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Diffstat (limited to 'src/base/ftpatent.c')
| -rw-r--r-- | src/base/ftpatent.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/src/base/ftpatent.c b/src/base/ftpatent.c new file mode 100644 index 0000000..d63f191 --- /dev/null +++ b/src/base/ftpatent.c @@ -0,0 +1,281 @@ +/***************************************************************************/ +/* */ +/* ftpatent.c */ +/* */ +/* FreeType API for checking patented TrueType bytecode instructions */ +/* (body). */ +/* */ +/* Copyright 2007 by David Turner. */ +/* */ +/* 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 FT_FREETYPE_H +#include FT_TRUETYPE_TAGS_H +#include FT_INTERNAL_OBJECTS_H +#include FT_INTERNAL_STREAM_H +#include FT_SERVICE_SFNT_H +#include FT_SERVICE_TRUETYPE_GLYF_H + + + static FT_Bool + _tt_check_patents_in_range( FT_Stream stream, + FT_ULong size ) + { + FT_Bool result = FALSE; + FT_Error error; + FT_Bytes p, end; + + + if ( FT_FRAME_ENTER( size ) ) + return 0; + + p = stream->cursor; + end = p + size; + + while ( p < end ) + { + switch (p[0]) + { + case 0x06: /* SPvTL // */ + case 0x07: /* SPvTL + */ + case 0x08: /* SFvTL // */ + case 0x09: /* SFvTL + */ + case 0x0A: /* SPvFS */ + case 0x0B: /* SFvFS */ + result = TRUE; + goto Exit; + + case 0x40: + if ( p + 1 >= end ) + goto Exit; + + p += p[1] + 2; + break; + + case 0x41: + if ( p + 1 >= end ) + goto Exit; + + p += p[1] * 2 + 2; + break; + + case 0x71: /* DELTAP2 */ + case 0x72: /* DELTAP3 */ + case 0x73: /* DELTAC0 */ + case 0x74: /* DELTAC1 */ + case 0x75: /* DELTAC2 */ + result = TRUE; + goto Exit; + + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + p += ( p[0] - 0xB0 ) + 2; + break; + + case 0xB8: + case 0xB9: + case 0xBA: + case 0xBB: + case 0xBC: + case 0xBD: + case 0xBE: + case 0xBF: + p += ( p[0] - 0xB8 ) * 2 + 3; + break; + + default: + p += 1; + break; + } + } + + Exit: + FT_FRAME_EXIT(); + return result; + } + + + static FT_Bool + _tt_check_patents_in_table( FT_Face face, + FT_ULong tag ) + { + FT_Stream stream = face->stream; + FT_Error error; + FT_Service_SFNT_Table service; + FT_Bool result = FALSE; + + + FT_FACE_FIND_SERVICE( face, service, SFNT_TABLE ); + + if ( service ) + { + FT_ULong offset, size; + + + error = service->table_info( face, tag, &offset, &size ); + if ( error || + FT_STREAM_SEEK( offset ) ) + goto Exit; + + result = _tt_check_patents_in_range( stream, size ); + } + + Exit: + return result; + } + + + static FT_Bool + _tt_face_check_patents( FT_Face face ) + { + FT_Stream stream = face->stream; + FT_UInt gindex; + FT_Error error; + FT_Bool result; + + FT_Service_TTGlyf service; + + + result = _tt_check_patents_in_table( face, TTAG_fpgm ); + if ( result ) + goto Exit; + + result = _tt_check_patents_in_table( face, TTAG_prep ); + if ( result ) + goto Exit; + + FT_FACE_FIND_SERVICE( face, service, TT_GLYF ); + if ( service == NULL ) + goto Exit; + + for ( gindex = 0; gindex < (FT_UInt)face->num_glyphs; gindex++ ) + { + FT_ULong offset, num_ins, size; + FT_Int num_contours; + + + offset = service->get_location( face, gindex, &size ); + if ( size == 0 ) + continue; + + if ( FT_STREAM_SEEK( offset ) || + FT_READ_SHORT( num_contours ) ) + continue; + + if ( num_contours >= 0 ) /* simple glyph */ + { + if ( FT_STREAM_SKIP( 8 + num_contours * 2 ) ) + continue; + } + else /* compound glyph */ + { + FT_Bool has_instr = 0; + + + if ( FT_STREAM_SKIP( 8 ) ) + continue; + + /* now read each component */ + for (;;) + { + FT_UInt flags, toskip; + + + if( FT_READ_USHORT( flags ) ) + break; + + toskip = 2 + 1 + 1; + + if ( ( flags & ( 1 << 0 ) ) != 0 ) /* ARGS_ARE_WORDS */ + toskip += 2; + + if ( ( flags & ( 1 << 3 ) ) != 0 ) /* WE_HAVE_A_SCALE */ + toskip += 2; + else if ( ( flags & ( 1 << 6 ) ) != 0 ) /* WE_HAVE_X_Y_SCALE */ + toskip += 4; + else if ( ( flags & ( 1 << 7 ) ) != 0 ) /* WE_HAVE_A_2x2 */ + toskip += 8; + + if ( ( flags & ( 1 << 8 ) ) != 0 ) /* WE_HAVE_INSTRUCTIONS */ + has_instr = 1; + + if ( FT_STREAM_SKIP( toskip ) ) + goto NextGlyph; + + if ( ( flags & ( 1 << 5 ) ) == 0 ) /* MORE_COMPONENTS */ + break; + } + + if ( !has_instr ) + goto NextGlyph; + } + + if ( FT_READ_USHORT( num_ins ) ) + continue; + + result = _tt_check_patents_in_range( stream, num_ins ); + if ( result ) + goto Exit; + + NextGlyph: + ; + } + + Exit: + return result; + } + + + /* documentation is in freetype.h */ + + FT_EXPORT_DEF( FT_Bool ) + FT_Face_CheckTrueTypePatents( FT_Face face ) + { + FT_Bool result = FALSE; + + + if ( face && FT_IS_SFNT( face ) ) + result = _tt_face_check_patents( face ); + + return result; + } + + + /* documentation is in freetype.h */ + + FT_EXPORT_DEF( FT_Bool ) + FT_Face_SetUnpatentedHinting( FT_Face face, + FT_Bool value ) + { + FT_Bool result = 0; + + +#if defined( TT_CONFIG_OPTION_UNPATENTED_HINTING ) && \ + !defined( TT_CONFIG_OPTION_BYTECODE_INTEPRETER ) + if ( face && FT_IS_SFNT( face ) ) + { + result = !face->internal->ignore_unpatented_hinter; + face->internal->ignore_unpatented_hinter = !value; + } +#else + FT_UNUSED( face ); + FT_UNUSED( value ); +#endif + + return result; + } + +/* END */ |