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harfbuzz/src/hb-subset-cff-common.hh

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/*
* 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
*/
#ifndef HB_SUBSET_CFF_COMMON_HH
#define HB_SUBSET_CFF_COMMON_HH
#include "hb.hh"
#include "hb-subset-plan.hh"
#include "hb-cff-interp-cs-common.hh"
namespace CFF {
/* Used for writing a temporary charstring */
struct str_encoder_t
{
str_encoder_t (str_buff_t &buff_)
: buff (buff_) {}
void reset () { buff.reset (); }
void encode_byte (unsigned char b)
{
if (likely ((signed) buff.length < buff.allocated))
buff.arrayZ[buff.length++] = b;
else
buff.push (b);
}
void encode_int (int v)
{
if ((-1131 <= v) && (v <= 1131))
{
if ((-107 <= v) && (v <= 107))
encode_byte (v + 139);
else if (v > 0)
{
v -= 108;
encode_byte ((v >> 8) + OpCode_TwoBytePosInt0);
encode_byte (v & 0xFF);
}
else
{
v = -v - 108;
encode_byte ((v >> 8) + OpCode_TwoByteNegInt0);
encode_byte (v & 0xFF);
}
}
else
{
if (unlikely (v < -32768))
v = -32768;
else if (unlikely (v > 32767))
v = 32767;
encode_byte (OpCode_shortint);
encode_byte ((v >> 8) & 0xFF);
encode_byte (v & 0xFF);
}
}
void encode_num (const number_t& n)
{
if (n.in_int_range ())
{
encode_int (n.to_int ());
}
else
{
int32_t v = n.to_fixed ();
encode_byte (OpCode_fixedcs);
encode_byte ((v >> 24) & 0xFF);
encode_byte ((v >> 16) & 0xFF);
encode_byte ((v >> 8) & 0xFF);
encode_byte (v & 0xFF);
}
}
void encode_op (op_code_t op)
{
if (Is_OpCode_ESC (op))
{
encode_byte (OpCode_escape);
encode_byte (Unmake_OpCode_ESC (op));
}
else
encode_byte (op);
}
void copy_str (const unsigned char *str, unsigned length)
{
assert ((signed) (buff.length + length) <= buff.allocated);
hb_memcpy (buff.arrayZ + buff.length, str, length);
buff.length += length;
}
bool in_error () const { return buff.in_error (); }
protected:
str_buff_t &buff;
};
struct cff_sub_table_info_t {
cff_sub_table_info_t ()
: fd_array_link (0),
char_strings_link (0)
{
fd_select.init ();
}
table_info_t fd_select;
objidx_t fd_array_link;
objidx_t char_strings_link;
};
template <typename OPSTR=op_str_t>
struct cff_top_dict_op_serializer_t : op_serializer_t
{
bool serialize (hb_serialize_context_t *c,
const OPSTR &opstr,
const cff_sub_table_info_t &info) const
{
TRACE_SERIALIZE (this);
switch (opstr.op)
{
case OpCode_CharStrings:
return_trace (FontDict::serialize_link4_op(c, opstr.op, info.char_strings_link, whence_t::Absolute));
case OpCode_FDArray:
return_trace (FontDict::serialize_link4_op(c, opstr.op, info.fd_array_link, whence_t::Absolute));
case OpCode_FDSelect:
return_trace (FontDict::serialize_link4_op(c, opstr.op, info.fd_select.link, whence_t::Absolute));
default:
return_trace (copy_opstr (c, opstr));
}
return_trace (true);
}
};
struct cff_font_dict_op_serializer_t : op_serializer_t
{
bool serialize (hb_serialize_context_t *c,
const op_str_t &opstr,
const table_info_t &privateDictInfo) const
{
TRACE_SERIALIZE (this);
if (opstr.op == OpCode_Private)
{
/* serialize the private dict size & offset as 2-byte & 4-byte integers */
return_trace (UnsizedByteStr::serialize_int2 (c, privateDictInfo.size) &&
Dict::serialize_link4_op (c, opstr.op, privateDictInfo.link, whence_t::Absolute));
}
else
{
unsigned char *d = c->allocate_size<unsigned char> (opstr.length);
if (unlikely (!d)) return_trace (false);
/* Faster than hb_memcpy for small strings. */
for (unsigned i = 0; i < opstr.length; i++)
d[i] = opstr.ptr[i];
//hb_memcpy (d, opstr.ptr, opstr.length);
}
return_trace (true);
}
};
