harfbuzz/src/hb-subset.cc

389 lines
11 KiB
C++

/*
* Copyright © 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, Rod Sheeter, Behdad Esfahbod
*/
#include "hb-private.hh"
#include "hb-open-type-private.hh"
#include "hb-subset-glyf.hh"
#include "hb-subset-private.hh"
#include "hb-subset-plan.hh"
#include "hb-open-file-private.hh"
#include "hb-ot-cmap-table.hh"
#include "hb-ot-glyf-table.hh"
#include "hb-ot-hdmx-table.hh"
#include "hb-ot-head-table.hh"
#include "hb-ot-hhea-table.hh"
#include "hb-ot-hmtx-table.hh"
#include "hb-ot-maxp-table.hh"
#include "hb-ot-os2-table.hh"
#include "hb-ot-post-table.hh"
#include "hb-ot-cff-table.hh"
#include "hb-ot-cff2-table.hh"
struct hb_subset_profile_t {
hb_object_header_t header;
ASSERT_POD ();
};
/**
* hb_subset_profile_create:
*
* Return value: New profile with default settings.
*
* Since: 1.8.0
**/
hb_subset_profile_t *
hb_subset_profile_create ()
{
return hb_object_create<hb_subset_profile_t>();
}
/**
* hb_subset_profile_destroy:
*
* Since: 1.8.0
**/
void
hb_subset_profile_destroy (hb_subset_profile_t *profile)
{
if (!hb_object_destroy (profile)) return;
free (profile);
}
template<typename TableType>
static bool
_subset (hb_subset_plan_t *plan)
{
hb_blob_t *source_blob = hb_sanitize_context_t ().reference_table<TableType> (plan->source);
const TableType *table = source_blob->as<TableType> ();
hb_tag_t tag = TableType::tableTag;
hb_bool_t result = false;
if (source_blob->data)
{
result = table->subset(plan);
} else {
DEBUG_MSG(SUBSET, nullptr, "OT::%c%c%c%c::subset sanitize failed on source table.", HB_UNTAG(tag));
}
hb_blob_destroy (source_blob);
DEBUG_MSG(SUBSET, nullptr, "OT::%c%c%c%c::subset %s", HB_UNTAG(tag), result ? "success" : "FAILED!");
return result;
}
/*
* A face that has add_table().
*/
struct hb_subset_face_data_t
{
struct table_entry_t
{
inline int cmp (const hb_tag_t *t) const
{
if (*t < tag) return -1;
if (*t > tag) return -1;
return 0;
}
hb_tag_t tag;
hb_blob_t *blob;
};
hb_vector_t<table_entry_t, 32> tables;
};
static hb_subset_face_data_t *
_hb_subset_face_data_create (void)
{
hb_subset_face_data_t *data = (hb_subset_face_data_t *) calloc (1, sizeof (hb_subset_face_data_t));
if (unlikely (!data))
return nullptr;
data->tables.init ();
return data;
}
static void
_hb_subset_face_data_destroy (void *user_data)
{
hb_subset_face_data_t *data = (hb_subset_face_data_t *) user_data;
for (unsigned int i = 0; i < data->tables.len; i++)
hb_blob_destroy (data->tables[i].blob);
data->tables.fini ();
free (data);
}
static hb_blob_t *
_hb_subset_face_data_reference_blob (hb_subset_face_data_t *data)
{
unsigned int table_count = data->tables.len;
unsigned int face_length = table_count * 16 + 12;
for (unsigned int i = 0; i < table_count; i++)
face_length += hb_ceil_to_4 (hb_blob_get_length (data->tables.arrayZ[i].blob));
char *buf = (char *) malloc (face_length);
if (unlikely (!buf))
return nullptr;
hb_serialize_context_t c (buf, face_length);
OT::OpenTypeFontFile *f = c.start_serialize<OT::OpenTypeFontFile> ();
bool is_cff = data->tables.lsearch (HB_TAG ('C','F','F',' ')) || data->tables.lsearch (HB_TAG ('C','F','F','2'));
hb_tag_t sfnt_tag = is_cff ? OT::OpenTypeFontFile::CFFTag : OT::OpenTypeFontFile::TrueTypeTag;
Supplier<hb_tag_t> tags_supplier (&data->tables[0].tag, table_count, sizeof (data->tables[0]));
Supplier<hb_blob_t *> blobs_supplier (&data->tables[0].blob, table_count, sizeof (data->tables[0]));
bool ret = f->serialize_single (&c,
sfnt_tag,
