1 /*
2  * Copyright © 2018  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_COLOR_SVG_TABLE_HH
26 #define HB_OT_COLOR_SVG_TABLE_HH
27 
28 #include "hb-open-type.hh"
29 
30 /*
31  * SVG -- SVG (Scalable Vector Graphics)
32  * https://docs.microsoft.com/en-us/typography/opentype/spec/svg
33  */
34 
35 #define HB_OT_TAG_SVG HB_TAG('S','V','G',' ')
36 
37 
38 namespace OT {
39 
40 
41 struct SVGDocumentIndexEntry
42 {
cmpOT::SVGDocumentIndexEntry43   int cmp (hb_codepoint_t g) const
44   { return g < startGlyphID ? -1 : g > endGlyphID ? 1 : 0; }
45 
reference_blobOT::SVGDocumentIndexEntry46   hb_blob_t *reference_blob (hb_blob_t *svg_blob, unsigned int index_offset) const
47   {
48     return hb_blob_create_sub_blob (svg_blob,
49 				    index_offset + (unsigned int) svgDoc,
50 				    svgDocLength);
51   }
52 
sanitizeOT::SVGDocumentIndexEntry53   bool sanitize (hb_sanitize_context_t *c, const void *base) const
54   {
55     TRACE_SANITIZE (this);
56     return_trace (c->check_struct (this) &&
57 		  svgDoc.sanitize (c, base, svgDocLength));
58   }
59 
60   protected:
61   HBUINT16	startGlyphID;	/* The first glyph ID in the range described by
62 				 * this index entry. */
63   HBUINT16	endGlyphID;	/* The last glyph ID in the range described by
64 				 * this index entry. Must be >= startGlyphID. */
65   NNOffset32To<UnsizedArrayOf<HBUINT8>>
66 		svgDoc;		/* Offset from the beginning of the SVG Document Index
67 				 * to an SVG document. Must be non-zero. */
68   HBUINT32	svgDocLength;	/* Length of the SVG document.
69 				 * Must be non-zero. */
70   public:
71   DEFINE_SIZE_STATIC (12);
72 };
73 
74 struct SVG
75 {
76   static constexpr hb_tag_t tableTag = HB_OT_TAG_SVG;
77 
has_dataOT::SVG78   bool has_data () const { return svgDocEntries; }
79 
80   struct accelerator_t
81   {
initOT::SVG::accelerator_t82     void init (hb_face_t *face)
83     { table = hb_sanitize_context_t ().reference_table<SVG> (face); }
finiOT::SVG::accelerator_t84     void fini () { table.destroy (); }
85 
reference_blob_for_glyphOT::SVG::accelerator_t86     hb_blob_t *reference_blob_for_glyph (hb_codepoint_t glyph_id) const
87     {
88       return table->get_glyph_entry (glyph_id).reference_blob (table.get_blob (),
89 							       table->svgDocEntries);
90     }
91 
has_dataOT::SVG::accelerator_t92     bool has_data () const { return table->has_data (); }
93 
94     private:
95     hb_blob_ptr_t<SVG> table;
96   };
97 
get_glyph_entryOT::SVG98   const SVGDocumentIndexEntry &get_glyph_entry (hb_codepoint_t glyph_id) const
99   { return (this+svgDocEntries).bsearch (glyph_id); }
100 
sanitizeOT::SVG101   bool sanitize (hb_sanitize_context_t *c) const
102   {
103     TRACE_SANITIZE (this);
104     return_trace (likely (c->check_struct (this) &&
105 			  (this+svgDocEntries).sanitize_shallow (c)));
106   }
107 
108   protected:
109   HBUINT16	version;	/* Table version (starting at 0). */
110   Offset32To<SortedArray16Of<SVGDocumentIndexEntry>>
111 		svgDocEntries;	/* Offset (relative to the start of the SVG table) to the
112 				 * SVG Documents Index. Must be non-zero. */
113 				/* Array of SVG Document Index Entries. */
114   HBUINT32	reserved;	/* Set to 0. */
115   public:
116   DEFINE_SIZE_STATIC (10);
117 };
118 
119 struct SVG_accelerator_t : SVG::accelerator_t {};
120 
121 } /* namespace OT */
122 
123 
124 #endif /* HB_OT_COLOR_SVG_TABLE_HH */
125