harfbuzz/src/hb-ot-layout-base-table.hh

510 lines
14 KiB
C++

/*
* Copyright © 2016 Elie Roux <elie.roux@telecom-bretagne.eu>
* Copyright © 2018 Google, Inc.
* Copyright © 2018-2019 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.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_LAYOUT_BASE_TABLE_HH
#define HB_OT_LAYOUT_BASE_TABLE_HH
#include "hb-open-type.hh"
#include "hb-ot-layout-common.hh"
namespace OT {
/*
* BASE -- Baseline
* https://docs.microsoft.com/en-us/typography/opentype/spec/base
*/
struct BaseCoordFormat1
{
hb_position_t get_coord () const { return coordinate; }
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this)));
}
protected:
HBUINT16 format; /* Format identifier--format = 1 */
FWORD coordinate; /* X or Y value, in design units */
public:
DEFINE_SIZE_STATIC (4);
};
struct BaseCoordFormat2
{
hb_position_t get_coord () const
{
/* TODO */
return coordinate;
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
protected:
HBUINT16 format; /* Format identifier--format = 2 */
FWORD coordinate; /* X or Y value, in design units */
HBGlyphID referenceGlyph; /* Glyph ID of control glyph */
HBUINT16 coordPoint; /* Index of contour point on the
* reference glyph */
public:
DEFINE_SIZE_STATIC (8);
};
struct BaseCoordFormat3
{
hb_position_t get_coord (hb_font_t *font,
const VariationStore &var_store,
hb_direction_t direction) const
{
const Device &device = this+deviceTable;
return coordinate + (HB_DIRECTION_IS_VERTICAL (direction) ?
device.get_y_delta (font, var_store) :
device.get_x_delta (font, var_store));
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
deviceTable.sanitize (c, this)));
}
protected:
HBUINT16 format; /* Format identifier--format = 3 */
FWORD coordinate; /* X or Y value, in design units */
OffsetTo<Device>
deviceTable; /* Offset to Device table for X or
* Y value, from beginning of
* BaseCoord table (may be NULL). */
public:
DEFINE_SIZE_STATIC (6);
};
struct BaseCoord
{
bool has_data () const { return u.format; }
hb_position_t get_coord (hb_font_t *font,
const VariationStore &var_store,
hb_direction_t direction) const
{
switch (u.format) {
case 1: return u.format1.get_coord ();
case 2: return u.format2.get_coord ();
case 3: return u.format3.get_coord (font, var_store, direction);
default:return 0;
}
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (unlikely (!u.format.sanitize (c))) return_trace (false);
switch (u.format) {
case 1: return_trace (u.format1.sanitize (c));
case 2: return_trace (u.format2.sanitize (c));
case 3: return_trace (u.format3.sanitize (c));
default:return_trace (false);
}
}
protected:
union {
HBUINT16 format;
BaseCoordFormat1 format1;
BaseCoordFormat2 format2;
BaseCoordFormat3 format3;
} u;
public:
DEFINE_SIZE_UNION (2, format);
};
struct FeatMinMaxRecord
{
int cmp (hb_tag_t key) const { return tag.cmp (key); }
bool has_data () const { return tag; }
void get_min_max (const BaseCoord **min, const BaseCoord **max) const
{
if (likely (min)) *min = &(this+minCoord);
if (likely (max)) *max = &(this+maxCoord);
}
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
minCoord.sanitize (c, this) &&
maxCoord.sanitize (c, this)));
}
protected:
Tag tag; /* 4-byte feature identification tag--must
* match feature tag in FeatureList */
OffsetTo<BaseCoord>
minCoord; /* Offset to BaseCoord table that defines
* the minimum extent value, from beginning
* of MinMax table (may be NULL) */
OffsetTo<BaseCoord>
maxCoord; /* Offset to BaseCoord table that defines
* the maximum extent value, from beginning
* of MinMax table (may be NULL) */
public:
DEFINE_SIZE_STATIC (8);
};
struct MinMax
{
void get_min_max (hb_tag_t feature_tag,
const BaseCoord **min,
const BaseCoord **max) const
{
const FeatMinMaxRecord &minMaxCoord = featMinMaxRecords.bsearch (feature_tag);
if (minMaxCoord.has_data ())