struct cff_private_dict_op_serializer_t : op_serializer_t
{
cff_private_dict_op_serializer_t (bool desubroutinize_, bool drop_hints_)
: desubroutinize (desubroutinize_), drop_hints (drop_hints_) {}
bool serialize (hb_serialize_context_t *c,
const op_str_t &opstr,
objidx_t subrs_link) const
{
TRACE_SERIALIZE (this);
if (drop_hints && dict_opset_t::is_hint_op (opstr.op))
return true;
if (opstr.op == OpCode_Subrs)
{
if (desubroutinize || !subrs_link)
return_trace (true);
else
return_trace (FontDict::serialize_link2_op (c, opstr.op, subrs_link));
}
else
return_trace (copy_opstr (c, opstr));
}
protected:
const bool desubroutinize;
const bool drop_hints;
};
struct flatten_param_t
{
str_buff_t &flatStr;
bool drop_hints;
};
template <typename ACC, typename ENV, typename OPSET, op_code_t endchar_op=OpCode_Invalid>
struct subr_flattener_t
{
subr_flattener_t (const ACC &acc_,
const hb_subset_plan_t *plan_)
: acc (acc_), plan (plan_) {}
bool flatten (str_buff_vec_t &flat_charstrings)
{
unsigned count = plan->num_output_glyphs ();
if (!flat_charstrings.resize (count))
return false;
for (unsigned int i = 0; i < count; i++)
{
hb_codepoint_t glyph;
if (!plan->old_gid_for_new_gid (i, &glyph))
{
/* add an endchar only charstring for a missing glyph if CFF1 */
if (endchar_op != OpCode_Invalid) flat_charstrings[i].push (endchar_op);
continue;
}
const hb_ubytes_t str = (*acc.charStrings)[glyph];
unsigned int fd = acc.fdSelect->get_fd (glyph);
if (unlikely (fd >= acc.fdCount))
return false;
ENV env (str, acc, fd);
cs_interpreter_t<ENV, OPSET, flatten_param_t> interp (env);
flatten_param_t param = {
flat_charstrings.arrayZ[i],
(bool) (plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
};
if (unlikely (!interp.interpret (param)))
return false;
}
return true;
}
const ACC &acc;
const hb_subset_plan_t *plan;
};
struct subr_closures_t
{
subr_closures_t (unsigned int fd_count) : global_closure (), local_closures ()
{
local_closures.resize (fd_count);
}
void reset ()
{
global_closure.clear();
for (unsigned int i = 0; i < local_closures.length; i++)
local_closures[i].clear();
}
bool in_error () const { return local_closures.in_error (); }
hb_set_t global_closure;
hb_vector_t<hb_set_t> local_closures;
};
struct parsed_cs_op_t : op_str_t
{
parsed_cs_op_t (unsigned int subr_num_ = 0) :
subr_num (subr_num_) {}
bool is_hinting () const { return hinting_flag; }
void set_hinting () { hinting_flag = true; }
/* The layout of this struct is designed to fit within the
* padding of op_str_t! */
protected:
bool hinting_flag = false;
public:
uint16_t subr_num;
};
struct parsed_cs_str_t : parsed_values_t<parsed_cs_op_t>
{
parsed_cs_str_t () :
parsed (false),
hint_dropped (false),
has_prefix_ (false),
has_calls_ (false)
{
SUPER::init ();
}
void add_op (op_code_t op, const byte_str_ref_t& str_ref)
{
if (!is_parsed ())
SUPER::add_op (op, str_ref);
}
void add_call_op (op_code_t op, const byte_str_ref_t& str_ref, unsigned int subr_num)
{
if (!is_parsed ())
{
has_calls_ = true;
/* Pop the subroutine number. */
values.pop ();
SUPER::add_op (op, str_ref, {subr_num});
}
}
void set_prefix (const number_t &num, op_code_t op = OpCode_Invalid)
{
has_prefix_ = true;
prefix_op_ = op;
prefix_num_ = num;
}
bool at_end (unsigned int pos) const
{
return ((pos + 1 >= values.length) /* CFF2 */
|| (values[pos + 1].op == OpCode_return));
}
bool is_parsed () const { return parsed; }
void set_parsed () { parsed = true; }
bool is_hint_dropped () const { return hint_dropped; }
void set_hint_dropped () { hint_dropped = true; }
