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harfbuzz/src/hb-ot-cmap-table.hh
Ebrahim Byagowi 63109432cf Cosmetic and minor changes
2018-10-13 07:23:33 -04:00

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/*
* 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.hh"
#include "hb-set.hh"
/*
* cmap -- Character to Glyph Index Mapping
* https://docs.microsoft.com/en-us/typography/opentype/spec/cmap
*/
#define HB_OT_TAG_cmap HB_TAG('c','m','a','p')
namespace OT {
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 void collect_unicodes (hb_set_t *out) const
{
for (unsigned int i = 0; i < 256; i++)
if (glyphIdArray[i])
out->add (i);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
protected:
HBUINT16 format; /* Format number is set to 0. */
HBUINT16 length; /* Byte length of this subtable. */
HBUINT16 language; /* Ignore. */
HBUINT8 glyphIdArray[256];/* An array that maps character
* code to glyph index values. */
public:
DEFINE_SIZE_STATIC (6 + 256);
};
struct CmapSubtableFormat4
{
struct segment_plan
{
HBUINT16 start_code;
HBUINT16 end_code;
bool use_delta;
};
bool serialize (hb_serialize_context_t *c,
const hb_subset_plan_t *plan,
const hb_vector_t<segment_plan> &segments)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
this->format.set (4);
this->length.set (get_sub_table_size (segments));
this->segCountX2.set (segments.len * 2);
this->entrySelector.set (MAX (1u, hb_bit_storage (segments.len)) - 1);
this->searchRange.set (2 * (1u << this->entrySelector));
this->rangeShift.set (segments.len * 2 > this->searchRange
? 2 * segments.len - this->searchRange
: 0);
HBUINT16 *end_count = c->allocate_size<HBUINT16> (HBUINT16::static_size * segments.len);
c->allocate_size<HBUINT16> (HBUINT16::static_size); // 2 bytes of padding.
HBUINT16 *start_count = c->allocate_size<HBUINT16> (HBUINT16::static_size * segments.len);
HBINT16 *id_delta = c->allocate_size<HBINT16> (HBUINT16::static_size * segments.len);
HBUINT16 *id_range_offset = c->allocate_size<HBUINT16> (HBUINT16::static_size * segments.len);
if (id_range_offset == nullptr)
return_trace (false);
for (unsigned int i = 0; i < segments.len; i++)
{
end_count[i].set (segments[i].end_code);
start_count[i].set (segments[i].start_code);
if (segments[i].use_delta)
{
hb_codepoint_t cp = segments[i].start_code;
hb_codepoint_t start_gid = 0;
if (unlikely (!plan->new_gid_for_codepoint (cp, &start_gid) && cp != 0xFFFF))
return_trace (false);
id_delta[i].set (start_gid - segments[i].start_code);
} else {
id_delta[i].set (0);
unsigned int num_codepoints = segments[i].end_code - segments[i].start_code + 1;
HBUINT16 *glyph_id_array = c->allocate_size<HBUINT16> (HBUINT16::static_size * num_codepoints);
if (glyph_id_array == nullptr)
return_trace (false);
// From the cmap spec:
//
// id_range_offset[i]/2
// + (cp - segments[i].start_code)
// + (id_range_offset + i)
// =
// glyph_id_array + (cp - segments[i].start_code)
//
// So, solve for id_range_offset[i]:
//
// id_range_offset[i]
// =
// 2 * (glyph_id_array - id_range_offset - i)
id_range_offset[i].set (2 * (
glyph_id_array - id_range_offset - i));
for (unsigned int j = 0; j < num_codepoints; j++)
{
hb_codepoint_t cp = segments[i].start_code + j;
hb_codepoint_t new_gid;
if (unlikely (!plan->new_gid_for_codepoint (cp, &new_gid)))
return_trace (false);
glyph_id_array[j].set (new_gid);
}
}
}
return_trace (true);
}
static inline size_t get_sub_table_size (const hb_vector_t<segment_plan> &segments)
{
size_t segment_size = 0;
for (unsigned int i = 0; i < segments.len; i++)
{
// Parallel array entries
segment_size +=
2 // end count
+ 2 // start count
+ 2 // delta
+ 2; // range offset
if (!segments[i].use_delta)
// Add bytes for the glyph index array entries for this segment.
