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[glyf] Split Glyph.hh

This commit is contained in:
Behdad Esfahbod 2022-06-25 16:38:50 -06:00
parent 3f9c6bf3fc
commit e4f2bc9342
5 changed files with 1096 additions and 1073 deletions
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1
src/Makefile.sources
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@ -90,6 +90,7 @@ HB_BASE_sources = \
hb-ot-layout-gsub-table.hh \
OT/glyf/glyf.hh \
OT/glyf/loca.hh \
OT/glyf/Glyph.hh \
OT/Layout/GSUB/Common.hh \
OT/Layout/GSUB/Sequence.hh \
OT/Layout/GSUB/SingleSubstFormat1.hh \

680
src/OT/glyf/Glyph.hh Normal file
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@ -0,0 +1,680 @@
#ifndef OT_GLYF_GLYPH_HH
#define OT_GLYF_GLYPH_HH
#include "hb-open-type.hh"
namespace OT {
struct glyf_accelerator_t;
struct CompositeGlyphChain
{
protected:
enum composite_glyph_flag_t
{
ARG_1_AND_2_ARE_WORDS = 0x0001,
ARGS_ARE_XY_VALUES = 0x0002,
ROUND_XY_TO_GRID = 0x0004,
WE_HAVE_A_SCALE = 0x0008,
MORE_COMPONENTS = 0x0020,
WE_HAVE_AN_X_AND_Y_SCALE = 0x0040,
WE_HAVE_A_TWO_BY_TWO = 0x0080,
WE_HAVE_INSTRUCTIONS = 0x0100,
USE_MY_METRICS = 0x0200,
OVERLAP_COMPOUND = 0x0400,
SCALED_COMPONENT_OFFSET = 0x0800,
UNSCALED_COMPONENT_OFFSET = 0x1000
};
public:
unsigned int get_size () const
{
unsigned int size = min_size;
/* arg1 and 2 are int16 */
if (flags & ARG_1_AND_2_ARE_WORDS) size += 4;
/* arg1 and 2 are int8 */
else size += 2;
/* One x 16 bit (scale) */
if (flags & WE_HAVE_A_SCALE) size += 2;
/* Two x 16 bit (xscale, yscale) */
else if (flags & WE_HAVE_AN_X_AND_Y_SCALE) size += 4;
/* Four x 16 bit (xscale, scale01, scale10, yscale) */
else if (flags & WE_HAVE_A_TWO_BY_TWO) size += 8;
return size;
}
void set_glyph_index (hb_codepoint_t new_gid) { glyphIndex = new_gid; }
hb_codepoint_t get_glyph_index () const { return glyphIndex; }
void drop_instructions_flag () { flags = (uint16_t) flags & ~WE_HAVE_INSTRUCTIONS; }
void set_overlaps_flag ()
{
flags = (uint16_t) flags | OVERLAP_COMPOUND;
}
bool has_instructions () const { return flags & WE_HAVE_INSTRUCTIONS; }
bool has_more () const { return flags & MORE_COMPONENTS; }
bool is_use_my_metrics () const { return flags & USE_MY_METRICS; }
bool is_anchored () const { return !(flags & ARGS_ARE_XY_VALUES); }
void get_anchor_points (unsigned int &point1, unsigned int &point2) const
{
const HBUINT8 *p = &StructAfter<const HBUINT8> (glyphIndex);
if (flags & ARG_1_AND_2_ARE_WORDS)
{
point1 = ((const HBUINT16 *) p)[0];
point2 = ((const HBUINT16 *) p)[1];
}
else
{
point1 = p[0];
point2 = p[1];
}
}
void transform_points (contour_point_vector_t &points) const
{
float matrix[4];
contour_point_t trans;
if (get_transformation (matrix, trans))
{
if (scaled_offsets ())
{
points.translate (trans);
points.transform (matrix);
}
else
{
points.transform (matrix);
points.translate (trans);
}
}
}
protected:
bool scaled_offsets () const
{ return (flags & (SCALED_COMPONENT_OFFSET | UNSCALED_COMPONENT_OFFSET)) == SCALED_COMPONENT_OFFSET; }
bool get_transformation (float (&matrix)[4], contour_point_t &trans) const
{
