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harfbuzz/src/hb-ot-color-cbdt-table.hh

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/*
* Copyright © 2016 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): Seigo Nonaka, Calder Kitagawa
*/
#ifndef HB_OT_COLOR_CBDT_TABLE_HH
#define HB_OT_COLOR_CBDT_TABLE_HH
#include "hb-open-type.hh"
/*
* CBLC -- Color Bitmap Location
* https://docs.microsoft.com/en-us/typography/opentype/spec/cblc
* https://docs.microsoft.com/en-us/typography/opentype/spec/eblc
* CBDT -- Color Bitmap Data
* https://docs.microsoft.com/en-us/typography/opentype/spec/cbdt
* https://docs.microsoft.com/en-us/typography/opentype/spec/ebdt
*/
#define HB_OT_TAG_CBLC HB_TAG('C','B','L','C')
#define HB_OT_TAG_CBDT HB_TAG('C','B','D','T')
namespace OT {
struct cblc_bitmap_size_subset_context_t
{
const char *cbdt;
unsigned int cbdt_length;
hb_vector_t<char> *cbdt_prime;
unsigned int size; /* INOUT
* Input: old size of IndexSubtable
* Output: new size of IndexSubtable
*/
unsigned int num_tables; /* INOUT
* Input: old number of subtables.
* Output: new number of subtables.
*/
hb_codepoint_t start_glyph; /* OUT */
hb_codepoint_t end_glyph; /* OUT */
};
static inline bool
_copy_data_to_cbdt (hb_vector_t<char> *cbdt_prime,
const void *data,
unsigned length)
{
unsigned int new_len = cbdt_prime->length + length;
if (unlikely (!cbdt_prime->alloc (new_len))) return false;
memcpy (cbdt_prime->arrayZ + cbdt_prime->length, data, length);
cbdt_prime->length = new_len;
return true;
}
struct SmallGlyphMetrics
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
void get_extents (hb_font_t *font, hb_glyph_extents_t *extents) const
{
extents->x_bearing = font->em_scale_x (bearingX);
extents->y_bearing = font->em_scale_y (bearingY);
extents->width = font->em_scale_x (width);
extents->height = font->em_scale_y (-static_cast<int>(height));
}
HBUINT8 height;
HBUINT8 width;
HBINT8 bearingX;
HBINT8 bearingY;
HBUINT8 advance;
public:
DEFINE_SIZE_STATIC (5);
};
struct BigGlyphMetrics : SmallGlyphMetrics
{
HBINT8 vertBearingX;
HBINT8 vertBearingY;
HBUINT8 vertAdvance;
public:
DEFINE_SIZE_STATIC (8);
};
struct SBitLineMetrics
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
HBINT8 ascender;
HBINT8 decender;
HBUINT8 widthMax;
HBINT8 caretSlopeNumerator;
HBINT8 caretSlopeDenominator;
HBINT8 caretOffset;
HBINT8 minOriginSB;
HBINT8 minAdvanceSB;
HBINT8 maxBeforeBL;
HBINT8 minAfterBL;
HBINT8 padding1;
HBINT8 padding2;
public:
DEFINE_SIZE_STATIC (12);
};
/*
* Index Subtables.
