harfbuzz/src/hb-subset-cff2.cc

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/*
* Copyright © 2018 Adobe Systems Incorporated.
*
* 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-private.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-private.hh"
using namespace CFF;
struct CFF2TopDict_OpSerializer : OpSerializer
{
inline bool serialize (hb_serialize_context_t *c,
const OpStr &opstr,
const SubTableOffsets &offsets) const
{
TRACE_SERIALIZE (this);
switch (opstr.op)
{
case OpCode_vstore:
return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.varStoreOffset));
case OpCode_CharStrings:
return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.charStringsOffset));
case OpCode_FDArray:
return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.FDArrayOffset));
case OpCode_FDSelect:
return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.FDSelectOffset));
default:
return_trace (copy_opstr (c, opstr));
}
return_trace (true);
}
inline unsigned int calculate_serialized_size (const OpStr &opstr) const
{
switch (opstr.op)
{
case OpCode_vstore:
case OpCode_CharStrings:
case OpCode_FDArray:
case OpCode_FDSelect:
return OpCode_Size (OpCode_longint) + 4 + OpCode_Size (opstr.op);
default:
return opstr.str.len;
}
}
};
struct CFF2FontDict_OpSerializer : OpSerializer
{
inline bool serialize (hb_serialize_context_t *c,
const OpStr &opstr,
const offset_size_pair& privOffSize) const
{
TRACE_SERIALIZE (this);
if (opstr.op == OpCode_Private)
{
/* serialize the private dict size as a 2-byte integer */
if (unlikely (!UnsizedByteStr::serialize_int2 (c, privOffSize.size)))
return_trace (false);
/* serialize the private dict offset as a 4-byte integer */
if (unlikely (!UnsizedByteStr::serialize_int4 (c, privOffSize.offset)))
return_trace (false);
/* serialize the opcode */
HBUINT8 *p = c->allocate_size<HBUINT8> (1);
if (unlikely (p == nullptr)) return_trace (false);
p->set (OpCode_Private);
return_trace (true);
}
else
{
HBUINT8 *d = c->allocate_size<HBUINT8> (opstr.str.len);
if (unlikely (d == nullptr)) return_trace (false);
memcpy (d, &opstr.str.str[0], opstr.str.len);
}
return_trace (true);
}
inline unsigned int calculate_serialized_size (const OpStr &opstr) const
{
if (opstr.op == OpCode_Private)
return OpCode_Size (OpCode_longint) + 4 + OpCode_Size (OpCode_shortint) + 2 + OpCode_Size (OpCode_Private);
else
return opstr.str.len;
}
};
struct CFF2PrivateDict_OpSerializer : OpSerializer
{
inline bool serialize (hb_serialize_context_t *c,
const OpStr &opstr,
const unsigned int subrsOffset) const
{
TRACE_SERIALIZE (this);
if (opstr.op == OpCode_Subrs)
return_trace (FontDict::serialize_offset2_op(c, OpCode_Subrs, subrsOffset));
else
return_trace (copy_opstr (c, opstr));
}
inline unsigned int calculate_serialized_size (const OpStr &opstr) const
{
if (opstr.op == OpCode_Subrs)
return OpCode_Size (OpCode_shortint) + 2 + OpCode_Size (OpCode_Subrs);
else
return opstr.str.len;
}
};
struct subset_plan {
inline subset_plan (void)
: final_size (0),
subst_fdcount(1)
{
subst_fdselect_first_glyphs.init ();
fdmap.init ();
subset_charstrings.init ();
private_off_and_size_pairs.init ();
}
inline ~subset_plan (void)
{
subst_fdselect_first_glyphs.fini ();
fdmap.fini ();
subset_charstrings.fini ();
private_off_and_size_pairs.fini ();
}
inline bool create (const OT::cff2::accelerator_subset_t &acc,
hb_subset_plan_t *plan)
{
final_size = 0;
orig_fdcount = acc.fdArray->count;
/* CFF2 header */
final_size += OT::cff2::static_size;
/* top dict */
{
CFF2TopDict_OpSerializer topSzr;
offsets.topDictSize = TopDict::calculate_serialized_size (acc.top, topSzr);
final_size += offsets.topDictSize;
}
/* global subrs */
final_size += acc.globalSubrs->get_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.FDSelectOffset = final_size;
if (unlikely (!hb_plan_subset_cff_fdselect (plan->glyphs,
orig_fdcount,
*acc.fdSelect,
subst_fdcount,
offsets.FDSelectSize,
subst_fdselect_format,
subst_fdselect_first_glyphs,
fdmap)))
return false;
if (!is_fds_subsetted ())
offsets.FDSelectSize = acc.fdSelect->calculate_serialized_size (acc.num_glyphs);
final_size += offsets.FDSelectSize;
}
/* FDArray (FDIndex) */
{
offsets.FDArrayOffset = final_size;
CFF2FontDict_OpSerializer fontSzr;
final_size += FDArray::calculate_serialized_size(offsets.FDArrayOffSize/*OUT*/, acc.fontDicts, subst_fdcount, fdmap, fontSzr);
}
/* CharStrings */
{
offsets.charStringsOffset = final_size;
unsigned int dataSize = 0;
for (unsigned int i = 0; i < plan->glyphs.len; i++)
{
const ByteStr str = (*acc.charStrings)[plan->glyphs[i]];
subset_charstrings.push (str);
dataSize += str.len;
}
offsets.charStringsOffSize = calcOffSize (dataSize + 1);
final_size += CharStrings::calculate_serialized_size (offsets.charStringsOffSize, plan->glyphs.len, dataSize);
}
/* private dicts & local subrs */
offsets.privateDictsOffset = final_size;
for (unsigned int i = 0; i < orig_fdcount; i++)
{
CFF2PrivateDict_OpSerializer privSzr;
unsigned int private_size = PrivateDict::calculate_serialized_size (acc.privateDicts[i], privSzr);
offset_size_pair pair = { final_size, private_size };
private_off_and_size_pairs.push (pair);
final_size += private_size + acc.privateDicts[i].localSubrs->get_size ();
}
return true;
}
inline unsigned int get_final_size (void) const { return final_size; }
unsigned int final_size;
SubTableOffsets offsets;
unsigned int orig_fdcount;
unsigned int subst_fdcount;
inline bool is_fds_subsetted (void) const { return subst_fdcount < orig_fdcount; }
unsigned int subst_fdselect_format;
hb_vector_t<hb_codepoint_t> subst_fdselect_first_glyphs;
/* font dict index remap table from fullset FDArray to subset FDArray.
