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flutter / third_party / harfbuzz / 59d8f6c8173a9054b2594f38c06d9aa635da04c9 / . / src / hb-ot-glyf-table.hh
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/*
* Copyright © 2015 Google, Inc.
* Copyright © 2019 Adobe Inc.
* Copyright © 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, Garret Rieger, Roderick Sheeter
* Adobe Author(s): Michiharu Ariza
*/
#ifndef HB_OT_GLYF_TABLE_HH
#define HB_OT_GLYF_TABLE_HH
#include "hb-open-type.hh"
#include "hb-ot-head-table.hh"
#include "hb-ot-hmtx-table.hh"
#include "hb-ot-var-gvar-table.hh"
#include "hb-draw.hh"
namespace OT {
/*
* loca -- Index to Location
* https://docs.microsoft.com/en-us/typography/opentype/spec/loca
*/
#define HB_OT_TAG_loca HB_TAG('l','o','c','a')
#ifndef HB_MAX_COMPOSITE_OPERATIONS
#define HB_MAX_COMPOSITE_OPERATIONS 100000
#endif
struct loca
{
friend struct glyf;
static constexpr hb_tag_t tableTag = HB_OT_TAG_loca;
bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const
{
TRACE_SANITIZE (this);
return_trace (true);
}
protected:
UnsizedArrayOf<HBUINT8>
dataZ; /* Location data. */
public:
DEFINE_SIZE_MIN (0); /* In reality, this is UNBOUNDED() type; but since we always
* check the size externally, allow Null() object of it by
* defining it _MIN instead. */
};
/*
* glyf -- TrueType Glyph Data
* https://docs.microsoft.com/en-us/typography/opentype/spec/glyf
*/
#define HB_OT_TAG_glyf HB_TAG('g','l','y','f')
struct glyf
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_glyf;
bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const
{
TRACE_SANITIZE (this);
/* Runtime checks as eager sanitizing each glyph is costy */
return_trace (true);
}
template<typename Iterator,
hb_requires (hb_is_source_of (Iterator, unsigned int))>
static bool
_add_loca_and_head (hb_subset_plan_t * plan, Iterator padded_offsets)
{
unsigned max_offset =
+ padded_offsets
| hb_reduce (hb_add, 0)
;
unsigned num_offsets = padded_offsets.len () + 1;
bool use_short_loca = max_offset < 0x1FFFF;
unsigned entry_size = use_short_loca ? 2 : 4;
char *loca_prime_data = (char *) hb_calloc (entry_size, num_offsets);
if (unlikely (!loca_prime_data)) return false;
DEBUG_MSG (SUBSET, nullptr, "loca entry_size %d num_offsets %d "
"max_offset %d size %d",
entry_size, num_offsets, max_offset, entry_size * num_offsets);
if (use_short_loca)
_write_loca (padded_offsets, 1, hb_array ((HBUINT16 *) loca_prime_data, num_offsets));
else
_write_loca (padded_offsets, 0, hb_array ((HBUINT32 *) loca_prime_data, num_offsets));
hb_blob_t *loca_blob = hb_blob_create (loca_prime_data,
entry_size * num_offsets,
HB_MEMORY_MODE_WRITABLE,
loca_prime_data,
hb_free);
bool result = plan->add_table (HB_OT_TAG_loca, loca_blob)
&& _add_head_and_set_loca_version (plan, use_short_loca);
hb_blob_destroy (loca_blob);
return result;
}
template<typename IteratorIn, typename IteratorOut,
hb_requires (hb_is_source_of (IteratorIn, unsigned int)),
hb_requires (hb_is_sink_of (IteratorOut, unsigned))>
static void
_write_loca (IteratorIn it, unsigned right_shift, IteratorOut dest)
{
unsigned int offset = 0;
dest << 0;
+ it
| hb_map ([=, &offset] (unsigned int padded_size)
{
offset += padded_size;
DEBUG_MSG (SUBSET, nullptr, "loca entry offset %d", offset);
return offset >> right_shift;
})
| hb_sink (dest)
;
}
/* requires source of SubsetGlyph complains the identifier isn't declared */
template <typename Iterator>
bool serialize (hb_serialize_context_t *c,
Iterator it,
const hb_subset_plan_t *plan)
{
TRACE_SERIALIZE (this);
unsigned init_len = c->length ();
for (const auto &_ : it) _.serialize (c, plan);
/* As a special case when all glyph in the font are empty, add a zero byte
* to the table, so that OTS doesn’t reject it, and to make the table work
* on Windows as well.
