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author | Ewald Hew <ewaldhew@gmail.com> | 2017-10-12 18:13:08 +0800 |
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committer | Ewald Hew <ewaldhew@gmail.com> | 2017-10-12 18:32:50 +0800 |
commit | 78df3c27b651e3de068437ac35ee2214849badb9 (patch) | |
tree | 2c8df4abbef62c434d8d10f53ba079a57e998802 /src | |
parent | 8768536c89d6bb3e747bc69a7c2c1e58d2ed4aa9 (diff) | |
download | freetype2-78df3c27b651e3de068437ac35ee2214849badb9.tar.gz |
Extract width parsing from Type 1 parser.
Duplicate the fast advance width calculations from the old parser. This
is to facilitate adding options for compiling out the old parser.
* src/psaux/t1decode.{c,h} (t1_decoder_parse_metrics): New function.
* include/freetype/internal/psaux.h (T1_Decoder_Funcs): New entry
`parse_metrics'.
* src/psaux/psauxmod.c: Set the new entry.
* src/type1/t1gload.c (T1_Parse_Glyph_And_Get_Char_String),
src/cid/cidgload.c (cid_load_glyph): Separate
conditional for selecting engine.
Diffstat (limited to 'src')
-rw-r--r-- | src/cid/cidgload.c | 5 | ||||
-rw-r--r-- | src/psaux/psauxmod.c | 1 | ||||
-rw-r--r-- | src/psaux/t1decode.c | 277 | ||||
-rw-r--r-- | src/psaux/t1decode.h | 4 | ||||
-rw-r--r-- | src/type1/t1gload.c | 5 |
5 files changed, 292 insertions, 0 deletions
diff --git a/src/cid/cidgload.c b/src/cid/cidgload.c index 8541cca5a..82be44008 100644 --- a/src/cid/cidgload.c +++ b/src/cid/cidgload.c @@ -183,6 +183,11 @@ decoder, charstring + cs_offset, glyph_length - cs_offset ); + else if ( decoder->builder.metrics_only ) + error = psaux->t1_decoder_funcs->parse_metrics( + decoder, + charstring + cs_offset, + glyph_length - cs_offset ); else { PS_Decoder psdecoder; diff --git a/src/psaux/psauxmod.c b/src/psaux/psauxmod.c index b539b1ac1..16e887dec 100644 --- a/src/psaux/psauxmod.c +++ b/src/psaux/psauxmod.c @@ -90,6 +90,7 @@ t1_decoder_init, /* init */ t1_decoder_done, /* done */ t1_decoder_parse_charstrings, /* parse_charstrings_old */ + t1_decoder_parse_metrics, /* parse_metrics */ cf2_decoder_parse_charstrings /* parse_charstrings */ }; diff --git a/src/psaux/t1decode.c b/src/psaux/t1decode.c index e68b76dac..61d246269 100644 --- a/src/psaux/t1decode.c +++ b/src/psaux/t1decode.c @@ -1628,6 +1628,283 @@ return FT_THROW( Stack_Underflow ); } + /*************************************************************************/ + /* */ + /* <Function> */ + /* t1_decoder_parse_metrics */ + /* */ + /* <Description> */ + /* Parses a given Type 1 charstrings program to extract width */ + /* */ + /* <Input> */ + /* decoder :: The current Type 1 decoder. */ + /* */ + /* charstring_base :: The base address of the charstring stream. */ + /* */ + /* charstring_len :: The length in bytes of the charstring stream. */ + /* */ + /* <Return> */ + /* FreeType error code. 0 means success. */ + /* */ + FT_LOCAL_DEF( FT_Error ) + t1_decoder_parse_metrics( T1_Decoder decoder, + FT_Byte* charstring_base, + FT_UInt charstring_len ) + { + T1_Decoder_Zone zone; + FT_Byte* ip; + FT_Byte* limit; + T1_Builder