/*
* Copyright © 2014 Google, Inc.
*
* 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.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_CMAP_TABLE_HH
#define HB_OT_CMAP_TABLE_HH
#include "hb-open-type-private.hh"
namespace OT {
/*
* cmap -- Character To Glyph Index Mapping Table
*/
#define HB_OT_TAG_cmap HB_TAG('c','m','a','p')
struct CmapSubtableFormat0
{
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
hb_codepoint_t gid = codepoint < 256 ? glyphIdArray[codepoint] : 0;
if (!gid)
return false;
*glyph = gid;
return true;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this));
}
protected:
USHORT format; /* Format number is set to 0. */
USHORT lengthZ; /* Byte length of this subtable. */
USHORT languageZ; /* Ignore. */
BYTE glyphIdArray[256];/* An array that maps character
* code to glyph index values. */
public:
DEFINE_SIZE_STATIC (6 + 256);
};
struct CmapSubtableFormat4
{
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
unsigned int segCount;
const USHORT *endCount;
const USHORT *startCount;
const USHORT *idDelta;
const USHORT *idRangeOffset;
const USHORT *glyphIdArray;
unsigned int glyphIdArrayLength;
segCount = this->segCountX2 / 2;
endCount = this->values;
startCount = endCount + segCount + 1;
idDelta = startCount + segCount;
idRangeOffset = idDelta + segCount;
glyphIdArray = idRangeOffset + segCount;
glyphIdArrayLength = (this->length - 16 - 8 * segCount) / 2;
/* Custom two-array bsearch. */
int min = 0, max = (int) segCount - 1;
unsigned int i;
while (min <= max)
{
int mid = (min + max) / 2;
if (codepoint < startCount[mid])
max = mid - 1;
else if (codepoint > endCount[mid])
min = mid + 1;
else
{
i = mid;
goto found;
}
}
return false;
found:
hb_codepoint_t gid;
unsigned int rangeOffset = idRangeOffset[i];
if (rangeOffset == 0)
gid = codepoint + idDelta[i];
else
{
/* Somebody has been smoking... */
unsigned int index = rangeOffset / 2 + (codepoint - startCount[i]) + i - segCount;
if (unlikely (index >= glyphIdArrayLength))
return false;
gid = glyphIdArray[index];
if (unlikely (!gid))
return false;
gid += idDelta[i];
}
*glyph = gid & 0xFFFFu;
return true;
}
inline bool sanitize (hb_sanitize_context_t *c)
{
TRACE_SANITIZE (this);
if (unlikely (!c->check_struct (this)))
return TRACE_RETURN (false);
if (unlikely (!c->check_range (this, length)))
{
/* Some broken fonts have too long of a "length" value.
* If that is the case, just change the value to truncate
* the subtable at the end of the blob. */
uint16_t new_length = (uint16_t) MIN ((uintptr_t) 65535,
(uintptr_t) (c->end -
(char *) this));
if (!c->try_set (&length, new_length))
return TRACE_RETURN (false);
}
return TRACE_RETURN (16 + 4 * (unsigned int) segCountX2 <= length);
}
protected:
USHORT format; /* Format number is set to 4. */
USHORT length; /* This is the length in bytes of the
* subtable. */
USHORT languageZ; /* Ignore. */
USHORT segCountX2; /* 2 x segCount. */
USHORT searchRangeZ; /* 2 * (2**floor(log2(segCount))) */
USHORT entrySelectorZ; /* log2(searchRange/2) */
USHORT rangeShiftZ; /* 2 x segCount - searchRange */
USHORT values[VAR];
#if 0
USHORT endCount[segCount]; /* End characterCode for each segment,
* last=0xFFFFu. */
USHORT reservedPad; /* Set to 0. */
USHORT startCount[segCount]; /* Start character code for each segment. */
SHORT idDelta[segCount]; /* Delta for all character codes in segment. */
USHORT idRangeOffset[segCount];/* Offsets into glyphIdArray or 0 */
USHORT glyphIdArray[VAR]; /* Glyph index array (arbitrary length) */
#endif
public:
DEFINE_SIZE_ARRAY (14, values);
};
struct CmapSubtableLongGroup
{
friend struct CmapSubtableFormat12;
friend struct CmapSubtableFormat13;
int cmp (hb_codepoint_t codepoint) const
{
if (codepoint < startCharCode) return -1;
if (codepoint > endCharCode) return +1;
return 0;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this));
}
private:
ULONG startCharCode; /* First character code in this group. */
ULONG endCharCode; /* Last character code in this group. */
