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

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/*
* Copyright © 2007,2008,2009,2010 Red Hat, Inc.
* Copyright © 2010,2012,2013 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.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_LAYOUT_GPOS_TABLE_HH
#define HB_OT_LAYOUT_GPOS_TABLE_HH
#include "hb-ot-layout-gsubgpos-private.hh"
namespace OT {
/* buffer **position** var allocations */
#define attach_lookback() var.u16[0] /* number of glyphs to go back to attach this glyph to its base */
#define cursive_chain() var.i16[1] /* character to which this connects, may be positive or negative */
/* Shared Tables: ValueRecord, Anchor Table, and MarkArray */
typedef USHORT Value;
typedef Value ValueRecord[VAR];
struct ValueFormat : USHORT
{
enum Flags {
xPlacement = 0x0001u, /* Includes horizontal adjustment for placement */
yPlacement = 0x0002u, /* Includes vertical adjustment for placement */
xAdvance = 0x0004u, /* Includes horizontal adjustment for advance */
yAdvance = 0x0008u, /* Includes vertical adjustment for advance */
xPlaDevice = 0x0010u, /* Includes horizontal Device table for placement */
yPlaDevice = 0x0020u, /* Includes vertical Device table for placement */
xAdvDevice = 0x0040u, /* Includes horizontal Device table for advance */
yAdvDevice = 0x0080u, /* Includes vertical Device table for advance */
ignored = 0x0F00u, /* Was used in TrueType Open for MM fonts */
reserved = 0xF000u, /* For future use */
devices = 0x00F0u /* Mask for having any Device table */
};
/* All fields are options. Only those available advance the value pointer. */
#if 0
SHORT xPlacement; /* Horizontal adjustment for
* placement--in design units */
SHORT yPlacement; /* Vertical adjustment for
* placement--in design units */
SHORT xAdvance; /* Horizontal adjustment for
* advance--in design units (only used
* for horizontal writing) */
SHORT yAdvance; /* Vertical adjustment for advance--in
* design units (only used for vertical
* writing) */
Offset xPlaDevice; /* Offset to Device table for
* horizontal placement--measured from
* beginning of PosTable (may be NULL) */
Offset yPlaDevice; /* Offset to Device table for vertical
* placement--measured from beginning
* of PosTable (may be NULL) */
Offset xAdvDevice; /* Offset to Device table for
* horizontal advance--measured from
* beginning of PosTable (may be NULL) */
Offset yAdvDevice; /* Offset to Device table for vertical
* advance--measured from beginning of
* PosTable (may be NULL) */
#endif
inline unsigned int get_len (void) const
{ return _hb_popcount32 ((unsigned int) *this); }
inline unsigned int get_size (void) const
{ return get_len () * Value::static_size; }
void apply_value (hb_font_t *font,
hb_direction_t direction,
const void *base,
const Value *values,
hb_glyph_position_t &glyph_pos) const
{
unsigned int x_ppem, y_ppem;
unsigned int format = *this;
hb_bool_t horizontal = HB_DIRECTION_IS_HORIZONTAL (direction);
if (!format) return;
if (format & xPlacement) glyph_pos.x_offset += font->em_scale_x (get_short (values++));
if (format & yPlacement) glyph_pos.y_offset += font->em_scale_y (get_short (values++));
if (format & xAdvance) {
if (likely (horizontal)) glyph_pos.x_advance += font->em_scale_x (get_short (values));
values++;
}
/* y_advance values grow downward but font-space grows upward, hence negation */
if (format & yAdvance) {
if (unlikely (!horizontal)) glyph_pos.y_advance -= font->em_scale_y (get_short (values));
values++;
}
if (!has_device ()) return;
x_ppem = font->x_ppem;
y_ppem = font->y_ppem;
if (!x_ppem && !y_ppem) return;
/* pixel -> fractional pixel */
if (format & xPlaDevice) {
if (x_ppem) glyph_pos.x_offset += (base + get_device (values)).get_x_delta (font);
values++;
}
if (format & yPlaDevice) {
if (y_ppem) glyph_pos.y_offset += (base + get_device (values)).get_y_delta (font);
values++;
}
if (format & xAdvDevice) {
if (horizontal && x_ppem) glyph_pos.x_advance += (base + get_device (values)).get_x_delta (font);
values++;
}
if (format & yAdvDevice) {
/* y_advance values grow downward but font-space grows upward, hence negation */
if (!horizontal && y_ppem) glyph_pos.y_advance -= (base + get_device (values)).get_y_delta (font);
values++;
}
}
private:
inline bool sanitize_value_devices (hb_sanitize_context_t *c, const void *base, const Value *values) const
{
unsigned int format = *this;
if (format & xPlacement) values++;
if (format & yPlacement) values++;
if (format & xAdvance) values++;
if (format & yAdvance) values++;
if ((format & xPlaDevice) && !get_device (values++).sanitize (c, base)) return false;
if ((format & yPlaDevice) && !get_device (values++).sanitize (c, base)) return false;
if ((format & xAdvDevice) && !get_device (values++).sanitize (c, base)) return false;
if ((format & yAdvDevice) && !get_device (values++).sanitize (c, base)) return false;
return true;
}
static inline OffsetTo<Device>& get_device (Value* value)
{ return *CastP<OffsetTo<Device> > (value); }
