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Diffstat (limited to '')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-meta-table.hh | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-meta-table.hh b/gfx/harfbuzz/src/hb-ot-meta-table.hh new file mode 100644 index 0000000000..e1b68bcf91 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-meta-table.hh @@ -0,0 +1,129 @@ +/* + * 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 */ |