* See https://github.com/khaledhosny/ots/issues/52 */
if (init_len == c->length ())
{
HBUINT8 empty_byte;
empty_byte = 0;
c->copy (empty_byte);
}
return_trace (true);
}
/* Byte region(s) per glyph to output
unpadded, hints removed if so requested
If we fail to process a glyph we produce an empty (0-length) glyph */
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
glyf *glyf_prime = c->serializer->start_embed <glyf> ();
if (unlikely (!c->serializer->check_success (glyf_prime))) return_trace (false);
hb_vector_t<SubsetGlyph> glyphs;
_populate_subset_glyphs (c->plan, &glyphs);
glyf_prime->serialize (c->serializer, hb_iter (glyphs), c->plan);
auto padded_offsets =
+ hb_iter (glyphs)
| hb_map (&SubsetGlyph::padded_size)
;
if (unlikely (c->serializer->in_error ())) return_trace (false);
return_trace (c->serializer->check_success (_add_loca_and_head (c->plan,
padded_offsets)));
}
template <typename SubsetGlyph>
void
_populate_subset_glyphs (const hb_subset_plan_t *plan,
hb_vector_t<SubsetGlyph> *glyphs /* OUT */) const
{
OT::glyf::accelerator_t glyf;
glyf.init (plan->source);
+ hb_range (plan->num_output_glyphs ())
| hb_map ([&] (hb_codepoint_t new_gid)
{
SubsetGlyph subset_glyph = {0};
subset_glyph.new_gid = new_gid;
/* should never fail: all old gids should be mapped */
if (!plan->old_gid_for_new_gid (new_gid, &subset_glyph.old_gid))
return subset_glyph;
if (new_gid == 0 &&
!(plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE))
subset_glyph.source_glyph = Glyph ();
else
subset_glyph.source_glyph = glyf.glyph_for_gid (subset_glyph.old_gid, true);
if (plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
subset_glyph.drop_hints_bytes ();
else
subset_glyph.dest_start = subset_glyph.source_glyph.get_bytes ();
return subset_glyph;
})
| hb_sink (glyphs)
;
glyf.fini ();
}
static bool
_add_head_and_set_loca_version (hb_subset_plan_t *plan, bool use_short_loca)
{
hb_blob_t *head_blob = hb_sanitize_context_t ().reference_table<head> (plan->source);
hb_blob_t *head_prime_blob = hb_blob_copy_writable_or_fail (head_blob);
hb_blob_destroy (head_blob);
if (unlikely (!head_prime_blob))
return false;
head *head_prime = (head *) hb_blob_get_data_writable (head_prime_blob, nullptr);
head_prime->indexToLocFormat = use_short_loca ? 0 : 1;
bool success = plan->add_table (HB_OT_TAG_head, head_prime_blob);
hb_blob_destroy (head_prime_blob);
return success;
}
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 accelerator_t;
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
};
private:
struct GlyphHeader
{
bool has_data () const { return numberOfContours; }
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 (length (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 ()
{
const_cast<CompositeGlyphChain &> (StructAfter<CompositeGlyphChain, GlyphHeader> (header))
.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
*/
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 + glyf_accelerator.vmtx->get_side_bearing (gid);
unsigned h_adv = glyf_accelerator.hmtx->get_advance (gid);
unsigned v_adv = glyf_accelerator.vmtx->get_advance (gid);
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
if (unlikely (!glyf_accelerator.gvar->apply_deltas_to_points (gid, font, points.as_array ())))
return false;
#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 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;
};
struct accelerator_t
{
void init (hb_face_t *face_)
{
short_offset = false;
num_glyphs = 0;
loca_table = nullptr;
glyf_table = nullptr;
#ifndef HB_NO_VAR
gvar = nullptr;
#endif
hmtx = nullptr;
vmtx = nullptr;
face = face_;
const OT::head &head = *face->table.head;
if (head.indexToLocFormat > 1 || head.glyphDataFormat > 0)
/* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */
return;
short_offset = 0 == head.indexToLocFormat;
loca_table = hb_sanitize_context_t ().reference_table<loca> (face);
glyf_table = hb_sanitize_context_t ().reference_table<glyf> (face);
#ifndef HB_NO_VAR
gvar = face->table.gvar;
#endif
hmtx = face->table.hmtx;
vmtx = face->table.vmtx;
num_glyphs = hb_max (1u, loca_table.get_length () / (short_offset ? 2 : 4)) - 1;
num_glyphs = hb_min (num_glyphs, face->get_num_glyphs ());
}
void fini ()
{
loca_table.destroy ();
glyf_table.destroy ();
}
protected:
template<typename T>
bool get_points (hb_font_t *font, hb_codepoint_t gid, T consumer) const
{
if (gid >= num_glyphs) return false;
/* Making this allocfree is not that easy
https://github.com/harfbuzz/harfbuzz/issues/2095
mostly because of gvar handling in VF fonts,
perhaps a separate path for non-VF fonts can be considered */
contour_point_vector_t all_points;
bool phantom_only = !consumer.is_consuming_contour_points ();
if (unlikely (!glyph_for_gid (gid).get_points (font, *this, all_points, phantom_only)))
return false;
if (consumer.is_consuming_contour_points ())
{
for (unsigned point_index = 0; point_index + 4 < all_points.length; ++point_index)
consumer.consume_point (all_points[point_index]);
consumer.points_end ();
}
/* Where to write phantoms, nullptr if not requested */
contour_point_t *phantoms = consumer.get_phantoms_sink ();
if (phantoms)
for (unsigned i = 0; i < PHANTOM_COUNT; ++i)
phantoms[i] = all_points[all_points.length - PHANTOM_COUNT + i];
return true;
}
#ifndef HB_NO_VAR
struct points_aggregator_t
{
hb_font_t *font;
hb_glyph_extents_t *extents;
contour_point_t *phantoms;
struct contour_bounds_t
{
contour_bounds_t () { min_x = min_y = FLT_MAX; max_x = max_y = -FLT_MAX; }
void add (const contour_point_t &p)
{
min_x = hb_min (min_x, p.x);
min_y = hb_min (min_y, p.y);
max_x = hb_max (max_x, p.x);
max_y = hb_max (max_y, p.y);
}
bool empty () const { return (min_x >= max_x) || (min_y >= max_y); }
void get_extents (hb_font_t *font, hb_glyph_extents_t *extents)
{
if (unlikely (empty ()))
{
extents->width = 0;
extents->x_bearing = 0;
extents->height = 0;
extents->y_bearing = 0;
return;
}
extents->x_bearing = font->em_scalef_x (min_x);
extents->width = font->em_scalef_x (max_x) - extents->x_bearing;
extents->y_bearing = font->em_scalef_y (max_y);
extents->height = font->em_scalef_y (min_y) - extents->y_bearing;
}
protected:
float min_x, min_y, max_x, max_y;
} bounds;
points_aggregator_t (hb_font_t *font_, hb_glyph_extents_t *extents_, contour_point_t *phantoms_)
{
font = font_;
extents = extents_;
phantoms = phantoms_;
if (extents) bounds = contour_bounds_t ();
}
void consume_point (const contour_point_t &point) { bounds.add (point); }
void points_end () { bounds.get_extents (font, extents); }
bool is_consuming_contour_points () { return extents; }
contour_point_t *get_phantoms_sink () { return phantoms; }
};
public:
unsigned
get_advance_var (hb_font_t *font, hb_codepoint_t gid, bool is_vertical) const
{
if (unlikely (gid >= num_glyphs)) return 0;
bool success = false;
contour_point_t phantoms[PHANTOM_COUNT];
if (likely (font->num_coords == gvar->get_axis_count ()))
success = get_points (font, gid, points_aggregator_t (font, nullptr, phantoms));
if (unlikely (!success))
return is_vertical ? vmtx->get_advance (gid) : hmtx->get_advance (gid);
float result = is_vertical
? phantoms[PHANTOM_TOP].y - phantoms[PHANTOM_BOTTOM].y
: phantoms[PHANTOM_RIGHT].x - phantoms[PHANTOM_LEFT].x;
return hb_clamp (roundf (result), 0.f, (float) UINT_MAX / 2);
}
int get_side_bearing_var (hb_font_t *font, hb_codepoint_t gid, bool is_vertical) const
{
if (unlikely (gid >= num_glyphs)) return 0;