static inline const OffsetTo<Device>& get_device (const Value* value)
{ return *CastP<OffsetTo<Device> > (value); }
static inline const SHORT& get_short (const Value* value)
{ return *CastP<SHORT> (value); }
public:
inline bool has_device (void) const {
unsigned int format = *this;
return (format & devices) != 0;
}
inline bool sanitize_value (hb_sanitize_context_t *c, const void *base, const Value *values) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_range (values, get_size ()) && (!has_device () || sanitize_value_devices (c, base, values)));
}
inline bool sanitize_values (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count) const
{
TRACE_SANITIZE (this);
unsigned int len = get_len ();
if (!c->check_array (values, get_size (), count)) return TRACE_RETURN (false);
if (!has_device ()) return TRACE_RETURN (true);
for (unsigned int i = 0; i < count; i++) {
if (!sanitize_value_devices (c, base, values))
return TRACE_RETURN (false);
values += len;
}
return TRACE_RETURN (true);
}
/* Just sanitize referenced Device tables. Doesn't check the values themselves. */
inline bool sanitize_values_stride_unsafe (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count, unsigned int stride) const
{
TRACE_SANITIZE (this);
if (!has_device ()) return TRACE_RETURN (true);
for (unsigned int i = 0; i < count; i++) {
if (!sanitize_value_devices (c, base, values))
return TRACE_RETURN (false);
values += stride;
}
return TRACE_RETURN (true);
}
};
struct AnchorFormat1
{
inline void get_anchor (hb_font_t *font, hb_codepoint_t glyph_id HB_UNUSED,
hb_position_t *x, hb_position_t *y) const
{
*x = font->em_scale_x (xCoordinate);
*y = font->em_scale_y (yCoordinate);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this));
}
protected:
USHORT format; /* Format identifier--format = 1 */
SHORT xCoordinate; /* Horizontal value--in design units */
SHORT yCoordinate; /* Vertical value--in design units */
public:
DEFINE_SIZE_STATIC (6);
};
struct AnchorFormat2
{
inline void get_anchor (hb_font_t *font, hb_codepoint_t glyph_id,
hb_position_t *x, hb_position_t *y) const
{
unsigned int x_ppem = font->x_ppem;
unsigned int y_ppem = font->y_ppem;
hb_position_t cx, cy;
hb_bool_t ret;
ret = (x_ppem || y_ppem) &&
font->get_glyph_contour_point_for_origin (glyph_id, anchorPoint, HB_DIRECTION_LTR, &cx, &cy);
*x = ret && x_ppem ? cx : font->em_scale_x (xCoordinate);
*y = ret && y_ppem ? cy : font->em_scale_y (yCoordinate);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this));
}
protected:
USHORT format; /* Format identifier--format = 2 */
SHORT xCoordinate; /* Horizontal value--in design units */
SHORT yCoordinate; /* Vertical value--in design units */
USHORT anchorPoint; /* Index to glyph contour point */
public:
DEFINE_SIZE_STATIC (8);
};
struct AnchorFormat3
{
inline void get_anchor (hb_font_t *font, hb_codepoint_t glyph_id HB_UNUSED,
hb_position_t *x, hb_position_t *y) const
{
*x = font->em_scale_x (xCoordinate);
*y = font->em_scale_y (yCoordinate);
if (font->x_ppem)
*x += (this+xDeviceTable).get_x_delta (font);
if (font->y_ppem)
*y += (this+yDeviceTable).get_x_delta (font);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) && xDeviceTable.sanitize (c, this) && yDeviceTable.sanitize (c, this));
}
protected:
USHORT format; /* Format identifier--format = 3 */
SHORT xCoordinate; /* Horizontal value--in design units */
SHORT yCoordinate; /* Vertical value--in design units */
OffsetTo<Device>
xDeviceTable; /* Offset to Device table for X
* coordinate-- from beginning of
* Anchor table (may be NULL) */
OffsetTo<Device>
yDeviceTable; /* Offset to Device table for Y
* coordinate-- from beginning of
* Anchor table (may be NULL) */
public:
DEFINE_SIZE_STATIC (10);
};
struct Anchor
{
inline void get_anchor (hb_font_t *font, hb_codepoint_t glyph_id,
hb_position_t *x, hb_position_t *y) const
{
*x = *y = 0;
switch (u.format) {
case 1: u.format1.get_anchor (font, glyph_id, x, y); return;
case 2: u.format2.get_anchor (font, glyph_id, x, y); return;
case 3: u.format3.get_anchor (font, glyph_id, x, y); return;
default: return;
}
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!u.format.sanitize (c)) return TRACE_RETURN (false);
switch (u.format) {
case 1: return TRACE_RETURN (u.format1.sanitize (c));
case 2: return TRACE_RETURN (u.format2.sanitize (c));
case 3: return TRACE_RETURN (u.format3.sanitize (c));
default:return TRACE_RETURN (true);
}
}
protected:
union {
USHORT format; /* Format identifier */
AnchorFormat1 format1;
AnchorFormat2 format2;
AnchorFormat3 format3;
} u;
public:
DEFINE_SIZE_UNION (2, format);
};
struct AnchorMatrix
{
inline const Anchor& get_anchor (unsigned int row, unsigned int col, unsigned int cols, bool *found) const {
*found = false;
if (unlikely (row >= rows || col >= cols)) return Null(Anchor);
*found = !matrixZ[row * cols + col].is_null ();
return this+matrixZ[row * cols + col];
}
inline bool sanitize (hb_sanitize_context_t *c, unsigned int cols) const
{