*/
struct IndexSubtableHeader
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
HBUINT16 indexFormat;
HBUINT16 imageFormat;
HBUINT32 imageDataOffset;
public:
DEFINE_SIZE_STATIC (8);
};
template <typename OffsetType>
struct IndexSubtableFormat1Or3
{
bool sanitize (hb_sanitize_context_t *c, unsigned int glyph_count) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
offsetArrayZ.sanitize (c, glyph_count + 1));
}
bool get_image_data (unsigned int idx,
unsigned int *offset,
unsigned int *length) const
{
if (unlikely (offsetArrayZ[idx + 1] <= offsetArrayZ[idx]))
return false;
*offset = header.imageDataOffset + offsetArrayZ[idx];
*length = offsetArrayZ[idx + 1] - offsetArrayZ[idx];
return true;
}
bool add_offset (hb_serialize_context_t *c,
unsigned int offset,
unsigned int *size /* OUT (accumulated) */)
{
TRACE_SERIALIZE (this);
Offset<OffsetType> embedded_offset;
embedded_offset = offset;
*size += sizeof (OffsetType);
auto *o = c->embed (embedded_offset);
return_trace ((bool) o);
}
IndexSubtableHeader header;
UnsizedArrayOf<Offset<OffsetType>>
offsetArrayZ;
public:
DEFINE_SIZE_ARRAY (8, offsetArrayZ);
};
struct IndexSubtableFormat1 : IndexSubtableFormat1Or3<HBUINT32> {};
struct IndexSubtableFormat3 : IndexSubtableFormat1Or3<HBUINT16> {};
struct IndexSubtable
{
bool sanitize (hb_sanitize_context_t *c, unsigned int glyph_count) const
{
TRACE_SANITIZE (this);
if (!u.header.sanitize (c)) return_trace (false);
switch (u.header.indexFormat)
{
case 1: return_trace (u.format1.sanitize (c, glyph_count));
case 3: return_trace (u.format3.sanitize (c, glyph_count));
default:return_trace (true);
}
}
bool
finish_subtable (hb_serialize_context_t *c,
unsigned int cbdt_prime_len,
unsigned int num_glyphs,
unsigned int *size /* OUT (accumulated) */)
{
TRACE_SERIALIZE (this);
unsigned int local_offset = cbdt_prime_len - u.header.imageDataOffset;
switch (u.header.indexFormat)
{
case 1: return_trace (u.format1.add_offset (c, local_offset, size));
case 3: {
if (!u.format3.add_offset (c, local_offset, size))
return_trace (false);
if (!(num_glyphs & 0x01)) // Pad to 32-bit alignment if needed.
return_trace (u.format3.add_offset (c, 0, size));
return_trace (true);
}
// TODO: implement 2, 4, 5.
case 2: case 4: // No-op.
case 5: // Pad to 32-bit aligned.
default: return_trace (false);
}
}
bool
fill_missing_glyphs (hb_serialize_context_t *c,
unsigned int cbdt_prime_len,
unsigned int num_missing,
unsigned int *size /* OUT (accumulated) */,
unsigned int *num_glyphs /* OUT (accumulated) */)
{
TRACE_SERIALIZE (this);
unsigned int local_offset = cbdt_prime_len - u.header.imageDataOffset;
switch (u.header.indexFormat)
{
case 1: {
for (unsigned int i = 0; i < num_missing; i++)
{
if (unlikely (!u.format1.add_offset (c, local_offset, size)))
return_trace (false);
*num_glyphs += 1;
}
return_trace (true);
}
case 3: {
for (unsigned int i = 0; i < num_missing; i++)
{
if (unlikely (!u.format3.add_offset (c, local_offset, size)))
return_trace (false);
*num_glyphs += 1;
}
return_trace (true);
}
// TODO: implement 2, 4, 5.
case 2: // Add empty space in cbdt_prime?.
case 4: case 5: // No-op as sparse is supported.
default: return_trace (false);
}
}
bool
copy_glyph_at_idx (hb_serialize_context_t *c, unsigned int idx,
const char *cbdt, unsigned int cbdt_length,
hb_vector_t<char> *cbdt_prime /* INOUT */,
IndexSubtable *subtable_prime /* INOUT */,
unsigned int *size /* OUT (accumulated) */) const
{
TRACE_SERIALIZE (this);
unsigned int offset, length, format;
if (unlikely (!get_image_data (idx, &offset, &length, &format))) return_trace (false);
if (unlikely (offset > cbdt_length || cbdt_length - offset < length)) return_trace (false);
auto *header_prime = subtable_prime->get_header ();
unsigned int new_local_offset = cbdt_prime->length - (unsigned int) header_prime->imageDataOffset;
if (unlikely (!_copy_data_to_cbdt (cbdt_prime, cbdt + offset, length))) return_trace (false);
return_trace (subtable_prime->add_offset (c, new_local_offset, size));
}
bool
add_offset (hb_serialize_context_t *c, unsigned int local_offset,
unsigned int *size /* OUT (accumulated) */)
{
TRACE_SERIALIZE (this);
switch (u.header.indexFormat)
{
case 1: return_trace (u.format1.add_offset (c, local_offset, size));
case 3: return_trace (u.format3.add_offset (c, local_offset, size));
// TODO: Implement tables 2, 4, 5
case 2: // Should be a no-op.
case 4: case 5: // Handle sparse cases.
