Hash :
10642b3f
Author :
Date :
2018-09-15T19:43:33
Disallow null-enabled offsets to unsized structures... ...like UnsizedArrayOf<>. This fixes a class of crasher bugs, mostly with color and AAT tables. We cannot use nullable offsets to varsized data that does not declare min_size, because it's nost safe to use our fixed-size null pool for types that have their size external. So, use non_null'able offsets for these. A further enhancement would be to make use of min_size in Null<> itself. Will try that after.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144
/*
* Copyright © 2018 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_COLOR_COLR_TABLE_HH
#define HB_OT_COLOR_COLR_TABLE_HH
#include "hb-open-type.hh"
/*
* COLR -- Color
* https://docs.microsoft.com/en-us/typography/opentype/spec/colr
*/
#define HB_OT_TAG_COLR HB_TAG('C','O','L','R')
namespace OT {
struct LayerRecord
{
friend struct COLR;
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
protected:
GlyphID glyphid; /* Glyph ID of layer glyph */
HBUINT16 colorIdx; /* Index value to use with a selected color palette */
public:
DEFINE_SIZE_STATIC (4);
};
struct BaseGlyphRecord
{
friend struct COLR;
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this)));
}
inline int cmp (hb_codepoint_t g) const {
return g < glyphid ? -1 : g > glyphid ? 1 : 0;
}
protected:
GlyphID glyphid; /* Glyph ID of reference glyph */
HBUINT16 firstLayerIdx; /* Index to the layer record */
HBUINT16 numLayers; /* Number of color layers associated with this glyph */
public:
DEFINE_SIZE_STATIC (6);
};
static int compare_bgr (const void *pa, const void *pb)
{
const hb_codepoint_t *a = (const hb_codepoint_t *) pa;
const BaseGlyphRecord *b = (const BaseGlyphRecord *) pb;
return b->cmp (*a);
}
struct COLR
{
static const hb_tag_t tableTag = HB_OT_TAG_COLR;
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
(this+baseGlyphsZ).sanitize (c, numBaseGlyphs) &&
(this+layersZ).sanitize (c, numLayers)));
}
inline bool get_base_glyph_record (hb_codepoint_t glyph_id,
unsigned int *first_layer /* OUT */,
unsigned int *num_layers /* OUT */) const
{
const BaseGlyphRecord* record;
record = (BaseGlyphRecord *) bsearch (&glyph_id, &(this+baseGlyphsZ), numBaseGlyphs,
sizeof (BaseGlyphRecord), compare_bgr);
if (unlikely (!record))
return false;
*first_layer = record->firstLayerIdx;
*num_layers = record->numLayers;
return true;
}
inline bool get_layer_record (unsigned int record,
hb_codepoint_t *glyph_id /* OUT */,
unsigned int *palette_index /* OUT */) const
{
if (unlikely (record >= numLayers))
{
*glyph_id = 0;
*palette_index = 0xFFFF;
return false;
}
const LayerRecord &layer = (this+layersZ)[record];
*glyph_id = layer.glyphid;
*palette_index = layer.colorIdx;
return true;
}
protected:
HBUINT16 version; /* Table version number */
HBUINT16 numBaseGlyphs; /* Number of Base Glyph Records */
LOffsetTo<UnsizedArrayOf<BaseGlyphRecord>, false>
baseGlyphsZ; /* Offset to Base Glyph records. */
LOffsetTo<UnsizedArrayOf<LayerRecord>, false>
layersZ; /* Offset to Layer Records */
HBUINT16 numLayers; /* Number of Layer Records */
public:
DEFINE_SIZE_STATIC (14);
};
} /* namespace OT */
#endif /* HB_OT_COLOR_COLR_TABLE_HH */