TRACE_SANITIZE (this);
if (!c->check_struct (this)) return TRACE_RETURN (false);
if (unlikely (rows > 0 && cols >= ((unsigned int) -1) / rows)) return TRACE_RETURN (false);
unsigned int count = rows * cols;
if (!c->check_array (matrixZ, matrixZ[0].static_size, count)) return TRACE_RETURN (false);
for (unsigned int i = 0; i < count; i++)
if (!matrixZ[i].sanitize (c, this)) return TRACE_RETURN (false);
return TRACE_RETURN (true);
}
USHORT rows; /* Number of rows */
protected:
OffsetTo<Anchor>
matrixZ[VAR]; /* Matrix of offsets to Anchor tables--
* from beginning of AnchorMatrix table */
public:
DEFINE_SIZE_ARRAY (2, matrixZ);
};
struct MarkRecord
{
friend struct MarkArray;
inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) && markAnchor.sanitize (c, base));
}
protected:
USHORT klass; /* Class defined for this mark */
OffsetTo<Anchor>
markAnchor; /* Offset to Anchor table--from
* beginning of MarkArray table */
public:
DEFINE_SIZE_STATIC (4);
};
struct MarkArray : ArrayOf<MarkRecord> /* Array of MarkRecords--in Coverage order */
{
inline bool apply (hb_apply_context_t *c,
unsigned int mark_index, unsigned int glyph_index,
const AnchorMatrix &anchors, unsigned int class_count,
unsigned int glyph_pos) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
const MarkRecord &record = ArrayOf<MarkRecord>::operator[](mark_index);
unsigned int mark_class = record.klass;
const Anchor& mark_anchor = this + record.markAnchor;
bool found;
const Anchor& glyph_anchor = anchors.get_anchor (glyph_index, mark_class, class_count, &found);
/* If this subtable doesn't have an anchor for this base and this class,
* return false such that the subsequent subtables have a chance at it. */
if (unlikely (!found)) return TRACE_RETURN (false);
hb_position_t mark_x, mark_y, base_x, base_y;
mark_anchor.get_anchor (c->font, buffer->cur().codepoint, &mark_x, &mark_y);
glyph_anchor.get_anchor (c->font, buffer->info[glyph_pos].codepoint, &base_x, &base_y);
hb_glyph_position_t &o = buffer->cur_pos();
o.x_offset = base_x - mark_x;
o.y_offset = base_y - mark_y;
o.attach_lookback() = buffer->idx - glyph_pos;
buffer->idx++;
return TRACE_RETURN (true);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (ArrayOf<MarkRecord>::sanitize (c, this));
}
};
/* Lookups */
struct SinglePosFormat1
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
(this+coverage).add_coverage (c->input);
}
inline const Coverage &get_coverage (void) const
{
return this+coverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
valueFormat.apply_value (c->font, c->direction, this,
values, buffer->cur_pos());
buffer->idx++;
return TRACE_RETURN (true);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this)
&& coverage.sanitize (c, this)
&& valueFormat.sanitize_value (c, this, values));
}
protected:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of subtable */
ValueFormat valueFormat; /* Defines the types of data in the
* ValueRecord */
ValueRecord values; /* Defines positioning
* value(s)--applied to all glyphs in
* the Coverage table */
public:
DEFINE_SIZE_ARRAY (6, values);
};
struct SinglePosFormat2
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
(this+coverage).add_coverage (c->input);
}
inline const Coverage &get_coverage (void) const
{
return this+coverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
if (likely (index >= valueCount)) return TRACE_RETURN (false);
valueFormat.apply_value (c->font, c->direction, this,
&values[index * valueFormat.get_len ()],
buffer->cur_pos());
buffer->idx++;
return TRACE_RETURN (true);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this)
&& coverage.sanitize (c, this)
&& valueFormat.sanitize_values (c, this, values, valueCount));
}
protected:
USHORT format; /* Format identifier--format = 2 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of subtable */
ValueFormat valueFormat; /* Defines the types of data in the
* ValueRecord */
USHORT valueCount; /* Number of ValueRecords */
ValueRecord values; /* Array of ValueRecords--positioning
* values applied to glyphs */
public:
DEFINE_SIZE_ARRAY (8, values);
};
struct SinglePos
{
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c) const
{
TRACE_DISPATCH (this, u.format);
if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
switch (u.format) {
case 1: return TRACE_RETURN (c->dispatch (u.format1));
case 2: return TRACE_RETURN (c->dispatch (u.format2));
default:return TRACE_RETURN (c->default_return_value ());
}
}
protected:
union {
USHORT format; /* Format identifier */
SinglePosFormat1 format1;
SinglePosFormat2 format2;
} u;
};
struct PairValueRecord
{
friend struct PairSet;
protected:
GlyphID secondGlyph; /* GlyphID of second glyph in the
* pair--first glyph is listed in the
* Coverage table */
ValueRecord values; /* Positioning data for the first glyph
* followed by for second glyph */
public:
DEFINE_SIZE_ARRAY (2, values);
};
struct PairSet
{
friend struct PairPosFormat1;
inline void collect_glyphs (hb_collect_glyphs_context_t *c,