matrix[0] = matrix[3] = 1.f;
matrix[1] = matrix[2] = 0.f;
int tx, ty;
const HBINT8 *p = &StructAfter<const HBINT8> (glyphIndex);
if (flags & ARG_1_AND_2_ARE_WORDS)
{
tx = *(const HBINT16 *) p;
p += HBINT16::static_size;
ty = *(const HBINT16 *) p;
p += HBINT16::static_size;
}
else
{
tx = *p++;
ty = *p++;
}
if (is_anchored ()) tx = ty = 0;
trans.init ((float) tx, (float) ty);
{
const F2DOT14 *points = (const F2DOT14 *) p;
if (flags & WE_HAVE_A_SCALE)
{
matrix[0] = matrix[3] = points[0].to_float ();
return true;
}
else if (flags & WE_HAVE_AN_X_AND_Y_SCALE)
{
matrix[0] = points[0].to_float ();
matrix[3] = points[1].to_float ();
return true;
}
else if (flags & WE_HAVE_A_TWO_BY_TWO)
{
matrix[0] = points[0].to_float ();
matrix[1] = points[1].to_float ();
matrix[2] = points[2].to_float ();
matrix[3] = points[3].to_float ();
return true;
}
}
return tx || ty;
}
protected:
HBUINT16 flags;
HBGlyphID16 glyphIndex;
public:
DEFINE_SIZE_MIN (4);
};
struct composite_iter_t : hb_iter_with_fallback_t<composite_iter_t, const CompositeGlyphChain &>
{
typedef const CompositeGlyphChain *__item_t__;
composite_iter_t (hb_bytes_t glyph_, __item_t__ current_) :
glyph (glyph_), current (nullptr), current_size (0)
{
set_next (current_);
}
composite_iter_t () : glyph (hb_bytes_t ()), current (nullptr), current_size (0) {}
const CompositeGlyphChain &__item__ () const { return *current; }
bool __more__ () const { return current; }
void __next__ ()
{
if (!current->has_more ()) { current = nullptr; return; }
set_next (&StructAtOffset<CompositeGlyphChain> (current, current_size));
}
bool operator != (const composite_iter_t& o) const
{ return glyph != o.glyph || current != o.current; }
void set_next (const CompositeGlyphChain *composite)
{
if (!glyph.check_range (composite, CompositeGlyphChain::min_size))
{
current = nullptr;
current_size = 0;
return;
}
unsigned size = composite->get_size ();
if (!glyph.check_range (composite, size))
{
current = nullptr;
current_size = 0;
return;
}
current = composite;
current_size = size;
}
private:
hb_bytes_t glyph;
__item_t__ current;
unsigned current_size;
};
enum phantom_point_index_t
{
PHANTOM_LEFT = 0,
PHANTOM_RIGHT = 1,
PHANTOM_TOP = 2,
PHANTOM_BOTTOM = 3,
PHANTOM_COUNT = 4
};
struct Glyph
{
enum simple_glyph_flag_t
{
FLAG_ON_CURVE = 0x01,
FLAG_X_SHORT = 0x02,
FLAG_Y_SHORT = 0x04,
FLAG_REPEAT = 0x08,
FLAG_X_SAME = 0x10,
FLAG_Y_SAME = 0x20,
FLAG_OVERLAP_SIMPLE = 0x40,
FLAG_RESERVED2 = 0x80
};
struct GlyphHeader
{
bool has_data () const { return numberOfContours; }
template <typename accelerator_t>
bool get_extents (hb_font_t *font, const accelerator_t &glyf_accelerator,
hb_codepoint_t gid, hb_glyph_extents_t *extents) const
{
/* Undocumented rasterizer behavior: shift glyph to the left by (lsb - xMin), i.e., xMin = lsb */
/* extents->x_bearing = hb_min (glyph_header.xMin, glyph_header.xMax); */
extents->x_bearing = font->em_scale_x (glyf_accelerator.hmtx->get_side_bearing (gid));
extents->y_bearing = font->em_scale_y (hb_max (yMin, yMax));
extents->width = font->em_scale_x (hb_max (xMin, xMax) - hb_min (xMin, xMax));