builder = &decoder->builder; + +#ifdef FT_DEBUG_LEVEL_TRACE + FT_Bool bol = TRUE; +#endif + + + /* First of all, initialize the decoder */ + decoder->top = decoder->stack; + decoder->zone = decoder->zones; + zone = decoder->zones; + + builder->parse_state = T1_Parse_Start; + + FT_TRACE4(( "\n" + "Start charstring: get width\n" )); + + zone->base = charstring_base; + limit = zone->limit = charstring_base + charstring_len; + ip = zone->cursor = zone->base; + + /* now, execute loop */ + while ( ip < limit ) + { + FT_Long* top = decoder->top; + T1_Operator op = op_none; + FT_Int32 value = 0; + + +#ifdef FT_DEBUG_LEVEL_TRACE + if ( bol ) + { + FT_TRACE5(( " (%d)", decoder->top - decoder->stack )); + bol = FALSE; + } +#endif + + /*********************************************************************/ + /* */ + /* Decode operator or operand */ + /* */ + /* */ + + /* first of all, decompress operator or value */ + switch ( *ip++ ) + { + case 1: + case 3: + case 4: + case 5: + case 6: + case 7: + case 8: + case 9: + case 10: + case 11: + case 14: + case 15: + case 21: + case 22: + case 30: + case 31: + goto No_Width; + + case 13: + op = op_hsbw; + break; + + case 12: + if ( ip >= limit ) + { + FT_ERROR(( "t1_decoder_parse_metrics:" + " invalid escape (12+EOF)\n" )); + goto Syntax_Error; + } + + switch ( *ip++ ) + { + case 7: + op = op_sbw; + break; + + default: + goto No_Width; + } + break; + + case 255: /* four bytes integer */ + if ( ip + 4 > limit ) + { + FT_ERROR(( "t1_decoder_parse_metrics:" + " unexpected EOF in integer\n" )); + goto Syntax_Error; + } + + value = (FT_Int32)( ( (FT_UInt32)ip[0] << 24 ) | + ( (FT_UInt32)ip[1] << 16 ) | + ( (FT_UInt32)ip[2] << 8 ) | + (FT_UInt32)ip[3] ); + ip += 4; + + /* According to the specification, values > 32000 or < -32000 must */ + /* be followed by a `div' operator to make the result be in the */ + /* range [-32000;32000]. We expect that the second argument of */ + /* `div' is not a large number. Additionally, we don't handle */ + /* stuff like `<large1> <large2> <num> div <num> div' or */ + /* <large1> <large2> <num> div div'. This is probably not allowed */ + /* anyway. */ + if ( value > 32000 || value < -32000 ) + { + FT_ERROR(( "t1_decoder_parse_metrics:" + " large integer found for width\n" )); + goto Syntax_Error; + } + else + { + value = (FT_Int32)( (FT_UInt32)value << 16 ); + } + + break; + + default: + if ( ip[-1] >= 32 ) + { + if ( ip[-1] < 247 ) + value = (FT_Int32)ip[-1] - 139; + else + { + if ( ++ip > limit ) + { + FT_ERROR(( "t1_decoder_parse_metrics:" + " unexpected EOF in integer\n" )); + goto Syntax_Error; + } + + if ( ip[-2] < 251 ) + value = ( ( ip[-2] - 247 ) * 256 ) + ip[-1] + 108; + else + value = -( ( ( ip[-2] - 251 ) * 256 ) + ip[-1] + 108 ); + } + + value = (FT_Int32)( (FT_UInt32)value << 16 ); + } + else + { + FT_ERROR(( "t1_decoder_parse_metrics:" + " invalid byte (%d)\n", ip[-1] )); + goto Syntax_Error; + } + } + + /*********************************************************************/ + /* */ + /* Push value on