const ValueFormat *valueFormats) const
{
TRACE_COLLECT_GLYPHS (this);
unsigned int len1 = valueFormats[0].get_len ();
unsigned int len2 = valueFormats[1].get_len ();
unsigned int record_size = USHORT::static_size * (1 + len1 + len2);
const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
{
c->input->add (record->secondGlyph);
record = &StructAtOffset<PairValueRecord> (record, record_size);
}
}
inline bool apply (hb_apply_context_t *c,
const ValueFormat *valueFormats,
unsigned int pos) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int len1 = valueFormats[0].get_len ();
unsigned int len2 = valueFormats[1].get_len ();
unsigned int record_size = USHORT::static_size * (1 + len1 + len2);
const PairValueRecord *record_array = CastP<PairValueRecord> (arrayZ);
unsigned int count = len;
/* Hand-coded bsearch. */
if (unlikely (!count))
return TRACE_RETURN (false);
hb_codepoint_t x = buffer->info[pos].codepoint;
int min = 0, max = (int) count - 1;
while (min <= max)
{
int mid = (min + max) / 2;
const PairValueRecord *record = &StructAtOffset<PairValueRecord> (record_array, record_size * mid);
hb_codepoint_t mid_x = record->secondGlyph;
if (x < mid_x)
max = mid - 1;
else if (x > mid_x)
min = mid + 1;
else
{
valueFormats[0].apply_value (c->font, c->direction, this,
&record->values[0], buffer->cur_pos());
valueFormats[1].apply_value (c->font, c->direction, this,
&record->values[len1], buffer->pos[pos]);
if (len2)
pos++;
buffer->idx = pos;
return TRACE_RETURN (true);
}
}
return TRACE_RETURN (false);
}
struct sanitize_closure_t {
const void *base;
const ValueFormat *valueFormats;
unsigned int len1; /* valueFormats[0].get_len() */
unsigned int stride; /* 1 + len1 + len2 */
};
inline bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) const
{
TRACE_SANITIZE (this);
if (!(c->check_struct (this)
&& c->check_array (arrayZ, USHORT::static_size * closure->stride, len))) return TRACE_RETURN (false);
unsigned int count = len;
const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
return TRACE_RETURN (closure->valueFormats[0].sanitize_values_stride_unsafe (c, closure->base, &record->values[0], count, closure->stride)
&& closure->valueFormats[1].sanitize_values_stride_unsafe (c, closure->base, &record->values[closure->len1], count, closure->stride));
}
protected:
USHORT len; /* Number of PairValueRecords */
USHORT arrayZ[VAR]; /* Array of PairValueRecords--ordered
* by GlyphID of the second glyph */
public:
DEFINE_SIZE_ARRAY (2, arrayZ);
};
struct PairPosFormat1
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
(this+coverage).add_coverage (c->input);
unsigned int count = pairSet.len;
for (unsigned int i = 0; i < count; i++)
(this+pairSet[i]).collect_glyphs (c, &valueFormat1);
}
inline const Coverage &get_coverage (void) const
{
return this+coverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
skippy_iter.reset (buffer->idx, 1);
if (!skippy_iter.next ()) return TRACE_RETURN (false);
return TRACE_RETURN ((this+pairSet[index]).apply (c, &valueFormat1, skippy_iter.idx));
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
unsigned int len1 = valueFormat1.get_len ();
unsigned int len2 = valueFormat2.get_len ();
PairSet::sanitize_closure_t closure = {
this,
&valueFormat1,
len1,
1 + len1 + len2
};
return TRACE_RETURN (c->check_struct (this) && coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
}
protected:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of subtable */
ValueFormat valueFormat1; /* Defines the types of data in
* ValueRecord1--for the first glyph
* in the pair--may be zero (0) */
ValueFormat valueFormat2; /* Defines the types of data in
* ValueRecord2--for the second glyph
* in the pair--may be zero (0) */
OffsetArrayOf<PairSet>
pairSet; /* Array of PairSet tables
* ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (10, pairSet);
};
struct PairPosFormat2
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
/* (this+coverage).add_coverage (c->input); // Don't need this. */
unsigned int count1 = class1Count;
const ClassDef &klass1 = this+classDef1;
for (unsigned int i = 0; i < count1; i++)
klass1.add_class (c->input, i);
unsigned int count2 = class2Count;
const ClassDef &klass2 = this+classDef2;
for (unsigned int i = 0; i < count2; i++)
klass2.add_class (c->input, i);
}
inline const Coverage &get_coverage (void) const
{
return this+coverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
skippy_iter.reset (buffer->idx, 1);
if (!skippy_iter.next ()) return TRACE_RETURN (false);
unsigned int len1 = valueFormat1.get_len ();
unsigned int len2 = valueFormat2.get_len ();
unsigned int record_len = len1 + len2;
unsigned int klass1 = (this+classDef1).get_class (buffer->cur().codepoint);
unsigned int klass2 = (this+classDef2).get_class (buffer->info[skippy_iter.idx].codepoint);
if (unlikely (klass1 >= class1Count || klass2 >= class2Count)) return TRACE_RETURN (false);
const Value *v = &values[record_len * (klass1 * class2Count + klass2)];