tags_supplier,
blobs_supplier,
table_count);
c.end_serialize ();
if (unlikely (!ret))
{
free (buf);
return nullptr;
}
return hb_blob_create (buf, face_length, HB_MEMORY_MODE_WRITABLE, buf, free);
}
static hb_blob_t *
_hb_subset_face_reference_table (hb_face_t *face, hb_tag_t tag, void *user_data)
{
hb_subset_face_data_t *data = (hb_subset_face_data_t *) user_data;
if (!tag)
return _hb_subset_face_data_reference_blob (data);
hb_subset_face_data_t::table_entry_t *entry = data->tables.lsearch (tag);
if (entry)
return hb_blob_reference (entry->blob);
return nullptr;
}
/* TODO: Move this to hb-face.h and rename to hb_face_builder_create()
* with hb_face_builder_add_table(). */
hb_face_t *
hb_subset_face_create (void)
{
hb_subset_face_data_t *data = _hb_subset_face_data_create ();
if (unlikely (!data)) return hb_face_get_empty ();
return hb_face_create_for_tables (_hb_subset_face_reference_table,
data,
_hb_subset_face_data_destroy);
}
hb_bool_t
hb_subset_face_add_table (hb_face_t *face, hb_tag_t tag, hb_blob_t *blob)
{
if (unlikely (face->destroy != (hb_destroy_func_t) _hb_subset_face_data_destroy))
return false;
hb_subset_face_data_t *data = (hb_subset_face_data_t *) face->user_data;
hb_subset_face_data_t::table_entry_t *entry = data->tables.push ();
entry->tag = tag;
entry->blob = hb_blob_reference (blob);
return true;
}
static bool
_subset_table (hb_subset_plan_t *plan,
hb_tag_t tag)
{
DEBUG_MSG(SUBSET, nullptr, "begin subset %c%c%c%c", HB_UNTAG(tag));
bool result = true;
switch (tag) {
case HB_OT_TAG_glyf:
result = _subset<const OT::glyf> (plan);
break;
case HB_OT_TAG_hdmx:
result = _subset<const OT::hdmx> (plan);
break;
case HB_OT_TAG_head:
// TODO that won't work well if there is no glyf
DEBUG_MSG(SUBSET, nullptr, "skip head, handled by glyf");
result = true;
break;
case HB_OT_TAG_hhea:
DEBUG_MSG(SUBSET, nullptr, "skip hhea handled by hmtx");
return true;
case HB_OT_TAG_hmtx:
result = _subset<const OT::hmtx> (plan);
break;
case HB_OT_TAG_vhea:
DEBUG_MSG(SUBSET, nullptr, "skip vhea handled by vmtx");
return true;
case HB_OT_TAG_vmtx:
result = _subset<const OT::vmtx> (plan);
break;
case HB_OT_TAG_maxp:
result = _subset<const OT::maxp> (plan);
break;
case HB_OT_TAG_loca:
DEBUG_MSG(SUBSET, nullptr, "skip loca handled by glyf");
return true;
case HB_OT_TAG_cmap:
result = _subset<const OT::cmap> (plan);
break;
case HB_OT_TAG_os2:
result = _subset<const OT::os2> (plan);
break;
case HB_OT_TAG_post:
result = _subset<const OT::post> (plan);
break;
case HB_OT_TAG_cff:
result = _subset<const OT::cff> (plan);
break;
case HB_OT_TAG_cff2:
result = _subset<const OT::cff2> (plan);
break;
default:
hb_blob_t *source_table = hb_face_reference_table(plan->source, tag);
if (likely (source_table))
result = plan->add_table(tag, source_table);
else
result = false;
hb_blob_destroy (source_table);
break;
}
DEBUG_MSG(SUBSET, nullptr, "subset %c%c%c%c %s", HB_UNTAG(tag), result ? "ok" : "FAILED");
return result;
}
static bool
_should_drop_table(hb_subset_plan_t *plan, hb_tag_t tag)
{
switch (tag) {
case HB_TAG ('c', 'v', 'a', 'r'): /* hint table, fallthrough */
case HB_TAG ('c', 'v', 't', ' '): /* hint table, fallthrough */
case HB_TAG ('f', 'p', 'g', 'm'): /* hint table, fallthrough */
case HB_TAG ('p', 'r', 'e', 'p'): /* hint table, fallthrough */
case HB_TAG ('h', 'd', 'm', 'x'): /* hint table, fallthrough */
case HB_TAG ('V', 'D', 'M', 'X'): /* hint table, fallthrough */
return plan->drop_hints;
// Drop Layout Tables if requested.
