harfbuzz/src/hb-subset-cff2.cc

629 lines
19 KiB
C++

/*
* Copyright © 2018 Adobe 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.
*
* Adobe Author(s): Michiharu Ariza
*/
#include "hb-open-type.hh"
#include "hb-ot-cff2-table.hh"
#include "hb-set.h"
#include "hb-subset-cff2.hh"
#include "hb-subset-plan.hh"
#include "hb-subset-cff-common.hh"
#include "hb-cff2-interp-cs.hh"
using namespace CFF;
struct cff2_sub_table_offsets_t : cff_sub_table_offsets_t
{
cff2_sub_table_offsets_t ()
: cff_sub_table_offsets_t (),
varStoreOffset (0)
{}
unsigned int varStoreOffset;
};
struct cff2_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<>
{
bool serialize (hb_serialize_context_t *c,
const op_str_t &opstr,
const cff2_sub_table_offsets_t &offsets) const
{
TRACE_SERIALIZE (this);
switch (opstr.op)
{
case OpCode_vstore:
return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.varStoreOffset));
default:
return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, offsets));
}
}
unsigned int calculate_serialized_size (const op_str_t &opstr) const
{
switch (opstr.op)
{
case OpCode_vstore:
return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (opstr.op);
default:
return cff_top_dict_op_serializer_t<>::calculate_serialized_size (opstr);
}
}
};
struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t>
{
static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
{
switch (op)
{
case OpCode_return:
case OpCode_endchar:
/* dummy opcodes in CFF2. ignore */
break;
case OpCode_hstem:
case OpCode_hstemhm:
case OpCode_vstem:
case OpCode_vstemhm:
case OpCode_hintmask:
case OpCode_cntrmask:
if (param.drop_hints)
{
env.clear_args ();
return;
}
HB_FALLTHROUGH;
default:
SUPER::flush_args_and_op (op, env, param);
break;
}
}
static void flush_args (cff2_cs_interp_env_t &env, flatten_param_t& param)
{
for (unsigned int i = 0; i < env.argStack.get_count ();)
{
const blend_arg_t &arg = env.argStack[i];
if (arg.blending ())
{
if (unlikely (!((arg.numValues > 0) && (env.argStack.get_count () >= arg.numValues))))
{
env.set_error ();
return;
}
flatten_blends (arg, i, env, param);
i += arg.numValues;
}
else
{
str_encoder_t encoder (param.flatStr);
encoder.encode_num (arg);
i++;
}
}
SUPER::flush_args (env, param);
}
static void flatten_blends (const blend_arg_t &arg, unsigned int i, cff2_cs_interp_env_t &env, flatten_param_t& param)
{
/* flatten the default values */
str_encoder_t encoder (param.flatStr);
for (unsigned int j = 0; j < arg.numValues; j++)
{
const blend_arg_t &arg1 = env.argStack[i + j];
if (unlikely (!((arg1.blending () && (arg.numValues == arg1.numValues) && (arg1.valueIndex == j) &&
(arg1.deltas.length == env.get_region_count ())))))
{
env.set_error ();
return;
}
encoder.encode_num (arg1);
}
/* flatten deltas for each value */
for (unsigned int j = 0; j < arg.numValues; j++)
{
const blend_arg_t &arg1 = env.argStack[i + j];
for (unsigned int k = 0; k < arg1.deltas.length; k++)
encoder.encode_num (arg1.deltas[k]);
}
/* flatten the number of values followed by blend operator */
encoder.encode_int (arg.numValues);
encoder.encode_op (OpCode_blendcs);
}
static void flush_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
{
switch (op)
{
case OpCode_return:
case OpCode_endchar:
return;
default:
str_encoder_t encoder (param.flatStr);
encoder.encode_op (op);
}
}
private:
typedef cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t> SUPER;
typedef cs_opset_t<blend_arg_t, cff2_cs_opset_flatten_t, cff2_cs_opset_flatten_t, cff2_cs_interp_env_t, flatten_param_t> CSOPSET;
};
struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t>
{
static void process_op (op_code_t op, cff2_cs_interp_env_t &env, subr_subset_param_t& param)
{
switch (op) {
case OpCode_return:
param.current_parsed_str->set_parsed ();
env.return_from_subr ();
param.set_current_str (env, false);
break;
case OpCode_endchar:
param.current_parsed_str->set_parsed ();
SUPER::process_op (op, env, param);
break;
case OpCode_callsubr:
process_call_subr (op, CSType_LocalSubr, env, param, env.localSubrs, param.local_closure);
