JDK14/Java14源码在线阅读
/*
* Copyright 漏 2018 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Garret Rieger, Roderick Sheeter
*/
#include "hb-open-type.hh"
#include "hb-ot-glyf-table.hh"
#include "hb-set.h"
#include "hb-subset-glyf.hh"
static bool
_calculate_glyf_and_loca_prime_size (const OT::glyf::accelerator_t &glyf,
hb_vector_t<hb_codepoint_t> &glyph_ids,
hb_bool_t drop_hints,
bool *use_short_loca /* OUT */,
unsigned int *glyf_size /* OUT */,
unsigned int *loca_size /* OUT */,
hb_vector_t<unsigned int> *instruction_ranges /* OUT */)
{
unsigned int total = 0;
for (unsigned int i = 0; i < glyph_ids.length; i++)
{
hb_codepoint_t next_glyph = glyph_ids[i];
if (!instruction_ranges->resize (instruction_ranges->length + 2))
{
DEBUG_MSG(SUBSET, nullptr, "Failed to resize instruction_ranges.");
return false;
}
unsigned int *instruction_start = &(*instruction_ranges)[instruction_ranges->length - 2];
*instruction_start = 0;
unsigned int *instruction_end = &(*instruction_ranges)[instruction_ranges->length - 1];
*instruction_end = 0;
unsigned int start_offset, end_offset;
if (unlikely (!(glyf.get_offsets (next_glyph, &start_offset, &end_offset) &&
glyf.remove_padding (start_offset, &end_offset))))
{
DEBUG_MSG(SUBSET, nullptr, "Invalid gid %d", next_glyph);
continue;
}
if (end_offset - start_offset < OT::glyf::GlyphHeader::static_size)
continue; /* 0-length glyph */
if (drop_hints)
{
if (unlikely (!glyf.get_instruction_offsets (start_offset, end_offset,
instruction_start, instruction_end)))
{
DEBUG_MSG(SUBSET, nullptr, "Unable to get instruction offsets for %d", next_glyph);
return false;
}
}
total += end_offset - start_offset - (*instruction_end - *instruction_start);
/* round2 so short loca will work */
total += total % 2;
}
*glyf_size = total;
*use_short_loca = (total <= 131070);
*loca_size = (glyph_ids.length + 1)
* (*use_short_loca ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32));
DEBUG_MSG(SUBSET, nullptr, "preparing to subset glyf: final size %d, loca size %d, using %s loca",
total,
*loca_size,
*use_short_loca ? "short" : "long");
return true;
}
static bool
_write_loca_entry (unsigned int id,
unsigned int offset,
bool is_short,
void *loca_prime,
unsigned int loca_size)
{
unsigned int entry_size = is_short ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32);
if ((id + 1) * entry_size <= loca_size)
{
if (is_short) {
((OT::HBUINT16*) loca_prime) [id].set (offset / 2);
} else {
((OT::HBUINT32*) loca_prime) [id].set (offset);
}
return true;
}
// Offset was not written because the write is out of bounds.
DEBUG_MSG(SUBSET,
nullptr,
"WARNING: Attempted to write an out of bounds loca entry at index %d. Loca size is %d.",
id,
loca_size);
return false;
}
static void
_update_components (hb_subset_plan_t * plan,
char * glyph_start,
unsigned int length)
{
OT::glyf::CompositeGlyphHeader::Iterator iterator;
if (OT::glyf::CompositeGlyphHeader::get_iterator (glyph_start,
length,
&iterator))
{
do
{
hb_codepoint_t new_gid;
if (!plan->new_gid_for_old_gid (iterator.current->glyphIndex,
&new_gid))
continue;
((OT::glyf::CompositeGlyphHeader *) iterator.current)->glyphIndex.set (new_gid);
} while (iterator.move_to_next ());
}
}
static bool _remove_composite_instruction_flag (char *glyf_prime, unsigned int length)
{
/* remove WE_HAVE_INSTRUCTIONS from flags in dest */
OT::glyf::CompositeGlyphHeader::Iterator composite_it;
if (unlikely (!OT::glyf::CompositeGlyphHeader::get_iterator (glyf_prime, length, &composite_it))) return false;
const OT::glyf::CompositeGlyphHeader *glyph;
do {
glyph = composite_it.current;
OT::HBUINT16 *flags = const_cast<OT::HBUINT16 *> (&glyph->flags);
flags->set ( (uint16_t) *flags & ~OT::glyf::CompositeGlyphHeader::WE_HAVE_INSTRUCTIONS);