default: return_trace (false);
}
}
bool get_extents (hb_glyph_extents_t *extents HB_UNUSED) const
{
switch (u.header.indexFormat)
{
case 2: case 5: /* TODO */
case 1: case 3: case 4: /* Variable-metrics formats do not have metrics here. */
default:return (false);
}
}
bool
get_image_data (unsigned int idx, unsigned int *offset,
unsigned int *length, unsigned int *format) const
{
*format = u.header.imageFormat;
switch (u.header.indexFormat)
{
case 1: return u.format1.get_image_data (idx, offset, length);
case 3: return u.format3.get_image_data (idx, offset, length);
default: return false;
}
}
const IndexSubtableHeader* get_header () const { return &u.header; }
void populate_header (unsigned index_format,
unsigned image_format,
unsigned int image_data_offset,
unsigned int *size)
{
u.header.indexFormat = index_format;
u.header.imageFormat = image_format;
u.header.imageDataOffset = image_data_offset;
switch (u.header.indexFormat)
{
case 1: *size += IndexSubtableFormat1::min_size; break;
case 3: *size += IndexSubtableFormat3::min_size; break;
}
}
protected:
union {
IndexSubtableHeader header;
IndexSubtableFormat1 format1;
IndexSubtableFormat3 format3;
/* TODO: Format 2, 4, 5. */
} u;
public:
DEFINE_SIZE_UNION (8, header);
};
struct IndexSubtableRecord
{
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
firstGlyphIndex <= lastGlyphIndex &&
offsetToSubtable.sanitize (c, base, lastGlyphIndex - firstGlyphIndex + 1));
}
const IndexSubtable* get_subtable (const void *base) const
{
return &(base+offsetToSubtable);
}
bool add_new_subtable (hb_subset_context_t* c,
cblc_bitmap_size_subset_context_t *bitmap_size_context,
IndexSubtableRecord *record,
const hb_vector_t<hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*>> *lookup, /* IN */
const void *base,
unsigned int *start /* INOUT */) const
{
TRACE_SERIALIZE (this);
auto *subtable = c->serializer->start_embed<IndexSubtable> ();
if (unlikely (!subtable)) return_trace (false);
if (unlikely (!c->serializer->extend_min (subtable))) return_trace (false);
auto *old_subtable = get_subtable (base);
auto *old_header = old_subtable->get_header ();
subtable->populate_header (old_header->indexFormat,
old_header->imageFormat,
bitmap_size_context->cbdt_prime->length,
&bitmap_size_context->size);
unsigned int num_glyphs = 0;
bool early_exit = false;
for (unsigned int i = *start; i < lookup->length; i++)
{
hb_codepoint_t new_gid = (*lookup)[i].first;
const IndexSubtableRecord *next_record = (*lookup)[i].second;
const IndexSubtable *next_subtable = next_record->get_subtable (base);
auto *next_header = next_subtable->get_header ();
if (next_header != old_header)
{
*start = i;
early_exit = true;
break;
}
unsigned int num_missing = record->add_glyph_for_subset (new_gid);
if (unlikely (!subtable->fill_missing_glyphs (c->serializer,
bitmap_size_context->cbdt_prime->length,
num_missing,
&bitmap_size_context->size,
&num_glyphs)))
return_trace (false);
hb_codepoint_t old_gid = 0;
c->plan->old_gid_for_new_gid (new_gid, &old_gid);
if (old_gid < next_record->firstGlyphIndex)
return_trace (false);
unsigned int old_idx = (unsigned int) old_gid - next_record->firstGlyphIndex;
if (unlikely (!next_subtable->copy_glyph_at_idx (c->serializer,
old_idx,
bitmap_size_context->cbdt,
bitmap_size_context->cbdt_length,
bitmap_size_context->cbdt_prime,
subtable,
&bitmap_size_context->size)))
return_trace (false);
num_glyphs += 1;
}
if (!early_exit)
*start = lookup->length;
if (unlikely (!subtable->finish_subtable (c->serializer,
bitmap_size_context->cbdt_prime->length,
num_glyphs,
&bitmap_size_context->size)))
return_trace (false);
return_trace (true);
}
bool add_new_record (hb_subset_context_t *c,
cblc_bitmap_size_subset_context_t *bitmap_size_context,
const hb_vector_t<hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*>> *lookup, /* IN */
const void *base,
unsigned int *start, /* INOUT */
hb_vector_t<IndexSubtableRecord>* records /* INOUT */) const
{
TRACE_SERIALIZE (this);
auto snap = c->serializer->snapshot ();
unsigned int old_size = bitmap_size_context->size;
unsigned int old_cbdt_prime_length = bitmap_size_context->cbdt_prime->length;
// Set to invalid state to indicate filling glyphs is not yet started.
