1 /* 2 * Copyright © 2019 Ebrahim Byagowi 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 */ 24 25 #ifndef HB_OT_META_TABLE_HH 26 #define HB_OT_META_TABLE_HH 27 28 #include "hb-open-type.hh" 29 30 /* 31 * meta -- Metadata Table 32 * https://docs.microsoft.com/en-us/typography/opentype/spec/meta 33 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6meta.html 34 */ 35 #define HB_OT_TAG_meta HB_TAG ('m','e','t','a') 36 37 38 namespace OT { 39 40 41 struct DataMap 42 { cmpOT::DataMap43 int cmp (hb_tag_t a) const { return tag.cmp (a); } 44 get_tagOT::DataMap45 hb_tag_t get_tag () const { return tag; } 46 reference_entryOT::DataMap47 hb_blob_t *reference_entry (hb_blob_t *meta_blob) const 48 { return hb_blob_create_sub_blob (meta_blob, dataZ, dataLength); } 49 sanitizeOT::DataMap50 bool sanitize (hb_sanitize_context_t *c, const void *base) const 51 { 52 TRACE_SANITIZE (this); 53 return_trace (likely (c->check_struct (this) && 54 dataZ.sanitize (c, base, dataLength))); 55 } 56 57 protected: 58 Tag tag; /* A tag indicating the type of metadata. */ 59 LOffsetTo<UnsizedArrayOf<HBUINT8>> 60 dataZ; /* Offset in bytes from the beginning of the 61 * metadata table to the data for this tag. */ 62 HBUINT32 dataLength; /* Length of the data. The data is not required to 63 * be padded to any byte boundary. */ 64 public: 65 DEFINE_SIZE_STATIC (12); 66 }; 67 68 struct meta 69 { 70 static constexpr hb_tag_t tableTag = HB_OT_TAG_meta; 71 72 struct accelerator_t 73 { initOT::meta::accelerator_t74 void init (hb_face_t *face) 75 { table = hb_sanitize_context_t ().reference_table<meta> (face); } finiOT::meta::accelerator_t76 void fini () { table.destroy (); } 77 reference_entryOT::meta::accelerator_t78 hb_blob_t *reference_entry (hb_tag_t tag) const 79 { return table->dataMaps.lsearch (tag).reference_entry (table.get_blob ()); } 80 get_entriesOT::meta::accelerator_t81 unsigned int get_entries (unsigned int start_offset, 82 unsigned int *count, 83 hb_ot_meta_tag_t *entries) const 84 { 85 if (count) 86 { 87 + table->dataMaps.sub_array (start_offset, count) 88 | hb_map (&DataMap::get_tag) 89 | hb_map ([](hb_tag_t tag) { return (hb_ot_meta_tag_t) tag; }) 90 | hb_sink (hb_array (entries, *count)) 91 ; 92 } 93 return table->dataMaps.len; 94 } 95 96 private: 97 hb_blob_ptr_t<meta> table; 98 }; 99 sanitizeOT::meta100 bool sanitize (hb_sanitize_context_t *c) const 101 { 102 TRACE_SANITIZE (this); 103 return_trace (likely (c->check_struct (this) && 104 version == 1 && 105 dataMaps.sanitize (c, this))); 106 } 107 108 protected: 109 HBUINT32 version; /* Version number of the metadata table — set to 1. */ 110 HBUINT32 flags; /* Flags — currently unused; set to 0. */ 111 HBUINT32 dataOffset; /* Per Apple specification: 112 * Offset from the beginning of the table to the data. 113 * Per OT specification: 114 * Reserved. Not used; should be set to 0. */ 115 LArrayOf<DataMap> 116 dataMaps; /* Array of data map records. */ 117 public: 118 DEFINE_SIZE_ARRAY (16, dataMaps); 119 }; 120 121 struct meta_accelerator_t : meta::accelerator_t {}; 122 123 } /* namespace OT */ 124 125 126 #endif /* HB_OT_META_TABLE_HH */ 127