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

454 lines
16 KiB
C++

/*
* 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-common.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; }
float x = 0.f;
float y = 0.f;
uint8_t flag = 0;
bool is_end_point = false;
};
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;
if (unlikely (!resize (old_len + a.length, false)))
return;
auto arrayZ = this->arrayZ + old_len;
unsigned count = a.length;
hb_memcpy (arrayZ, a.arrayZ, count * sizeof (arrayZ[0]));
}
void transform (const float (&matrix)[4])
{
if (matrix[0] == 1.f && matrix[1] == 0.f &&
matrix[2] == 0.f && matrix[3] == 1.f)
return;
auto arrayZ = this->arrayZ;
unsigned count = length;
for (unsigned i = 0; i < count; i++)
{
contour_point_t &p = arrayZ[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)
{
if (delta.x == 0.f && delta.y == 0.f)
return;
auto arrayZ = this->arrayZ;
unsigned count = length;
for (unsigned i = 0; i < count; i++)
arrayZ[i].translate (delta);
}
};
struct GlyphVariationData : TupleVariationData
{};
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) &&
sharedTuples.sanitize (c, this, axisCount * sharedTupleCount) &&
(is_long_offset () ?
c->check_array (get_long_offset_array (), c->get_num_glyphs () + 1) :
c->check_array (get_short_offset_array (), c->get_num_glyphs () + 1)));
}
/* GlyphVariationData not sanitized here; must be checked while accessing each glyph variation data */
bool sanitize (hb_sanitize_context_t *c) const
{ return sanitize_shallow (c); }
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
unsigned glyph_count = version.to_int () ? c->plan->source->get_num_glyphs () : 0;
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->glyphCountX = hb_min (0xFFFFu, num_glyphs);
unsigned int subset_data_size = 0;
for (hb_codepoint_t gid = (c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE) ? 0 : 1;
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, glyph_count, 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;
hb_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 = (c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE) ? 0 : 1;
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,
glyph_count,
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)
hb_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,
unsigned glyph_count,
hb_codepoint_t glyph) const
{
unsigned start_offset = get_offset (glyph_count, glyph);
unsigned end_offset = get_offset (glyph_count, glyph+1);
if (unlikely (end_offset < start_offset)) return hb_bytes_t ();
unsigned length = end_offset - start_offset;
hb_bytes_t var_data = blob->as_bytes ().sub_array (((unsigned) dataZ) + start_offset, length);
return likely (var_data.length >= GlyphVariationData::min_size) ? var_data : hb_bytes_t ();
}
bool is_long_offset () const { return flags & 1; }
unsigned get_offset (unsigned glyph_count, unsigned i) const
{
if (unlikely (i > glyph_count)) return 0;
_hb_compiler_memory_r_barrier ();
return is_long_offset () ? get_long_offset_array ()[i] : 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
{
accelerator_t (hb_face_t *face)
{
table = hb_sanitize_context_t ().reference_table<gvar> (face);
/* If sanitize failed, set glyphCount to 0. */
glyphCount = table->version.to_int () ? face->get_num_glyphs () : 0;
}
~accelerator_t () { table.destroy (); }
private:
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 contour_point_t::*m)
{
float target_val = points.arrayZ[target].*m;
float prev_val = points.arrayZ[prev].*m;
float next_val = points.arrayZ[next].*m;
float prev_delta = deltas.arrayZ[prev].*m;
float next_delta = deltas.arrayZ[next].*m;
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 prev_delta + r * (next_delta - prev_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,
hb_array_t<int> coords,
const hb_array_t<contour_point_t> points) const
{
if (!coords) return true;
if (unlikely (glyph >= glyphCount)) return true;
hb_bytes_t var_data_bytes = table->get_glyph_var_data_bytes (table.get_blob (), glyphCount, glyph);
if (!var_data_bytes.as<GlyphVariationData> ()->has_data ()) return true;
hb_vector_t<unsigned int> shared_indices;
GlyphVariationData::tuple_iterator_t iterator;
if (!GlyphVariationData::get_tuple_iterator (var_data_bytes, table->axisCount,
var_data_bytes.arrayZ,
shared_indices, &iterator))
return true; /* so isn't applied at all */
/* Save original points for inferred delta calculation */
contour_point_vector_t orig_points_vec;
orig_points_vec.extend (points);
if (unlikely (orig_points_vec.in_error ())) return false;
auto orig_points = orig_points_vec.as_array ();
contour_point_vector_t deltas_vec; /* flag is used to indicate referenced point */
if (unlikely (!deltas_vec.resize (points.length, false))) return false;