records->resize (records->length + 1);
(*records)[records->length - 1].firstGlyphIndex = 1;
(*records)[records->length - 1].lastGlyphIndex = 0;
bitmap_size_context->size += IndexSubtableRecord::min_size;
c->serializer->push ();
if (unlikely (!add_new_subtable (c, bitmap_size_context, &((*records)[records->length - 1]), lookup, base, start)))
{
c->serializer->pop_discard ();
c->serializer->revert (snap);
bitmap_size_context->cbdt_prime->shrink (old_cbdt_prime_length);
bitmap_size_context->size = old_size;
records->resize (records->length - 1);
return_trace (false);
}
bitmap_size_context->num_tables += 1;
return_trace (true);
}
unsigned int add_glyph_for_subset (hb_codepoint_t gid)
{
if (firstGlyphIndex > lastGlyphIndex)
{
firstGlyphIndex = gid;
lastGlyphIndex = gid;
return 0;
}
// TODO maybe assert? this shouldn't occur.
if (lastGlyphIndex > gid)
return 0;
unsigned int num_missing = (unsigned int) (gid - lastGlyphIndex - 1);
lastGlyphIndex = gid;
return num_missing;
}
bool get_extents (hb_glyph_extents_t *extents, const void *base) const
{ return (base+offsetToSubtable).get_extents (extents); }
bool get_image_data (unsigned int gid,
const void *base,
unsigned int *offset,
unsigned int *length,
unsigned int *format) const
{
if (gid < firstGlyphIndex || gid > lastGlyphIndex) return false;
return (base+offsetToSubtable).get_image_data (gid - firstGlyphIndex,
offset, length, format);
}
HBGlyphID firstGlyphIndex;
HBGlyphID lastGlyphIndex;
LOffsetTo<IndexSubtable> offsetToSubtable;
public:
DEFINE_SIZE_STATIC (8);
};
struct IndexSubtableArray
{
friend struct CBDT;
bool sanitize (hb_sanitize_context_t *c, unsigned int count) const
{
TRACE_SANITIZE (this);
return_trace (indexSubtablesZ.sanitize (c, count, this));
}
void
build_lookup (hb_subset_context_t *c, cblc_bitmap_size_subset_context_t *bitmap_size_context,
hb_vector_t<hb_pair_t<hb_codepoint_t,
const IndexSubtableRecord*>> *lookup /* OUT */) const
{
bool start_glyph_is_set = false;
for (hb_codepoint_t new_gid = 0; new_gid < c->plan->num_output_glyphs (); new_gid++)
{
hb_codepoint_t old_gid;
if (unlikely (!c->plan->old_gid_for_new_gid (new_gid, &old_gid))) continue;
const IndexSubtableRecord* record = find_table (old_gid, bitmap_size_context->num_tables);
if (unlikely (!record)) continue;
// Don't add gaps to the lookup. The best way to determine if a glyph is a
// gap is that it has no image data.
unsigned int offset, length, format;
if (unlikely (!record->get_image_data (old_gid, this, &offset, &length, &format))) continue;
lookup->push (hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*> (new_gid, record));
if (!start_glyph_is_set)
{
bitmap_size_context->start_glyph = new_gid;
start_glyph_is_set = true;
}
bitmap_size_context->end_glyph = new_gid;
}
}
bool
subset (hb_subset_context_t *c,
cblc_bitmap_size_subset_context_t *bitmap_size_context) const
{
TRACE_SUBSET (this);
auto *dst = c->serializer->start_embed<IndexSubtableArray> ();
if (unlikely (!dst)) return_trace (false);
hb_vector_t<hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*>> lookup;
build_lookup (c, bitmap_size_context, &lookup);
bitmap_size_context->size = 0;
bitmap_size_context->num_tables = 0;
hb_vector_t<IndexSubtableRecord> records;
for (unsigned int start = 0; start < lookup.length;)
{
if (unlikely (!lookup[start].second->add_new_record (c, bitmap_size_context, &lookup, this, &start, &records)))
return_trace (false);
}
// Workaround to ensure offset ordering is from least to greatest when
// resolving links.
