harfbuzz/src/OT/glyf/glyf.hh

497 lines
14 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.

#ifndef OT_GLYF_GLYF_HH
#define OT_GLYF_GLYF_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"
#include "../../hb-paint.hh"
#include "glyf-helpers.hh"
#include "Glyph.hh"
#include "SubsetGlyph.hh"
#include "loca.hh"
#include "path-builder.hh"
namespace OT {
/*
* 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
{
friend struct glyf_accelerator_t;
static constexpr hb_tag_t tableTag = HB_OT_TAG_glyf;
static bool has_valid_glyf_format(const hb_face_t* face)
{
const OT::head &head = *face->table.head;
return head.indexToLocFormat <= 1 && head.glyphDataFormat <= 1;
}
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);
}
/* 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 (auto &_ : it)
if (unlikely (!_.serialize (c, use_short_loca, plan)))
return false;
/* As a special case when all glyph in the font are empty, add a zero byte
* to the table, so that OTS doesnt 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);
if (!has_valid_glyf_format (c->plan->source)) {
// glyf format is unknown don't attempt to subset it.
DEBUG_MSG (SUBSET, nullptr,
"unkown glyf format, dropping from subset.");
return_trace (false);
}
glyf *glyf_prime = c->serializer->start_embed <glyf> ();
if (unlikely (!c->serializer->check_success (glyf_prime))) return_trace (false);
hb_font_t *font = nullptr;
if (c->plan->normalized_coords)
{
font = _create_font_for_instancing (c->plan);
if (unlikely (!font)) return false;
}
hb_vector_t<unsigned> padded_offsets;
unsigned num_glyphs = c->plan->num_output_glyphs ();
if (unlikely (!padded_offsets.resize (num_glyphs)))
{
hb_font_destroy (font);
return false;
}
hb_vector_t<glyf_impl::SubsetGlyph> glyphs;
if (!_populate_subset_glyphs (c->plan, font, glyphs))
{
hb_font_destroy (font);
return false;
}
if (font)
hb_font_destroy (font);
unsigned max_offset = 0;
for (unsigned i = 0; i < num_glyphs; i++)
{
padded_offsets[i] = glyphs[i].padded_size ();
max_offset += padded_offsets[i];
}
bool use_short_loca = false;
if (likely (!c->plan->force_long_loca))
use_short_loca = max_offset < 0x1FFFF;
if (!use_short_loca) {
for (unsigned i = 0; i < num_glyphs; i++)
padded_offsets[i] = glyphs[i].length ();
}
bool result = glyf_prime->serialize (c->serializer, glyphs.writer (), use_short_loca, c->plan);
if (c->plan->normalized_coords && !c->plan->pinned_at_default)
_free_compiled_subset_glyphs (glyphs, glyphs.length - 1);
if (!result) return false;
if (unlikely (c->serializer->in_error ())) return_trace (false);
return_trace (c->serializer->check_success (glyf_impl::_add_loca_and_head (c->plan,
padded_offsets.iter (),
use_short_loca)));
}
bool
_populate_subset_glyphs (const hb_subset_plan_t *plan,
hb_font_t *font,
hb_vector_t<glyf_impl::SubsetGlyph> &glyphs /* OUT */) const;
hb_font_t *
_create_font_for_instancing (const hb_subset_plan_t *plan) const;
void _free_compiled_subset_glyphs (hb_vector_t<glyf_impl::SubsetGlyph> &glyphs, unsigned index) const
{
for (unsigned i = 0; i <= index && i < glyphs.length; i++)
glyphs[i].free_compiled_bytes ();
}
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 (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 (!glyf::has_valid_glyf_format (face))
/* 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 ());
}
~glyf_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, nullptr, nullptr, nullptr, true, true, phantom_only)))
return false;
if (consumer.is_consuming_contour_points ())
{
unsigned count = all_points.length;
assert (count >= glyf_impl::PHANTOM_COUNT);
count -= glyf_impl::PHANTOM_COUNT;
for (unsigned point_index = 0; point_index < count; 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 < glyf_impl::PHANTOM_COUNT; ++i)
phantoms[i] = all_points[all_points.length - glyf_impl::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;
bool scaled;
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, bool scaled)
{
if (unlikely (empty ()))
{
extents->width = 0;
extents->x_bearing = 0;
extents->height = 0;
extents->y_bearing = 0;
return;
}
{
extents->x_bearing = roundf (min_x);
extents->width = roundf (max_x - extents->x_bearing);
extents->y_bearing = roundf (max_y);
extents->height = roundf (min_y - extents->y_bearing);
if (scaled)
font->scale_glyph_extents (extents);
}
}
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_, bool scaled_)
{
font = font_;
extents = extents_;
phantoms = phantoms_;
