harfbuzz/src/hb-cff-interp-dict-common.hh

295 lines
6.4 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
*/
#ifndef HB_CFF_INTERP_DICT_COMMON_HH
#define HB_CFF_INTERP_DICT_COMMON_HH
#include "hb-cff-interp-common.hh"
#include <math.h>
#include <float.h>
namespace CFF {
using namespace OT;
/* an opstr and the parsed out dict value(s) */
struct dict_val_t : op_str_t
{
void init () { single_val.set_int (0); }
void fini () {}
number_t single_val;
};
typedef dict_val_t num_dict_val_t;
template <typename VAL> struct dict_values_t : parsed_values_t<VAL> {};
template <typename OPSTR=op_str_t>
struct top_dict_values_t : dict_values_t<OPSTR>
{
void init ()
{
dict_values_t<OPSTR>::init ();
charStringsOffset = 0;
FDArrayOffset = 0;
}
void fini () { dict_values_t<OPSTR>::fini (); }
unsigned int calculate_serialized_op_size (const OPSTR& opstr) const
{
switch (opstr.op)
{
case OpCode_CharStrings:
case OpCode_FDArray:
return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (opstr.op);
default:
return opstr.str.length;
}
}
unsigned int charStringsOffset;
unsigned int FDArrayOffset;
};
struct dict_opset_t : opset_t<number_t>
{
static void process_op (op_code_t op, interp_env_t<number_t>& env)
{
switch (op) {
case OpCode_longintdict: /* 5-byte integer */
env.argStack.push_longint_from_substr (env.str_ref);
break;
case OpCode_BCD: /* real number */
env.argStack.push_real (parse_bcd (env.str_ref));
break;
default:
opset_t<number_t>::process_op (op, env);
break;
}
}
static double parse_bcd (byte_str_ref_t& str_ref)
{
bool neg = false;
double int_part = 0;
uint64_t frac_part = 0;
uint32_t frac_count = 0;
bool exp_neg = false;
uint32_t exp_part = 0;
bool exp_overflow = false;
enum Part { INT_PART=0, FRAC_PART, EXP_PART } part = INT_PART;
enum Nibble { DECIMAL=10, EXP_POS, EXP_NEG, RESERVED, NEG, END };
const uint64_t MAX_FRACT = 0xFFFFFFFFFFFFFull; /* 1^52-1 */
const uint32_t MAX_EXP = 0x7FFu; /* 1^11-1 */
double value = 0.0;
unsigned char byte = 0;
for (uint32_t i = 0;; i++)
{
char d;
if ((i & 1) == 0)
{
if (!str_ref.avail ())
{
str_ref.set_error ();
return 0.0;
}
byte = str_ref[0];
str_ref.inc ();
d = byte >> 4;
}
else
d = byte & 0x0F;
switch (d)
{
case RESERVED:
str_ref.set_error ();
return value;
case END:
value = (double)(neg? -int_part: int_part);
if (frac_count > 0)
{
double frac = (frac_part / pow (10.0, (double)frac_count));
if (neg) frac = -frac;
value += frac;
}
if (unlikely (exp_overflow))
{
if (value == 0.0)
return value;
if (exp_neg)
return neg? -DBL_MIN: DBL_MIN;
else
return neg? -DBL_MAX: DBL_MAX;
}
if (exp_part != 0)
{
if (exp_neg)
value /= pow (10.0, (double)exp_part);
else
value *= pow (10.0, (double)exp_part);
}
return value;
case NEG:
if (i != 0)
{
str_ref.set_error ();
return 0.0;
}
neg = true;
break;
case DECIMAL:
if (part != INT_PART)
{
str_ref.set_error ();
return value;
}
part = FRAC_PART;
break;
case EXP_NEG:
exp_neg = true;
HB_FALLTHROUGH;
case EXP_POS:
if (part == EXP_PART)
{
str_ref.set_error ();
return value;
}
part = EXP_PART;
break;
default:
switch (part) {
default:
case INT_PART:
int_part = (int_part * 10) + d;
break;
case FRAC_PART:
if (likely (frac_part <= MAX_FRACT / 10))
{
frac_part = (frac_part * 10) + (unsigned)d;
frac_count++;
}
break;
case EXP_PART:
if (likely (exp_part * 10 + d <= MAX_EXP))
{
exp_part = (exp_part * 10) + d;
}
else
exp_overflow = true;
break;
}
}
}
return value;
}
static bool is_hint_op (op_code_t op)
{
switch (op)
{
case OpCode_BlueValues:
case OpCode_OtherBlues:
case OpCode_FamilyBlues:
case OpCode_FamilyOtherBlues:
case OpCode_StemSnapH:
case OpCode_StemSnapV:
case OpCode_StdHW:
case OpCode_StdVW:
case OpCode_BlueScale:
case OpCode_BlueShift:
case OpCode_BlueFuzz:
case OpCode_ForceBold:
case OpCode_LanguageGroup:
case OpCode_ExpansionFactor:
return true;
default:
return false;
}
}
};
template <typename VAL=op_str_t>
struct top_dict_opset_t : dict_opset_t
{
static void process_op (op_code_t op, interp_env_t<number_t>& env, top_dict_values_t<VAL> & dictval)
{
switch (op) {
case OpCode_CharStrings:
dictval.charStringsOffset = env.argStack.pop_uint ();
env.clear_args ();
break;
case OpCode_FDArray:
dictval.FDArrayOffset = env.argStack.pop_uint ();
env.clear_args ();
break;
case OpCode_FontMatrix:
env.clear_args ();
break;
default:
dict_opset_t::process_op (op, env);
break;
}
}
};
template <typename OPSET, typename PARAM, typename ENV=num_interp_env_t>
struct dict_interpreter_t : interpreter_t<ENV>
{
bool interpret (PARAM& param)
{
param.init ();
while (SUPER::env.str_ref.avail ())
{
OPSET::process_op (SUPER::env.fetch_op (), SUPER::env, param);
if (unlikely (SUPER::env.in_error ()))
return false;
}
return true;
}
private:
typedef interpreter_t<ENV> SUPER;
};
} /* namespace CFF */
#endif /* HB_CFF_INTERP_DICT_COMMON_HH */