extents->height = font->em_scale_y (hb_min (yMin, yMax) - hb_max (yMin, yMax));
return true;
}
HBINT16 numberOfContours;
/* If the number of contours is
* greater than or equal to zero,
* this is a simple glyph; if negative,
* this is a composite glyph. */
FWORD xMin; /* Minimum x for coordinate data. */
FWORD yMin; /* Minimum y for coordinate data. */
FWORD xMax; /* Maximum x for coordinate data. */
FWORD yMax; /* Maximum y for coordinate data. */
public:
DEFINE_SIZE_STATIC (10);
};
struct SimpleGlyph
{
const GlyphHeader &header;
hb_bytes_t bytes;
SimpleGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
header (header_), bytes (bytes_) {}
unsigned int instruction_len_offset () const
{ return GlyphHeader::static_size + 2 * header.numberOfContours; }
unsigned int length (unsigned int instruction_len) const
{ return instruction_len_offset () + 2 + instruction_len; }
unsigned int instructions_length () const
{
unsigned int instruction_length_offset = instruction_len_offset ();
if (unlikely (instruction_length_offset + 2 > bytes.length)) return 0;
const HBUINT16 &instructionLength = StructAtOffset<HBUINT16> (&bytes, instruction_length_offset);
/* Out of bounds of the current glyph */
if (unlikely (length (instructionLength) > bytes.length)) return 0;
return instructionLength;
}
const Glyph trim_padding () const
{
/* based on FontTools _g_l_y_f.py::trim */
const uint8_t *glyph = (uint8_t*) bytes.arrayZ;
const uint8_t *glyph_end = glyph + bytes.length;
/* simple glyph w/contours, possibly trimmable */
glyph += instruction_len_offset ();
if (unlikely (glyph + 2 >= glyph_end)) return Glyph ();
unsigned int num_coordinates = StructAtOffset<HBUINT16> (glyph - 2, 0) + 1;
unsigned int num_instructions = StructAtOffset<HBUINT16> (glyph, 0);
glyph += 2 + num_instructions;
unsigned int coord_bytes = 0;
unsigned int coords_with_flags = 0;
while (glyph < glyph_end)
{
uint8_t flag = *glyph;
glyph++;
unsigned int repeat = 1;
if (flag & FLAG_REPEAT)
{
if (unlikely (glyph >= glyph_end)) return Glyph ();
repeat = *glyph + 1;
glyph++;
}
unsigned int xBytes, yBytes;
xBytes = yBytes = 0;
if (flag & FLAG_X_SHORT) xBytes = 1;
else if ((flag & FLAG_X_SAME) == 0) xBytes = 2;
if (flag & FLAG_Y_SHORT) yBytes = 1;
else if ((flag & FLAG_Y_SAME) == 0) yBytes = 2;
coord_bytes += (xBytes + yBytes) * repeat;
coords_with_flags += repeat;
if (coords_with_flags >= num_coordinates) break;
}
if (unlikely (coords_with_flags != num_coordinates)) return Glyph ();
return Glyph (bytes.sub_array (0, bytes.length + coord_bytes - (glyph_end - glyph)));
}
/* zero instruction length */
void drop_hints ()
{
GlyphHeader &glyph_header = const_cast<GlyphHeader &> (header);
(HBUINT16 &) StructAtOffset<HBUINT16> (&glyph_header, instruction_len_offset ()) = 0;
}
void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const
{
unsigned int instructions_len = instructions_length ();
unsigned int glyph_length = length (instructions_len);
dest_start = bytes.sub_array (0, glyph_length - instructions_len);
dest_end = bytes.sub_array (glyph_length, bytes.length - glyph_length);
}