valueFormat1.apply_value (c->font, c->direction, this,
v, buffer->cur_pos());
valueFormat2.apply_value (c->font, c->direction, this,
v + len1, buffer->pos[skippy_iter.idx]);
buffer->idx = skippy_iter.idx;
if (len2)
buffer->idx++;
return TRACE_RETURN (true);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!(c->check_struct (this)
&& coverage.sanitize (c, this)
&& classDef1.sanitize (c, this)
&& classDef2.sanitize (c, this))) return TRACE_RETURN (false);
unsigned int len1 = valueFormat1.get_len ();
unsigned int len2 = valueFormat2.get_len ();
unsigned int stride = len1 + len2;
unsigned int record_size = valueFormat1.get_size () + valueFormat2.get_size ();
unsigned int count = (unsigned int) class1Count * (unsigned int) class2Count;
return TRACE_RETURN (c->check_array (values, record_size, count) &&
valueFormat1.sanitize_values_stride_unsafe (c, this, &values[0], count, stride) &&
valueFormat2.sanitize_values_stride_unsafe (c, this, &values[len1], count, stride));
}
protected:
USHORT format; /* Format identifier--format = 2 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of subtable */
ValueFormat valueFormat1; /* ValueRecord definition--for the
* first glyph of the pair--may be zero
* (0) */
ValueFormat valueFormat2; /* ValueRecord definition--for the
* second glyph of the pair--may be
* zero (0) */
OffsetTo<ClassDef>
classDef1; /* Offset to ClassDef table--from
* beginning of PairPos subtable--for
* the first glyph of the pair */
OffsetTo<ClassDef>
classDef2; /* Offset to ClassDef table--from
* beginning of PairPos subtable--for
* the second glyph of the pair */
USHORT class1Count; /* Number of classes in ClassDef1
* table--includes Class0 */
USHORT class2Count; /* Number of classes in ClassDef2
* table--includes Class0 */
ValueRecord values; /* Matrix of value pairs:
* class1-major, class2-minor,
* Each entry has value1 and value2 */
public:
DEFINE_SIZE_ARRAY (16, values);
};
struct PairPos
{
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c) const
{
TRACE_DISPATCH (this, u.format);
if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
switch (u.format) {
case 1: return TRACE_RETURN (c->dispatch (u.format1));
case 2: return TRACE_RETURN (c->dispatch (u.format2));
default:return TRACE_RETURN (c->default_return_value ());
}
}
protected:
union {
USHORT format; /* Format identifier */
PairPosFormat1 format1;
PairPosFormat2 format2;
} u;
};
struct EntryExitRecord
{
friend struct CursivePosFormat1;
inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (entryAnchor.sanitize (c, base) && exitAnchor.sanitize (c, base));
}
protected:
OffsetTo<Anchor>
entryAnchor; /* Offset to EntryAnchor table--from
* beginning of CursivePos
* subtable--may be NULL */
OffsetTo<Anchor>
exitAnchor; /* Offset to ExitAnchor table--from
* beginning of CursivePos
* subtable--may be NULL */
public:
DEFINE_SIZE_STATIC (4);
};
struct CursivePosFormat1
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
(this+coverage).add_coverage (c->input);
}
inline const Coverage &get_coverage (void) const
{
return this+coverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
/* We don't handle mark glyphs here. */
if (unlikely (_hb_glyph_info_is_mark (&buffer->cur()))) return TRACE_RETURN (false);
const EntryExitRecord &this_record = entryExitRecord[(this+coverage).get_coverage (buffer->cur().codepoint)];
if (!this_record.exitAnchor) return TRACE_RETURN (false);
hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
skippy_iter.reset (buffer->idx, 1);
if (!skippy_iter.next ()) return TRACE_RETURN (false);
const EntryExitRecord &next_record = entryExitRecord[(this+coverage).get_coverage (buffer->info[skippy_iter.idx].codepoint)];
if (!next_record.entryAnchor) return TRACE_RETURN (false);
unsigned int i = buffer->idx;
unsigned int j = skippy_iter.idx;
hb_position_t entry_x, entry_y, exit_x, exit_y;
(this+this_record.exitAnchor).get_anchor (c->font, buffer->info[i].codepoint, &exit_x, &exit_y);
(this+next_record.entryAnchor).get_anchor (c->font, buffer->info[j].codepoint, &entry_x, &entry_y);
hb_glyph_position_t *pos = buffer->pos;
hb_position_t d;
/* Main-direction adjustment */
switch (c->direction) {
case HB_DIRECTION_LTR:
pos[i].x_advance = exit_x + pos[i].x_offset;
d = entry_x + pos[j].x_offset;
pos[j].x_advance -= d;
pos[j].x_offset -= d;
break;
case HB_DIRECTION_RTL:
d = exit_x + pos[i].x_offset;
pos[i].x_advance -= d;
pos[i].x_offset -= d;
pos[j].x_advance = entry_x + pos[j].x_offset;
break;
case HB_DIRECTION_TTB:
pos[i].y_advance = exit_y + pos[i].y_offset;
d = entry_y + pos[j].y_offset;
pos[j].y_advance -= d;
pos[j].y_offset -= d;
break;
case HB_DIRECTION_BTT:
d = exit_y + pos[i].y_offset;
pos[i].y_advance -= d;
pos[i].y_offset -= d;
pos[j].y_advance = entry_y;
break;
case HB_DIRECTION_INVALID:
default:
break;
}
/* Cross-direction adjustment */
/* We attach child to parent (think graph theory and rooted trees whereas
* the root stays on baseline and each node aligns itself against its
* parent.