segment_size += (segments[i].end_code - segments[i].start_code + 1) * 2;
}
return min_size
+ 2 // Padding
+ segment_size;
}
static inline bool create_sub_table_plan (const hb_subset_plan_t *plan,
hb_vector_t<segment_plan> *segments)
{
segment_plan *segment = nullptr;
hb_codepoint_t last_gid = 0;
hb_codepoint_t cp = HB_SET_VALUE_INVALID;
while (plan->unicodes->next (&cp)) {
hb_codepoint_t new_gid;
if (unlikely (!plan->new_gid_for_codepoint (cp, &new_gid)))
{
DEBUG_MSG(SUBSET, nullptr, "Unable to find new gid for %04x", cp);
return false;
}
if (cp > 0xFFFF) {
// We are now outside of unicode BMP, stop adding to this cmap.
break;
}
if (!segment
|| cp != segment->end_code + 1u)
{
segment = segments->push ();
segment->start_code.set (cp);
segment->end_code.set (cp);
segment->use_delta = true;
} else {
segment->end_code.set (cp);
if (last_gid + 1u != new_gid)
// gid's are not consecutive in this segment so delta
// cannot be used.
segment->use_delta = false;
}
last_gid = new_gid;
}
// There must be a final entry with end_code == 0xFFFF. Check if we need to add one.
if (segment == nullptr || segment->end_code != 0xFFFF)
{
segment = segments->push ();
segment->start_code.set (0xFFFF);
segment->end_code.set (0xFFFF);
segment->use_delta = true;
}
return true;
}
struct accelerator_t
{
inline void init (const CmapSubtableFormat4 *subtable)
{
segCount = subtable->segCountX2 / 2;
endCount = subtable->values.arrayZ;
startCount = endCount + segCount + 1;
idDelta = startCount + segCount;
idRangeOffset = idDelta + segCount;
glyphIdArray = idRangeOffset + segCount;
glyphIdArrayLength = (subtable->length - 16 - 8 * segCount) / 2;
}
inline void fini (void) {}
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
/* Custom two-array bsearch. */
int min = 0, max = (int) this->segCount - 1;
const HBUINT16 *startCount = this->startCount;
const HBUINT16 *endCount = this->endCount;
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 = this->idRangeOffset[i];
if (rangeOffset == 0)
gid = codepoint + this->idDelta[i];
else
{
/* Somebody has been smoking... */
unsigned int index = rangeOffset / 2 + (codepoint - this->startCount[i]) + i - this->segCount;
if (unlikely (index >= this->glyphIdArrayLength))
return false;
gid = this->glyphIdArray[index];
if (unlikely (!gid))
return false;
gid += this->idDelta[i];
}
gid &= 0xFFFFu;
if (!gid)
return false;
*glyph = gid;
return true;
}
static inline bool get_glyph_func (const void *obj, hb_codepoint_t codepoint, hb_codepoint_t *glyph)
{
return ((const accelerator_t *) obj)->get_glyph (codepoint, glyph);
}
inline void collect_unicodes (hb_set_t *out) const
{
unsigned int count = this->segCount;
if (count && this->startCount[count - 1] == 0xFFFFu)
count--; /* Skip sentinel segment. */
for (unsigned int i = 0; i < count; i++)
{
unsigned int rangeOffset = this->idRangeOffset[i];
if (rangeOffset == 0)
out->add_range (this->startCount[i], this->endCount[i]);
else
{
for (hb_codepoint_t codepoint = this->startCount[i];
codepoint <= this->endCount[i];
codepoint++)
{
unsigned int index = rangeOffset / 2 + (codepoint - this->startCount[i]) + i - this->segCount;
if (unlikely (index >= this->glyphIdArrayLength))
break;
hb_codepoint_t gid = this->glyphIdArray[index];
if (unlikely (!gid))
continue;
out->add (codepoint);
}
}
}
}
const HBUINT16 *endCount;
const HBUINT16 *startCount;
const HBUINT16 *idDelta;
const HBUINT16 *idRangeOffset;
const HBUINT16 *glyphIdArray;
unsigned int segCount;
unsigned int glyphIdArrayLength;
};
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
hb_auto_t<accelerator_t> accel (this);
return accel.get_glyph_func (&accel, codepoint, glyph);
}
inline void collect_unicodes (hb_set_t *out) const
{
hb_auto_t<accelerator_t> accel (this);