scaled = scaled_;
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, scaled); }
bool is_consuming_contour_points () { return extents; }
contour_point_t *get_phantoms_sink () { return phantoms; }
};
public:
unsigned
get_advance_with_var_unscaled (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[glyf_impl::PHANTOM_COUNT];
if (font->num_coords)
success = get_points (font, gid, points_aggregator_t (font, nullptr, phantoms, false));
if (unlikely (!success))
return
#ifndef HB_NO_VERTICAL
is_vertical ? vmtx->get_advance_without_var_unscaled (gid) :
#endif
hmtx->get_advance_without_var_unscaled (gid);
float result = is_vertical
? phantoms[glyf_impl::PHANTOM_TOP].y - phantoms[glyf_impl::PHANTOM_BOTTOM].y
: phantoms[glyf_impl::PHANTOM_RIGHT].x - phantoms[glyf_impl::PHANTOM_LEFT].x;
return hb_clamp (roundf (result), 0.f, (float) UINT_MAX / 2);
}
bool get_leading_bearing_with_var_unscaled (hb_font_t *font, hb_codepoint_t gid, bool is_vertical, int *lsb) const
{
if (unlikely (gid >= num_glyphs)) return false;
hb_glyph_extents_t extents;
contour_point_t phantoms[glyf_impl::PHANTOM_COUNT];
if (unlikely (!get_points (font, gid, points_aggregator_t (font, &extents, phantoms, false))))
return false;
*lsb = is_vertical
? roundf (phantoms[glyf_impl::PHANTOM_TOP].y) - extents.y_bearing
: roundf (phantoms[glyf_impl::PHANTOM_LEFT].x);
return true;
}
#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)
return get_points (font, gid, points_aggregator_t (font, extents, nullptr, true));
#endif
return glyph_for_gid (gid).get_extents_without_var_scaled (font, *this, extents);
}
bool paint_glyph (hb_font_t *font, hb_codepoint_t gid, hb_paint_funcs_t *funcs, void *data, hb_color_t foreground) const
{
funcs->push_clip_glyph (data, gid, font);
funcs->color (data, true, foreground);
funcs->pop_clip (data);
return true;
}
const glyf_impl::Glyph
glyph_for_gid (hb_codepoint_t gid, bool needs_padding_removal = false) const
{
if (unlikely (gid >= num_glyphs)) return glyf_impl::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 glyf_impl::Glyph ();
glyf_impl::Glyph glyph (hb_bytes_t ((const char *) this->glyf_table + start_offset,
end_offset - start_offset), gid);
return needs_padding_removal ? glyf_impl::Glyph (glyph.trim_padding (), gid) : glyph;
}
bool
get_path (hb_font_t *font, hb_codepoint_t gid, hb_draw_session_t &draw_session) const
{ return get_points (font, gid, glyf_impl::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;
};
inline bool
glyf::_populate_subset_glyphs (const hb_subset_plan_t *plan,
hb_font_t *font,
hb_vector_t<glyf_impl::SubsetGlyph>& glyphs /* OUT */) const
{
OT::glyf_accelerator_t glyf (plan->source);
unsigned num_glyphs = plan->num_output_glyphs ();
if (!glyphs.resize (num_glyphs)) return false;
unsigned idx = 0;
for (auto p : plan->glyph_map->iter ())
{
unsigned new_gid = p.second;
glyf_impl::SubsetGlyph& subset_glyph = glyphs.arrayZ[new_gid];
subset_glyph.old_gid = p.first;
if (unlikely (new_gid == 0 &&
!(plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE)) &&
!plan->normalized_coords)
subset_glyph.source_glyph = glyf_impl::Glyph ();
else
{
/* If plan has an accelerator, the preprocessing step already trimmed glyphs.
* Don't trim them again! */
subset_glyph.source_glyph = glyf.glyph_for_gid (subset_glyph.old_gid, !plan->accelerator);
}
if (plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
subset_glyph.drop_hints_bytes ();
else
subset_glyph.dest_start = subset_glyph.source_glyph.get_bytes ();
if (font)
{
if (unlikely (!subset_glyph.compile_bytes_with_deltas (plan, font, glyf)))
{
// when pinned at default, only bounds are updated, thus no need to free
if (!plan->pinned_at_default && idx > 0)
_free_compiled_subset_glyphs (glyphs, idx - 1);
return false;
}
idx++;
}
}
return true;
}
inline hb_font_t *
glyf::_create_font_for_instancing (const hb_subset_plan_t *plan) const
{
hb_font_t *font = hb_font_create (plan->source);
if (unlikely (font == hb_font_get_empty ())) return nullptr;
hb_vector_t<hb_variation_t> vars;
if (unlikely (!vars.alloc (plan->user_axes_location.get_population (), true)))
{
hb_font_destroy (font);
return nullptr;
}
for (auto _ : plan->user_axes_location)
{
hb_variation_t var;
var.tag = _.first;
var.value = _.second;
vars.push (var);
}
#ifndef HB_NO_VAR
hb_font_set_variations (font, vars.arrayZ, plan->user_axes_location.get_population ());
#endif
return font;
}
} /* namespace OT */
#endif /* OT_GLYF_GLYF_HH */