*
* Optimize things for the case of RightToLeft, as that's most common in
* Arabinc. */
unsigned int child = i;
unsigned int parent = j;
hb_position_t x_offset = entry_x - exit_x;
hb_position_t y_offset = entry_y - exit_y;
if (!(c->lookup_props & LookupFlag::RightToLeft))
{
unsigned int k = child;
child = parent;
parent = k;
x_offset = -x_offset;
y_offset = -y_offset;
}
pos[child].cursive_chain() = parent - child;
if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
pos[child].y_offset = y_offset;
else
pos[child].x_offset = x_offset;
buffer->idx = j;
return TRACE_RETURN (true);
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (coverage.sanitize (c, this) && entryExitRecord.sanitize (c, this));
}
protected:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of subtable */
ArrayOf<EntryExitRecord>
entryExitRecord; /* Array of EntryExit records--in
* Coverage Index order */
public:
DEFINE_SIZE_ARRAY (6, entryExitRecord);
};
struct CursivePos
{
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c) const
{
TRACE_DISPATCH (this, u.format);
if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
switch (u.format) {
case 1: return TRACE_RETURN (c->dispatch (u.format1));
default:return TRACE_RETURN (c->default_return_value ());
}
}
protected:
union {
USHORT format; /* Format identifier */
CursivePosFormat1 format1;
} u;
};
typedef AnchorMatrix BaseArray; /* base-major--
* in order of BaseCoverage Index--,
* mark-minor--
* ordered by class--zero-based. */
struct MarkBasePosFormat1
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
(this+markCoverage).add_coverage (c->input);
(this+baseCoverage).add_coverage (c->input);
}
inline const Coverage &get_coverage (void) const
{
return this+markCoverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
if (likely (mark_index == NOT_COVERED)) return TRACE_RETURN (false);
/* now we search backwards for a non-mark glyph */
hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
skippy_iter.reset (buffer->idx, 1);
skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
do {
if (!skippy_iter.prev ()) return TRACE_RETURN (false);
/* We only want to attach to the first of a MultipleSubst sequence. Reject others. */
if (0 == _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx])) break;
skippy_iter.reject ();
} while (1);
/* Checking that matched glyph is actually a base glyph by GDEF is too strong; disabled */
if (!_hb_glyph_info_is_base_glyph (&buffer->info[skippy_iter.idx])) { /*return TRACE_RETURN (false);*/ }
unsigned int base_index = (this+baseCoverage).get_coverage (buffer->info[skippy_iter.idx].codepoint);
if (base_index == NOT_COVERED) return TRACE_RETURN (false);
return TRACE_RETURN ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, skippy_iter.idx));
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) && markCoverage.sanitize (c, this) && baseCoverage.sanitize (c, this) &&
markArray.sanitize (c, this) && baseArray.sanitize (c, this, (unsigned int) classCount));
}
protected:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
markCoverage; /* Offset to MarkCoverage table--from
* beginning of MarkBasePos subtable */
OffsetTo<Coverage>
baseCoverage; /* Offset to BaseCoverage table--from
* beginning of MarkBasePos subtable */
USHORT classCount; /* Number of classes defined for marks */
OffsetTo<MarkArray>
markArray; /* Offset to MarkArray table--from
* beginning of MarkBasePos subtable */
OffsetTo<BaseArray>
baseArray; /* Offset to BaseArray table--from
* beginning of MarkBasePos subtable */
public:
DEFINE_SIZE_STATIC (12);
};
struct MarkBasePos
{
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c) const
{
TRACE_DISPATCH (this, u.format);
if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
switch (u.format) {
case 1: return TRACE_RETURN (c->dispatch (u.format1));
default:return TRACE_RETURN (c->default_return_value ());
}
}
protected:
union {
USHORT format; /* Format identifier */
MarkBasePosFormat1 format1;
} u;
};
typedef AnchorMatrix LigatureAttach; /* component-major--
* in order of writing direction--,
* mark-minor--
* ordered by class--zero-based. */
typedef OffsetListOf<LigatureAttach> LigatureArray;
/* Array of LigatureAttach
* tables ordered by
* LigatureCoverage Index */
struct MarkLigPosFormat1
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
(this+markCoverage).add_coverage (c->input);
(this+ligatureCoverage).add_coverage (c->input);
}
inline const Coverage &get_coverage (void) const
{
return this+markCoverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int mark_index = (this+markCoverage).get_coverage (buffer->cur().codepoint);
if (likely (mark_index == NOT_COVERED)) return TRACE_RETURN (false);
/* now we search backwards for a non-mark glyph */
hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
skippy_iter.reset (buffer->idx, 1);
skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
if (!skippy_iter.prev ()) return TRACE_RETURN (false);
/* Checking that matched glyph is actually a ligature by GDEF is too strong; disabled */
if (!_hb_glyph_info_is_ligature (&buffer->info[skippy_iter.idx])) { /*return TRACE_RETURN (false);*/ }
unsigned int j = skippy_iter.idx;
unsigned int lig_index = (this+ligatureCoverage).get_coverage (buffer->info[j].codepoint);
if (lig_index == NOT_COVERED) return TRACE_RETURN (false);
const LigatureArray& lig_array = this+ligatureArray;
const LigatureAttach& lig_attach = lig_array[lig_index];
/* Find component to attach to */
unsigned int comp_count = lig_attach.rows;
if (unlikely (!comp_count)) return TRACE_RETURN (false);