accel.collect_unicodes (out);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (unlikely (!c->check_struct (this)))
return_trace (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 (false);
}
return_trace (16 + 4 * (unsigned int) segCountX2 <= length);
}
protected:
HBUINT16 format; /* Format number is set to 4. */
HBUINT16 length; /* This is the length in bytes of the
* subtable. */
HBUINT16 language; /* Ignore. */
HBUINT16 segCountX2; /* 2 x segCount. */
HBUINT16 searchRange; /* 2 * (2**floor(log2(segCount))) */
HBUINT16 entrySelector; /* log2(searchRange/2) */
HBUINT16 rangeShift; /* 2 x segCount - searchRange */
UnsizedArrayOf<HBUINT16>
values;
#if 0
HBUINT16 endCount[segCount]; /* End characterCode for each segment,
* last=0xFFFFu. */
HBUINT16 reservedPad; /* Set to 0. */
HBUINT16 startCount[segCount]; /* Start character code for each segment. */
HBINT16 idDelta[segCount]; /* Delta for all character codes in segment. */
HBUINT16 idRangeOffset[segCount];/* Offsets into glyphIdArray or 0 */
UnsizedArrayOf<HBUINT16>
glyphIdArray; /* Glyph index array (arbitrary length) */
#endif
public:
DEFINE_SIZE_ARRAY (14, values);
};
struct CmapSubtableLongGroup
{
friend struct CmapSubtableFormat12;
friend struct CmapSubtableFormat13;
template<typename U>
friend struct CmapSubtableLongSegmented;
friend struct cmap;
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) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
private:
HBUINT32 startCharCode; /* First character code in this group. */
HBUINT32 endCharCode; /* Last character code in this group. */
HBUINT32 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 void collect_unicodes (hb_set_t *out) const
{
hb_codepoint_t start = startCharCode;
unsigned int count = glyphIdArray.len;
for (unsigned int i = 0; i < count; i++)
if (glyphIdArray[i])
out->add (start + i);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) && glyphIdArray.sanitize (c));
}
protected:
UINT formatReserved; /* Subtable format and (maybe) padding. */
UINT length; /* Byte length of this subtable. */
UINT language; /* 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<HBUINT16> {};
struct CmapSubtableFormat10 : CmapSubtableTrimmed<HBUINT32 > {};
template <typename T>
struct CmapSubtableLongSegmented
{
friend struct cmap;
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
int i = groups.bsearch (codepoint);
if (i == -1)
return false;
hb_codepoint_t gid = T::group_get_glyph (groups[i], codepoint);
if (!gid)
return false;
*glyph = gid;
return true;
}
inline void collect_unicodes (hb_set_t *out) const
{
for (unsigned int i = 0; i < this->groups.len; i++) {
out->add_range (this->groups[i].startCharCode,
MIN ((hb_codepoint_t) this->groups[i].endCharCode,
(hb_codepoint_t) HB_UNICODE_MAX));
}
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) && groups.sanitize (c));
}
inline bool serialize (hb_serialize_context_t *c,
const hb_vector_t<CmapSubtableLongGroup> &group_data)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (*this))) return_trace (false);
Supplier<CmapSubtableLongGroup> supplier (group_data.arrayZ(), group_data.len);
if (unlikely (!groups.serialize (c, supplier, group_data.len))) return_trace (false);
return true;
}
protected:
HBUINT16 format; /* Subtable format; set to 12. */
HBUINT16 reserved; /* Reserved; set to 0. */
HBUINT32 length; /* Byte length of this subtable. */
HBUINT32 language; /* Ignore. */
SortedArrayOf<CmapSubtableLongGroup, HBUINT32>
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); }
bool serialize (hb_serialize_context_t *c,
const hb_vector_t<CmapSubtableLongGroup> &groups)
{
if (unlikely (!c->extend_min (*this))) return false;
this->format.set (12);
this->reserved.set (0);
this->length.set (get_sub_table_size (groups));
return CmapSubtableLongSegmented<CmapSubtableFormat12>::serialize (c, groups);