* set to HB_SET_VALUE_INVALID if excluded from subset */
hb_vector_t<hb_codepoint_t> fdmap;
hb_vector_t<ByteStr> subset_charstrings;
hb_vector_t<offset_size_pair> private_off_and_size_pairs;
};
static inline bool _write_cff2 (const subset_plan &plan,
const OT::cff2::accelerator_subset_t &acc,
const hb_vector_t<hb_codepoint_t>& 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.set (0x02);
cff2->version.minor.set (0x00);
cff2->topDict.set (OT::cff2::static_size);
/* top dict */
{
assert (cff2->topDict == c.head - c.start);
cff2->topDictSize.set (plan.offsets.topDictSize);
TopDict &dict = cff2 + cff2->topDict;
CFF2TopDict_OpSerializer topSzr;
if (unlikely (!dict.serialize (&c, acc.top, topSzr, plan.offsets)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 top dict");
return false;
}
}
/* global subrs */
{
assert (cff2->topDict + plan.offsets.topDictSize == c.head - c.start);
Subrs *dest = c.start_embed<Subrs> ();
if (unlikely (dest == nullptr)) return false;
if (unlikely (!dest->serialize (&c, *acc.globalSubrs)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 global subrs");
return false;
}
}
/* variation store */
if (acc.varStore != &Null(CFF2VariationStore))
{
assert (plan.offsets.varStoreOffset == 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.FDSelectOffset == c.head - c.start);
if (plan.is_fds_subsetted ())
{
if (unlikely (!hb_serialize_cff_fdselect (&c, glyphs, *acc.fdSelect, acc.fdArray->count,
plan.subst_fdselect_format, plan.offsets.FDSelectSize,
plan.subst_fdselect_first_glyphs,
plan.fdmap)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 subset FDSelect");
return false;
}
}
else
{
CFF2FDSelect *dest = c.start_embed<CFF2FDSelect> ();
if (unlikely (!dest->serialize (&c, *acc.fdSelect, acc.num_glyphs)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 FDSelect");
return false;
}
}
}
/* FDArray (FD Index) */
{
assert (plan.offsets.FDArrayOffset == c.head - c.start);
FDArray *fda = c.start_embed<FDArray> ();
if (unlikely (fda == nullptr)) return false;
CFF2FontDict_OpSerializer fontSzr;
if (unlikely (!fda->serialize (&c, plan.offsets.FDArrayOffSize,
acc.fontDicts, plan.subst_fdcount, plan.fdmap,
fontSzr, plan.private_off_and_size_pairs)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 FDArray");
return false;
}
}
/* CharStrings */
{
assert (plan.offsets.charStringsOffset == c.head - c.start);
CharStrings *cs = c.start_embed<CharStrings> ();
if (unlikely (cs == nullptr)) return false;
if (unlikely (!cs->serialize (&c, plan.offsets.charStringsOffSize, plan.subset_charstrings)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 CharStrings");
return false;
}
}
/* private dicts & local subrs */
assert (plan.offsets.privateDictsOffset == c.head - c.start);
for (unsigned int i = 0; i < acc.privateDicts.len; i++)
{
PrivateDict *pd = c.start_embed<PrivateDict> ();
if (unlikely (pd == nullptr)) return false;
CFF2PrivateDict_OpSerializer privSzr;
/* N.B. local subrs immediately follows its corresponding private dict. i.e., subr offset == private dict size */
if (unlikely (!pd->serialize (&c, acc.privateDicts[i], privSzr, plan.private_off_and_size_pairs[i].size)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 Private Dict[%d]", i);
return false;
}
if (acc.privateDicts[i].subrsOffset != 0)
{
Subrs *subrs = c.start_embed<Subrs> ();
if (unlikely (subrs == nullptr) || acc.privateDicts[i].localSubrs == &Null(Subrs))
{
DEBUG_MSG (SUBSET, nullptr, "CFF2 subset: local subrs unexpectedly null [%d]", i);
return false;
}
if (unlikely (!subrs->serialize (&c, *acc.privateDicts[i].localSubrs)))
{
DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 local subrs [%d]", i);
return false;
}
}
}
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 */)
{
subset_plan cff2_subset_plan;
if (unlikely (!cff2_subset_plan.create (acc, plan)))
{
DEBUG_MSG(SUBSET, nullptr, "Failed to generate a cff2 subsetting plan.");
return false;
}
unsigned int cff2_prime_size = cff2_subset_plan.get_final_size ();
char *cff2_prime_data = (char *) calloc (1, cff2_prime_size);
if (unlikely (!_write_cff2 (cff2_subset_plan, acc, plan->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 */)
{
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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;
}