHeaders[] */
public:
DEFINE_SIZE_MIN (4);
};
struct gvar
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_gvar;
bool sanitize_shallow (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) && (version.major == 1) &&
(glyphCount == c->get_num_glyphs ()) &&
c->check_array (&(this+sharedTuples), axisCount * sharedTupleCount) &&
(is_long_offset ()?
c->check_array (get_long_offset_array (), glyphCount+1):
c->check_array (get_short_offset_array (), glyphCount+1)) &&
c->check_array (((const HBUINT8*)&(this+dataZ)) + get_offset (0),
get_offset (glyphCount) - get_offset (0)));
}
/* GlyphVarData not sanitized here; must be checked while accessing each glyph varation data */
bool sanitize (hb_sanitize_context_t *c) const
{ return sanitize_shallow (c); }
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
gvar *out = c->serializer->allocate_min<gvar> ();
if (unlikely (!out)) return_trace (false);
out->version.major.set (1);
out->version.minor.set (0);
out->axisCount.set (axisCount);
out->sharedTupleCount.set (sharedTupleCount);
unsigned int num_glyphs = c->plan->num_output_glyphs ();
out->glyphCount.set (num_glyphs);
unsigned int subset_data_size = 0;
for (hb_codepoint_t gid = 0; gid < num_glyphs; gid++)
{
hb_codepoint_t old_gid;
if (!c->plan->old_gid_for_new_gid (gid, &old_gid)) continue;
subset_data_size += get_glyph_var_data_length (old_gid);
}
bool long_offset = subset_data_size & ~0xFFFFu;
out->flags.set (long_offset? 1: 0);
HBUINT8 *subset_offsets = c->serializer->allocate_size<HBUINT8> ((long_offset? 4: 2) * (num_glyphs+1));
if (!subset_offsets) return_trace (false);
/* shared tuples */
if (!sharedTupleCount || !sharedTuples)
out->sharedTuples.set (0);
else
{
unsigned int shared_tuple_size = F2DOT14::static_size * axisCount * sharedTupleCount;
F2DOT14 *tuples = c->serializer->allocate_size<F2DOT14> (shared_tuple_size);
if (!tuples) return_trace (false);
out->sharedTuples.set ((char *)tuples - (char *)out);
memcpy (tuples, &(this+sharedTuples), shared_tuple_size);
}
char *subset_data = c->serializer->allocate_size<char>(subset_data_size);
if (!subset_data) return_trace (false);
out->dataZ.set (subset_data - (char *)out);
unsigned int glyph_offset = 0;
for (hb_codepoint_t gid = 0; gid < num_glyphs; gid++)
{
hb_codepoint_t old_gid;
unsigned int length = c->plan->old_gid_for_new_gid (gid, &old_gid)? get_glyph_var_data_length (old_gid): 0;
if (long_offset)
((HBUINT32 *)subset_offsets)[gid].set (glyph_offset);
else
((HBUINT16 *)subset_offsets)[gid].set (glyph_offset / 2);
if (length > 0) memcpy (subset_data, get_glyph_var_data (old_gid), length);
subset_data += length;
glyph_offset += length;
}
if (long_offset)
((HBUINT32 *)subset_offsets)[num_glyphs].set (glyph_offset);
else
((HBUINT16 *)subset_offsets)[num_glyphs].set (glyph_offset / 2);
return_trace (true);
}
protected:
const GlyphVarData *get_glyph_var_data (hb_codepoint_t glyph) const
{
unsigned int start_offset = get_offset (glyph);
unsigned int end_offset = get_offset (glyph+1);
if ((start_offset == end_offset) ||
unlikely ((start_offset > get_offset (glyphCount)) ||
(start_offset + GlyphVarData::min_size > end_offset)))
return &Null(GlyphVarData);
return &(((unsigned char *)this+start_offset)+dataZ);
}
bool is_long_offset () const { return (flags & 1)!=0; }
unsigned int get_offset (unsigned int i) const
{
if (is_long_offset ())
return get_long_offset_array ()[i];
else
return get_short_offset_array ()[i] * 2;
}
unsigned int get_glyph_var_data_length (unsigned int glyph) const
{ return get_offset (glyph+1) - get_offset (glyph); }
const HBUINT32 *get_long_offset_array () const { return (const HBUINT32 *)&offsetZ; }
const HBUINT16 *get_short_offset_array () const { return (const HBUINT16 *)&offsetZ; }
public:
struct accelerator_t
{
void init (hb_face_t *face)
{
memset (this, 0, sizeof (accelerator_t));
gvar_table = hb_sanitize_context_t ().reference_table<gvar> (face);
hb_blob_ptr_t<fvar> fvar_table = hb_sanitize_context_t ().reference_table<fvar> (face);
unsigned int axis_count = fvar_table->get_axis_count ();
fvar_table.destroy ();
if (unlikely ((gvar_table->glyphCount != face->get_num_glyphs ()) ||
(gvar_table->axisCount != axis_count)))
fini ();
unsigned int num_shared_coord = gvar_table->sharedTupleCount * gvar_table->axisCount;
shared_tuples.resize (num_shared_coord);
for (unsigned int i = 0; i < num_shared_coord; i++)
shared_tuples[i] = (&(gvar_table+gvar_table->sharedTuples))[i];
}
void fini ()
{
gvar_table.destroy ();
shared_tuples.fini ();
}
private:
struct x_getter { static float get (const contour_point_t &p) { return p.x; } };
struct y_getter { static float get (const contour_point_t &p) { return p.y; } };
template <typename T>
static float infer_delta (const hb_array_t<contour_point_t> points,
const hb_array_t<contour_point_t> deltas,
unsigned int target, unsigned int prev, unsigned int next)
{