}
static inline size_t get_sub_table_size (const hb_vector_t<CmapSubtableLongGroup> &groups)
{
return 16 + 12 * groups.len;
}
static inline bool create_sub_table_plan (const hb_subset_plan_t *plan,
hb_vector_t<CmapSubtableLongGroup> *groups)
{
CmapSubtableLongGroup *group = nullptr;
hb_codepoint_t cp = HB_SET_VALUE_INVALID;
while (plan->unicodes->next (&cp)) {
hb_codepoint_t new_gid;
if (unlikely (!plan->new_gid_for_codepoint (cp, &new_gid)))
{
DEBUG_MSG(SUBSET, nullptr, "Unable to find new gid for %04x", cp);
return false;
}
if (!group || !_is_gid_consecutive (group, cp, new_gid))
{
group = groups->push ();
group->startCharCode.set (cp);
group->endCharCode.set (cp);
group->glyphID.set (new_gid);
} else
{
group->endCharCode.set (cp);
}
}
DEBUG_MSG(SUBSET, nullptr, "cmap");
for (unsigned int i = 0; i < groups->len; i++) {
CmapSubtableLongGroup& group = (*groups)[i];
DEBUG_MSG(SUBSET, nullptr, " %d: U+%04X-U+%04X, gid %d-%d", i, (uint32_t) group.startCharCode, (uint32_t) group.endCharCode, (uint32_t) group.glyphID, (uint32_t) group.glyphID + ((uint32_t) group.endCharCode - (uint32_t) group.startCharCode));
}
return true;
}
private:
static inline bool _is_gid_consecutive (CmapSubtableLongGroup *group,
hb_codepoint_t cp,
hb_codepoint_t new_gid)
{
return (cp - 1 == group->endCharCode) &&
new_gid == group->glyphID + (cp - 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) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
HBUINT24 startUnicodeValue; /* First value in this range. */
HBUINT8 additionalCount; /* Number of additional values in this
* range. */
public:
DEFINE_SIZE_STATIC (4);
};
struct DefaultUVS : SortedArrayOf<UnicodeValueRange, HBUINT32>
{
inline void collect_unicodes (hb_set_t *out) const
{
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
{
hb_codepoint_t first = arrayZ[i].startUnicodeValue;
hb_codepoint_t last = MIN ((hb_codepoint_t) (first + arrayZ[i].additionalCount),
(hb_codepoint_t) HB_UNICODE_MAX);
out->add_range (first, last);
}
}
public:
DEFINE_SIZE_ARRAY (4, arrayZ);
};
struct UVSMapping
{
inline int cmp (const hb_codepoint_t &codepoint) const
{
return unicodeValue.cmp (codepoint);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
HBUINT24 unicodeValue; /* Base Unicode value of the UVS */
GlyphID glyphID; /* Glyph ID of the UVS */
public:
DEFINE_SIZE_STATIC (5);
};
struct NonDefaultUVS : SortedArrayOf<UVSMapping, HBUINT32>
{
inline void collect_unicodes (hb_set_t *out) const
{
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
out->add (arrayZ[i].glyphID);
}
public:
DEFINE_SIZE_ARRAY (4, arrayZ);
};
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 && nonDefaults[i].glyphID)
{
*glyph = nonDefaults[i].glyphID;
return GLYPH_VARIANT_FOUND;
}
return GLYPH_VARIANT_NOT_FOUND;
}
inline void collect_unicodes (hb_set_t *out, const void *base) const
{
(base+defaultUVS).collect_unicodes (out);
(base+nonDefaultUVS).collect_unicodes (out);
}
inline int cmp (const hb_codepoint_t &variation_selector) const
{
return varSelector.cmp (variation_selector);
}
inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
defaultUVS.sanitize (c, base) &&
nonDefaultUVS.sanitize (c, base));
}
HBUINT24 varSelector; /* Variation selector. */
LOffsetTo<DefaultUVS>
defaultUVS; /* Offset to Default UVS Table. May be 0. */
LOffsetTo<NonDefaultUVS>
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 void collect_variation_selectors (hb_set_t *out) const
{
unsigned int count = record.len;
for (unsigned int i = 0; i < count; i++)
out->add (record.arrayZ[i].varSelector);
}
inline void collect_variation_unicodes (hb_codepoint_t variation_selector,
hb_set_t *out) const
{
record[record.bsearch (variation_selector)].collect_unicodes (out, this);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