void set_overlaps_flag ()
{
if (unlikely (!header.numberOfContours)) return;
unsigned flags_offset = length (instructions_length ());
if (unlikely (flags_offset + 1 > bytes.length)) return;
HBUINT8 &first_flag = (HBUINT8 &) StructAtOffset<HBUINT16> (&bytes, flags_offset);
first_flag = (uint8_t) first_flag | FLAG_OVERLAP_SIMPLE;
}
static bool read_points (const HBUINT8 *&p /* IN/OUT */,
contour_point_vector_t &points_ /* IN/OUT */,
const hb_bytes_t &bytes,
void (* setter) (contour_point_t &_, float v),
const simple_glyph_flag_t short_flag,
const simple_glyph_flag_t same_flag)
{
float v = 0;
for (unsigned i = 0; i < points_.length; i++)
{
uint8_t flag = points_[i].flag;
if (flag & short_flag)
{
if (unlikely (!bytes.check_range (p))) return false;
if (flag & same_flag)
v += *p++;
else
v -= *p++;
}
else
{
if (!(flag & same_flag))
{
if (unlikely (!bytes.check_range ((const HBUINT16 *) p))) return false;
v += *(const HBINT16 *) p;
p += HBINT16::static_size;
}
}
setter (points_[i], v);
}
return true;
}
bool get_contour_points (contour_point_vector_t &points_ /* OUT */,
bool phantom_only = false) const
{
const HBUINT16 *endPtsOfContours = &StructAfter<HBUINT16> (header);
int num_contours = header.numberOfContours;
if (unlikely (!bytes.check_range (&endPtsOfContours[num_contours + 1]))) return false;
unsigned int num_points = endPtsOfContours[num_contours - 1] + 1;
points_.resize (num_points);
for (unsigned int i = 0; i < points_.length; i++) points_[i].init ();
if (phantom_only) return true;
for (int i = 0; i < num_contours; i++)
points_[endPtsOfContours[i]].is_end_point = true;
/* Skip instructions */
const HBUINT8 *p = &StructAtOffset<HBUINT8> (&endPtsOfContours[num_contours + 1],
endPtsOfContours[num_contours]);
/* Read flags */
for (unsigned int i = 0; i < num_points; i++)
{
if (unlikely (!bytes.check_range (p))) return false;
uint8_t flag = *p++;
points_[i].flag = flag;
if (flag & FLAG_REPEAT)
{
if (unlikely (!bytes.check_range (p))) return false;
unsigned int repeat_count = *p++;
while ((repeat_count-- > 0) && (++i < num_points))
points_[i].flag = flag;
}
}
/* Read x & y coordinates */
return read_points (p, points_, bytes, [] (contour_point_t &p, float v) { p.x = v; },
FLAG_X_SHORT, FLAG_X_SAME)
&& read_points (p, points_, bytes, [] (contour_point_t &p, float v) { p.y = v; },
FLAG_Y_SHORT, FLAG_Y_SAME);
}
};
struct CompositeGlyph
{
const GlyphHeader &header;
hb_bytes_t bytes;
CompositeGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
header (header_), bytes (bytes_) {}
composite_iter_t get_iterator () const
{ return composite_iter_t (bytes, &StructAfter<CompositeGlyphChain, GlyphHeader> (header)); }
unsigned int instructions_length (hb_bytes_t bytes) const
{
unsigned int start = bytes.length;
unsigned int end = bytes.length;
const CompositeGlyphChain *last = nullptr;
for (auto &item : get_iterator ())
last = &item;
if (unlikely (!last)) return 0;
if (last->has_instructions ())
start = (char *) last - &bytes + last->get_size ();
if (unlikely (start > end)) return 0;
return end - start;
}
/* Trimming for composites not implemented.
