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/*
* 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.
*/
#ifndef HB_OT_META_TABLE_HH
#define HB_OT_META_TABLE_HH
#include "hb-open-type.hh"
/*
* meta -- Metadata Table
* https://docs.microsoft.com/en-us/typography/opentype/spec/meta
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6meta.html
*/
#define HB_OT_TAG_meta HB_TAG ('m','e','t','a')
namespace OT {
struct DataMap
{
int cmp (hb_tag_t a) const { return tag.cmp (a); }
hb_tag_t get_tag () const { return tag; }
hb_blob_t *reference_entry (hb_blob_t *meta_blob) const
{ return hb_blob_create_sub_blob (meta_blob, dataZ, dataLength); }
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
dataZ.sanitize (c, base, dataLength)));
}
protected:
Tag tag; /* A tag indicating the type of metadata. */
NNOffset32To<UnsizedArrayOf<HBUINT8>>
dataZ; /* Offset in bytes from the beginning of the
* metadata table to the data for this tag. */
HBUINT32 dataLength; /* Length of the data. The data is not required to
* be padded to any byte boundary. */
public:
DEFINE_SIZE_STATIC (12);
};
struct meta
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_meta;
struct accelerator_t
{
accelerator_t (hb_face_t *face)
{ table = hb_sanitize_context_t ().reference_table<meta> (face); }
~accelerator_t () { table.destroy (); }
hb_blob_t *reference_entry (hb_tag_t tag) const
{ return table->dataMaps.lsearch (tag).reference_entry (table.get_blob ()); }
unsigned int get_entries (unsigned int start_offset,
unsigned int *count,
hb_ot_meta_tag_t *entries) const
{
if (count)
{
+ table->dataMaps.as_array ().sub_array (start_offset, count)
| hb_map (&DataMap::get_tag)
| hb_map ([](hb_tag_t tag) { return (hb_ot_meta_tag_t) tag; })
| hb_sink (hb_array (entries, *count))
;
}
return table->dataMaps.len;
}
private:
hb_blob_ptr_t<meta> table;
};
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
version == 1 &&
dataMaps.sanitize (c, this)));
}
protected:
HBUINT32 version; /* Version number of the metadata table — set to 1. */
HBUINT32 flags; /* Flags — currently unused; set to 0. */
HBUINT32 dataOffset;
/* Per Apple specification:
* Offset from the beginning of the table to the data.
* Per OT specification:
* Reserved. Not used; should be set to 0. */
Array32Of<DataMap>
dataMaps;/* Array of data map records. */
public:
DEFINE_SIZE_ARRAY (16, dataMaps);
};
struct meta_accelerator_t : meta::accelerator_t {
meta_accelerator_t (hb_face_t *face) : meta::accelerator_t (face) {}
};
} /* namespace OT */
#endif /* HB_OT_META_TABLE_HH */
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