bool is_vsindex_dropped () const { return vsindex_dropped; }
void set_vsindex_dropped () { vsindex_dropped = true; }
bool has_prefix () const { return has_prefix_; }
op_code_t prefix_op () const { return prefix_op_; }
const number_t &prefix_num () const { return prefix_num_; }
bool has_calls () const { return has_calls_; }
protected:
bool parsed : 1;
bool hint_dropped : 1;
bool vsindex_dropped : 1;
bool has_prefix_ : 1;
bool has_calls_ : 1;
op_code_t prefix_op_;
number_t prefix_num_;
private:
typedef parsed_values_t<parsed_cs_op_t> SUPER;
};
struct parsed_cs_str_vec_t : hb_vector_t<parsed_cs_str_t>
{
private:
typedef hb_vector_t<parsed_cs_str_t> SUPER;
};
struct cff_subset_accelerator_t
{
static cff_subset_accelerator_t* create (
hb_blob_t* original_blob,
const parsed_cs_str_vec_t& parsed_charstrings,
const parsed_cs_str_vec_t& parsed_global_subrs,
const hb_vector_t<parsed_cs_str_vec_t>& parsed_local_subrs) {
cff_subset_accelerator_t* accel =
(cff_subset_accelerator_t*) hb_malloc (sizeof(cff_subset_accelerator_t));
new (accel) cff_subset_accelerator_t (original_blob,
parsed_charstrings,
parsed_global_subrs,
parsed_local_subrs);
return accel;
}
static void destroy (void* value) {
if (!value) return;
cff_subset_accelerator_t* accel = (cff_subset_accelerator_t*) value;
accel->~cff_subset_accelerator_t ();
hb_free (accel);
}
cff_subset_accelerator_t(
hb_blob_t* original_blob_,
const parsed_cs_str_vec_t& parsed_charstrings_,
const parsed_cs_str_vec_t& parsed_global_subrs_,
const hb_vector_t<parsed_cs_str_vec_t>& parsed_local_subrs_)
{
parsed_charstrings = parsed_charstrings_;
parsed_global_subrs = parsed_global_subrs_;
parsed_local_subrs = parsed_local_subrs_;
// the parsed charstrings point to memory in the original CFF table so we must hold a reference
// to it to keep the memory valid.
original_blob = hb_blob_reference (original_blob_);
}
~cff_subset_accelerator_t() {
hb_blob_destroy (original_blob);
hb_map_destroy (glyph_to_sid_map.get_relaxed ());
}
parsed_cs_str_vec_t parsed_charstrings;
parsed_cs_str_vec_t parsed_global_subrs;
hb_vector_t<parsed_cs_str_vec_t> parsed_local_subrs;
mutable hb_atomic_ptr_t<hb_map_t> glyph_to_sid_map = nullptr;
private:
hb_blob_t* original_blob;
};
struct subr_subset_param_t
{
subr_subset_param_t (parsed_cs_str_t *parsed_charstring_,
parsed_cs_str_vec_t *parsed_global_subrs_,
parsed_cs_str_vec_t *parsed_local_subrs_,
hb_set_t *global_closure_,
hb_set_t *local_closure_,
bool drop_hints_) :
current_parsed_str (parsed_charstring_),
parsed_charstring (parsed_charstring_),
parsed_global_subrs (parsed_global_subrs_),
parsed_local_subrs (parsed_local_subrs_),
global_closure (global_closure_),
local_closure (local_closure_),
drop_hints (drop_hints_) {}
parsed_cs_str_t *get_parsed_str_for_context (call_context_t &context)
{
switch (context.type)
{
case CSType_CharString:
return parsed_charstring;
case CSType_LocalSubr:
if (likely (context.subr_num < parsed_local_subrs->length))
return &(*parsed_local_subrs)[context.subr_num];
break;
case CSType_GlobalSubr:
if (likely (context.subr_num < parsed_global_subrs->length))
return &(*parsed_global_subrs)[context.subr_num];
break;
}
return nullptr;
}
template <typename ENV>
void set_current_str (ENV &env, bool calling)
{
parsed_cs_str_t *parsed_str = get_parsed_str_for_context (env.context);
if (unlikely (!parsed_str))
{
env.set_error ();
return;
}
/* If the called subroutine is parsed partially but not completely yet,
* it must be because we are calling it recursively.