* If removing hints it falls out of that. */
const Glyph trim_padding () const { return Glyph (bytes); }
void drop_hints ()
{
for (const auto &_ : get_iterator ())
const_cast<CompositeGlyphChain &> (_).drop_instructions_flag ();
}
/* Chop instructions off the end */
void drop_hints_bytes (hb_bytes_t &dest_start) const
{ dest_start = bytes.sub_array (0, bytes.length - instructions_length (bytes)); }
void set_overlaps_flag ()
{
CompositeGlyphChain& glyph_chain = const_cast<CompositeGlyphChain &> (
StructAfter<CompositeGlyphChain, GlyphHeader> (header));
if (!bytes.check_range(&glyph_chain, CompositeGlyphChain::min_size))
return;
glyph_chain.set_overlaps_flag ();
}
};
enum glyph_type_t { EMPTY, SIMPLE, COMPOSITE };
public:
composite_iter_t get_composite_iterator () const
{
if (type != COMPOSITE) return composite_iter_t ();
return CompositeGlyph (*header, bytes).get_iterator ();
}
const Glyph trim_padding () const
{
switch (type) {
case COMPOSITE: return CompositeGlyph (*header, bytes).trim_padding ();
case SIMPLE: return SimpleGlyph (*header, bytes).trim_padding ();
default: return bytes;
}
}
void drop_hints ()
{
switch (type) {
case COMPOSITE: CompositeGlyph (*header, bytes).drop_hints (); return;
case SIMPLE: SimpleGlyph (*header, bytes).drop_hints (); return;
default: return;
}
}
void set_overlaps_flag ()
{
switch (type) {
case COMPOSITE: CompositeGlyph (*header, bytes).set_overlaps_flag (); return;
case SIMPLE: SimpleGlyph (*header, bytes).set_overlaps_flag (); return;
default: return;
}
}
void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const
{
switch (type) {
case COMPOSITE: CompositeGlyph (*header, bytes).drop_hints_bytes (dest_start); return;
case SIMPLE: SimpleGlyph (*header, bytes).drop_hints_bytes (dest_start, dest_end); return;
default: return;
}
}
/* Note: Recursively calls itself.
* all_points includes phantom points
*/
template <typename accelerator_t>
bool get_points (hb_font_t *font, const accelerator_t &glyf_accelerator,
contour_point_vector_t &all_points /* OUT */,
bool phantom_only = false,
unsigned int depth = 0) const
{
if (unlikely (depth > HB_MAX_NESTING_LEVEL)) return false;
contour_point_vector_t points;
switch (type) {
case COMPOSITE:
{
/* pseudo component points for each component in composite glyph */
unsigned num_points = hb_len (CompositeGlyph (*header, bytes).get_iterator ());
if (unlikely (!points.resize (num_points))) return false;
for (unsigned i = 0; i < points.length; i++)
points[i].init ();
break;
}
case SIMPLE:
if (unlikely (!SimpleGlyph (*header, bytes).get_contour_points (points, phantom_only)))
return false;
break;
}
/* Init phantom points */
if (unlikely (!points.resize (points.length + PHANTOM_COUNT))) return false;
hb_array_t<contour_point_t> phantoms = points.sub_array (points.length - PHANTOM_COUNT, PHANTOM_COUNT);
{
for (unsigned i = 0; i < PHANTOM_COUNT; ++i) phantoms[i].init ();
int h_delta = (int) header->xMin -
glyf_accelerator.hmtx->get_side_bearing (gid);
int v_orig = (int) header->yMax +
#ifndef HB_NO_VERTICAL
glyf_accelerator.vmtx->get_side_bearing (gid)
#else
0
#endif
;
unsigned h_adv = glyf_accelerator.hmtx->get_advance (gid);
unsigned v_adv =
#ifndef HB_NO_VERTICAL
glyf_accelerator.vmtx->get_advance (gid)
#else
- font->face->get_upem ()
