[subset] add a subset accelerator.

Can be optionally attached to the face during subsetting. Contains data which can accelerate future subsets.
This commit is contained in:
Garret Rieger 2022-10-13 19:40:31 +00:00
parent f105c28749
commit 4ec5eb955f
3 changed files with 102 additions and 0 deletions

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@ -0,0 +1,75 @@
/*
* Copyright © 2022 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
*/
#ifndef HB_SUBSET_ACCELERATOR_HH
#define HB_SUBSET_ACCELERATOR_HH
#include "hb.hh"
#include "hb-map.hh"
#include "hb-set.hh"
struct hb_subset_accelerator_t
{
static hb_user_data_key_t* user_data_key()
{
static hb_user_data_key_t key;
return &key;
}
static hb_subset_accelerator_t* create(const hb_map_t& unicode_to_gid_,
const hb_set_t& unicodes_) {
hb_subset_accelerator_t* accel =
(hb_subset_accelerator_t*) hb_malloc (sizeof(hb_subset_accelerator_t));
new (accel) hb_subset_accelerator_t (unicode_to_gid_, unicodes_);
return accel;
}
static void destroy(void* value) {
if (!value) return;
hb_subset_accelerator_t* accel = (hb_subset_accelerator_t*) value;
accel->~hb_subset_accelerator_t ();
hb_free (accel);
}
hb_subset_accelerator_t(const hb_map_t& unicode_to_gid_,
const hb_set_t& unicodes_)
: unicode_to_gid(unicode_to_gid_), unicodes(unicodes_) {}
hb_map_t unicode_to_gid;
hb_set_t unicodes;
// TODO(garretrieger): cumulative glyf checksum map
bool in_error () const
{
return unicode_to_gid.in_error() || unicodes.in_error ();
}
};
#endif /* HB_SUBSET_ACCELERATOR_HH */

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@ -56,6 +56,7 @@
#include "hb-ot-math-table.hh" #include "hb-ot-math-table.hh"
#include "hb-ot-stat-table.hh" #include "hb-ot-stat-table.hh"
#include "hb-repacker.hh" #include "hb-repacker.hh"
#include "hb-subset-accelerator.hh"
using OT::Layout::GSUB; using OT::Layout::GSUB;
using OT::Layout::GPOS; using OT::Layout::GPOS;
@ -494,6 +495,27 @@ _subset_table (hb_subset_plan_t *plan,
} }
} }
static void _attach_accelerator_data (const hb_subset_plan_t* plan,
hb_face_t* face /* IN/OUT */)
{
hb_subset_accelerator_t* accel =
hb_subset_accelerator_t::create (*plan->codepoint_to_glyph,
*plan->unicodes);
if (accel->in_error ())
{
hb_subset_accelerator_t::destroy (accel);
return;
}
if (!hb_face_set_user_data(face,
hb_subset_accelerator_t::user_data_key(),
&accel,
hb_subset_accelerator_t::destroy,
true))
hb_subset_accelerator_t::destroy (accel);
}
/** /**
* hb_subset_or_fail: * hb_subset_or_fail:
* @source: font face data to be subset. * @source: font face data to be subset.
@ -576,6 +598,10 @@ hb_subset_plan_execute_or_fail (hb_subset_plan_t *plan)
offset += num_tables; offset += num_tables;
} }
if (success && plan->flags & HB_SUBSET_FLAGS_ADD_ACCELERATOR_DATA) {
_attach_accelerator_data (plan, plan->dest);
}
end: end:
return success ? hb_face_reference (plan->dest) : nullptr; return success ? hb_face_reference (plan->dest) : nullptr;
} }

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@ -334,6 +334,7 @@ hb_subset_sources = files(
'hb-ot-cff1-table.cc', 'hb-ot-cff1-table.cc',
'hb-ot-cff2-table.cc', 'hb-ot-cff2-table.cc',
'hb-static.cc', 'hb-static.cc',
'hb-subset-accelerator.hh',
'hb-subset-cff-common.cc', 'hb-subset-cff-common.cc',
'hb-subset-cff-common.hh', 'hb-subset-cff-common.hh',
'hb-subset-cff1.cc', 'hb-subset-cff1.cc',