hb_vector_t<hb_serialize_context_t::objidx_t> objidxs;
for (unsigned int i = 0; i < records.length; i++)
objidxs.push (c->serializer->pop_pack ());
for (unsigned int i = 0; i < records.length; i++)
{
IndexSubtableRecord* record = c->serializer->embed (records[i]);
if (unlikely (!record)) return_trace (false);
c->serializer->add_link (record->offsetToSubtable, objidxs[records.length - 1 - i], dst);
}
return_trace (true);
}
public:
const IndexSubtableRecord* find_table (hb_codepoint_t glyph, unsigned int numTables) const
{
for (unsigned int i = 0; i < numTables; ++i)
{
unsigned int firstGlyphIndex = indexSubtablesZ[i].firstGlyphIndex;
unsigned int lastGlyphIndex = indexSubtablesZ[i].lastGlyphIndex;
if (firstGlyphIndex <= glyph && glyph <= lastGlyphIndex)
return &indexSubtablesZ[i];
}
return nullptr;
}
protected:
UnsizedArrayOf<IndexSubtableRecord> indexSubtablesZ;
};
struct BitmapSizeTable
{
friend struct CBLC;
friend struct CBDT;
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
indexSubtableArrayOffset.sanitize (c, base, numberOfIndexSubtables) &&
horizontal.sanitize (c) &&
vertical.sanitize (c));
}
const IndexSubtableRecord *
find_table (hb_codepoint_t glyph, const void *base, const void **out_base) const
{
*out_base = &(base+indexSubtableArrayOffset);
return (base+indexSubtableArrayOffset).find_table (glyph, numberOfIndexSubtables);
}
bool
subset (hb_subset_context_t *c, const void *src_base, const void *dst_base,
const char *cbdt, unsigned int cbdt_length,
hb_vector_t<char> *cbdt_prime /* INOUT */) const
{
TRACE_SUBSET (this);
auto *out_table = c->serializer->embed (this);
if (unlikely (!out_table)) return_trace (false);
cblc_bitmap_size_subset_context_t bitmap_size_context;
bitmap_size_context.cbdt = cbdt;
bitmap_size_context.cbdt_length = cbdt_length;
bitmap_size_context.cbdt_prime = cbdt_prime;
bitmap_size_context.size = indexTablesSize;
bitmap_size_context.num_tables = numberOfIndexSubtables;
bitmap_size_context.start_glyph = 1;
bitmap_size_context.end_glyph = 0;
if (!out_table->indexSubtableArrayOffset.serialize_subset (c,
indexSubtableArrayOffset,
src_base,
dst_base,
&bitmap_size_context))
return_trace (false);
if (!bitmap_size_context.size ||
!bitmap_size_context.num_tables ||
bitmap_size_context.start_glyph > bitmap_size_context.end_glyph)
return_trace (false);
out_table->indexTablesSize = bitmap_size_context.size;
out_table->numberOfIndexSubtables = bitmap_size_context.num_tables;
out_table->startGlyphIndex = bitmap_size_context.start_glyph;
out_table->endGlyphIndex = bitmap_size_context.end_glyph;
return_trace (true);
}
protected:
LNNOffsetTo<IndexSubtableArray>
indexSubtableArrayOffset;
HBUINT32 indexTablesSize;
HBUINT32 numberOfIndexSubtables;
HBUINT32 colorRef;
SBitLineMetrics horizontal;
SBitLineMetrics vertical;
HBGlyphID startGlyphIndex;
HBGlyphID endGlyphIndex;
HBUINT8 ppemX;
HBUINT8 ppemY;
HBUINT8 bitDepth;
HBINT8 flags;
public:
DEFINE_SIZE_STATIC (48);
};
/*
* Glyph Bitmap Data Formats.