#endif
;
phantoms[PHANTOM_LEFT].x = h_delta;
phantoms[PHANTOM_RIGHT].x = h_adv + h_delta;
phantoms[PHANTOM_TOP].y = v_orig;
phantoms[PHANTOM_BOTTOM].y = v_orig - (int) v_adv;
}
#ifndef HB_NO_VAR
glyf_accelerator.gvar->apply_deltas_to_points (gid, font, points.as_array ());
#endif
switch (type) {
case SIMPLE:
all_points.extend (points.as_array ());
break;
case COMPOSITE:
{
unsigned int comp_index = 0;
for (auto &item : get_composite_iterator ())
{
contour_point_vector_t comp_points;
if (unlikely (!glyf_accelerator.glyph_for_gid (item.get_glyph_index ())
.get_points (font, glyf_accelerator, comp_points,
phantom_only, depth + 1)
|| comp_points.length < PHANTOM_COUNT))
return false;
/* Copy phantom points from component if USE_MY_METRICS flag set */
if (item.is_use_my_metrics ())
for (unsigned int i = 0; i < PHANTOM_COUNT; i++)
phantoms[i] = comp_points[comp_points.length - PHANTOM_COUNT + i];
/* Apply component transformation & translation */
item.transform_points (comp_points);
/* Apply translation from gvar */
comp_points.translate (points[comp_index]);
if (item.is_anchored ())
{
unsigned int p1, p2;
item.get_anchor_points (p1, p2);
if (likely (p1 < all_points.length && p2 < comp_points.length))
{
contour_point_t delta;
delta.init (all_points[p1].x - comp_points[p2].x,
all_points[p1].y - comp_points[p2].y);
comp_points.translate (delta);
}
}
all_points.extend (comp_points.sub_array (0, comp_points.length - PHANTOM_COUNT));
comp_index++;
}
all_points.extend (phantoms);
} break;
default:
all_points.extend (phantoms);
}
if (depth == 0) /* Apply at top level */
{
/* Undocumented rasterizer behavior:
* Shift points horizontally by the updated left side bearing
*/
contour_point_t delta;
delta.init (-phantoms[PHANTOM_LEFT].x, 0.f);
if (delta.x) all_points.translate (delta);
}
return true;
}
bool get_extents (hb_font_t *font, const glyf_accelerator_t &glyf_accelerator,
hb_glyph_extents_t *extents) const
{
if (type == EMPTY) return true; /* Empty glyph; zero extents. */
return header->get_extents (font, glyf_accelerator, gid, extents);
}
hb_bytes_t get_bytes () const { return bytes; }
Glyph (hb_bytes_t bytes_ = hb_bytes_t (),
hb_codepoint_t gid_ = (hb_codepoint_t) -1) : bytes (bytes_), gid (gid_),
header (bytes.as<GlyphHeader> ())
{
int num_contours = header->numberOfContours;
if (unlikely (num_contours == 0)) type = EMPTY;
else if (num_contours > 0) type = SIMPLE;
else type = COMPOSITE; /* negative numbers */
}
protected:
hb_bytes_t bytes;
hb_codepoint_t gid;
const GlyphHeader *header;
unsigned type;
};
} /* namespace OT */
#endif /* OT_GLYF_GLYPH_HH */

1486
src/OT/glyf/glyf.hh
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File diff suppressed because it is too large Load Diff

1
src/OT/glyf/loca.hh
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@ -17,6 +17,7 @@ namespace OT {
struct loca
{
friend struct glyf;
friend struct glyf_accelerator_t;
static constexpr hb_tag_t tableTag = HB_OT_TAG_loca;

1
src/meson.build
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@ -94,6 +94,7 @@ hb_base_sources = files(
'hb-ot-layout-gsub-table.hh',
'OT/glyf/glyf.hh',
'OT/glyf/loca.hh',
'OT/glyf/Glyph.hh',
'OT/Layout/GSUB/Common.hh',
'OT/Layout/GSUB/Sequence.hh',
'OT/Layout/GSUB/SingleSubstFormat1.hh',