break;
case OpCode_callgsubr:
process_call_subr (op, CSType_GlobalSubr, env, param, env.globalSubrs, param.global_closure);
break;
default:
SUPER::process_op (op, env, param);
param.current_parsed_str->add_op (op, env.str_ref);
break;
}
}
protected:
static void process_call_subr (op_code_t op, cs_type_t type,
cff2_cs_interp_env_t &env, subr_subset_param_t& param,
cff2_biased_subrs_t& subrs, hb_set_t *closure)
{
byte_str_ref_t str_ref = env.str_ref;
env.call_subr (subrs, type);
param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);
hb_set_add (closure, env.context.subr_num);
param.set_current_str (env, true);
}
private:
typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t> SUPER;
};
struct cff2_subr_subsetter_t : subr_subsetter_t<cff2_subr_subsetter_t, CFF2Subrs, const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t, cff2_cs_opset_subr_subset_t>
{
cff2_subr_subsetter_t (const OT::cff2::accelerator_subset_t &acc, const hb_subset_plan_t *plan)
: subr_subsetter_t (acc, plan) {}
static void finalize_parsed_str (cff2_cs_interp_env_t &env, subr_subset_param_t& param, parsed_cs_str_t &charstring)
{
/* vsindex is inserted at the beginning of the charstring as necessary */
if (env.seen_vsindex ())
{
number_t ivs;
ivs.set_int ((int)env.get_ivs ());
charstring.set_prefix (ivs, OpCode_vsindexcs);
}
}
};
struct cff2_subset_plan {
cff2_subset_plan ()
: final_size (0),
orig_fdcount (0),
subset_fdcount(1),
subset_fdselect_format (0),
drop_hints (false),
desubroutinize (false)
{
subset_fdselect_ranges.init ();
fdmap.init ();
subset_charstrings.init ();
subset_globalsubrs.init ();
subset_localsubrs.init ();
privateDictInfos.init ();
}
~cff2_subset_plan ()
{
subset_fdselect_ranges.fini ();
fdmap.fini ();
subset_charstrings.fini_deep ();
subset_globalsubrs.fini_deep ();
subset_localsubrs.fini_deep ();
privateDictInfos.fini ();
}
bool create (const OT::cff2::accelerator_subset_t &acc,
hb_subset_plan_t *plan)
{
final_size = 0;
orig_fdcount = acc.fdArray->count;
drop_hints = plan->drop_hints;
desubroutinize = plan->desubroutinize;
/* CFF2 header */
final_size += OT::cff2::static_size;
/* top dict */
{
cff2_top_dict_op_serializer_t topSzr;
offsets.topDictInfo.size = TopDict::calculate_serialized_size (acc.topDict, topSzr);
final_size += offsets.topDictInfo.size;
}
if (desubroutinize)
{
/* Flatten global & local subrs */
subr_flattener_t<const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t, cff2_cs_opset_flatten_t>
flattener(acc, plan);
if (!flattener.flatten (subset_charstrings))
return false;
/* no global/local subroutines */
offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (1, 0, 0);
}
else
{
cff2_subr_subsetter_t subr_subsetter (acc, plan);
/* Subset subrs: collect used subroutines, leaving all unused ones behind */
if (!subr_subsetter.subset ())
return false;
/* encode charstrings, global subrs, local subrs with new subroutine numbers */
if (!subr_subsetter.encode_charstrings (subset_charstrings))
return false;
if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))
return false;
/* global subrs */
unsigned int dataSize = subset_globalsubrs.total_size ();
offsets.globalSubrsInfo.offSize = calcOffSize (dataSize);
offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (offsets.globalSubrsInfo.offSize, subset_globalsubrs.length, dataSize);
/* local subrs */
if (!offsets.localSubrsInfos.resize (orig_fdcount))
return false;
if (!subset_localsubrs.resize (orig_fdcount))
return false;
for (unsigned int fd = 0; fd < orig_fdcount; fd++)
{
subset_localsubrs[fd].init ();
offsets.localSubrsInfos[fd].init ();
if (fdmap.includes (fd))
{
if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))
return false;
unsigned int dataSize = subset_localsubrs[fd].total_size ();
if (dataSize > 0)
{
offsets.localSubrsInfos[fd].offset = final_size;
offsets.localSubrsInfos[fd].offSize = calcOffSize (dataSize);
offsets.localSubrsInfos[fd].size = CFF2Subrs::calculate_serialized_size (offsets.localSubrsInfos[fd].offSize, subset_localsubrs[fd].length, dataSize);