record.sanitize (c, this));
}
protected:
HBUINT16 format; /* Format number is set to 14. */
HBUINT32 length; /* Byte length of this subtable. */
SortedArrayOf<VariationSelectorRecord, HBUINT32>
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 void collect_unicodes (hb_set_t *out) const
{
switch (u.format) {
case 0: u.format0 .collect_unicodes (out); return;
case 4: u.format4 .collect_unicodes (out); return;
case 6: u.format6 .collect_unicodes (out); return;
case 10: u.format10.collect_unicodes (out); return;
case 12: u.format12.collect_unicodes (out); return;
case 13: u.format13.collect_unicodes (out); return;
case 14:
default: return;
}
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!u.format.sanitize (c)) return_trace (false);
switch (u.format) {
case 0: return_trace (u.format0 .sanitize (c));
case 4: return_trace (u.format4 .sanitize (c));
case 6: return_trace (u.format6 .sanitize (c));
case 10: return_trace (u.format10.sanitize (c));
case 12: return_trace (u.format12.sanitize (c));
case 13: return_trace (u.format13.sanitize (c));
case 14: return_trace (u.format14.sanitize (c));
default:return_trace (true);
}
}
public:
union {
HBUINT16 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, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
subtable.sanitize (c, base));
}
HBUINT16 platformID; /* Platform ID. */
HBUINT16 encodingID; /* Platform-specific encoding ID. */
LOffsetTo<CmapSubtable>
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;
struct subset_plan
{
subset_plan(void)
{
format4_segments.init();
format12_groups.init();
}
~subset_plan(void)
{
format4_segments.fini();
format12_groups.fini();
}
inline size_t final_size() const
{
return 4 // header
+ 8 * 3 // 3 EncodingRecord
+ CmapSubtableFormat4::get_sub_table_size (this->format4_segments)
+ CmapSubtableFormat12::get_sub_table_size (this->format12_groups);
}
// Format 4
hb_vector_t<CmapSubtableFormat4::segment_plan> format4_segments;
// Format 12
hb_vector_t<CmapSubtableLongGroup> format12_groups;
};
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
likely (version == 0) &&
encodingRecord.sanitize (c, this));
}
inline bool _create_plan (const hb_subset_plan_t *plan,
subset_plan *cmap_plan) const
{
if (unlikely( !CmapSubtableFormat4::create_sub_table_plan (plan, &cmap_plan->format4_segments)))
return false;
return CmapSubtableFormat12::create_sub_table_plan (plan, &cmap_plan->format12_groups);
}
inline bool _subset (const hb_subset_plan_t *plan,
const subset_plan &cmap_subset_plan,
size_t dest_sz,
void *dest) const
{
hb_serialize_context_t c (dest, dest_sz);
cmap *table = c.start_serialize<cmap> ();
if (unlikely (!c.extend_min (*table)))
{
return false;
}
table->version.set (0);
if (unlikely (!table->encodingRecord.serialize (&c, /* numTables */ 3)))
return false;
// TODO(grieger): Convert the below to a for loop
// Format 4, Plat 0 Encoding Record
EncodingRecord &format4_plat0_rec = table->encodingRecord[0];
format4_plat0_rec.platformID.set (0); // Unicode
format4_plat0_rec.encodingID.set (3);
// Format 4, Plat 3 Encoding Record
EncodingRecord &format4_plat3_rec = table->encodingRecord[1];
format4_plat3_rec.platformID.set (3); // Windows
format4_plat3_rec.encodingID.set (1); // Unicode BMP
// Format 12 Encoding Record
EncodingRecord &format12_rec = table->encodingRecord[2];
format12_rec.platformID.set (3); // Windows
format12_rec.encodingID.set (10); // Unicode UCS-4
// Write out format 4 sub table
{
CmapSubtable &subtable = format4_plat0_rec.subtable.serialize (&c, table);
format4_plat3_rec.subtable.set (format4_plat0_rec.subtable);
subtable.u.format.set (4);
CmapSubtableFormat4 &format4 = subtable.u.format4;
if (unlikely (!format4.serialize (&c, plan, cmap_subset_plan.format4_segments)))
return false;
}
// Write out format 12 sub table.