/* We must now check whether the ligature ID of the current mark glyph
* is identical to the ligature ID of the found ligature. If yes, we
* can directly use the component index. If not, we attach the mark
* glyph to the last component of the ligature. */
unsigned int comp_index;
unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[j]);
unsigned int mark_id = _hb_glyph_info_get_lig_id (&buffer->cur());
unsigned int mark_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
if (lig_id && lig_id == mark_id && mark_comp > 0)
comp_index = MIN (comp_count, _hb_glyph_info_get_lig_comp (&buffer->cur())) - 1;
else
comp_index = comp_count - 1;
return TRACE_RETURN ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) && markCoverage.sanitize (c, this) && ligatureCoverage.sanitize (c, this) &&
markArray.sanitize (c, this) && ligatureArray.sanitize (c, this, (unsigned int) classCount));
}
protected:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
markCoverage; /* Offset to Mark Coverage table--from
* beginning of MarkLigPos subtable */
OffsetTo<Coverage>
ligatureCoverage; /* Offset to Ligature Coverage
* table--from beginning of MarkLigPos
* subtable */
USHORT classCount; /* Number of defined mark classes */
OffsetTo<MarkArray>
markArray; /* Offset to MarkArray table--from
* beginning of MarkLigPos subtable */
OffsetTo<LigatureArray>
ligatureArray; /* Offset to LigatureArray table--from
* beginning of MarkLigPos subtable */
public:
DEFINE_SIZE_STATIC (12);
};
struct MarkLigPos
{
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c) const
{
TRACE_DISPATCH (this, u.format);
if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
switch (u.format) {
case 1: return TRACE_RETURN (c->dispatch (u.format1));
default:return TRACE_RETURN (c->default_return_value ());
}
}
protected:
union {
USHORT format; /* Format identifier */
MarkLigPosFormat1 format1;
} u;
};
typedef AnchorMatrix Mark2Array; /* mark2-major--
* in order of Mark2Coverage Index--,
* mark1-minor--
* ordered by class--zero-based. */
struct MarkMarkPosFormat1
{
inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
(this+mark1Coverage).add_coverage (c->input);
(this+mark2Coverage).add_coverage (c->input);
}
inline const Coverage &get_coverage (void) const
{
return this+mark1Coverage;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
unsigned int mark1_index = (this+mark1Coverage).get_coverage (buffer->cur().codepoint);
if (likely (mark1_index == NOT_COVERED)) return TRACE_RETURN (false);
/* now we search backwards for a suitable mark glyph until a non-mark glyph */
hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
skippy_iter.reset (buffer->idx, 1);
skippy_iter.set_lookup_props (c->lookup_props & ~LookupFlag::IgnoreFlags);
if (!skippy_iter.prev ()) return TRACE_RETURN (false);
if (!_hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx])) { return TRACE_RETURN (false); }
unsigned int j = skippy_iter.idx;
unsigned int id1 = _hb_glyph_info_get_lig_id (&buffer->cur());
unsigned int id2 = _hb_glyph_info_get_lig_id (&buffer->info[j]);
unsigned int comp1 = _hb_glyph_info_get_lig_comp (&buffer->cur());
unsigned int comp2 = _hb_glyph_info_get_lig_comp (&buffer->info[j]);
if (likely (id1 == id2)) {
if (id1 == 0) /* Marks belonging to the same base. */
goto good;
else if (comp1 == comp2) /* Marks belonging to the same ligature component. */
goto good;
} else {
/* If ligature ids don't match, it may be the case that one of the marks
* itself is a ligature. In which case match. */
if ((id1 > 0 && !comp1) || (id2 > 0 && !comp2))
goto good;
}
/* Didn't match. */
return TRACE_RETURN (false);
good:
unsigned int mark2_index = (this+mark2Coverage).get_coverage (buffer->info[j].codepoint);
if (mark2_index == NOT_COVERED) return TRACE_RETURN (false);
return TRACE_RETURN ((this+mark1Array).apply (c, mark1_index, mark2_index, this+mark2Array, classCount, j));
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return TRACE_RETURN (c->check_struct (this) && mark1Coverage.sanitize (c, this) &&
mark2Coverage.sanitize (c, this) && mark1Array.sanitize (c, this)
&& mark2Array.sanitize (c, this, (unsigned int) classCount));
}
protected:
USHORT format; /* Format identifier--format = 1 */
OffsetTo<Coverage>
mark1Coverage; /* Offset to Combining Mark1 Coverage
* table--from beginning of MarkMarkPos
* subtable */
OffsetTo<Coverage>
mark2Coverage; /* Offset to Combining Mark2 Coverage
* table--from beginning of MarkMarkPos
* subtable */
USHORT classCount; /* Number of defined mark classes */
OffsetTo<MarkArray>
mark1Array; /* Offset to Mark1Array table--from
* beginning of MarkMarkPos subtable */
OffsetTo<Mark2Array>
mark2Array; /* Offset to Mark2Array table--from
* beginning of MarkMarkPos subtable */
public:
DEFINE_SIZE_STATIC (12);
};
struct MarkMarkPos
{
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c) const
{
TRACE_DISPATCH (this, u.format);
if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
switch (u.format) {
case 1: return TRACE_RETURN (c->dispatch (u.format1));
default:return TRACE_RETURN (c->default_return_value ());
}
}
protected:
union {
USHORT format; /* Format identifier */
MarkMarkPosFormat1 format1;
} u;
};
struct ContextPos : Context {};
struct ChainContextPos : ChainContext {};
struct ExtensionPos : Extension<ExtensionPos>
{
typedef struct PosLookupSubTable LookupSubTable;
};
/*
* PosLookup
*/
struct PosLookupSubTable
{
friend struct PosLookup;
enum Type {
Single = 1,
Pair = 2,
Cursive = 3,
MarkBase = 4,
MarkLig = 5,
MarkMark = 6,
Context = 7,
ChainContext = 8,
Extension = 9