hb_glyph_extents_t extents;
contour_point_t phantoms[PHANTOM_COUNT];
if (unlikely (!get_points (font, gid, points_aggregator_t (font, &extents, phantoms))))
return is_vertical ? vmtx->get_side_bearing (gid) : hmtx->get_side_bearing (gid);
return is_vertical
? ceilf (phantoms[PHANTOM_TOP].y) - extents.y_bearing
: floorf (phantoms[PHANTOM_LEFT].x);
}
#endif
public:
bool get_extents (hb_font_t *font, hb_codepoint_t gid, hb_glyph_extents_t *extents) const
{
if (unlikely (gid >= num_glyphs)) return false;
#ifndef HB_NO_VAR
if (font->num_coords && font->num_coords == gvar->get_axis_count ())
return get_points (font, gid, points_aggregator_t (font, extents, nullptr));
#endif
return glyph_for_gid (gid).get_extents (font, *this, extents);
}
const Glyph
glyph_for_gid (hb_codepoint_t gid, bool needs_padding_removal = false) const
{
if (unlikely (gid >= num_glyphs)) return Glyph ();
unsigned int start_offset, end_offset;
if (short_offset)
{
const HBUINT16 *offsets = (const HBUINT16 *) loca_table->dataZ.arrayZ;
start_offset = 2 * offsets[gid];
end_offset = 2 * offsets[gid + 1];
}
else
{
const HBUINT32 *offsets = (const HBUINT32 *) loca_table->dataZ.arrayZ;
start_offset = offsets[gid];
end_offset = offsets[gid + 1];
}
if (unlikely (start_offset > end_offset || end_offset > glyf_table.get_length ()))
return Glyph ();
Glyph glyph (hb_bytes_t ((const char *) this->glyf_table + start_offset,
end_offset - start_offset), gid);
return needs_padding_removal ? glyph.trim_padding () : glyph;
}
unsigned
add_gid_and_children (hb_codepoint_t gid,
hb_set_t *gids_to_retain,
unsigned depth = 0,
unsigned operation_count = 0) const
{
if (unlikely (depth++ > HB_MAX_NESTING_LEVEL)) return operation_count;
if (unlikely (operation_count++ > HB_MAX_COMPOSITE_OPERATIONS)) return operation_count;
/* Check if is already visited */
if (gids_to_retain->has (gid)) return operation_count;
gids_to_retain->add (gid);
auto it = glyph_for_gid (gid).get_composite_iterator ();
while (it)
{
auto item = *(it++);
operation_count =
add_gid_and_children (item.get_glyph_index (), gids_to_retain, depth, operation_count);
}
return operation_count;
}
#ifdef HB_EXPERIMENTAL_API
struct path_builder_t
{
hb_font_t *font;
draw_helper_t *draw_helper;
struct optional_point_t
{
optional_point_t () { has_data = false; }
optional_point_t (float x_, float y_) { x = x_; y = y_; has_data = true; }
bool has_data;
float x;
float y;
optional_point_t lerp (optional_point_t p, float t)
{ return optional_point_t (x + t * (p.x - x), y + t * (p.y - y)); }
} first_oncurve, first_offcurve, last_offcurve;
path_builder_t (hb_font_t *font_, draw_helper_t &draw_helper_)
{
font = font_;
draw_helper = &draw_helper_;
first_oncurve = first_offcurve = last_offcurve = optional_point_t ();
}
/* based on https://github.com/RazrFalcon/ttf-parser/blob/4f32821/src/glyf.rs#L287
See also:
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM01/Chap1.html
* https://stackoverflow.com/a/20772557 */
void consume_point (const contour_point_t &point)
{
/* Skip empty contours */
if (unlikely (point.is_end_point && !first_oncurve.has_data && !first_offcurve.has_data))
return;
bool is_on_curve = point.flag & Glyph::FLAG_ON_CURVE;
optional_point_t p (point.x, point.y);
if (!first_oncurve.has_data)
{
if (is_on_curve)
{
first_oncurve = p;
draw_helper->move_to (font->em_scalef_x (p.x), font->em_scalef_y (p.y));
}
else
{
if (first_offcurve.has_data)
{
optional_point_t mid = first_offcurve.lerp (p, .5f);
first_oncurve = mid;
last_offcurve = p;
draw_helper->move_to (font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
}
else
first_offcurve = p;
}
}
else
{
if (last_offcurve.has_data)
{
if (is_on_curve)
{
draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