minMaxCoord.get_min_max (min, max);
else
{
if (likely (min)) *min = &(this+minCoord);
if (likely (max)) *max = &(this+maxCoord);
}
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
minCoord.sanitize (c, this) &&
maxCoord.sanitize (c, this) &&
featMinMaxRecords.sanitize (c, this)));
}
protected:
OffsetTo<BaseCoord>
minCoord; /* Offset to BaseCoord table that defines
* minimum extent value, from the beginning
* of MinMax table (may be NULL) */
OffsetTo<BaseCoord>
maxCoord; /* Offset to BaseCoord table that defines
* maximum extent value, from the beginning
* of MinMax table (may be NULL) */
SortedArrayOf<FeatMinMaxRecord>
featMinMaxRecords;
/* Array of FeatMinMaxRecords, in alphabetical
* order by featureTableTag */
public:
DEFINE_SIZE_ARRAY (6, featMinMaxRecords);
};
struct BaseValues
{
const BaseCoord &get_base_coord (int baseline_tag_index) const
{
if (baseline_tag_index == -1) baseline_tag_index = defaultIndex;
return this+baseCoords[baseline_tag_index];
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
baseCoords.sanitize (c, this)));
}
protected:
Index defaultIndex; /* Index number of default baseline for this
* script — equals index position of baseline tag
* in baselineTags array of the BaseTagList */
OffsetArrayOf<BaseCoord>
baseCoords; /* Number of BaseCoord tables defined — should equal
* baseTagCount in the BaseTagList
*
* Array of offsets to BaseCoord tables, from beginning of
* BaseValues table — order matches baselineTags array in
* the BaseTagList */
public:
DEFINE_SIZE_ARRAY (4, baseCoords);
};
struct BaseLangSysRecord
{
int cmp (hb_tag_t key) const { return baseLangSysTag.cmp (key); }
bool has_data () const { return baseLangSysTag; }
const MinMax &get_min_max () const { return this+minMax; }
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
minMax.sanitize (c, this)));
}
protected:
Tag baseLangSysTag; /* 4-byte language system identification tag */
OffsetTo<MinMax>
minMax; /* Offset to MinMax table, from beginning
* of BaseScript table */
public:
DEFINE_SIZE_STATIC (6);
};
struct BaseScript
{
const MinMax &get_min_max (hb_tag_t language_tag) const
{
const BaseLangSysRecord& record = baseLangSysRecords.bsearch (language_tag);
return record.has_data () ? record.get_min_max () : this+defaultMinMax;
}
const BaseCoord &get_base_coord (int baseline_tag_index) const
{ return (this+baseValues).get_base_coord (baseline_tag_index); }
bool has_data () const { return baseValues; }
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
baseValues.sanitize (c, this) &&
defaultMinMax.sanitize (c, this) &&
baseLangSysRecords.sanitize (c, this)));
}
protected:
OffsetTo<BaseValues>
baseValues; /* Offset to BaseValues table, from beginning
* of BaseScript table (may be NULL) */
OffsetTo<MinMax>
defaultMinMax; /* Offset to MinMax table, from beginning of
* BaseScript table (may be NULL) */
SortedArrayOf<BaseLangSysRecord>
baseLangSysRecords;
/* Number of BaseLangSysRecords
* defined — may be zero (0) */
public:
DEFINE_SIZE_ARRAY (6, baseLangSysRecords);
};
struct BaseScriptList;
struct BaseScriptRecord
{
int cmp (hb_tag_t key) const { return baseScriptTag.cmp (key); }
bool has_data () const { return baseScriptTag; }
const BaseScript &get_base_script (const BaseScriptList *list) const
{ return list+baseScript; }
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
baseScript.sanitize (c, base)));
}
protected:
Tag baseScriptTag; /* 4-byte script identification tag */
OffsetTo<BaseScript>
baseScript; /* Offset to BaseScript table, from beginning
* of BaseScriptList */
public:
DEFINE_SIZE_STATIC (6);
};
struct BaseScriptList
{
const BaseScript &get_base_script (hb_tag_t script) const
{
const BaseScriptRecord *record = &baseScriptRecords.bsearch (script);
if (!record->has_data ()) record = &baseScriptRecords.bsearch (HB_TAG ('D','F','L','T'));