float target_val = T::get (points[target]);
float prev_val = T::get (points[prev]);
float next_val = T::get (points[next]);
float prev_delta = T::get (deltas[prev]);
float next_delta = T::get (deltas[next]);
if (prev_val == next_val)
return (prev_delta == next_delta)? prev_delta: 0.f;
else if (target_val <= MIN (prev_val, next_val))
return (prev_val < next_val) ? prev_delta: next_delta;
else if (target_val >= MAX (prev_val, next_val))
return (prev_val > next_val)? prev_delta: next_delta;
/* linear interpolation */
float r = (target_val - prev_val) / (next_val - prev_val);
return (1.f - r) * prev_delta + r * next_delta;
}
public:
bool apply_deltas_to_points (hb_codepoint_t glyph,
const int *coords, unsigned int coord_count,
const hb_array_t<contour_point_t> points,
const hb_array_t<unsigned int> end_points) const
{
if (unlikely (coord_count != gvar_table->axisCount)) return false;
const GlyphVarData *var_data = gvar_table->get_glyph_var_data (glyph);
if (var_data == &Null(GlyphVarData)) return true;
hb_vector_t <unsigned int> shared_indices;
GlyphVarData::tuple_iterator_t iterator;
if (!GlyphVarData::get_tuple_iterator (var_data,
gvar_table->get_glyph_var_data_length (glyph),
gvar_table->axisCount,
shared_indices,
&iterator))
return false;
contour_point_vector_t deltas; /* flag is used to indicate referenced point */
deltas.resize (points.length);
for (unsigned int i = 0; i < deltas.length; i++)
deltas[i].init ();
do {
float scalar = iterator.current_tuple->calculate_scalar (coords, coord_count, shared_tuples.as_array ());
if (scalar == 0.f) continue;
const HBUINT8 *p = iterator.get_serialized_data ();
unsigned int length = iterator.current_tuple->get_data_size ();
if (unlikely (!iterator.in_range (p, length)))
return false;
range_checker_t checker (p, 0, length);
hb_vector_t <unsigned int> private_indices;
if (iterator.current_tuple->has_private_points () &&
!GlyphVarData::unpack_points (p, private_indices, checker))
return false;
const hb_array_t<unsigned int> &indices = shared_indices.length? shared_indices: private_indices;
bool apply_to_all = (indices.length == 0);
unsigned int num_deltas = apply_to_all? points.length: indices.length;
hb_vector_t <int> x_deltas;
x_deltas.resize (num_deltas);
if (!GlyphVarData::unpack_deltas (p, x_deltas, checker))
return false;
hb_vector_t <int> y_deltas;
y_deltas.resize (num_deltas);
if (!GlyphVarData::unpack_deltas (p, y_deltas, checker))
return false;
for (unsigned int i = 0; i < num_deltas; i++)
{
unsigned int pt_index = apply_to_all? i: indices[i];
deltas[pt_index].flag = 1; /* this point is referenced, i.e., explicit deltas specified */
deltas[pt_index].x += x_deltas[i] * scalar;
deltas[pt_index].y += y_deltas[i] * scalar;
}
} while (iterator.move_to_next ());
/* infer deltas for unreferenced points */
contour_point_vector_t orig_points;
orig_points.resize (points.length);
for (unsigned int i = 0; i < orig_points.length; i++)
orig_points[i] = points[i];
unsigned int start_point = 0;
for (unsigned int c = 0; c < end_points.length; c++)
{
unsigned int end_point = end_points[c];
for (unsigned int i = start_point; i < end_point; i++)
{
if (deltas[i].flag) continue;
/* search in both directions within the contour for a pair of referenced points */
unsigned int prev;
for (prev = i;;)
{
if (prev-- <= start_point) prev = end_point;
if (prev == i || deltas[prev].flag) break;
}
if (prev == i) continue; /* no (previous) referenced point was found */
unsigned int next;
for (next = i;;)
{
if (next++ >= end_point) next = start_point;
if (next == i || deltas[next].flag) break;
}
assert (next != i);
deltas[i].x = infer_delta<x_getter> (orig_points.as_array (), deltas.as_array (), i, prev, next);
deltas[i].y = infer_delta<y_getter> (orig_points.as_array (), deltas.as_array (), i, prev, next);
}
start_point = end_point + 1;
}
/* apply accumulated / inferred deltas to points */
for (unsigned int i = 0; i < points.length; i++)
{
points[i].x += deltas[i].x;
points[i].y += deltas[i].y;
}
return true;
}
unsigned int get_axis_count () const { return gvar_table->axisCount; }
protected:
const GlyphVarData *get_glyph_var_data (hb_codepoint_t glyph) const
{ return gvar_table->get_glyph_var_data (glyph); }
private:
hb_blob_ptr_t<gvar> gvar_table;
hb_vector_t<F2DOT14> shared_tuples;
};
protected:
FixedVersion<> version; /* Version of gvar table. Set to 0x00010000u. */
HBUINT16 axisCount;
HBUINT16 sharedTupleCount;
LOffsetTo<F2DOT14> sharedTuples; /* LOffsetTo<UnsizedArrayOf<Tupple>> */
HBUINT16 glyphCount;
HBUINT16 flags;
LOffsetTo<GlyphVarData> dataZ; /* Array of GlyphVarData */
UnsizedArrayOf<HBUINT8> offsetZ; /* Array of 16-bit or 32-bit (glyphCount+1) offsets */
public:
DEFINE_SIZE_MIN (20);
};
struct gvar_accelerator_t : gvar::accelerator_t {};
} /* namespace OT */
#endif /* HB_OT_VAR_GVAR_TABLE_HH */
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