gfx/harfbuzz/src/hb-ot-maxp-table.hh

   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 {
  44   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
  76   unsigned int get_num_glyphs () const { return numGlyphs; }
  77
  78   void set_num_glyphs (unsigned int count)
  79   {
  80     numGlyphs = count;
  81   }
  82
  83   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
  97   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 = hb_min (c->plan->num_output_glyphs (), 0xFFFFu);
 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->flags & HB_SUBSET_FLAGS_NO_HINTING)
 111         drop_hint_fields (dest_v1);
 112
 113       if (c->plan->normalized_coords)
 114         instancing_update_fields (c->plan->head_maxp_info, dest_v1);
 115     }
 116
 117     return_trace (true);
 118   }
 119
 120   void instancing_update_fields (head_maxp_info_t& maxp_info, maxpV1Tail* dest_v1) const
 121   {
 122     dest_v1->maxPoints = maxp_info.maxPoints;
 123     dest_v1->maxContours = maxp_info.maxContours;
 124     dest_v1->maxCompositePoints = maxp_info.maxCompositePoints;
 125     dest_v1->maxCompositeContours = maxp_info.maxCompositeContours;
 126     dest_v1->maxComponentElements = maxp_info.maxComponentElements;
 127     dest_v1->maxComponentDepth = maxp_info.maxComponentDepth;
 128   }
 129
 130   static void drop_hint_fields (maxpV1Tail* dest_v1)
 131   {
 132     dest_v1->maxZones = 1;
 133     dest_v1->maxTwilightPoints = 0;
 134     dest_v1->maxStorage = 0;
 135     dest_v1->maxFunctionDefs = 0;
 136     dest_v1->maxInstructionDefs = 0;
 137     dest_v1->maxStackElements = 0;
 138     dest_v1->maxSizeOfInstructions = 0;
 139   }
 140
 141   protected:
 142   FixedVersion<>version;/* Version of the maxp table (0.5 or 1.0),
 143                          * 0x00005000u or 0x00010000u. */
 144   HBUINT16      numGlyphs;
 145                         /* The number of glyphs in the font. */
 146 /*maxpV1Tail    v1Tail[HB_VAR_ARRAY]; */
 147   public:
 148   DEFINE_SIZE_STATIC (6);
 149 };
 150
 151
 152 } /* namespace OT */
 153
 154
 155 #endif /* HB_OT_MAXP_TABLE_HH */