}
}
}
}
/* global subrs */
offsets.globalSubrsInfo.offset = final_size;
final_size += offsets.globalSubrsInfo.size;
/* variation store */
if (acc.varStore != &Null(CFF2VariationStore))
{
offsets.varStoreOffset = final_size;
final_size += acc.varStore->get_size ();
}
/* FDSelect */
if (acc.fdSelect != &Null(CFF2FDSelect))
{
offsets.FDSelectInfo.offset = final_size;
if (unlikely (!hb_plan_subset_cff_fdselect (plan,
orig_fdcount,
*(const FDSelect *)acc.fdSelect,
subset_fdcount,
offsets.FDSelectInfo.size,
subset_fdselect_format,
subset_fdselect_ranges,
fdmap)))
return false;
final_size += offsets.FDSelectInfo.size;
}
else
fdmap.identity (1);
/* FDArray (FDIndex) */
{
offsets.FDArrayInfo.offset = final_size;
cff_font_dict_op_serializer_t fontSzr;
unsigned int dictsSize = 0;
for (unsigned int i = 0; i < acc.fontDicts.length; i++)
if (fdmap.includes (i))
dictsSize += FontDict::calculate_serialized_size (acc.fontDicts[i], fontSzr);
offsets.FDArrayInfo.offSize = calcOffSize (dictsSize);
final_size += CFF2Index::calculate_serialized_size (offsets.FDArrayInfo.offSize, subset_fdcount, dictsSize);
}
/* CharStrings */
{
offsets.charStringsInfo.offset = final_size;
unsigned int dataSize = subset_charstrings.total_size ();
offsets.charStringsInfo.offSize = calcOffSize (dataSize);
final_size += CFF2CharStrings::calculate_serialized_size (offsets.charStringsInfo.offSize, plan->num_output_glyphs (), dataSize);
}
/* private dicts & local subrs */
offsets.privateDictsOffset = final_size;
for (unsigned int i = 0; i < orig_fdcount; i++)
{
if (fdmap.includes (i))
{
bool has_localsubrs = offsets.localSubrsInfos[i].size > 0;
cff_private_dict_op_serializer_t privSzr (desubroutinize, drop_hints);
unsigned int priv_size = PrivateDict::calculate_serialized_size (acc.privateDicts[i], privSzr, has_localsubrs);
table_info_t privInfo = { final_size, priv_size, 0 };
privateDictInfos.push (privInfo);
final_size += privInfo.size;
if (!plan->desubroutinize && has_localsubrs)
{
offsets.localSubrsInfos[i].offset = final_size;
final_size += offsets.localSubrsInfos[i].size;
}
}
}
return true;
}
unsigned int get_final_size () const { return final_size; }
unsigned int final_size;
cff2_sub_table_offsets_t offsets;
unsigned int orig_fdcount;
unsigned int subset_fdcount;
unsigned int subset_fdselect_format;
hb_vector_t<code_pair_t> subset_fdselect_ranges;
remap_t fdmap;
str_buff_vec_t subset_charstrings;
str_buff_vec_t subset_globalsubrs;
hb_vector_t<str_buff_vec_t> subset_localsubrs;
hb_vector_t<table_info_t> privateDictInfos;
bool drop_hints;
bool desubroutinize;
};
static inline bool _write_cff2 (const cff2_subset_plan &plan,
const OT::cff2::accelerator_subset_t &acc,
unsigned int num_glyphs,
unsigned int dest_sz,
void *dest)
{
hb_serialize_context_t c (dest, dest_sz);
OT::cff2 *cff2 = c.start_serialize<OT::cff2> ();
if (unlikely (!c.extend_min (*cff2)))
return false;
/* header */
cff2->version.major = 0x02;
cff2->version.minor = 0x00;
cff2->topDict = OT::cff2::static_size;
/* top dict */
{
assert (cff2->topDict == (unsigned) (c.head - c.start));
cff2->topDictSize = plan.offsets.topDictInfo.size;
TopDict &dict = cff2 + cff2->topDict;
cff2_top_dict_op_serializer_t topSzr;
if (unlikely (!dict.serialize (&c, acc.topDict, topSzr, plan.offsets)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 top dict");
return false;
}
}
/* global subrs */
{
assert (cff2->topDict + plan.offsets.topDictInfo.size == (unsigned) (c.head - c.start));
CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
if (unlikely (dest == nullptr)) return false;
if (unlikely (!dest->serialize (&c, plan.offsets.globalSubrsInfo.offSize, plan.subset_globalsubrs)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize global subroutines");
return false;
}
}
/* variation store */
if (acc.varStore != &Null(CFF2VariationStore))
{
assert (plan.offsets.varStoreOffset == (unsigned) (c.head - c.start));
CFF2VariationStore *dest = c.start_embed<CFF2VariationStore> ();