font->em_scalef_x (p.x), font->em_scalef_y (p.y));
last_offcurve = optional_point_t ();
}
else
{
optional_point_t mid = last_offcurve.lerp (p, .5f);
draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
last_offcurve = p;
}
}
else
{
if (is_on_curve)
draw_helper->line_to (font->em_scalef_x (p.x), font->em_scalef_y (p.y));
else
last_offcurve = p;
}
}
if (point.is_end_point)
{
if (first_offcurve.has_data && last_offcurve.has_data)
{
optional_point_t mid = last_offcurve.lerp (first_offcurve, .5f);
draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
last_offcurve = optional_point_t ();
/* now check the rest */
}
if (first_offcurve.has_data && first_oncurve.has_data)
draw_helper->quadratic_to (font->em_scalef_x (first_offcurve.x), font->em_scalef_y (first_offcurve.y),
font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
else if (last_offcurve.has_data && first_oncurve.has_data)
draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
else if (first_oncurve.has_data)
draw_helper->line_to (font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
/* Getting ready for the next contour */
first_oncurve = first_offcurve = last_offcurve = optional_point_t ();
draw_helper->end_path ();
}
}
void points_end () {}
bool is_consuming_contour_points () { return true; }
contour_point_t *get_phantoms_sink () { return nullptr; }
};
bool
get_path (hb_font_t *font, hb_codepoint_t gid, draw_helper_t &draw_helper) const
{ return get_points (font, gid, path_builder_t (font, draw_helper)); }
#endif
#ifndef HB_NO_VAR
const gvar_accelerator_t *gvar;
#endif
const hmtx_accelerator_t *hmtx;
const vmtx_accelerator_t *vmtx;
private:
bool short_offset;
unsigned int num_glyphs;
hb_blob_ptr_t<loca> loca_table;
hb_blob_ptr_t<glyf> glyf_table;
hb_face_t *face;
};
struct SubsetGlyph
{
hb_codepoint_t new_gid;
hb_codepoint_t old_gid;
Glyph source_glyph;
hb_bytes_t dest_start; /* region of source_glyph to copy first */
hb_bytes_t dest_end; /* region of source_glyph to copy second */
bool serialize (hb_serialize_context_t *c,
const hb_subset_plan_t *plan) const
{
TRACE_SERIALIZE (this);
hb_bytes_t dest_glyph = dest_start.copy (c);
dest_glyph = hb_bytes_t (&dest_glyph, dest_glyph.length + dest_end.copy (c).length);
unsigned int pad_length = padding ();
DEBUG_MSG (SUBSET, nullptr, "serialize %d byte glyph, width %d pad %d", dest_glyph.length, dest_glyph.length + pad_length, pad_length);
HBUINT8 pad;
pad = 0;
while (pad_length > 0)
{
c->embed (pad);
pad_length--;
}
if (unlikely (!dest_glyph.length)) return_trace (true);
/* update components gids */
for (auto &_ : Glyph (dest_glyph).get_composite_iterator ())
{
hb_codepoint_t new_gid;
if (plan->new_gid_for_old_gid (_.get_glyph_index (), &new_gid))
const_cast<CompositeGlyphChain &> (_).set_glyph_index (new_gid);
}
if (plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
Glyph (dest_glyph).drop_hints ();
if (plan->flags & HB_SUBSET_FLAGS_SET_OVERLAPS_FLAG)
Glyph (dest_glyph).set_overlaps_flag ();
return_trace (true);
}
void drop_hints_bytes ()
{ source_glyph.drop_hints_bytes (dest_start, dest_end); }
unsigned int length () const { return dest_start.length + dest_end.length; }
/* pad to 2 to ensure 2-byte loca will be ok */
unsigned int padding () const { return length () % 2; }
unsigned int padded_size () const { return length () + padding (); }
};
protected:
UnsizedArrayOf<HBUINT8>
dataZ; /* Glyphs data. */
public:
DEFINE_SIZE_MIN (0); /* In reality, this is UNBOUNDED() type; but since we always
* check the size externally, allow Null() object of it by
* defining it _MIN instead. */
};
struct glyf_accelerator_t : glyf::accelerator_t {};
} /* namespace OT */
#endif /* HB_OT_GLYF_TABLE_HH */