ref: 9d83d290287d6c844a7fe514050604cd75a76b3a
dir: /src/cff/cffparse.c/
/***************************************************************************/
/* */
/* cffparse.c */
/* */
/* CFF token stream parser (body) */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2007, 2008 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#include <ft2build.h>
#include "cffparse.h"
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_DEBUG_H
#include "cfferrs.h"
/*************************************************************************/
/* */
/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
/* messages during execution. */
/* */
#undef FT_COMPONENT
#define FT_COMPONENT trace_cffparse
enum
{
cff_kind_none = 0,
cff_kind_num,
cff_kind_fixed,
cff_kind_fixed_thousand,
cff_kind_string,
cff_kind_bool,
cff_kind_delta,
cff_kind_callback,
cff_kind_max /* do not remove */
};
/* now generate handlers for the most simple fields */
typedef FT_Error (*CFF_Field_Reader)( CFF_Parser parser );
typedef struct CFF_Field_Handler_
{
int kind;
int code;
FT_UInt offset;
FT_Byte size;
CFF_Field_Reader reader;
FT_UInt array_max;
FT_UInt count_offset;
} CFF_Field_Handler;
FT_LOCAL_DEF( void )
cff_parser_init( CFF_Parser parser,
FT_UInt code,
void* object )
{
FT_MEM_ZERO( parser, sizeof ( *parser ) );
parser->top = parser->stack;
parser->object_code = code;
parser->object = object;
}
/* read an integer */
static FT_Long
cff_parse_integer( FT_Byte* start,
FT_Byte* limit )
{
FT_Byte* p = start;
FT_Int v = *p++;
FT_Long val = 0;
if ( v == 28 )
{
if ( p + 2 > limit )
goto Bad;
val = (FT_Short)( ( (FT_Int)p[0] << 8 ) | p[1] );
p += 2;
}
else if ( v == 29 )
{
if ( p + 4 > limit )
goto Bad;
val = ( (FT_Long)p[0] << 24 ) |
( (FT_Long)p[1] << 16 ) |
( (FT_Long)p[2] << 8 ) |
p[3];
p += 4;
}
else if ( v < 247 )
{
val = v - 139;
}
else if ( v < 251 )
{
if ( p + 1 > limit )
goto Bad;
val = ( v - 247 ) * 256 + p[0] + 108;
p++;
}
else
{
if ( p + 1 > limit )
goto Bad;
val = -( v - 251 ) * 256 - p[0] - 108;
p++;
}
Exit:
return val;
Bad:
val = 0;
goto Exit;
}
static const FT_Long power_tens[] =
{
1L,
10L,
100L,
1000L,
10000L,
100000L,
1000000L,
10000000L,
100000000L,
1000000000L
};
/* read a real */
static FT_Fixed
cff_parse_real( FT_Byte* start,
FT_Byte* limit,
FT_Int power_ten,
FT_Int* scaling )
{
FT_Byte* p = start;
FT_UInt nib;
FT_UInt phase;
FT_Long result, number, rest, exponent;
FT_Int sign = 0, exponent_sign = 0;
FT_Int exponent_add, integer_length, fraction_length;
if ( scaling )
*scaling = 0;
result = 0;
number = 0;
rest = 0;
exponent = 0;
exponent_add = 0;
integer_length = 0;
fraction_length = 0;
/* First of all, read the integer part. */
phase = 4;
for (;;)
{
/* If we entered this iteration with phase == 4, we need to */
/* read a new byte. This also skips past the initial 0x1E. */
if ( phase )
{
p++;
/* Make sure we don't read past the end. */
if ( p >= limit )
goto Exit;
}
/* Get the nibble. */
nib = ( p[0] >> phase ) & 0xF;
phase = 4 - phase;
if ( nib == 0xE )
sign = 1;
else if ( nib > 9 )
break;
else
{
/* Increase exponent if we can't add the digit. */
if ( number >= 0xCCCCCCCL )
exponent_add++;
/* Skip leading zeros. */
else if ( nib || number )
{
integer_length++;
number = number * 10 + nib;
}
}
}
/* Read fraction part, if any. */
if ( nib == 0xa )
for (;;)
{
/* If we entered this iteration with phase == 4, we need */
/* to read a new byte. */
if ( phase )
{
p++;
/* Make sure we don't read past the end. */
if ( p >= limit )
goto Exit;
}
/* Get the nibble. */
nib = ( p[0] >> phase ) & 0xF;
phase = 4 - phase;
if ( nib >= 10 )
break;
/* Skip leading zeros if possible. */
if ( !nib && !number )
exponent_add--;