*/
struct GlyphBitmapDataFormat17
{
SmallGlyphMetrics glyphMetrics;
LArrayOf<HBUINT8> data;
public:
DEFINE_SIZE_ARRAY (9, data);
};
struct GlyphBitmapDataFormat18
{
BigGlyphMetrics glyphMetrics;
LArrayOf<HBUINT8> data;
public:
DEFINE_SIZE_ARRAY (12, data);
};
struct GlyphBitmapDataFormat19
{
LArrayOf<HBUINT8> data;
public:
DEFINE_SIZE_ARRAY (4, data);
};
struct CBLC
{
friend struct CBDT;
static constexpr hb_tag_t tableTag = HB_OT_TAG_CBLC;
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
likely (version.major == 2 || version.major == 3) &&
sizeTables.sanitize (c, this));
}
static bool
sink_cbdt (hb_subset_context_t *c, hb_vector_t<char>* cbdt_prime)
{
hb_blob_t *cbdt_prime_blob = hb_blob_create (cbdt_prime->arrayZ,
cbdt_prime->length,
HB_MEMORY_MODE_WRITABLE,
cbdt_prime->arrayZ,
free);
cbdt_prime->init (); // Leak arrayZ to the blob.
bool ret = c->plan->add_table (HB_OT_TAG_CBDT, cbdt_prime_blob);
hb_blob_destroy (cbdt_prime_blob);
return ret;
}
bool
subset_size_table (hb_subset_context_t *c, const BitmapSizeTable& table,
const char *cbdt /* IN */, unsigned int cbdt_length,
CBLC *cblc_prime /* INOUT */, hb_vector_t<char> *cbdt_prime /* INOUT */) const
{
TRACE_SUBSET (this);
cblc_prime->sizeTables.len++;
auto snap = c->serializer->snapshot ();
auto cbdt_prime_len = cbdt_prime->length;
if (!table.subset (c, this, cblc_prime, cbdt, cbdt_length, cbdt_prime))
{
cblc_prime->sizeTables.len--;
c->serializer->revert (snap);
cbdt_prime->shrink (cbdt_prime_len);
return_trace (false);
}
return_trace (true);
}
// Implemented in cc file as it depends on definition of CBDT.
HB_INTERNAL bool subset (hb_subset_context_t *c) const;
protected:
const BitmapSizeTable &choose_strike (hb_font_t *font) const
{
unsigned count = sizeTables.len;
if (unlikely (!count))
return Null (BitmapSizeTable);
unsigned int requested_ppem = hb_max (font->x_ppem, font->y_ppem);
if (!requested_ppem)
requested_ppem = 1<<30; /* Choose largest strike. */
unsigned int best_i = 0;
unsigned int best_ppem = hb_max (sizeTables[0].ppemX, sizeTables[0].ppemY);
for (unsigned int i = 1; i < count; i++)
{
unsigned int ppem = hb_max (sizeTables[i].ppemX, sizeTables[i].ppemY);
if ((requested_ppem <= ppem && ppem < best_ppem) ||
(requested_ppem > best_ppem && ppem > best_ppem))
{
best_i = i;
best_ppem = ppem;
}
}
return sizeTables[best_i];
}
protected:
FixedVersion<> version;
LArrayOf<BitmapSizeTable> sizeTables;
public:
DEFINE_SIZE_ARRAY (8, sizeTables);
};
struct CBDT
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_CBDT;
struct accelerator_t
{
void init (hb_face_t *face)
{
cblc = hb_sanitize_context_t ().reference_table<CBLC> (face);
cbdt = hb_sanitize_context_t ().reference_table<CBDT> (face);
upem = hb_face_get_upem (face);
}
void fini ()
{
this->cblc.destroy ();
this->cbdt.destroy ();
}
bool
get_extents (hb_font_t *font, hb_codepoint_t glyph, hb_glyph_extents_t *extents) const
{
const void *base;
const BitmapSizeTable &strike = this->cblc->choose_strike (font);
const IndexSubtableRecord *subtable_record = strike.find_table (glyph, cblc, &base);
if (!subtable_record || !strike.ppemX || !strike.ppemY)
return false;
if (subtable_record->get_extents (extents, base))
return true;
unsigned int image_offset = 0, image_length = 0, image_format = 0;
if (!subtable_record->get_image_data (glyph, base, &image_offset, &image_length, &image_format))
return false;
unsigned int cbdt_len = cbdt.get_length ();
if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length))
return false;
switch (image_format)
{
case 17: {
if (unlikely (image_length < GlyphBitmapDataFormat17::min_size))
return false;
auto &glyphFormat17 = StructAtOffset<GlyphBitmapDataFormat17> (this->cbdt, image_offset);
glyphFormat17.glyphMetrics.get_extents (font, extents);
break;
}
case 18: {
if (unlikely (image_length < GlyphBitmapDataFormat18::min_size))