* Handle it as an error. */
if (unlikely (calling && !parsed_str->is_parsed () && (parsed_str->values.length > 0)))
env.set_error ();
else
{
if (!parsed_str->is_parsed ())
parsed_str->alloc (env.str_ref.total_size ());
current_parsed_str = parsed_str;
}
}
parsed_cs_str_t *current_parsed_str;
parsed_cs_str_t *parsed_charstring;
parsed_cs_str_vec_t *parsed_global_subrs;
parsed_cs_str_vec_t *parsed_local_subrs;
hb_set_t *global_closure;
hb_set_t *local_closure;
bool drop_hints;
};
struct subr_remap_t : hb_inc_bimap_t
{
void create (const hb_set_t *closure)
{
/* create a remapping of subroutine numbers from old to new.
* no optimization based on usage counts. fonttools doesn't appear doing that either.
*/
resize (closure->get_population ());
hb_codepoint_t old_num = HB_SET_VALUE_INVALID;
while (hb_set_next (closure, &old_num))
add (old_num);
if (get_population () < 1240)
bias = 107;
else if (get_population () < 33900)
bias = 1131;
else
bias = 32768;
}
int biased_num (unsigned int old_num) const
{
hb_codepoint_t new_num = get (old_num);
return (int)new_num - bias;
}
protected:
int bias;
};
struct subr_remaps_t
{
subr_remaps_t (unsigned int fdCount)
{
local_remaps.resize (fdCount);
}
bool in_error()
{
return local_remaps.in_error ();
}
void create (subr_closures_t& closures)
{
global_remap.create (&closures.global_closure);
for (unsigned int i = 0; i < local_remaps.length; i++)
local_remaps.arrayZ[i].create (&closures.local_closures[i]);
}
subr_remap_t global_remap;
hb_vector_t<subr_remap_t> local_remaps;
};
template <typename SUBSETTER, typename SUBRS, typename ACC, typename ENV, typename OPSET, op_code_t endchar_op=OpCode_Invalid>
struct subr_subsetter_t
{
subr_subsetter_t (ACC &acc_, const hb_subset_plan_t *plan_)
: acc (acc_), plan (plan_), closures(acc_.fdCount),
remaps(acc_.fdCount)
{}
/* Subroutine subsetting with --no-desubroutinize runs in phases:
*
* 1. execute charstrings/subroutines to determine subroutine closures
* 2. parse out all operators and numbers
* 3. mark hint operators and operands for removal if --no-hinting
* 4. re-encode all charstrings and subroutines with new subroutine numbers
*
* Phases #1 and #2 are done at the same time in collect_subrs ().
* Phase #3 walks charstrings/subroutines forward then backward (hence parsing required),
* because we can't tell if a number belongs to a hint op until we see the first moveto.
*
* Assumption: a callsubr/callgsubr operator must immediately follow a (biased) subroutine number
* within the same charstring/subroutine, e.g., not split across a charstring and a subroutine.