case HB_TAG ('G', 'D', 'E', 'F'): /* temporary */
case HB_TAG ('G', 'P', 'O', 'S'): /* temporary */
case HB_TAG ('G', 'S', 'U', 'B'): /* temporary */
return plan->drop_ot_layout;
// Drop these tables below by default, list pulled
// from fontTools:
case HB_TAG ('B', 'A', 'S', 'E'):
case HB_TAG ('J', 'S', 'T', 'F'):
case HB_TAG ('D', 'S', 'I', 'G'):
case HB_TAG ('E', 'B', 'D', 'T'):
case HB_TAG ('E', 'B', 'L', 'C'):
case HB_TAG ('E', 'B', 'S', 'C'):
case HB_TAG ('S', 'V', 'G', ' '):
case HB_TAG ('P', 'C', 'L', 'T'):
case HB_TAG ('L', 'T', 'S', 'H'):
// Graphite tables:
case HB_TAG ('F', 'e', 'a', 't'):
case HB_TAG ('G', 'l', 'a', 't'):
case HB_TAG ('G', 'l', 'o', 'c'):
case HB_TAG ('S', 'i', 'l', 'f'):
case HB_TAG ('S', 'i', 'l', 'l'):
// Colour
case HB_TAG ('s', 'b', 'i', 'x'):
return true;
default:
return false;
}
}
/**
* hb_subset:
* @source: font face data to be subset.
* @profile: profile to use for the subsetting.
* @input: input to use for the subsetting.
*
* Subsets a font according to provided profile and input.
**/
hb_face_t *
hb_subset (hb_face_t *source,
hb_subset_profile_t *profile,
hb_subset_input_t *input)
{
if (unlikely (!profile || !input || !source)) return hb_face_get_empty();
hb_subset_plan_t *plan = hb_subset_plan_create (source, profile, input);
hb_tag_t table_tags[32];
unsigned int offset = 0, count;
bool success = true;
do {
count = ARRAY_LENGTH (table_tags);
hb_face_get_table_tags (source, offset, &count, table_tags);
for (unsigned int i = 0; i < count; i++)
{
hb_tag_t tag = table_tags[i];
if (_should_drop_table(plan, tag))
{
DEBUG_MSG(SUBSET, nullptr, "drop %c%c%c%c", HB_UNTAG(tag));
continue;
}
success = success && _subset_table (plan, tag);
}
offset += count;
} while (count == ARRAY_LENGTH (table_tags));
hb_face_t *result = success ? hb_face_reference(plan->dest) : hb_face_get_empty();
hb_subset_plan_destroy (plan);
return result;
}
/**
* hb_subset_get_all_codepoints:
* @source: font face data to load.
* @out: set to add the all codepoints covered by font face, source.
*/
void
hb_subset_get_all_codepoints (hb_face_t *source, hb_set_t *out)
{
OT::cmap::accelerator_t cmap;
cmap.init (source);
cmap.get_all_codepoints (out);
cmap.fini();
}