/* Only add digit if we don't overflow. */
else if ( number < 0xCCCCCCCL )
{
fraction_length++;
number = number * 10 + nib;
}
}
/* Read exponent, if any. */
if ( nib == 12 )
{
exponent_sign = 1;
nib = 11;
}
if ( nib == 11 )
{
for (;;)
{
/* If we entered this iteration with phase == 4, */
/* we need to read a new byte. */
if ( phase )
{
p++;
/* Make sure we don't read past the end. */
if ( p >= limit )
goto Exit;
}
/* Get the nibble. */
nib = ( p[0] >> phase ) & 0xF;
phase = 4 - phase;
if ( nib >= 10 )
break;
exponent = exponent * 10 + nib;
/* Arbitrarily limit exponent. */
if ( exponent > 1000 )
goto Exit;
}
if ( exponent_sign )
exponent = -exponent;
}
/* We don't check `power_ten' and `exponent_add'. */
exponent += power_ten + exponent_add;
if ( scaling )
{
/* Only use `fraction_length'. */
fraction_length += integer_length;
exponent += integer_length;
if ( fraction_length <= 5 )
{
if ( number > 0x7FFFL )
{
result = FT_DivFix( number, 10 );
*scaling = exponent - fraction_length + 1;
}
else
{
if ( exponent > 0 )
{
FT_Int new_fraction_length, shift;
/* Make `scaling' as small as possible. */
new_fraction_length = FT_MIN( exponent, 5 );
exponent -= new_fraction_length;
shift = new_fraction_length - fraction_length;
number *= power_tens[shift];
if ( number > 0x7FFFL )
{
number /= 10;
exponent += 1;
}
}
else
exponent -= fraction_length;
result = number << 16;
*scaling = exponent;
}
}
else
{
if ( ( number / power_tens[fraction_length - 5] ) > 0x7FFFL )
{
result = FT_DivFix( number, power_tens[fraction_length - 4] );
*scaling = exponent - 4;
}
else
{
result = FT_DivFix( number, power_tens[fraction_length - 5] );
*scaling = exponent - 5;
}
}
}
else
{
integer_length += exponent;
fraction_length -= exponent;
/* Check for overflow and underflow. */
if ( FT_ABS( integer_length ) > 5 )
goto Exit;
/* Remove non-significant digits. */
if ( integer_length < 0 ) {
number /= power_tens[-integer_length];
fraction_length += integer_length;
}
/* Convert into 16.16 format. */
if ( fraction_length > 0 )
{
if ( ( number / power_tens[fraction_length] ) > 0x7FFFL )
goto Exit;
result = FT_DivFix( number, power_tens[fraction_length] );
}
else
{
number *= power_tens[-fraction_length];
if ( number > 0x7FFFL )
goto Exit;
result = number << 16;
}
}
if ( sign )
result = -result;
Exit:
return result;
}
/* read a number, either integer or real */
static FT_Long
cff_parse_num( FT_Byte** d )
{
return **d == 30 ? ( cff_parse_real( d[0], d[1], 0, NULL ) >> 16 )
: cff_parse_integer( d[0], d[1] );
}
/* read a floating point number, either integer or real */
static FT_Fixed
cff_parse_fixed( FT_Byte** d )
{
return **d == 30 ? cff_parse_real( d[0], d[1], 0, NULL )
: cff_parse_integer( d[0], d[1] ) << 16;
}
/* read a floating point number, either integer or real, */
/* but return `10^scaling' times the number read in */
static FT_Fixed
cff_parse_fixed_scaled( FT_Byte** d,
FT_Int scaling )
{
return **d == 30 ? cff_parse_real( d[0], d[1], scaling, NULL )
: ( cff_parse_integer( d[0], d[1] ) *
power_tens[scaling] ) << 16;
}
/* read a floating point number, either integer or real, */
/* and return it as precise as possible -- `scaling' returns */
/* the scaling factor (as a power of 10) */
static FT_Fixed
cff_parse_fixed_dynamic( FT_Byte** d,
FT_Int* scaling )
{
FT_ASSERT( scaling );
if ( **d == 30 )
return cff_parse_real( d[0], d[1], 0, scaling );
else
{
FT_Long number;
FT_Int integer_length;
number = cff_parse_integer( d[0], d[1] );
if ( number > 0x7FFFL )
{
for ( integer_length = 5; integer_length < 10; integer_length++ )
if ( number < power_tens[integer_length] )
break;
if ( ( number / power_tens[integer_length - 5] ) > 0x7FFFL )