ULONG glyphID; /* Glyph index; interpretation depends on
* subtable format. */
public:
DEFINE_SIZE_STATIC (12);
};
template <typename UINT>
struct CmapSubtableTrimmed
{
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
/* Rely on our implicit array bound-checking. */
hb_codepoint_t gid = glyphIdArray[codepoint - startCharCode];
if (!gid)
return false;
*glyph = gid;
return true;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) && glyphIdArray.sanitize (c));
}
protected:
UINT formatReserved; /* Subtable format and (maybe) padding. */
UINT lengthZ; /* Byte length of this subtable. */
UINT languageZ; /* Ignore. */
UINT startCharCode; /* First character code covered. */
ArrayOf<GlyphID, UINT>
glyphIdArray; /* Array of glyph index values for character
* codes in the range. */
public:
DEFINE_SIZE_ARRAY (5 * sizeof (UINT), glyphIdArray);
};
struct CmapSubtableFormat6 : CmapSubtableTrimmed<USHORT> {};
struct CmapSubtableFormat10 : CmapSubtableTrimmed<ULONG > {};
template <typename T>
struct CmapSubtableLongSegmented
{
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
int i = groups.bsearch (codepoint);
if (i == -1)
return false;
*glyph = T::group_get_glyph (groups[i], codepoint);
return true;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) && groups.sanitize (c));
}
protected:
USHORT format; /* Subtable format; set to 12. */
USHORT reservedZ; /* Reserved; set to 0. */
ULONG lengthZ; /* Byte length of this subtable. */
ULONG languageZ; /* Ignore. */
SortedArrayOf<CmapSubtableLongGroup, ULONG>
groups; /* Groupings. */
public:
DEFINE_SIZE_ARRAY (16, groups);
};
struct CmapSubtableFormat12 : CmapSubtableLongSegmented<CmapSubtableFormat12>
{
static inline hb_codepoint_t group_get_glyph (const CmapSubtableLongGroup &group,
hb_codepoint_t u)
{ return group.glyphID + (u - group.startCharCode); }
};
struct CmapSubtableFormat13 : CmapSubtableLongSegmented<CmapSubtableFormat13>
{
static inline hb_codepoint_t group_get_glyph (const CmapSubtableLongGroup &group,
hb_codepoint_t u HB_UNUSED)
{ return group.glyphID; }
};
typedef enum
{
GLYPH_VARIANT_NOT_FOUND = 0,
GLYPH_VARIANT_FOUND = 1,
GLYPH_VARIANT_USE_DEFAULT = 2
} glyph_variant_t;
struct UnicodeValueRange
{
inline int cmp (const hb_codepoint_t &codepoint) const
{
if (codepoint < startUnicodeValue) return -1;
if (codepoint > startUnicodeValue + additionalCount) return +1;
return 0;
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this));
}
UINT24 startUnicodeValue; /* First value in this range. */
BYTE additionalCount; /* Number of additional values in this
* range. */
public:
DEFINE_SIZE_STATIC (4);
};
typedef SortedArrayOf<UnicodeValueRange, ULONG> DefaultUVS;
struct UVSMapping
{
inline int cmp (const hb_codepoint_t &codepoint) const
{
return unicodeValue.cmp (codepoint);
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this));
}
UINT24 unicodeValue; /* Base Unicode value of the UVS */
GlyphID glyphID; /* Glyph ID of the UVS */
public:
DEFINE_SIZE_STATIC (5);
};
typedef SortedArrayOf<UVSMapping, ULONG> NonDefaultUVS;
struct VariationSelectorRecord
{
inline glyph_variant_t get_glyph (hb_codepoint_t codepoint,
hb_codepoint_t *glyph,
const void *base) const
{
int i;
const DefaultUVS &defaults = base+defaultUVS;
i = defaults.bsearch (codepoint);
if (i != -1)
return GLYPH_VARIANT_USE_DEFAULT;
const NonDefaultUVS &nonDefaults = base+nonDefaultUVS;
i = nonDefaults.bsearch (codepoint);
if (i != -1)
{
*glyph = nonDefaults[i].glyphID;
return GLYPH_VARIANT_FOUND;
}
return GLYPH_VARIANT_NOT_FOUND;
}
inline int cmp (const hb_codepoint_t &variation_selector) const
{
return varSelector.cmp (variation_selector);
}
inline bool sanitize (hb_sanitize_context_t *c, void *base) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) &&
defaultUVS.sanitize (c, base) &&
nonDefaultUVS.sanitize (c, base));
}
UINT24 varSelector; /* Variation selector. */
OffsetTo<DefaultUVS, ULONG>
defaultUVS; /* Offset to Default UVS Table. May be 0. */
OffsetTo<NonDefaultUVS, ULONG>