*/
bool subset (void)
{
unsigned fd_count = acc.fdCount;
const cff_subset_accelerator_t* cff_accelerator = nullptr;
if (plan->accelerator && plan->accelerator->cff_accelerator) {
cff_accelerator = plan->accelerator->cff_accelerator;
fd_count = cff_accelerator->parsed_local_subrs.length;
}
if (cff_accelerator) {
// If we are not dropping hinting then charstrings are not modified so we can
// just use a reference to the cached copies.
cached_charstrings.resize (plan->num_output_glyphs ());
parsed_global_subrs = &cff_accelerator->parsed_global_subrs;
parsed_local_subrs = &cff_accelerator->parsed_local_subrs;
} else {
parsed_charstrings.resize (plan->num_output_glyphs ());
parsed_global_subrs_storage.resize (acc.globalSubrs->count);
if (unlikely (!parsed_local_subrs_storage.resize (fd_count))) return false;
for (unsigned int i = 0; i < acc.fdCount; i++)
{
unsigned count = acc.privateDicts[i].localSubrs->count;
parsed_local_subrs_storage[i].resize (count);
if (unlikely (parsed_local_subrs_storage[i].in_error ())) return false;
}
parsed_global_subrs = &parsed_global_subrs_storage;
parsed_local_subrs = &parsed_local_subrs_storage;
}
if (unlikely (remaps.in_error()
|| cached_charstrings.in_error ()
|| parsed_charstrings.in_error ()
|| parsed_global_subrs->in_error ()
|| closures.in_error ())) {
return false;
}
/* phase 1 & 2 */
for (unsigned int i = 0; i < plan->num_output_glyphs (); i++)
{
hb_codepoint_t glyph;
if (!plan->old_gid_for_new_gid (i, &glyph))
continue;
const hb_ubytes_t str = (*acc.charStrings)[glyph];
unsigned int fd = acc.fdSelect->get_fd (glyph);
if (unlikely (fd >= acc.fdCount))
return false;
if (cff_accelerator)
{
// parsed string already exists in accelerator, copy it and move
// on.
if (cached_charstrings)
cached_charstrings[i] = &cff_accelerator->parsed_charstrings[glyph];
else
parsed_charstrings[i] = cff_accelerator->parsed_charstrings[glyph];
continue;
}
ENV env (str, acc, fd);
cs_interpreter_t<ENV, OPSET, subr_subset_param_t> interp (env);
parsed_charstrings[i].alloc (str.length);
subr_subset_param_t param (&parsed_charstrings[i],
&parsed_global_subrs_storage,
&parsed_local_subrs_storage[fd],
&closures.global_closure,
&closures.local_closures[fd],
plan->flags & HB_SUBSET_FLAGS_NO_HINTING);
if (unlikely (!interp.interpret (param)))
return false;
/* complete parsed string esp. copy CFF1 width or CFF2 vsindex to the parsed charstring for encoding */
SUBSETTER::complete_parsed_str (interp.env, param, parsed_charstrings[i]);
/* mark hint ops and arguments for drop */
if ((plan->flags & HB_SUBSET_FLAGS_NO_HINTING) || plan->inprogress_accelerator)
{
subr_subset_param_t param (&parsed_charstrings[i],
&parsed_global_subrs_storage,
&parsed_local_subrs_storage[fd],
&closures.global_closure,
&closures.local_closures[fd],
plan->flags & HB_SUBSET_FLAGS_NO_HINTING);
drop_hints_param_t drop;
if (drop_hints_in_str (parsed_charstrings[i], param, drop))
{
parsed_charstrings[i].set_hint_dropped ();
if (drop.vsindex_dropped)
parsed_charstrings[i].set_vsindex_dropped ();
}
}
/* Doing this here one by one instead of compacting all at the en
* has massive peak-memory saving. */
if (plan->inprogress_accelerator)
compact_string (parsed_charstrings[i]);
}
// Since parsed strings were loaded from accelerator, we still need
// to compute the subroutine closures which would have normally happened during
// parsing.