stack, or process operator */ + /* */ + /* */ + if ( op == op_none ) + { + if ( top - decoder->stack >= T1_MAX_CHARSTRINGS_OPERANDS ) + { + FT_ERROR(( "t1_decoder_parse_metrics: stack overflow\n" )); + goto Syntax_Error; + } + +#ifdef FT_DEBUG_LEVEL_TRACE + FT_TRACE4(( " %d", value / 65536 )); +#endif + + *top++ = value; + decoder->top = top; + } + else /* general operator */ + { + FT_Int num_args = t1_args_count[op]; + + + FT_ASSERT( num_args >= 0 ); + + if ( top - decoder->stack < num_args ) + goto Stack_Underflow; + +#ifdef FT_DEBUG_LEVEL_TRACE + + if ( top - decoder->stack != num_args ) + FT_TRACE0(( "t1_decoder_parse_metrics:" + " too much operands on the stack" + " (seen %d, expected %d)\n", + top - decoder->stack, num_args )); + +#endif /* FT_DEBUG_LEVEL_TRACE */ + + top -= num_args; + + switch ( op ) + { + case op_hsbw: + FT_TRACE4(( " hsbw" )); + + builder->parse_state = T1_Parse_Have_Width; + + builder->left_bearing.x = ADD_LONG( builder->left_bearing.x, + top[0] ); + + builder->advance.x = top[1]; + builder->advance.y = 0; + + /* we only want to compute the glyph's metrics */ + /* (lsb + advance width), not load the rest of */ + /* it; so exit immediately */ + return FT_Err_Ok; + + case op_sbw: + FT_TRACE4(( " sbw" )); + + builder->parse_state = T1_Parse_Have_Width; + + builder->left_bearing.x = ADD_LONG( builder->left_bearing.x, + top[0] ); + builder->left_bearing.y = ADD_LONG( builder->left_bearing.y, + top[1] ); + + builder->advance.x = top[2]; + builder->advance.y = top[3]; + + /* we only want to compute the glyph's metrics */ + /* (lsb + advance width), not load the rest of */ + /* it; so exit immediately */ + return FT_Err_Ok; + + default: + FT_ERROR(( "t1_decoder_parse_metrics:" + " unhandled opcode %d\n", op )); + goto Syntax_Error; + } + + } /* general operator processing */ + + } /* while ip < limit */ + + FT_TRACE4(( "..end..\n\n" )); + + No_Width: + FT_ERROR(( "t1_decoder_parse_metrics:" + " no width, found op %d instead\n", + ip[-1] )); + Syntax_Error: + return FT_THROW( Syntax_Error ); + + Stack_Underflow: + return FT_THROW( Stack_Underflow ); + } /* parse a single Type 1 glyph */ FT_LOCAL_DEF( FT_Error ) diff --git a/src/psaux/t1decode.h b/src/psaux/t1decode.h index 1ca7e013d..420d120ff 100644 --- a/src/psaux/t1decode.h +++ b/src/psaux/t1decode.h @@ -43,6 +43,10 @@ FT_BEGIN_HEADER t1_decoder_parse_charstrings( T1_Decoder decoder, FT_Byte* base, FT_UInt len ); + FT_LOCAL( FT_Error ) + t1_decoder_parse_metrics( T1_Decoder decoder, + FT_Byte* charstring_base, + FT_UInt charstring_len ); FT_LOCAL( FT_Error ) t1_decoder_init( T1_Decoder decoder, diff --git a/src/type1/t1gload.c b/src/type1/t1gload.c index 30ca186fc..53f89b230 100644 --- a/src/type1/t1gload.c +++ b/src/type1/t1gload.c @@ -90,6 +90,11 @@ decoder, (FT_Byte*)char_string->pointer, (FT_UInt)char_string->length ); + else if ( decoder->builder.metrics_only ) + error = decoder_funcs->parse_metrics( + decoder, + (FT_Byte*)char_string->pointer, + (FT_UInt)char_string->length ); else { CFF_SubFontRec subfont; |