auto deltas = deltas_vec.as_array ();
hb_vector_t<unsigned> end_points;
for (unsigned i = 0; i < points.length; ++i)
if (points.arrayZ[i].is_end_point)
end_points.push (i);
unsigned num_coords = table->axisCount;
hb_array_t<const F2DOT14> shared_tuples = (table+table->sharedTuples).as_array (table->sharedTupleCount * table->axisCount);
hb_vector_t<unsigned int> private_indices;
hb_vector_t<int> x_deltas;
hb_vector_t<int> y_deltas;
do
{
float scalar = iterator.current_tuple->calculate_scalar (coords, num_coords, shared_tuples);
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;
const HBUINT8 *end = p + length;
bool has_private_points = iterator.current_tuple->has_private_points ();
if (has_private_points &&
!GlyphVariationData::unpack_points (p, private_indices, end))
return false;
const hb_array_t<unsigned int> &indices = has_private_points ? private_indices : shared_indices;
bool apply_to_all = (indices.length == 0);
unsigned int num_deltas = apply_to_all ? points.length : indices.length;
if (unlikely (!x_deltas.resize (num_deltas, false))) return false;
if (unlikely (!GlyphVariationData::unpack_deltas (p, x_deltas, end))) return false;
if (unlikely (!y_deltas.resize (num_deltas, false))) return false;
if (unlikely (!GlyphVariationData::unpack_deltas (p, y_deltas, end))) return false;
hb_memset (deltas.arrayZ, 0, deltas.get_size ());
unsigned ref_points = 0;
if (scalar != 1.0f)
for (unsigned int i = 0; i < num_deltas; i++)
{
unsigned int pt_index = apply_to_all ? i : indices[i];
if (unlikely (pt_index >= deltas.length)) continue;
auto &delta = deltas.arrayZ[pt_index];
ref_points += !delta.flag;
delta.flag = 1; /* this point is referenced, i.e., explicit deltas specified */
delta.x += x_deltas.arrayZ[i] * scalar;
delta.y += y_deltas.arrayZ[i] * scalar;
}
else
for (unsigned int i = 0; i < num_deltas; i++)
{
unsigned int pt_index = apply_to_all ? i : indices[i];
if (unlikely (pt_index >= deltas.length)) continue;
auto &delta = deltas.arrayZ[pt_index];
ref_points += !delta.flag;
delta.flag = 1; /* this point is referenced, i.e., explicit deltas specified */
delta.x += x_deltas.arrayZ[i];
delta.y += y_deltas.arrayZ[i];
}
/* infer deltas for unreferenced points */
if (ref_points && ref_points < orig_points.length)
{
unsigned start_point = 0;
for (unsigned c = 0; c < end_points.length; c++)
{
unsigned end_point = end_points.arrayZ[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 + 1; i++)
unref_count += deltas.arrayZ[i].flag;
unref_count = (end_point - start_point + 1) - 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.arrayZ[i].flag && !deltas.arrayZ[j].flag) break;
}
prev = j = i;
for (;;)
{
i = j;
j = next_index (i, start_point, end_point);
if (!deltas.arrayZ[i].flag && deltas.arrayZ[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.arrayZ[i].x = infer_delta (orig_points, deltas, i, prev, next, &contour_point_t::x);
deltas.arrayZ[i].y = infer_delta (orig_points, deltas, i, prev, next, &contour_point_t::y);
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.arrayZ[i].x += deltas.arrayZ[i].x;
points.arrayZ[i].y += deltas.arrayZ[i].y;
}
} while (iterator.move_to_next ());
return true;
}
unsigned int get_axis_count () const { return table->axisCount; }
private:
hb_blob_ptr_t<gvar> table;
unsigned glyphCount;
};
protected:
FixedVersion<>version; /* Version number of the glyph variations table
* Set to 0x00010000u. */
HBUINT16 axisCount; /* The number of variation axes for this font. This must be
* the same number as axisCount in the 'fvar' table. */
HBUINT16 sharedTupleCount;
/* The number of shared tuple records. Shared tuple records
* can be referenced within glyph variation data tables for
* multiple glyphs, as opposed to other tuple records stored
* directly within a glyph variation data table. */
NNOffset32To<UnsizedArrayOf<F2DOT14>>
sharedTuples; /* Offset from the start of this table to the shared tuple records.
* Array of tuple records shared across all glyph variation data tables. */
HBUINT16 glyphCountX; /* The number of glyphs in this font. This must match the number of
* glyphs stored elsewhere in the font. */
HBUINT16 flags; /* Bit-field that gives the format of the offset array that follows.
* If bit 0 is clear, the offsets are uint16; if bit 0 is set, the
* offsets are uint32. */
Offset32To<GlyphVariationData>
dataZ; /* Offset from the start of this table to the array of
* GlyphVariationData tables. */
UnsizedArrayOf<HBUINT8>
offsetZ; /* Offsets from the start of the GlyphVariationData array
* to each GlyphVariationData table. */
public:
DEFINE_SIZE_ARRAY (20, offsetZ);
};
struct gvar_accelerator_t : gvar::accelerator_t {
gvar_accelerator_t (hb_face_t *face) : gvar::accelerator_t (face) {}
};
} /* namespace OT */
#endif /* HB_OT_VAR_GVAR_TABLE_HH */