{
CmapSubtable &subtable = format12_rec.subtable.serialize (&c, table);
subtable.u.format.set (12);
CmapSubtableFormat12 &format12 = subtable.u.format12;
if (unlikely (!format12.serialize (&c, cmap_subset_plan.format12_groups)))
return false;
}
c.end_serialize ();
return true;
}
inline bool subset (hb_subset_plan_t *plan) const
{
subset_plan cmap_subset_plan;
if (unlikely (!_create_plan (plan, &cmap_subset_plan)))
{
DEBUG_MSG(SUBSET, nullptr, "Failed to generate a cmap subsetting plan.");
return false;
}
// We now know how big our blob needs to be
size_t dest_sz = cmap_subset_plan.final_size();
void *dest = malloc (dest_sz);
if (unlikely (!dest)) {
DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for cmap subset output", (unsigned long) dest_sz);
return false;
}
if (unlikely (!_subset (plan, cmap_subset_plan, dest_sz, dest)))
{
DEBUG_MSG(SUBSET, nullptr, "Failed to perform subsetting of cmap.");
free (dest);
return false;
}
// all done, write the blob into dest
hb_blob_t *cmap_prime = hb_blob_create ((const char *)dest,
dest_sz,
HB_MEMORY_MODE_READONLY,
dest,
free);
bool result = plan->add_table (HB_OT_TAG_cmap, cmap_prime);
hb_blob_destroy (cmap_prime);
return result;
}
const CmapSubtable *find_best_subtable (bool *symbol = nullptr) const
{
if (symbol) *symbol = false;
const CmapSubtable *subtable;
/* 32-bit subtables. */
if ((subtable = this->find_subtable (3, 10))) return subtable;
if ((subtable = this->find_subtable (0, 6))) return subtable;
if ((subtable = this->find_subtable (0, 4))) return subtable;
/* 16-bit subtables. */
if ((subtable = this->find_subtable (3, 1))) return subtable;
if ((subtable = this->find_subtable (0, 3))) return subtable;
if ((subtable = this->find_subtable (0, 2))) return subtable;
if ((subtable = this->find_subtable (0, 1))) return subtable;
if ((subtable = this->find_subtable (0, 0))) return subtable;
/* Symbol subtable. */
if ((subtable = this->find_subtable (3, 0)))
{
if (symbol) *symbol = true;
return subtable;
}
/* Meh. */
return &Null(CmapSubtable);
}
struct accelerator_t
{
inline void init (hb_face_t *face)
{
this->blob = hb_sanitize_context_t().reference_table<cmap> (face);
const cmap *table = this->blob->as<cmap> ();
const CmapSubtableFormat14 *subtable_uvs = nullptr;
bool symbol;
subtable = table->find_best_subtable (&symbol);
/* UVS subtable. */
if (!subtable_uvs)
{
const CmapSubtable *st = table->find_subtable (0, 5);
if (st && st->u.format == 14)
subtable_uvs = &st->u.format14;
}
/* Meh. */
if (!subtable_uvs) subtable_uvs = &Null(CmapSubtableFormat14);
this->subtable_uvs = subtable_uvs;
this->get_glyph_data = subtable;
if (unlikely (symbol))
{
this->get_glyph_func = get_glyph_from_symbol<CmapSubtable>;
} else {
switch (subtable->u.format) {
/* Accelerate format 4 and format 12. */
default:
this->get_glyph_func = get_glyph_from<CmapSubtable>;
break;
case 12:
this->get_glyph_func = get_glyph_from<CmapSubtableFormat12>;