};
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
{
TRACE_DISPATCH (this, lookup_type);
/* The sub_format passed to may_dispatch is unnecessary but harmless. */
if (unlikely (!c->may_dispatch (this, &u.sub_format))) TRACE_RETURN (c->default_return_value ());
switch (lookup_type) {
case Single: return TRACE_RETURN (u.single.dispatch (c));
case Pair: return TRACE_RETURN (u.pair.dispatch (c));
case Cursive: return TRACE_RETURN (u.cursive.dispatch (c));
case MarkBase: return TRACE_RETURN (u.markBase.dispatch (c));
case MarkLig: return TRACE_RETURN (u.markLig.dispatch (c));
case MarkMark: return TRACE_RETURN (u.markMark.dispatch (c));
case Context: return TRACE_RETURN (u.context.dispatch (c));
case ChainContext: return TRACE_RETURN (u.chainContext.dispatch (c));
case Extension: return TRACE_RETURN (u.extension.dispatch (c));
default: return TRACE_RETURN (c->default_return_value ());
}
}
protected:
union {
USHORT sub_format;
SinglePos single;
PairPos pair;
CursivePos cursive;
MarkBasePos markBase;
MarkLigPos markLig;
MarkMarkPos markMark;
ContextPos context;
ChainContextPos chainContext;
ExtensionPos extension;
} u;
public:
DEFINE_SIZE_UNION (2, sub_format);
};
struct PosLookup : Lookup
{
inline const PosLookupSubTable& get_subtable (unsigned int i) const
{ return Lookup::get_subtable<PosLookupSubTable> (i); }
inline bool is_reverse (void) const
{
return false;
}
inline bool apply (hb_apply_context_t *c) const
{
TRACE_APPLY (this);
return TRACE_RETURN (dispatch (c));
}
inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
{
TRACE_COLLECT_GLYPHS (this);
return TRACE_RETURN (dispatch (c));
}
template <typename set_t>
inline void add_coverage (set_t *glyphs) const
{
hb_add_coverage_context_t<set_t> c (glyphs);
dispatch (&c);
}
static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
template <typename context_t>
static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
template <typename context_t>
inline typename context_t::return_t dispatch (context_t *c) const
{ return Lookup::dispatch<PosLookupSubTable> (c); }
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (unlikely (!Lookup::sanitize (c))) return TRACE_RETURN (false);
return TRACE_RETURN (dispatch (c));
}
};
typedef OffsetListOf<PosLookup> PosLookupList;
/*
* GPOS -- The Glyph Positioning Table
*/
struct GPOS : GSUBGPOS
{
static const hb_tag_t tableTag = HB_OT_TAG_GPOS;
inline const PosLookup& get_lookup (unsigned int i) const
{ return CastR<PosLookup> (GSUBGPOS::get_lookup (i)); }
static inline void position_start (hb_font_t *font, hb_buffer_t *buffer);
static inline void position_finish (hb_font_t *font, hb_buffer_t *buffer);
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (unlikely (!GSUBGPOS::sanitize (c))) return TRACE_RETURN (false);
const OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
return TRACE_RETURN (list.sanitize (c, this));
}
public:
DEFINE_SIZE_STATIC (10);
};
static void
fix_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
{
unsigned int j = pos[i].cursive_chain();
if (likely (!j))
return;
j += i;
pos[i].cursive_chain() = 0;
fix_cursive_minor_offset (pos, j, direction);
if (HB_DIRECTION_IS_HORIZONTAL (direction))
pos[i].y_offset += pos[j].y_offset;
else
pos[i].x_offset += pos[j].x_offset;
}
static void
fix_mark_attachment (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
{
if (likely (!(pos[i].attach_lookback())))
return;
unsigned int j = i - pos[i].attach_lookback();
pos[i].x_offset += pos[j].x_offset;
pos[i].y_offset += pos[j].y_offset;
if (HB_DIRECTION_IS_FORWARD (direction))
for (unsigned int k = j; k < i; k++) {
pos[i].x_offset -= pos[k].x_advance;
pos[i].y_offset -= pos[k].y_advance;
}
else
for (unsigned int k = j + 1; k < i + 1; k++) {
pos[i].x_offset += pos[k].x_advance;
pos[i].y_offset += pos[k].y_advance;
}
}
void
GPOS::position_start (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
{
buffer->clear_positions ();
unsigned int count = buffer->len;
for (unsigned int i = 0; i < count; i++)
buffer->pos[i].attach_lookback() = buffer->pos[i].cursive_chain() = 0;
}
void
GPOS::position_finish (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
{
_hb_buffer_assert_gsubgpos_vars (buffer);
unsigned int len;
hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer, &len);
hb_direction_t direction = buffer->props.direction;
/* Handle cursive connections */
for (unsigned int i = 0; i < len; i++)
fix_cursive_minor_offset (pos, i, direction);
/* Handle attachments */
for (unsigned int i = 0; i < len; i++)
fix_mark_attachment (pos, i, direction);
}
/* Out-of-class implementation for methods recursing */
template <typename context_t>
/*static*/ inline typename context_t::return_t PosLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
{
const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
const PosLookup &l = gpos.get_lookup (lookup_index);
return l.dispatch (c);
}
/*static*/ inline bool PosLookup::apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index)
{
const GPOS &gpos = *(hb_ot_layout_from_face (c->face)->gpos);
const PosLookup &l = gpos.get_lookup (lookup_index);
unsigned int saved_lookup_props = c->lookup_props;
unsigned int saved_lookup_index = c->lookup_index;
c->set_lookup_index (lookup_index);
c->set_lookup_props (l.get_props ());
bool ret = l.dispatch (c);
c->set_lookup_index (saved_lookup_index);
c->set_lookup_props (saved_lookup_props);
return ret;
}
#undef attach_lookback
#undef cursive_chain
} /* namespace OT */
#endif /* HB_OT_LAYOUT_GPOS_TABLE_HH */
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