return false;
auto &glyphFormat18 = StructAtOffset<GlyphBitmapDataFormat18> (this->cbdt, image_offset);
glyphFormat18.glyphMetrics.get_extents (font, extents);
break;
}
default: return false; /* TODO: Support other image formats. */
}
/* Convert to font units. */
float x_scale = upem / (float) strike.ppemX;
float y_scale = upem / (float) strike.ppemY;
extents->x_bearing = roundf (extents->x_bearing * x_scale);
extents->y_bearing = roundf (extents->y_bearing * y_scale);
extents->width = roundf (extents->width * x_scale);
extents->height = roundf (extents->height * y_scale);
return true;
}
hb_blob_t*
reference_png (hb_font_t *font, hb_codepoint_t glyph) const
{
const void *base;
const BitmapSizeTable &strike = this->cblc->choose_strike (font);
const IndexSubtableRecord *subtable_record = strike.find_table (glyph, cblc, &base);
if (!subtable_record || !strike.ppemX || !strike.ppemY)
return hb_blob_get_empty ();
unsigned int image_offset = 0, image_length = 0, image_format = 0;
if (!subtable_record->get_image_data (glyph, base, &image_offset, &image_length, &image_format))
return hb_blob_get_empty ();
unsigned int cbdt_len = cbdt.get_length ();
if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length))
return hb_blob_get_empty ();
switch (image_format)
{
case 17:
{
if (unlikely (image_length < GlyphBitmapDataFormat17::min_size))
return hb_blob_get_empty ();
auto &glyphFormat17 = StructAtOffset<GlyphBitmapDataFormat17> (this->cbdt, image_offset);
return hb_blob_create_sub_blob (cbdt.get_blob (),
image_offset + GlyphBitmapDataFormat17::min_size,
glyphFormat17.data.len);
}
case 18:
{
if (unlikely (image_length < GlyphBitmapDataFormat18::min_size))
return hb_blob_get_empty ();
auto &glyphFormat18 = StructAtOffset<GlyphBitmapDataFormat18> (this->cbdt, image_offset);
return hb_blob_create_sub_blob (cbdt.get_blob (),
image_offset + GlyphBitmapDataFormat18::min_size,
glyphFormat18.data.len);
}
case 19:
{
if (unlikely (image_length < GlyphBitmapDataFormat19::min_size))
return hb_blob_get_empty ();
auto &glyphFormat19 = StructAtOffset<GlyphBitmapDataFormat19> (this->cbdt, image_offset);
return hb_blob_create_sub_blob (cbdt.get_blob (),
image_offset + GlyphBitmapDataFormat19::min_size,
glyphFormat19.data.len);
}
default: return hb_blob_get_empty (); /* TODO: Support other image formats. */
}
}
bool has_data () const { return cbdt.get_length (); }
private:
hb_blob_ptr_t<CBLC> cblc;
hb_blob_ptr_t<CBDT> cbdt;
unsigned int upem;
};
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
likely (version.major == 2 || version.major == 3));
}
protected:
FixedVersion<> version;
UnsizedArrayOf<HBUINT8> dataZ;
public:
DEFINE_SIZE_ARRAY (4, dataZ);
};
inline bool
CBLC::subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
auto *cblc_prime = c->serializer->start_embed<CBLC> ();
// Use a vector as a secondary buffer as the tables need to be built in parallel.
hb_vector_t<char> cbdt_prime;
if (unlikely (!cblc_prime)) return_trace (false);
if (unlikely (!c->serializer->extend_min (cblc_prime))) return_trace (false);
cblc_prime->version = version;
hb_blob_t* cbdt_blob = hb_sanitize_context_t ().reference_table<CBDT> (c->plan->source);
unsigned int cbdt_length;
CBDT* cbdt = (CBDT *) hb_blob_get_data (cbdt_blob, &cbdt_length);
if (unlikely (cbdt_length < CBDT::min_size)) return_trace (false);
_copy_data_to_cbdt (&cbdt_prime, cbdt, CBDT::min_size);
for (const BitmapSizeTable& table : + sizeTables.iter ())
subset_size_table (c, table, (const char *) cbdt, cbdt_length, cblc_prime, &cbdt_prime);
hb_blob_destroy (cbdt_blob);
return_trace (CBLC::sink_cbdt (c, &cbdt_prime));
}
struct CBDT_accelerator_t : CBDT::accelerator_t {};
} /* namespace OT */
#endif /* HB_OT_COLOR_CBDT_TABLE_HH */
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