} while (composite_it.move_to_next ());
return true;
}
static bool
_write_glyf_and_loca_prime (hb_subset_plan_t *plan,
const OT::glyf::accelerator_t &glyf,
const char *glyf_data,
bool use_short_loca,
hb_vector_t<unsigned int> &instruction_ranges,
unsigned int glyf_prime_size,
char *glyf_prime_data /* OUT */,
unsigned int loca_prime_size,
char *loca_prime_data /* OUT */)
{
hb_vector_t<hb_codepoint_t> &glyph_ids = plan->glyphs;
char *glyf_prime_data_next = glyf_prime_data;
bool success = true;
for (unsigned int i = 0; i < glyph_ids.length; i++)
{
unsigned int start_offset, end_offset;
if (unlikely (!(glyf.get_offsets (glyph_ids[i], &start_offset, &end_offset) &&
glyf.remove_padding (start_offset, &end_offset))))
end_offset = start_offset = 0;
unsigned int instruction_start = instruction_ranges[i * 2];
unsigned int instruction_end = instruction_ranges[i * 2 + 1];
int length = end_offset - start_offset - (instruction_end - instruction_start);
if (glyf_prime_data_next + length > glyf_prime_data + glyf_prime_size)
{
DEBUG_MSG(SUBSET,
nullptr,
"WARNING: Attempted to write an out of bounds glyph entry for gid %d (length %d)",
i, length);
return false;
}
if (instruction_start == instruction_end)
memcpy (glyf_prime_data_next, glyf_data + start_offset, length);
else
{
memcpy (glyf_prime_data_next, glyf_data + start_offset, instruction_start - start_offset);
memcpy (glyf_prime_data_next + instruction_start - start_offset, glyf_data + instruction_end, end_offset - instruction_end);
/* if the instructions end at the end this was a composite glyph, else simple */
if (instruction_end == end_offset)
{
if (unlikely (!_remove_composite_instruction_flag (glyf_prime_data_next, length))) return false;
}
else
/* zero instruction length, which is just before instruction_start */
memset (glyf_prime_data_next + instruction_start - start_offset - 2, 0, 2);
}
success = success && _write_loca_entry (i,
glyf_prime_data_next - glyf_prime_data,
use_short_loca,
loca_prime_data,
loca_prime_size);
_update_components (plan, glyf_prime_data_next, length);
// TODO: don't align to two bytes if using long loca.
glyf_prime_data_next += length + (length % 2); // Align to 2 bytes for short loca.
}
success = success && _write_loca_entry (glyph_ids.length,
glyf_prime_data_next - glyf_prime_data,
use_short_loca,
loca_prime_data,
loca_prime_size);
return success;
}
static bool
_hb_subset_glyf_and_loca (const OT::glyf::accelerator_t &glyf,
const char *glyf_data,
hb_subset_plan_t *plan,
bool *use_short_loca,
hb_blob_t **glyf_prime /* OUT */,
hb_blob_t **loca_prime /* OUT */)
{
// TODO(grieger): Sanity check allocation size for the new table.
hb_vector_t<hb_codepoint_t> &glyphs_to_retain = plan->glyphs;
unsigned int glyf_prime_size;
unsigned int loca_prime_size;
hb_vector_t<unsigned int> instruction_ranges;
instruction_ranges.init ();
if (unlikely (!_calculate_glyf_and_loca_prime_size (glyf,
glyphs_to_retain,
plan->drop_hints,
use_short_loca,
&glyf_prime_size,
&loca_prime_size,
&instruction_ranges))) {
instruction_ranges.fini ();
return false;
}
char *glyf_prime_data = (char *) calloc (1, glyf_prime_size);
char *loca_prime_data = (char *) calloc (1, loca_prime_size);
if (unlikely (!_write_glyf_and_loca_prime (plan, glyf, glyf_data,
*use_short_loca,
instruction_ranges,
glyf_prime_size, glyf_prime_data,
loca_prime_size, loca_prime_data))) {
free (glyf_prime_data);
free (loca_prime_data);
instruction_ranges.fini ();
return false;
}
instruction_ranges.fini ();
*glyf_prime = hb_blob_create (glyf_prime_data,
glyf_prime_size,
HB_MEMORY_MODE_READONLY,
glyf_prime_data,
free);
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