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

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16 KiB
C++

/*
* 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
*/
#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 SmallGlyphMetrics
{
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
inline void get_extents (hb_glyph_extents_t *extents) const
{
extents->x_bearing = bearingX;
extents->y_bearing = bearingY;
extents->width = width;
extents->height = -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
{
inline 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
{
inline 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
{
inline 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;
}
IndexSubtableHeader header;
UnsizedArrayOf<Offset<OffsetType> >
offsetArrayZ;
public:
DEFINE_SIZE_ARRAY(8, offsetArrayZ);
};
struct IndexSubtableFormat1 : IndexSubtableFormat1Or3<HBUINT32> {};
struct IndexSubtableFormat3 : IndexSubtableFormat1Or3<HBUINT16> {};
struct IndexSubtable
{
inline 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);
}
}
inline 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;
}
}
protected:
union {
IndexSubtableHeader header;
IndexSubtableFormat1 format1;
IndexSubtableFormat3 format3;
/* TODO: Format 2, 4, 5. */
} u;
public:
DEFINE_SIZE_UNION (8, header);
};
struct IndexSubtableRecord
{
inline 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));
}
inline 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);
}
GlyphID firstGlyphIndex;
GlyphID lastGlyphIndex;
LOffsetTo<IndexSubtable> offsetToSubtable;
public:
DEFINE_SIZE_STATIC(8);
};
struct IndexSubtableArray
{
friend struct CBDT;
inline bool sanitize (hb_sanitize_context_t *c, unsigned int count) const
{
TRACE_SANITIZE (this);
return_trace (indexSubtablesZ.sanitize (c, count, this));
}
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;
inline 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);
}
protected:
LOffsetTo<IndexSubtableArray, false>
indexSubtableArrayOffset;
HBUINT32 indexTablesSize;
HBUINT32 numberOfIndexSubtables;
HBUINT32 colorRef;
SBitLineMetrics horizontal;
SBitLineMetrics vertical;
GlyphID startGlyphIndex;
GlyphID 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 const hb_tag_t tableTag = HB_OT_TAG_CBLC;
inline 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));
}
protected:
const IndexSubtableRecord *find_table (hb_codepoint_t glyph,
unsigned int *x_ppem, unsigned int *y_ppem,
const void **base) const
{
/* TODO: Make it possible to select strike. */
unsigned int count = sizeTables.len;
for (uint32_t i = 0; i < count; ++i)
{
unsigned int startGlyphIndex = sizeTables.arrayZ[i].startGlyphIndex;
unsigned int endGlyphIndex = sizeTables.arrayZ[i].endGlyphIndex;
if (startGlyphIndex <= glyph && glyph <= endGlyphIndex)
{
*x_ppem = sizeTables[i].ppemX;
*y_ppem = sizeTables[i].ppemY;
return sizeTables[i].find_table (glyph, this, base);
}
}
return nullptr;
}
protected:
FixedVersion<> version;
LArrayOf<BitmapSizeTable> sizeTables;
public:
DEFINE_SIZE_ARRAY(8, sizeTables);
};
struct CBDT
{
static const hb_tag_t tableTag = HB_OT_TAG_CBDT;
struct accelerator_t
{
inline void init (hb_face_t *face)
{
upem = hb_face_get_upem (face);
cblc_blob = hb_sanitize_context_t().reference_table<CBLC> (face);
cbdt_blob = hb_sanitize_context_t().reference_table<CBDT> (face);
cbdt_len = hb_blob_get_length (cbdt_blob);
if (hb_blob_get_length (cblc_blob) == 0) {
cblc = nullptr;
cbdt = nullptr;
return; /* Not a bitmap font. */
}
cblc = cblc_blob->as<CBLC> ();
cbdt = cbdt_blob->as<CBDT> ();
}
inline void fini (void)
{
hb_blob_destroy (this->cblc_blob);
hb_blob_destroy (this->cbdt_blob);
}
inline bool get_extents (hb_codepoint_t glyph, hb_glyph_extents_t *extents) const
{
unsigned int x_ppem = upem, y_ppem = upem; /* TODO Use font ppem if available. */
if (!cblc)
return false; // Not a color bitmap font.
const void *base;
const IndexSubtableRecord *subtable_record = this->cblc->find_table (glyph, &x_ppem, &y_ppem, &base);
if (!subtable_record || !x_ppem || !y_ppem)
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;
{
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;
const GlyphBitmapDataFormat17& glyphFormat17 =
StructAtOffset<GlyphBitmapDataFormat17> (this->cbdt, image_offset);
glyphFormat17.glyphMetrics.get_extents (extents);
}
break;
default:
// TODO: Support other image formats.
