[instance] Add struct definition for cvar table
Also add functions to add cvt tables with cvar deltas applied
diff --git a/src/Makefile.sources b/src/Makefile.sources
index 9a96ad6..fd7c3b5 100644
--- a/src/Makefile.sources
+++ b/src/Makefile.sources
@@ -225,6 +225,7 @@
hb-ot-tag.cc \
hb-ot-var-avar-table.hh \
hb-ot-var-common.hh \
+ hb-ot-var-cvar-table.hh \
hb-ot-var-fvar-table.hh \
hb-ot-var-gvar-table.hh \
hb-ot-var-hvar-table.hh \
diff --git a/src/hb-ot-var-common.hh b/src/hb-ot-var-common.hh
index 936de68..cdc6a27 100644
--- a/src/hb-ot-var-common.hh
+++ b/src/hb-ot-var-common.hh
@@ -346,6 +346,25 @@
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 ();
+
+ return total_size;
+ }
+
const TupleVariationHeader &get_tuple_var_header (void) const
{ return StructAfter<TupleVariationHeader> (data); }
diff --git a/src/hb-ot-var-cvar-table.hh b/src/hb-ot-var-cvar-table.hh
new file mode 100644
index 0000000..7d4acc1
--- /dev/null
+++ b/src/hb-ot-var-cvar-table.hh
@@ -0,0 +1,151 @@
+/*
+ * 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));
+ }
+
+ bool calculate_cvt_deltas (unsigned axis_count,
+ hb_array_t<int> coords,
+ unsigned num_cvt_item,
+ hb_vector_t<float>& cvt_deltas /* OUT */) const
+ {
+ if (!coords) return true;
+ hb_vector_t<unsigned> shared_indices;
+ TupleVariationData::tuple_iterator_t iterator;
+ unsigned var_data_length = tupleVariationData.get_size (axis_count);
+ hb_bytes_t var_data_bytes = hb_bytes_t (reinterpret_cast<const char*> (&tupleVariationData), var_data_length);
+ if (!TupleVariationData::get_tuple_iterator (var_data_bytes, axis_count,
+ this,
+ 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;
+ }
+
+ bool add_cvt_and_apply_deltas (hb_subset_plan_t *plan) const
+ {
+ 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, 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] += 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 */
diff --git a/src/meson.build b/src/meson.build
index 435201c..93991ab 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -226,6 +226,7 @@
'hb-ot-tag.cc',
'hb-ot-var-avar-table.hh',
'hb-ot-var-common.hh',
+ 'hb-ot-var-cvar-table.hh',
'hb-ot-var-fvar-table.hh',
'hb-ot-var-gvar-table.hh',
'hb-ot-var-hvar-table.hh',
