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

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/*
* Copyright © 2019 Adobe Inc.
* Copyright © 2019 Ebrahim Byagowi
*
* 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-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, bool is_end_point_ = false)
{ flag = 0; x = x_; y = y_; is_end_point = is_end_point_; }
void translate (const contour_point_t &p) { x += p.x; y += p.y; }
uint8_t flag;
float x, y;
bool is_end_point;
};
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[2];
p.y = p.x * matrix[1] + 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 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 < hb_min (0, peak) || v > hb_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 *(const Tuple *) &get_peak_tuple ()[has_peak () ? axis_count : 0]; }
const Tuple &get_end_tuple (unsigned int axis_count) const
{ return *(const Tuple *) &get_peak_tuple ()[has_peak () ? (axis_count * 2) : axis_count]; }
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 (hb_bytes_t var_data_bytes_, unsigned int axis_count_)
{
var_data_bytes = var_data_bytes_;
var_data = var_data_bytes_.as<GlyphVarData> ();
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 ())
{
const HBUINT8 *base = &(var_data+var_data->data);
const HBUINT8 *p = base;
if (!unpack_points (p, shared_indices, var_data_bytes)) 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, TupleVarHeader::min_size) &&
var_data_bytes.check_range (current_tuple, hb_max (current_tuple->get_data_size (), current_tuple->get_size (axis_count))) &&
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 &(var_data+var_data->data) + data_offset; }
private:
const GlyphVarData *var_data;
unsigned int index;
unsigned int axis_count;
unsigned int data_offset;
public:
hb_bytes_t var_data_bytes;
const TupleVarHeader *current_tuple;
};
static bool get_tuple_iterator (hb_bytes_t var_data_bytes, unsigned axis_count,
hb_vector_t<unsigned int> &shared_indices /* OUT */,
tuple_iterator_t *iterator /* OUT */)
{
iterator->init (var_data_bytes, 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 hb_bytes_t &bytes)
{
enum packed_point_flag_t
{
POINTS_ARE_WORDS = 0x80,
POINT_RUN_COUNT_MASK = 0x7F
};
if (unlikely (!bytes.check_range (p))) return false;
uint16_t count = *p++;
if (count & POINTS_ARE_WORDS)
{
if (unlikely (!bytes.check_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 (unlikely (!bytes.check_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 (unlikely (!bytes.check_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 (unlikely (!bytes.check_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 hb_bytes_t &bytes)
{
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 (unlikely (!bytes.check_range (p))) return false;
uint8_t control = *p++;
unsigned int run_count = (control & DELTA_RUN_COUNT_MASK) + 1;
unsigned int j;
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 (unlikely (!bytes.check_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 (unlikely (!bytes.check_range (p)))
return false;
deltas[i] = *(const HBINT8 *) p++;
}
if (j < run_count)
return false;
}
return true;
}
bool has_data () const { return tupleVarCount; }
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 = 1;
out->version.minor = 0;
out->axisCount = axisCount;
out->sharedTupleCount = sharedTupleCount;
unsigned int num_glyphs = c->plan->num_output_glyphs ();
out->glyphCount = 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_bytes (c->source_blob, old_gid).length;
}
bool long_offset = subset_data_size & ~0xFFFFu;
out->flags = 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 = 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 = (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 = subset_data - (char *) out;
unsigned int glyph_offset = 0;
for (hb_codepoint_t gid = 0; gid < num_glyphs; gid++)
{
hb_codepoint_t old_gid;
hb_bytes_t var_data_bytes = c->plan->old_gid_for_new_gid (gid, &old_gid)
? get_glyph_var_data_bytes (c->source_blob, old_gid)
: hb_bytes_t ();
if (long_offset)
((HBUINT32 *) subset_offsets)[gid] = glyph_offset;
else
((HBUINT16 *) subset_offsets)[gid] = glyph_offset / 2;
if (var_data_bytes.length > 0)
memcpy (subset_data, var_data_bytes.arrayZ, var_data_bytes.length);
subset_data += var_data_bytes.length;
glyph_offset += var_data_bytes.length;
}
if (long_offset)