if (unlikely (!dest->serialize (&c, acc.varStore)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 Variation Store");
return false;
}
}
/* FDSelect */
if (acc.fdSelect != &Null(CFF2FDSelect))
{
assert (plan.offsets.FDSelectInfo.offset == (unsigned) (c.head - c.start));
if (unlikely (!hb_serialize_cff_fdselect (&c, num_glyphs, *(const FDSelect *)acc.fdSelect, acc.fdArray->count,
plan.subset_fdselect_format, plan.offsets.FDSelectInfo.size,
plan.subset_fdselect_ranges)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 subset FDSelect");
return false;
}
}
/* FDArray (FD Index) */
{
assert (plan.offsets.FDArrayInfo.offset == (unsigned) (c.head - c.start));
CFF2FDArray *fda = c.start_embed<CFF2FDArray> ();
if (unlikely (fda == nullptr)) return false;
cff_font_dict_op_serializer_t fontSzr;
if (unlikely (!fda->serialize (&c, plan.offsets.FDArrayInfo.offSize,
acc.fontDicts, plan.subset_fdcount, plan.fdmap,
fontSzr, plan.privateDictInfos)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 FDArray");
return false;
}
}
/* CharStrings */
{
assert (plan.offsets.charStringsInfo.offset == (unsigned) (c.head - c.start));
CFF2CharStrings *cs = c.start_embed<CFF2CharStrings> ();
if (unlikely (cs == nullptr)) return false;
if (unlikely (!cs->serialize (&c, plan.offsets.charStringsInfo.offSize, plan.subset_charstrings)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 CharStrings");
return false;
}
}
/* private dicts & local subrs */
assert (plan.offsets.privateDictsOffset == (unsigned) (c.head - c.start));
for (unsigned int i = 0; i < acc.privateDicts.length; i++)
{
if (plan.fdmap.includes (i))
{
PrivateDict *pd = c.start_embed<PrivateDict> ();
if (unlikely (pd == nullptr)) return false;
unsigned int priv_size = plan.privateDictInfos[plan.fdmap[i]].size;
bool result;
cff_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints);
/* N.B. local subrs immediately follows its corresponding private dict. i.e., subr offset == private dict size */
unsigned int subroffset = (plan.offsets.localSubrsInfos[i].size > 0)? priv_size: 0;
result = pd->serialize (&c, acc.privateDicts[i], privSzr, subroffset);
if (unlikely (!result))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF Private Dict[%d]", i);
return false;
}
if (plan.offsets.localSubrsInfos[i].size > 0)
{
CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
if (unlikely (dest == nullptr)) return false;
if (unlikely (!dest->serialize (&c, plan.offsets.localSubrsInfos[i].offSize, plan.subset_localsubrs[i])))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize local subroutines");
return false;
}
}
}
}
assert (c.head == c.end);
c.end_serialize ();
return true;
}
static bool
_hb_subset_cff2 (const OT::cff2::accelerator_subset_t &acc,
const char *data,
hb_subset_plan_t *plan,
hb_blob_t **prime /* OUT */)
{
cff2_subset_plan cff2_plan;
if (unlikely (!cff2_plan.create (acc, plan)))
{
DEBUG_MSG(SUBSET, nullptr, "Failed to generate a cff2 subsetting plan.");
return false;
}
unsigned int cff2_prime_size = cff2_plan.get_final_size ();
char *cff2_prime_data = (char *) calloc (1, cff2_prime_size);
if (unlikely (!_write_cff2 (cff2_plan, acc, plan->num_output_glyphs (),
cff2_prime_size, cff2_prime_data))) {
DEBUG_MSG(SUBSET, nullptr, "Failed to write a subset cff2.");
free (cff2_prime_data);
return false;
}
*prime = hb_blob_create (cff2_prime_data,
cff2_prime_size,
HB_MEMORY_MODE_READONLY,
cff2_prime_data,
free);
return true;
}
/**
* hb_subset_cff2:
* Subsets the CFF2 table according to a provided plan.
*
* Return value: subsetted cff2 table.
**/
bool
hb_subset_cff2 (hb_subset_plan_t *plan,
hb_blob_t **prime /* OUT */)
{
hb_blob_t *cff2_blob = hb_sanitize_context_t().reference_table<CFF::cff2> (plan->source);
const char *data = hb_blob_get_data(cff2_blob, nullptr);
OT::cff2::accelerator_subset_t acc;
acc.init(plan->source);
bool result = likely (acc.is_valid ()) &&
_hb_subset_cff2 (acc, data, plan, prime);
hb_blob_destroy (cff2_blob);
acc.fini ();
return result;
}