nonDefaultUVS; /* Offset to Non-Default UVS Table. May be 0. */
public:
DEFINE_SIZE_STATIC (11);
};
struct CmapSubtableFormat14
{
inline glyph_variant_t get_glyph_variant (hb_codepoint_t codepoint,
hb_codepoint_t variation_selector,
hb_codepoint_t *glyph) const
{
return record[record.bsearch(variation_selector)].get_glyph (codepoint, glyph, this);
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) &&
record.sanitize (c, this));
}
protected:
USHORT format; /* Format number is set to 0. */
ULONG lengthZ; /* Byte length of this subtable. */
SortedArrayOf<VariationSelectorRecord, ULONG>
record; /* Variation selector records; sorted
* in increasing order of `varSelector'. */
public:
DEFINE_SIZE_ARRAY (10, record);
};
struct CmapSubtable
{
/* Note: We intentionally do NOT implement subtable formats 2 and 8. */
inline bool get_glyph (hb_codepoint_t codepoint,
hb_codepoint_t *glyph) const
{
switch (u.format) {
case 0: return u.format0 .get_glyph(codepoint, glyph);
case 4: return u.format4 .get_glyph(codepoint, glyph);
case 6: return u.format6 .get_glyph(codepoint, glyph);
case 10: return u.format10.get_glyph(codepoint, glyph);
case 12: return u.format12.get_glyph(codepoint, glyph);
case 13: return u.format13.get_glyph(codepoint, glyph);
case 14:
default: return false;
}
}
inline glyph_variant_t get_glyph_variant (hb_codepoint_t codepoint,
hb_codepoint_t variation_selector,
hb_codepoint_t *glyph) const
{
switch (u.format) {
case 14: return u.format14.get_glyph_variant(codepoint, variation_selector, glyph);
default: return GLYPH_VARIANT_NOT_FOUND;
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
if (!u.format.sanitize (c)) return TRACE_RETURN (false);
switch (u.format) {
case 0: return TRACE_RETURN (u.format0 .sanitize (c));
case 4: return TRACE_RETURN (u.format4 .sanitize (c));
case 6: return TRACE_RETURN (u.format6 .sanitize (c));
case 10: return TRACE_RETURN (u.format10.sanitize (c));
case 12: return TRACE_RETURN (u.format12.sanitize (c));
case 13: return TRACE_RETURN (u.format13.sanitize (c));
case 14: return TRACE_RETURN (u.format14.sanitize (c));
default:return TRACE_RETURN (true);
}
}
protected:
union {
USHORT format; /* Format identifier */
CmapSubtableFormat0 format0;
CmapSubtableFormat4 format4;
CmapSubtableFormat6 format6;
CmapSubtableFormat10 format10;
CmapSubtableFormat12 format12;
CmapSubtableFormat13 format13;
CmapSubtableFormat14 format14;
} u;
public:
DEFINE_SIZE_UNION (2, format);
};
struct EncodingRecord
{
inline int cmp (const EncodingRecord &other) const
{
int ret;
ret = platformID.cmp (other.platformID);
if (ret) return ret;
ret = encodingID.cmp (other.encodingID);
if (ret) return ret;
return 0;
}
inline bool sanitize (hb_sanitize_context_t *c, void *base) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) &&
subtable.sanitize (c, base));
}
USHORT platformID; /* Platform ID. */
USHORT encodingID; /* Platform-specific encoding ID. */
OffsetTo<CmapSubtable, ULONG>
subtable; /* Byte offset from beginning of table to the subtable for this encoding. */
public:
DEFINE_SIZE_STATIC (8);
};
struct cmap
{
static const hb_tag_t tableTag = HB_OT_TAG_cmap;
inline const CmapSubtable *find_subtable (unsigned int platform_id,
unsigned int encoding_id) const
{
EncodingRecord key;
key.platformID.set (platform_id);
key.encodingID.set (encoding_id);
/* Note: We can use bsearch, but since it has no performance
* implications, we use lsearch and as such accept fonts with
* unsorted subtable list. */
int result = encodingRecord./*bsearch*/lsearch (key);
if (result == -1 || !encodingRecord[result].subtable)
return NULL;
return &(this+encodingRecord[result].subtable);
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) &&
likely (version == 0) &&
encodingRecord.sanitize (c, this));
}
USHORT version; /* Table version number (0). */
SortedArrayOf<EncodingRecord>
encodingRecord; /* Encoding tables. */
public:
DEFINE_SIZE_ARRAY (4, encodingRecord);
};
} /* namespace OT */
#endif /* HB_OT_CMAP_TABLE_HH */