break;
case 4:
{
this->format4_accel.init (&subtable->u.format4);
this->get_glyph_data = &this->format4_accel;
this->get_glyph_func = this->format4_accel.get_glyph_func;
}
break;
}
}
}
inline void fini (void)
{
hb_blob_destroy (this->blob);
}
inline bool get_nominal_glyph (hb_codepoint_t unicode,
hb_codepoint_t *glyph) const
{
return this->get_glyph_func (this->get_glyph_data, unicode, glyph);
}
inline bool get_variation_glyph (hb_codepoint_t unicode,
hb_codepoint_t variation_selector,
hb_codepoint_t *glyph) const
{
switch (this->subtable_uvs->get_glyph_variant (unicode,
variation_selector,
glyph))
{
case GLYPH_VARIANT_NOT_FOUND: return false;
case GLYPH_VARIANT_FOUND: return true;
case GLYPH_VARIANT_USE_DEFAULT: break;
}
return get_nominal_glyph (unicode, glyph);
}
inline void collect_unicodes (hb_set_t *out) const
{
subtable->collect_unicodes (out);
}
inline void collect_variation_selectors (hb_set_t *out) const
{
subtable_uvs->collect_variation_selectors (out);
}
inline void collect_variation_unicodes (hb_codepoint_t variation_selector,
hb_set_t *out) const
{
subtable_uvs->collect_variation_unicodes (variation_selector, out);
}
protected:
typedef bool (*hb_cmap_get_glyph_func_t) (const void *obj,
hb_codepoint_t codepoint,
hb_codepoint_t *glyph);
template <typename Type>
static inline bool get_glyph_from (const void *obj,
hb_codepoint_t codepoint,
hb_codepoint_t *glyph)
{
const Type *typed_obj = (const Type *) obj;
return typed_obj->get_glyph (codepoint, glyph);
}
template <typename Type>
static inline bool get_glyph_from_symbol (const void *obj,
hb_codepoint_t codepoint,
hb_codepoint_t *glyph)
{
const Type *typed_obj = (const Type *) obj;
if (likely (typed_obj->get_glyph (codepoint, glyph)))
return true;
if (codepoint <= 0x00FFu)
{
/* For symbol-encoded OpenType fonts, we duplicate the
* U+F000..F0FF range at U+0000..U+00FF. That's what
* Windows seems to do, and that's hinted about at:
* https://docs.microsoft.com/en-us/typography/opentype/spec/recom
* under "Non-Standard (Symbol) Fonts". */
return typed_obj->get_glyph (0xF000u + codepoint, glyph);
}
return false;
}
private:
const CmapSubtable *subtable;
const CmapSubtableFormat14 *subtable_uvs;
hb_cmap_get_glyph_func_t get_glyph_func;
const void *get_glyph_data;
CmapSubtableFormat4::accelerator_t format4_accel;
hb_blob_t *blob;
};
protected:
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);
int result = encodingRecord.bsearch (key);
if (result == -1 || !encodingRecord[result].subtable)
return nullptr;
return &(this+encodingRecord[result].subtable);
}
protected:
HBUINT16 version; /* Table version number (0). */
SortedArrayOf<EncodingRecord>
encodingRecord; /* Encoding tables. */
public:
DEFINE_SIZE_ARRAY (4, encodingRecord);
};
struct cmap_accelerator_t : cmap::accelerator_t {};
} /* namespace OT */
#endif /* HB_OT_CMAP_TABLE_HH */
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