walkero
/
harfbuzz
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
harfbuzz/src/hb-ot-glyf-table.hh

1364 lines
40 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* 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, bool use_short_loca)
{
unsigned num_offsets = padded_offsets.len () + 1;
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 size %d",
entry_size, num_offsets, 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,
bool use_short_loca,
const hb_subset_plan_t *plan)
{
TRACE_SERIALIZE (this);
unsigned init_len = c->length ();
for (const auto &_ : it) _.serialize (c, use_short_loca, 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);
auto padded_offsets =
+ hb_iter (glyphs)
| hb_map (&SubsetGlyph::padded_size)
;
unsigned max_offset = + padded_offsets | hb_reduce (hb_add, 0);
bool use_short_loca = max_offset < 0x1FFFF;
glyf_prime->serialize (c->serializer, hb_iter (glyphs), use_short_loca, c->plan);
if (!use_short_loca) {
padded_offsets =
+ hb_iter (glyphs)
| hb_map (&SubsetGlyph::length)
;
}
if (unlikely (c->serializer->in_error ())) return_trace (false);
return_trace (c->serializer->check_success (_add_loca_and_head (c->plan,
padded_offsets,
use_short_loca)));
}
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 (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)
;
}
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 (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 +
#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 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
{
accelerator_t (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;
#ifndef HB_NO_VERTICAL
vmtx = nullptr;
#endif
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 = face->table.loca.get_blob (); // Needs no destruct!
glyf_table = hb_sanitize_context_t ().reference_table<glyf> (face);
#ifndef HB_NO_VAR
gvar = face->table.gvar;
#endif
hmtx = face->table.hmtx;
#ifndef HB_NO_VERTICAL
vmtx = face->table.vmtx;
#endif
num_glyphs = hb_max (1u, loca_table.get_length () / (short_offset ? 2 : 4)) - 1;
num_glyphs = hb_min (num_glyphs, face->get_num_glyphs ());
}
~accelerator_t ()
{
glyf_table.destroy ();
}
bool has_data () const { return num_glyphs; }
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
#ifndef HB_NO_VERTICAL
is_vertical ? vmtx->get_advance (gid) :
#endif
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
#ifndef HB_NO_VERTICAL
is_vertical ? vmtx->get_side_bearing (gid) :
#endif
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;
}
struct path_builder_t
{
hb_font_t *font;
hb_draw_session_t *draw_session;
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_, hb_draw_session_t &draw_session_)
{
font = font_;
draw_session = &draw_session_;
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)
{
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_session->move_to (font->em_fscalef_x (p.x), font->em_fscalef_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_session->move_to (font->em_fscalef_x (mid.x), font->em_fscalef_y (mid.y));
}
else
first_offcurve = p;
}
}
else
{
if (last_offcurve.has_data)
{
if (is_on_curve)
{
draw_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
font->em_fscalef_x (p.x), font->em_fscalef_y (p.y));
last_offcurve = optional_point_t ();
}
else
{
optional_point_t mid = last_offcurve.lerp (p, .5f);
draw_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
font->em_fscalef_x (mid.x), font->em_fscalef_y (mid.y));
last_offcurve = p;
}
}
else
{
if (is_on_curve)
draw_session->line_to (font->em_fscalef_x (p.x), font->em_fscalef_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_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
font->em_fscalef_x (mid.x), font->em_fscalef_y (mid.y));
last_offcurve = optional_point_t ();
/* now check the rest */
}
if (first_offcurve.has_data && first_oncurve.has_data)
draw_session->quadratic_to (font->em_fscalef_x (first_offcurve.x), font->em_fscalef_y (first_offcurve.y),
font->em_fscalef_x (first_oncurve.x), font->em_fscalef_y (first_oncurve.y));
else if (last_offcurve.has_data && first_oncurve.has_data)
draw_session->quadratic_to (font->em_fscalef_x (last_offcurve.x), font->em_fscalef_y (last_offcurve.y),
font->em_fscalef_x (first_oncurve.x), font->em_fscalef_y (first_oncurve.y));
else if (first_oncurve.has_data)
draw_session->line_to (font->em_fscalef_x (first_oncurve.x), font->em_fscalef_y (first_oncurve.y));
else if (first_offcurve.has_data)
{
float x = font->em_fscalef_x (first_offcurve.x), y = font->em_fscalef_x (first_offcurve.y);
draw_session->move_to (x, y);
draw_session->quadratic_to (x, y, x, y);
}
/* Getting ready for the next contour */
first_oncurve = first_offcurve = last_offcurve = optional_point_t ();
draw_session->close_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, hb_draw_session_t &draw_session) const
{ return get_points (font, gid, path_builder_t (font, draw_session)); }
#ifndef HB_NO_VAR
const gvar_accelerator_t *gvar;
#endif
const hmtx_accelerator_t *hmtx;
#ifndef HB_NO_VERTICAL
const vmtx_accelerator_t *vmtx;
#endif
private:
bool short_offset;
unsigned int num_glyphs;
hb_blob_ptr_t<loca> loca_table;
hb_blob_ptr_t<glyf> glyf_table;
};
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,
bool use_short_loca,
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 = use_short_loca ? padding () : 0;
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 {
glyf_accelerator_t (hb_face_t *face) : glyf::accelerator_t (face) {}
};
} /* namespace OT */
#endif /* HB_OT_GLYF_TABLE_HH */
Reference in New Issue View Git Blame Copy Permalink