return false;
}
}
/* Convert to the font units. */
extents->x_bearing *= upem / (float) x_ppem;
extents->y_bearing *= upem / (float) y_ppem;
extents->width *= upem / (float) x_ppem;
extents->height *= upem / (float) y_ppem;
return true;
}
inline void dump (void (*callback) (const uint8_t* data, unsigned int length,
unsigned int group, unsigned int gid)) const
{
if (!cblc)
return; // Not a color bitmap font.
for (unsigned int i = 0; i < cblc->sizeTables.len; ++i)
{
const BitmapSizeTable &sizeTable = cblc->sizeTables[i];
const IndexSubtableArray &subtable_array = cblc+sizeTable.indexSubtableArrayOffset;
for (unsigned int j = 0; j < sizeTable.numberOfIndexSubtables; ++j)
{
const IndexSubtableRecord &subtable_record = subtable_array.indexSubtablesZ[j];
for (unsigned int gid = subtable_record.firstGlyphIndex;
gid <= subtable_record.lastGlyphIndex; ++gid)
{
unsigned int image_offset = 0, image_length = 0, image_format = 0;
if (!subtable_record.get_image_data (gid, &subtable_array,
&image_offset, &image_length, &image_format))
continue;
switch (image_format)
{
case 17: {
const GlyphBitmapDataFormat17& glyphFormat17 =
StructAtOffset<GlyphBitmapDataFormat17> (this->cbdt, image_offset);
callback ((const uint8_t *) &glyphFormat17.data.arrayZ,
glyphFormat17.data.len, i, gid);
}
break;
case 18: {
const GlyphBitmapDataFormat18& glyphFormat18 =
StructAtOffset<GlyphBitmapDataFormat18> (this->cbdt, image_offset);
callback ((const uint8_t *) &glyphFormat18.data.arrayZ,
glyphFormat18.data.len, i, gid);
}
break;
case 19: {
const GlyphBitmapDataFormat19& glyphFormat19 =
StructAtOffset<GlyphBitmapDataFormat19> (this->cbdt, image_offset);
callback ((const uint8_t *) &glyphFormat19.data.arrayZ,
glyphFormat19.data.len, i, gid);
}
break;
default:
continue;
}
}
}
}
}
inline hb_blob_t* reference_png (hb_codepoint_t glyph_id,
unsigned int x_ppem,
unsigned int y_ppem) const
{
if (!cblc)
return hb_blob_get_empty ();
if (x_ppem == 0) x_ppem = upem;
if (y_ppem == 0) y_ppem = upem;
const void *base;
const IndexSubtableRecord *subtable_record = this->cblc->find_table (glyph_id, &x_ppem, &y_ppem, &base);
if (!subtable_record || !x_ppem || !y_ppem)
return hb_blob_get_empty ();
unsigned int image_offset = 0, image_length = 0, image_format = 0;
if (!subtable_record->get_image_data (glyph_id, base, &image_offset, &image_length, &image_format))
return hb_blob_get_empty ();
switch (image_format)
{
case 17: {
const GlyphBitmapDataFormat17& glyphFormat17 =
StructAtOffset<GlyphBitmapDataFormat17> (this->cbdt, image_offset);
return hb_blob_create_sub_blob (cbdt_blob,
image_offset + GlyphBitmapDataFormat17::min_size,
glyphFormat17.data.len);
}
case 18: {
const GlyphBitmapDataFormat18& glyphFormat18 =
StructAtOffset<GlyphBitmapDataFormat18> (this->cbdt, image_offset);
return hb_blob_create_sub_blob (cbdt_blob,
image_offset + GlyphBitmapDataFormat18::min_size,
glyphFormat18.data.len);
}
case 19: {
const GlyphBitmapDataFormat19& glyphFormat19 =
StructAtOffset<GlyphBitmapDataFormat19> (this->cbdt, image_offset);
return hb_blob_create_sub_blob (cbdt_blob,
image_offset + GlyphBitmapDataFormat19::min_size,
glyphFormat19.data.len);
}
}
return hb_blob_get_empty ();
}
inline bool has_data () const
{ return cbdt_len; }
private:
hb_blob_t *cblc_blob;
hb_blob_t *cbdt_blob;
const CBLC *cblc;
const CBDT *cbdt;
unsigned int cbdt_len;
unsigned int upem;
};
inline 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);
};
struct CBDT_accelerator_t : CBDT::accelerator_t {};
} /* namespace OT */
#endif /* HB_OT_COLOR_CBDT_TABLE_HH */