//
// Or if we are dropping hinting, redo closure to get actually used subrs.
if ((cff_accelerator ||
(!cff_accelerator && plan->flags & HB_SUBSET_FLAGS_NO_HINTING)) &&
!closure_subroutines(*parsed_global_subrs,
*parsed_local_subrs))
return false;
remaps.create (closures);
populate_subset_accelerator ();
return true;
}
bool encode_charstrings (str_buff_vec_t &buffArray) const
{
if (unlikely (!buffArray.resize (plan->num_output_glyphs ())))
return false;
for (unsigned int i = 0; i < plan->num_output_glyphs (); i++)
{
hb_codepoint_t glyph;
if (!plan->old_gid_for_new_gid (i, &glyph))
{
/* add an endchar only charstring for a missing glyph if CFF1 */
if (endchar_op != OpCode_Invalid) buffArray.arrayZ[i].push (endchar_op);
continue;
}
unsigned int fd = acc.fdSelect->get_fd (glyph);
if (unlikely (fd >= acc.fdCount))
return false;
if (unlikely (!encode_str (get_parsed_charstring (i), fd, buffArray.arrayZ[i])))
return false;
}
return true;
}
bool encode_subrs (const parsed_cs_str_vec_t &subrs, const subr_remap_t& remap, unsigned int fd, str_buff_vec_t &buffArray) const
{
unsigned int count = remap.get_population ();
if (unlikely (!buffArray.resize (count)))
return false;
for (unsigned int new_num = 0; new_num < count; new_num++)
{
hb_codepoint_t old_num = remap.backward (new_num);
assert (old_num != CFF_UNDEF_CODE);
if (unlikely (!encode_str (subrs[old_num], fd, buffArray[new_num])))
return false;
}
return true;
}
bool encode_globalsubrs (str_buff_vec_t &buffArray)
{
return encode_subrs (*parsed_global_subrs, remaps.global_remap, 0, buffArray);
}
bool encode_localsubrs (unsigned int fd, str_buff_vec_t &buffArray) const
{
return encode_subrs ((*parsed_local_subrs)[fd], remaps.local_remaps[fd], fd, buffArray);
}
protected:
struct drop_hints_param_t
{
drop_hints_param_t ()
: seen_moveto (false),
ends_in_hint (false),
all_dropped (false),
vsindex_dropped (false) {}
bool seen_moveto;
bool ends_in_hint;
bool all_dropped;
bool vsindex_dropped;
};
bool drop_hints_in_subr (parsed_cs_str_t &str, unsigned int pos,
parsed_cs_str_vec_t &subrs, unsigned int subr_num,
const subr_subset_param_t &param, drop_hints_param_t &drop)
{
drop.ends_in_hint = false;
bool has_hint = drop_hints_in_str (subrs[subr_num], param, drop);
/* if this subr ends with a stem hint (i.e., not a number; potential argument for moveto),
* then this entire subroutine must be a hint. drop its call. */
if (drop.ends_in_hint)
{
str.values[pos].set_hinting ();
/* if this subr call is at the end of the parent subr, propagate the flag
* otherwise reset the flag */
if (!str.at_end (pos))
drop.ends_in_hint = false;
}
else if (drop.all_dropped)
{
str.values[pos].set_hinting ();
}
return has_hint;
}
/* returns true if it sees a hint op before the first moveto */
bool drop_hints_in_str (parsed_cs_str_t &str, const subr_subset_param_t &param, drop_hints_param_t &drop)
{
bool seen_hint = false;
unsigned count = str.values.length;
auto *values = str.values.arrayZ;
for (unsigned int pos = 0; pos < count; pos++)
{
bool has_hint = false;
switch (values[pos].op)
{
case OpCode_callsubr:
has_hint = drop_hints_in_subr (str, pos,
*param.parsed_local_subrs, values[pos].subr_num,
param, drop);
break;
case OpCode_callgsubr:
has_hint = drop_hints_in_subr (str, pos,
*param.parsed_global_subrs, values[pos].subr_num,
param, drop);
break;
case OpCode_rmoveto:
case OpCode_hmoveto:
case OpCode_vmoveto:
drop.seen_moveto = true;
break;
case OpCode_hintmask:
case OpCode_cntrmask:
if (drop.seen_moveto)
{
values[pos].set_hinting ();
break;
}
HB_FALLTHROUGH;
case OpCode_hstemhm:
case OpCode_vstemhm:
case OpCode_hstem:
case OpCode_vstem:
has_hint = true;
values[pos].set_hinting ();
if (str.at_end (pos))
drop.ends_in_hint = true;
break;
case OpCode_dotsection:
values[pos].set_hinting ();
break;
default:
/* NONE */
break;
}
if (has_hint)
{
for (int i = pos - 1; i >= 0; i--)
{
parsed_cs_op_t &csop = values[(unsigned)i];
if (csop.is_hinting ())
break;
csop.set_hinting ();
if (csop.op == OpCode_vsindexcs)
drop.vsindex_dropped = true;
}
seen_hint |= has_hint;
}
}
/* Raise all_dropped flag if all operators except return are dropped from a subr.