((HBUINT32 *) subset_offsets)[num_glyphs] = glyph_offset;
else
((HBUINT16 *) subset_offsets)[num_glyphs] = glyph_offset / 2;
return_trace (true);
}
protected:
const hb_bytes_t get_glyph_var_data_bytes (hb_blob_t *blob, hb_codepoint_t glyph) const
{
unsigned start_offset = get_offset (glyph);
unsigned length = get_offset (glyph+1) - start_offset;
hb_bytes_t var_data = blob->as_bytes ().sub_array (((unsigned) dataZ) + start_offset, length);
return likely (var_data.length >= GlyphVarData::min_size) ? var_data : hb_bytes_t ();
}
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;
}
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)
{
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 <= hb_min (prev_val, next_val))
return (prev_val < next_val) ? prev_delta : next_delta;
else if (target_val >= hb_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;
}
static unsigned int next_index (unsigned int i, unsigned int start, unsigned int end)
{ return (i >= end) ? start : (i + 1); }
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
{
coord_count = hb_min (coord_count, gvar_table->axisCount);
if (!coord_count || coord_count != gvar_table->axisCount) return true;
hb_bytes_t var_data_bytes = gvar_table->get_glyph_var_data_bytes (gvar_table.get_blob (), glyph);
if (!var_data_bytes.as<GlyphVarData> ()->has_data ()) return true;
hb_vector_t<unsigned int> shared_indices;
GlyphVarData::tuple_iterator_t iterator;
if (!GlyphVarData::get_tuple_iterator (var_data_bytes, gvar_table->axisCount,
shared_indices, &iterator))
return true; /* so isn't applied at all */
/* Save original points for inferred delta calculation */
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];
contour_point_vector_t deltas; /* flag is used to indicate referenced point */
deltas.resize (points.length);
hb_vector_t<unsigned> end_points;
for (unsigned i = 0; i < points.length; ++i)
if (points[i].is_end_point)
end_points.push (i);
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.var_data_bytes.check_range (p, length)))
return false;
hb_bytes_t bytes ((const char *) p, length);
hb_vector_t<unsigned int> private_indices;
if (iterator.current_tuple->has_private_points () &&
!GlyphVarData::unpack_points (p, private_indices, bytes))
return false;
const hb_array_t<unsigned int> &indices = private_indices.length ? private_indices : shared_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, bytes))
return false;
hb_vector_t<int> y_deltas;
y_deltas.resize (num_deltas);
if (!GlyphVarData::unpack_deltas (p, y_deltas, bytes))
return false;
for (unsigned int i = 0; i < deltas.length; i++)
deltas[i].init ();
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;
}
/* infer deltas for unreferenced points */
unsigned start_point = 0;
for (unsigned c = 0; c < end_points.length; c++)
{
unsigned end_point = end_points[c];
/* Check the number of unreferenced points in a contour. If no unref points or no ref points, nothing to do. */
unsigned unref_count = 0;
for (unsigned i = start_point; i <= end_point; i++)
if (!deltas[i].flag) unref_count++;
unsigned j = start_point;
if (unref_count == 0 || unref_count > end_point - start_point)
goto no_more_gaps;
for (;;)
{
/* Locate the next gap of unreferenced points between two referenced points prev and next.
* Note that a gap may wrap around at left (start_point) and/or at right (end_point).
*/
unsigned int prev, next, i;
for (;;)
{
i = j;
j = next_index (i, start_point, end_point);
if (deltas[i].flag && !deltas[j].flag) break;
}
prev = j = i;
for (;;)
{
i = j;
j = next_index (i, start_point, end_point);
if (!deltas[i].flag && deltas[j].flag) break;
}
next = j;
/* Infer deltas for all unref points in the gap between prev and next */
i = prev;
for (;;)
{
i = next_index (i, start_point, end_point);
if (i == next) break;
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);
if (--unref_count == 0) goto no_more_gaps;
}
}
no_more_gaps:
start_point = end_point + 1;
}
/* apply specified / inferred deltas to points */
for (unsigned int i = 0; i < points.length; i++)
{
points[i].x += (float) roundf (deltas[i].x);
points[i].y += (float) roundf (deltas[i].y);
}
} while (iterator.move_to_next ());
return true;
}
unsigned int get_axis_count () const { return gvar_table->axisCount; }
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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