{
*scaling = integer_length - 4;
return FT_DivFix( number, power_tens[integer_length - 4] );
}
else
{
*scaling = integer_length - 5;
return FT_DivFix( number, power_tens[integer_length - 5] );
}
}
else
{
*scaling = 0;
return number << 16;
}
}
}
static FT_Error
cff_parse_font_matrix( CFF_Parser parser )
{
CFF_FontRecDict dict = (CFF_FontRecDict)parser->object;
FT_Matrix* matrix = &dict->font_matrix;
FT_Vector* offset = &dict->font_offset;
FT_ULong* upm = &dict->units_per_em;
FT_Byte** data = parser->stack;
FT_Error error = CFF_Err_Stack_Underflow;
if ( parser->top >= parser->stack + 6 )
{
FT_Int scaling;
error = CFF_Err_Ok;
/* We expect a well-formed font matrix, this is, the matrix elements */
/* `xx' and `yy' are of approximately the same magnitude. To avoid */
/* loss of precision, we use the magnitude of element `xx' to scale */
/* all other elements. The scaling factor is then contained in the */
/* `units_per_em' value. */
matrix->xx = cff_parse_fixed_dynamic( data++, &scaling );
scaling = -scaling;
if ( scaling < 0 || scaling > 9 )
{
/* Return default matrix in case of unlikely values. */
matrix->xx = 0x10000L;
matrix->yx = 0;
matrix->yx = 0;
matrix->yy = 0x10000L;
offset->x = 0;
offset->y = 0;
*upm = 1;
goto Exit;
}
matrix->yx = cff_parse_fixed_scaled( data++, scaling );
matrix->xy = cff_parse_fixed_scaled( data++, scaling );
matrix->yy = cff_parse_fixed_scaled( data++, scaling );
offset->x = cff_parse_fixed_scaled( data++, scaling );
offset->y = cff_parse_fixed_scaled( data, scaling );
*upm = power_tens[scaling];
}
Exit:
return error;
}
static FT_Error
cff_parse_font_bbox( CFF_Parser parser )
{
CFF_FontRecDict dict = (CFF_FontRecDict)parser->object;
FT_BBox* bbox = &dict->font_bbox;
FT_Byte** data = parser->stack;
FT_Error error;
error = CFF_Err_Stack_Underflow;
if ( parser->top >= parser->stack + 4 )
{
bbox->xMin = FT_RoundFix( cff_parse_fixed( data++ ) );
bbox->yMin = FT_RoundFix( cff_parse_fixed( data++ ) );
bbox->xMax = FT_RoundFix( cff_parse_fixed( data++ ) );
bbox->yMax = FT_RoundFix( cff_parse_fixed( data ) );
error = CFF_Err_Ok;
}
return error;
}
static FT_Error
cff_parse_private_dict( CFF_Parser parser )
{
CFF_FontRecDict dict = (CFF_FontRecDict)parser->object;
FT_Byte** data = parser->stack;
FT_Error error;
error = CFF_Err_Stack_Underflow;
if ( parser->top >= parser->stack + 2 )
{
dict->private_size = cff_parse_num( data++ );
dict->private_offset = cff_parse_num( data );
error = CFF_Err_Ok;
}
return error;
}
static FT_Error
cff_parse_cid_ros( CFF_Parser parser )
{
CFF_FontRecDict dict = (CFF_FontRecDict)parser->object;
FT_Byte** data = parser->stack;
FT_Error error;
error = CFF_Err_Stack_Underflow;
if ( parser->top >= parser->stack + 3 )
{
dict->cid_registry = (FT_UInt)cff_parse_num ( data++ );
dict->cid_ordering = (FT_UInt)cff_parse_num ( data++ );
dict->cid_supplement = (FT_ULong)cff_parse_num( data );
error = CFF_Err_Ok;
}
return error;
}
#define CFF_FIELD_NUM( code, name ) \
CFF_FIELD( code, name, cff_kind_num )
#define CFF_FIELD_FIXED( code, name ) \
CFF_FIELD( code, name, cff_kind_fixed )
#define CFF_FIELD_FIXED_1000( code, name ) \
CFF_FIELD( code, name, cff_kind_fixed_thousand )
#define CFF_FIELD_STRING( code, name ) \
CFF_FIELD( code, name, cff_kind_string )
#define CFF_FIELD_BOOL( code, name ) \
CFF_FIELD( code, name, cff_kind_bool )
#define CFF_FIELD_DELTA( code, name, max ) \
CFF_FIELD( code, name, cff_kind_delta )
#define CFF_FIELD_CALLBACK( code, name ) \
{ \
cff_kind_callback, \
code | CFFCODE, \
0, 0, \
cff_parse_ ## name, \
0, 0 \
},
#undef CFF_FIELD
#define CFF_FIELD( code, name, kind ) \
{ \
kind, \
code | CFFCODE, \