* It may happen even after seeing the first moveto if a subr contains
* only (usually one) hintmask operator, then calls to this subr can be dropped.
*/
drop.all_dropped = true;
for (unsigned int pos = 0; pos < count; pos++)
{
parsed_cs_op_t &csop = values[pos];
if (csop.op == OpCode_return)
break;
if (!csop.is_hinting ())
{
drop.all_dropped = false;
break;
}
}
return seen_hint;
}
bool closure_subroutines (const parsed_cs_str_vec_t& global_subrs,
const hb_vector_t<parsed_cs_str_vec_t>& local_subrs)
{
closures.reset ();
for (unsigned int i = 0; i < plan->num_output_glyphs (); i++)
{
hb_codepoint_t glyph;
if (!plan->old_gid_for_new_gid (i, &glyph))
continue;
unsigned int fd = acc.fdSelect->get_fd (glyph);
if (unlikely (fd >= acc.fdCount))
return false;
// Note: const cast is safe here because the collect_subr_refs_in_str only performs a
// closure and does not modify any of the charstrings.
subr_subset_param_t param (const_cast<parsed_cs_str_t*> (&get_parsed_charstring (i)),
const_cast<parsed_cs_str_vec_t*> (&global_subrs),
const_cast<parsed_cs_str_vec_t*> (&local_subrs[fd]),
&closures.global_closure,
&closures.local_closures[fd],
plan->flags & HB_SUBSET_FLAGS_NO_HINTING);
collect_subr_refs_in_str (get_parsed_charstring (i), param);
}
return true;
}
void collect_subr_refs_in_subr (unsigned int subr_num, parsed_cs_str_vec_t &subrs,
hb_set_t *closure,
const subr_subset_param_t &param)
{
if (closure->has (subr_num))
return;
closure->add (subr_num);
collect_subr_refs_in_str (subrs[subr_num], param);
}
void collect_subr_refs_in_str (const parsed_cs_str_t &str,
const subr_subset_param_t &param)
{
if (!str.has_calls ())
return;
for (auto &opstr : str.values)
{
if (!param.drop_hints || !opstr.is_hinting ())
{
switch (opstr.op)
{
case OpCode_callsubr:
collect_subr_refs_in_subr (opstr.subr_num, *param.parsed_local_subrs,
param.local_closure, param);
break;
case OpCode_callgsubr:
collect_subr_refs_in_subr (opstr.subr_num, *param.parsed_global_subrs,
param.global_closure, param);
break;
default: break;
}
}
}
}
bool encode_str (const parsed_cs_str_t &str, const unsigned int fd, str_buff_t &buff) const
{
str_encoder_t encoder (buff);
encoder.reset ();
bool hinting = !(plan->flags & HB_SUBSET_FLAGS_NO_HINTING);
/* if a prefix (CFF1 width or CFF2 vsindex) has been removed along with hints,
* re-insert it at the beginning of charstreing */
if (str.has_prefix () && !hinting && str.is_hint_dropped ())
{
encoder.encode_num (str.prefix_num ());
if (str.prefix_op () != OpCode_Invalid)
encoder.encode_op (str.prefix_op ());
}
unsigned size = 0;
for (auto &opstr : str.values)
{
size += opstr.length;
if (opstr.op == OpCode_callsubr || opstr.op == OpCode_callgsubr)
size += 3;
}
if (!buff.alloc (buff.length + size, true))
return false;
for (auto &opstr : str.values)
{
if (hinting || !opstr.is_hinting ())
{
switch (opstr.op)
{
case OpCode_callsubr:
encoder.encode_int (remaps.local_remaps[fd].biased_num (opstr.subr_num));
