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

159 lines
5.8 KiB
C++

/*
* Copyright © 2023 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_CVAR_TABLE_HH
#define HB_OT_VAR_CVAR_TABLE_HH
#include "hb-ot-var-common.hh"
namespace OT {
/*
* cvar -- control value table (CVT) Variations
* https://docs.microsoft.com/en-us/typography/opentype/spec/cvar
*/
#define HB_OT_TAG_cvar HB_TAG('c','v','a','r')
struct cvar
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_cvar;
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
version.sanitize (c) && likely (version.major == 1) &&
tupleVariationData.sanitize (c));
}
const TupleVariationData* get_tuple_var_data (void) const
{ return &tupleVariationData; }
static bool calculate_cvt_deltas (unsigned axis_count,
hb_array_t<int> coords,
unsigned num_cvt_item,
const TupleVariationData *tuple_var_data,
const void *base,
hb_vector_t<float>& cvt_deltas /* OUT */)
{
if (!coords) return true;
hb_vector_t<unsigned> shared_indices;
TupleVariationData::tuple_iterator_t iterator;
unsigned var_data_length = tuple_var_data->get_size (axis_count);
hb_bytes_t var_data_bytes = hb_bytes_t (reinterpret_cast<const char*> (tuple_var_data), var_data_length);
if (!TupleVariationData::get_tuple_iterator (var_data_bytes, axis_count, base,
shared_indices, &iterator))
return true; /* isn't applied at all */
hb_array_t<const F2DOT14> shared_tuples = hb_array<F2DOT14> ();
hb_vector_t<unsigned> private_indices;
hb_vector_t<int> unpacked_deltas;
do
{
float scalar = iterator.current_tuple->calculate_scalar (coords, axis_count, 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 &&
!TupleVariationData::unpack_points (p, private_indices, end))
return false;
const hb_vector_t<unsigned int> &indices = has_private_points ? private_indices : shared_indices;
bool apply_to_all = (indices.length == 0);
unsigned num_deltas = apply_to_all ? num_cvt_item : indices.length;
if (unlikely (!unpacked_deltas.resize (num_deltas, false))) return false;
if (unlikely (!TupleVariationData::unpack_deltas (p, unpacked_deltas, end))) return false;
for (unsigned int i = 0; i < num_deltas; i++)
{
unsigned int idx = apply_to_all ? i : indices[i];
if (unlikely (idx >= num_cvt_item)) continue;
if (scalar != 1.0f) cvt_deltas[idx] += unpacked_deltas[i] * scalar ;
else cvt_deltas[idx] += unpacked_deltas[i];
}
} while (iterator.move_to_next ());
return true;
}
static bool add_cvt_and_apply_deltas (hb_subset_plan_t *plan,
const TupleVariationData *tuple_var_data,
const void *base)
{
const hb_tag_t cvt = HB_TAG('c','v','t',' ');
hb_blob_t *cvt_blob = hb_face_reference_table (plan->source, cvt);
hb_blob_t *cvt_prime_blob = hb_blob_copy_writable_or_fail (cvt_blob);
hb_blob_destroy (cvt_blob);
if (unlikely (!cvt_prime_blob))
return false;
unsigned cvt_blob_length = hb_blob_get_length (cvt_prime_blob);
unsigned num_cvt_item = cvt_blob_length / FWORD::static_size;
hb_vector_t<float> cvt_deltas;
if (unlikely (!cvt_deltas.resize (num_cvt_item)))
{
hb_blob_destroy (cvt_prime_blob);
return false;
}
hb_memset (cvt_deltas.arrayZ, 0, cvt_deltas.get_size ());
if (!calculate_cvt_deltas (plan->normalized_coords.length, plan->normalized_coords.as_array (),
num_cvt_item, tuple_var_data, base, cvt_deltas))
{
hb_blob_destroy (cvt_prime_blob);
return false;
}
FWORD *cvt_prime = (FWORD *) hb_blob_get_data_writable (cvt_prime_blob, nullptr);
for (unsigned i = 0; i < num_cvt_item; i++)
cvt_prime[i] += (int) roundf (cvt_deltas[i]);
bool success = plan->add_table (cvt, cvt_prime_blob);
hb_blob_destroy (cvt_prime_blob);
return success;
}
protected:
FixedVersion<>version; /* Version of the CVT variation table
* initially set to 0x00010000u */
TupleVariationData tupleVariationData; /* TupleVariationDate for cvar table */
public:
DEFINE_SIZE_MIN (8);
};
} /* namespace OT */
#endif /* HB_OT_VAR_CVAR_TABLE_HH */