FT_FIELD_OFFSET( name ), \
FT_FIELD_SIZE( name ), \
0, 0, 0 \
},
#undef CFF_FIELD_DELTA
#define CFF_FIELD_DELTA( code, name, max ) \
{ \
cff_kind_delta, \
code | CFFCODE, \
FT_FIELD_OFFSET( name ), \
FT_FIELD_SIZE_DELTA( name ), \
0, \
max, \
FT_FIELD_OFFSET( num_ ## name ) \
},
#define CFFCODE_TOPDICT 0x1000
#define CFFCODE_PRIVATE 0x2000
static const CFF_Field_Handler cff_field_handlers[] =
{
#include "cfftoken.h"
{ 0, 0, 0, 0, 0, 0, 0 }
};
FT_LOCAL_DEF( FT_Error )
cff_parser_run( CFF_Parser parser,
FT_Byte* start,
FT_Byte* limit )
{
FT_Byte* p = start;
FT_Error error = CFF_Err_Ok;
parser->top = parser->stack;
parser->start = start;
parser->limit = limit;
parser->cursor = start;
while ( p < limit )
{
FT_UInt v = *p;
if ( v >= 27 && v != 31 )
{
/* it's a number; we will push its position on the stack */
if ( parser->top - parser->stack >= CFF_MAX_STACK_DEPTH )
goto Stack_Overflow;
*parser->top ++ = p;
/* now, skip it */
if ( v == 30 )
{
/* skip real number */
p++;
for (;;)
{
if ( p >= limit )
goto Syntax_Error;
v = p[0] >> 4;
if ( v == 15 )
break;
v = p[0] & 0xF;
if ( v == 15 )
break;
p++;
}
}
else if ( v == 28 )
p += 2;
else if ( v == 29 )
p += 4;
else if ( v > 246 )
p += 1;
}
else
{
/* This is not a number, hence it's an operator. Compute its code */
/* and look for it in our current list. */
FT_UInt code;
FT_UInt num_args = (FT_UInt)
( parser->top - parser->stack );
const CFF_Field_Handler* field;
*parser->top = p;
code = v;
if ( v == 12 )
{
/* two byte operator */
p++;
if ( p >= limit )
goto Syntax_Error;
code = 0x100 | p[0];
}
code = code | parser->object_code;
for ( field = cff_field_handlers; field->kind; field++ )
{
if ( field->code == (FT_Int)code )
{
/* we found our field's handler; read it */
FT_Long val;
FT_Byte* q = (FT_Byte*)parser->object + field->offset;
/* check that we have enough arguments -- except for */
/* delta encoded arrays, which can be empty */
if ( field->kind != cff_kind_delta && num_args < 1 )
goto Stack_Underflow;
switch ( field->kind )
{
case cff_kind_bool:
case cff_kind_string:
case cff_kind_num:
val = cff_parse_num( parser->stack );
goto Store_Number;
case cff_kind_fixed:
val = cff_parse_fixed( parser->stack );
goto Store_Number;
case cff_kind_fixed_thousand:
val = cff_parse_fixed_scaled( parser->stack, 3 );
Store_Number:
switch ( field->size )
{
case (8 / FT_CHAR_BIT):
*(FT_Byte*)q = (FT_Byte)val;
break;
case (16 / FT_CHAR_BIT):
*(FT_Short*)q = (FT_Short)val;
break;
case (32 / FT_CHAR_BIT):
*(FT_Int32*)q = (FT_Int)val;
break;
default: /* for 64-bit systems */
*(FT_Long*)q = val;
}
break;
case cff_kind_delta:
{
FT_Byte* qcount = (FT_Byte*)parser->object +
field->count_offset;
FT_Byte** data = parser->stack;
if ( num_args > field->array_max )
num_args = field->array_max;
/* store count */
*qcount = (FT_Byte)num_args;
val = 0;
while ( num_args > 0 )
{
val += cff_parse_num( data++ );
switch ( field->size )
{
case (8 / FT_CHAR_BIT):
*(FT_Byte*)q = (FT_Byte)val;
break;
case (16 / FT_CHAR_BIT):
*(FT_Short*)q = (FT_Short)val;
break;
case (32 / FT_CHAR_BIT):
*(FT_Int32*)q = (FT_Int)val;
break;
default: /* for 64-bit systems */
*(FT_Long*)q = val;
}
q += field->size;
num_args--;
}
}
break;
default: /* callback */
error = field->reader( parser );
if ( error )
goto Exit;
}
goto Found;
}
}
/* this is an unknown operator, or it is unsupported; */
/* we will ignore it for now. */
Found:
/* clear stack */
parser->top = parser->stack;
}
p++;
}
Exit:
return error;
Stack_Overflow:
error = CFF_Err_Invalid_Argument;
goto Exit;
Stack_Underflow:
error = CFF_Err_Invalid_Argument;
goto Exit;
Syntax_Error:
error = CFF_Err_Invalid_Argument;
goto Exit;
}
/* END */