encoder.copy_str (opstr.ptr, opstr.length);
break;
case OpCode_callgsubr:
encoder.encode_int (remaps.global_remap.biased_num (opstr.subr_num));
encoder.copy_str (opstr.ptr, opstr.length);
break;
default:
encoder.copy_str (opstr.ptr, opstr.length);
break;
}
}
}
return !encoder.in_error ();
}
void compact_parsed_subrs () const
{
for (auto &cs : parsed_global_subrs_storage)
compact_string (cs);
for (auto &vec : parsed_local_subrs_storage)
for (auto &cs : vec)
compact_string (cs);
}
static void compact_string (parsed_cs_str_t &str)
{
unsigned count = str.values.length;
if (unlikely (!count)) return;
auto &opstr = str.values.arrayZ;
unsigned j = 0;
for (unsigned i = 1; i < count; i++)
{
/* See if we can combine op j and op i. */
bool combine =
(opstr[j].op != OpCode_callsubr && opstr[j].op != OpCode_callgsubr) &&
(opstr[i].op != OpCode_callsubr && opstr[i].op != OpCode_callgsubr) &&
(opstr[j].is_hinting () == opstr[i].is_hinting ()) &&
(opstr[j].ptr + opstr[j].length == opstr[i].ptr) &&
(opstr[j].length + opstr[i].length <= 255);
if (combine)
{
opstr[j].length += opstr[i].length;
opstr[j].op = OpCode_Invalid;
}
else
{
opstr[++j] = opstr[i];
}
}
str.values.shrink (j + 1);
}
void populate_subset_accelerator () const
{
if (!plan->inprogress_accelerator) return;
compact_parsed_subrs ();
plan->inprogress_accelerator->cff_accelerator =
cff_subset_accelerator_t::create(acc.blob,
parsed_charstrings,
parsed_global_subrs_storage,
parsed_local_subrs_storage);
plan->inprogress_accelerator->destroy_cff_accelerator =
cff_subset_accelerator_t::destroy;
}
const parsed_cs_str_t& get_parsed_charstring (unsigned i) const
{
if (cached_charstrings) return *(cached_charstrings[i]);
return parsed_charstrings[i];
}
protected:
const ACC &acc;
const hb_subset_plan_t *plan;
subr_closures_t closures;
hb_vector_t<const parsed_cs_str_t*> cached_charstrings;
const parsed_cs_str_vec_t* parsed_global_subrs;
const hb_vector_t<parsed_cs_str_vec_t>* parsed_local_subrs;
subr_remaps_t remaps;
private:
parsed_cs_str_vec_t parsed_charstrings;
parsed_cs_str_vec_t parsed_global_subrs_storage;
hb_vector_t<parsed_cs_str_vec_t> parsed_local_subrs_storage;
typedef typename SUBRS::count_type subr_count_type;
};
} /* namespace CFF */
HB_INTERNAL bool
hb_plan_subset_cff_fdselect (const hb_subset_plan_t *plan,
unsigned int fdCount,
const CFF::FDSelect &src, /* IN */
unsigned int &subset_fd_count /* OUT */,
unsigned int &subset_fdselect_size /* OUT */,
unsigned int &subset_fdselect_format /* OUT */,
hb_vector_t<CFF::code_pair_t> &fdselect_ranges /* OUT */,
hb_inc_bimap_t &fdmap /* OUT */);
HB_INTERNAL bool
hb_serialize_cff_fdselect (hb_serialize_context_t *c,
unsigned int num_glyphs,
const CFF::FDSelect &src,
unsigned int fd_count,
unsigned int fdselect_format,
unsigned int size,
const hb_vector_t<CFF::code_pair_t> &fdselect_ranges);
#endif /* HB_SUBSET_CFF_COMMON_HH */
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