1 /*
2  * Copyright © 2011,2012  Google, Inc.
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  * Google Author(s): Behdad Esfahbod
25  */
26 
27 #ifndef HB_OT_MAXP_TABLE_HH
28 #define HB_OT_MAXP_TABLE_HH
29 
30 #include "hb-open-type.hh"
31 
32 namespace OT {
33 
34 
35 /*
36  * maxp -- Maximum Profile
37  * https://docs.microsoft.com/en-us/typography/opentype/spec/maxp
38  */
39 
40 #define HB_OT_TAG_maxp HB_TAG('m','a','x','p')
41 
42 struct maxpV1Tail
43 {
sanitizeOT::maxpV1Tail44   bool sanitize (hb_sanitize_context_t *c) const
45   {
46     TRACE_SANITIZE (this);
47     return_trace (c->check_struct (this));
48   }
49 
50   HBUINT16 maxPoints;		  /* Maximum points in a non-composite glyph. */
51   HBUINT16 maxContours;		  /* Maximum contours in a non-composite glyph. */
52   HBUINT16 maxCompositePoints;	  /* Maximum points in a composite glyph. */
53   HBUINT16 maxCompositeContours;  /* Maximum contours in a composite glyph. */
54   HBUINT16 maxZones;		  /* 1 if instructions do not use the twilight zone (Z0),
55 				   * or 2 if instructions do use Z0; should be set to 2 in
56 				   * most cases. */
57   HBUINT16 maxTwilightPoints;	  /* Maximum points used in Z0. */
58   HBUINT16 maxStorage;		  /* Number of Storage Area locations. */
59   HBUINT16 maxFunctionDefs;	  /* Number of FDEFs, equal to the highest function number + 1. */
60   HBUINT16 maxInstructionDefs;	  /* Number of IDEFs. */
61   HBUINT16 maxStackElements;	  /* Maximum stack depth. (This includes Font and CVT
62 				   * Programs, as well as the instructions for each glyph.) */
63   HBUINT16 maxSizeOfInstructions; /* Maximum byte count for glyph instructions. */
64   HBUINT16 maxComponentElements;  /* Maximum number of components referenced at
65 				   * "top level" for any composite glyph. */
66   HBUINT16 maxComponentDepth;	  /* Maximum levels of recursion; 1 for simple components. */
67  public:
68   DEFINE_SIZE_STATIC (26);
69 };
70 
71 
72 struct maxp
73 {
74   static constexpr hb_tag_t tableTag = HB_OT_TAG_maxp;
75 
get_num_glyphsOT::maxp76   unsigned int get_num_glyphs () const { return numGlyphs; }
77 
set_num_glyphsOT::maxp78   void set_num_glyphs (unsigned int count)
79   {
80     numGlyphs = count;
81   }
82 
sanitizeOT::maxp83   bool sanitize (hb_sanitize_context_t *c) const
84   {
85     TRACE_SANITIZE (this);
86     if (unlikely (!c->check_struct (this)))
87       return_trace (false);
88 
89     if (version.major == 1)
90     {
91       const maxpV1Tail &v1 = StructAfter<maxpV1Tail> (*this);
92       return_trace (v1.sanitize (c));
93     }
94     return_trace (likely (version.major == 0 && version.minor == 0x5000u));
95   }
96 
subsetOT::maxp97   bool subset (hb_subset_context_t *c) const
98   {
99     TRACE_SUBSET (this);
100     maxp *maxp_prime = c->serializer->embed (this);
101     if (unlikely (!maxp_prime)) return_trace (false);
102 
103     maxp_prime->numGlyphs = c->plan->num_output_glyphs ();
104     if (maxp_prime->version.major == 1)
105     {
106       const maxpV1Tail *src_v1 = &StructAfter<maxpV1Tail> (*this);
107       maxpV1Tail *dest_v1 = c->serializer->embed<maxpV1Tail> (src_v1);
108       if (unlikely (!dest_v1)) return_trace (false);
109 
110       if (c->plan->drop_hints)
111 	drop_hint_fields (dest_v1);
112     }
113 
114     return_trace (true);
115   }
116 
drop_hint_fieldsOT::maxp117   static void drop_hint_fields (maxpV1Tail* dest_v1)
118   {
119     dest_v1->maxZones = 1;
120     dest_v1->maxTwilightPoints = 0;
121     dest_v1->maxStorage = 0;
122     dest_v1->maxFunctionDefs = 0;
123     dest_v1->maxInstructionDefs = 0;
124     dest_v1->maxStackElements = 0;
125     dest_v1->maxSizeOfInstructions = 0;
126   }
127 
128   protected:
129   FixedVersion<>version;/* Version of the maxp table (0.5 or 1.0),
130 			 * 0x00005000u or 0x00010000u. */
131   HBUINT16	numGlyphs;
132 			/* The number of glyphs in the font. */
133 /*maxpV1Tail	v1Tail[HB_VAR_ARRAY]; */
134   public:
135   DEFINE_SIZE_STATIC (6);
136 };
137 
138 
139 } /* namespace OT */
140 
141 
142 #endif /* HB_OT_MAXP_TABLE_HH */
143