return record->has_data () ? record->get_base_script (this) : Null (BaseScript);
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
baseScriptRecords.sanitize (c, this));
}
protected:
SortedArrayOf<BaseScriptRecord>
baseScriptRecords;
public:
DEFINE_SIZE_ARRAY (2, baseScriptRecords);
};
struct Axis
{
bool get_baseline (hb_tag_t baseline_tag,
hb_tag_t script_tag,
hb_tag_t language_tag,
const BaseCoord **coord) const
{
const BaseScript &base_script = (this+baseScriptList).get_base_script (script_tag);
if (!base_script.has_data ()) return false;
if (likely (coord))
{
unsigned int tag_index = 0;
(this+baseTagList).bfind (baseline_tag, &tag_index);
*coord = &base_script.get_base_coord (tag_index);
}
return true;
}
bool get_min_max (hb_tag_t script_tag,
hb_tag_t language_tag,
hb_tag_t feature_tag,
const BaseCoord **min_coord,
const BaseCoord **max_coord) const
{
const BaseScript &base_script = (this+baseScriptList).get_base_script (script_tag);
if (!base_script.has_data ()) return false;
base_script.get_min_max (language_tag).get_min_max (feature_tag, min_coord, max_coord);
return true;
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
(this+baseTagList).sanitize (c) &&
(this+baseScriptList).sanitize (c)));
}
protected:
OffsetTo<SortedArrayOf<Tag>>
baseTagList; /* Offset to BaseTagList table, from beginning
* of Axis table (may be NULL)
* Array of 4-byte baseline identification tags — must
* be in alphabetical order */
OffsetTo<BaseScriptList>
baseScriptList; /* Offset to BaseScriptList table, from beginning
* of Axis table
* Array of BaseScriptRecords, in alphabetical order
* by baseScriptTag */
public:
DEFINE_SIZE_STATIC (4);
};
struct BASE
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_BASE;
const Axis &get_axis (hb_direction_t direction) const
{ return HB_DIRECTION_IS_VERTICAL (direction) ? this+vAxis : this+hAxis; }
const VariationStore &get_var_store () const
{ return version.to_int () < 0x00010001u ? Null (VariationStore) : this+varStore; }
bool get_baseline (hb_font_t *font,
hb_tag_t baseline_tag,
hb_direction_t direction,
hb_tag_t script_tag,
hb_tag_t language_tag,
hb_position_t *base) const
{
const BaseCoord *base_coord = nullptr;
if (unlikely (!get_axis (direction).get_baseline (baseline_tag, script_tag, language_tag, &base_coord) ||
!base_coord || !base_coord->has_data ()))
return false;
if (likely (base))
*base = base_coord->get_coord (font, get_var_store (), direction);
return true;
}
/* TODO: Expose this separately sometime? */
bool get_min_max (hb_font_t *font,
hb_direction_t direction,
hb_tag_t script_tag,
hb_tag_t language_tag,
hb_tag_t feature_tag,
hb_position_t *min,
hb_position_t *max)
{
const BaseCoord *min_coord, *max_coord;
if (!get_axis (direction).get_min_max (script_tag, language_tag, feature_tag,
&min_coord, &max_coord))
return false;
const VariationStore &var_store = get_var_store ();
if (likely (min && min_coord)) *min = min_coord->get_coord (font, var_store, direction);
if (likely (max && max_coord)) *max = max_coord->get_coord (font, var_store, direction);
return true;
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
likely (version.major == 1) &&
hAxis.sanitize (c, this) &&
vAxis.sanitize (c, this) &&
(version.to_int () < 0x00010001u || varStore.sanitize (c, this))));
}
protected:
FixedVersion<>version; /* Version of the BASE table */
OffsetTo<Axis>hAxis; /* Offset to horizontal Axis table, from beginning
* of BASE table (may be NULL) */
OffsetTo<Axis>vAxis; /* Offset to vertical Axis table, from beginning
* of BASE table (may be NULL) */
LOffsetTo<VariationStore>
varStore; /* Offset to the table of Item Variation
* Store--from beginning of BASE
* header (may be NULL). Introduced
* in version 0x00010001. */
public:
DEFINE_SIZE_MIN (8);
};
} /* namespace OT */
#endif /* HB_OT_LAYOUT_BASE_TABLE_HH */