/***************************************************************************/ /* */ /* psobjs.c */ /* */ /* Auxiliary functions for PostScript fonts (body). */ /* */ /* Copyright 1996-2001 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 #include FT_INTERNAL_POSTSCRIPT_AUX_H #include FT_INTERNAL_DEBUG_H #include "psobjs.h" #include "psauxerr.h" /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** PS_TABLE *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /* */ /* */ /* PS_Table_New */ /* */ /* */ /* Initializes a PS_Table. */ /* */ /* */ /* table :: The address of the target table. */ /* */ /* */ /* count :: The table size = the maximum number of elements. */ /* */ /* memory :: The memory object to use for all subsequent */ /* reallocations. */ /* */ /* */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF FT_Error PS_Table_New( PS_Table* table, FT_Int count, FT_Memory memory ) { FT_Error error; table->memory = memory; if ( ALLOC_ARRAY( table->elements, count, FT_Byte* ) || ALLOC_ARRAY( table->lengths, count, FT_Byte* ) ) goto Exit; table->max_elems = count; table->init = 0xDEADBEEFUL; table->num_elems = 0; table->block = 0; table->capacity = 0; table->cursor = 0; table->funcs = ps_table_funcs; Exit: if ( error ) FREE( table->elements ); return error; } static void shift_elements( PS_Table* table, FT_Byte* old_base ) { FT_Long delta = (FT_Long)( table->block - old_base ); FT_Byte** offset = table->elements; FT_Byte** limit = offset + table->max_elems; for ( ; offset < limit; offset++ ) { if ( offset[0] ) offset[0] += delta; } } static FT_Error reallocate_t1_table( PS_Table* table, FT_Int new_size ) { FT_Memory memory = table->memory; FT_Byte* old_base = table->block; FT_Error error; /* allocate new base block */ if ( ALLOC( table->block, new_size ) ) return error; /* copy elements and shift offsets */ if (old_base ) { MEM_Copy( table->block, old_base, table->capacity ); shift_elements( table, old_base ); FREE( old_base ); } table->capacity = new_size; return PSaux_Err_Ok; } /*************************************************************************/ /* */ /* */ /* PS_Table_Add */ /* */ /* */ /* Adds an object to a PS_Table, possibly growing its memory block. */ /* */ /* */ /* table :: The target table. */ /* */ /* */ /* index :: The index of the object in the table. */ /* */ /* object :: The address of the object to copy in memory. */ /* */ /* length :: The length in bytes of the source object. */ /* */ /* */ /* FreeType error code. 0 means success. An error is returned if a */ /* reallocation fails. */ /* */ FT_LOCAL_DEF FT_Error PS_Table_Add( PS_Table* table, FT_Int index, void* object, FT_Int length ) { if ( index < 0 || index > table->max_elems ) { FT_ERROR(( "PS_Table_Add: invalid index\n" )); return PSaux_Err_Invalid_Argument; } /* grow the base block if needed */ if ( table->cursor + length > table->capacity ) { FT_Error error; FT_Offset new_size = table->capacity; FT_Long in_offset; in_offset = (FT_Long)((FT_Byte*)object - table->block); if ( (FT_ULong)in_offset >= table->capacity ) in_offset = -1; while ( new_size < table->cursor + length ) new_size += 1024; error = reallocate_t1_table( table, new_size ); if ( error ) return error; if ( in_offset >= 0 ) object = table->block + in_offset; } /* add the object to the base block and adjust offset */ table->elements[index] = table->block + table->cursor; table->lengths [index] = length; MEM_Copy( table->block + table->cursor, object, length ); table->cursor += length; return PSaux_Err_Ok; } /*************************************************************************/ /* */ /* */ /* PS_Table_Done */ /* */ /* */ /* Finalizes a PS_Table (i.e., reallocate it to its current cursor). */ /* */ /* */ /* table :: The target table. */ /* */ /* */ /* This function does NOT release the heap's memory block. It is up */ /* to the caller to clean it, or reference it in its own structures. */ /* */ FT_LOCAL_DEF void PS_Table_Done( PS_Table* table ) { FT_Memory memory = table->memory; FT_Error error; FT_Byte* old_base = table->block; /* should never fail, because rec.cursor <= rec.size */ if ( !old_base ) return; if ( ALLOC( table->block, table->cursor ) ) return; MEM_Copy( table->block, old_base, table->cursor ); shift_elements( table, old_base ); table->capacity = table->cursor; FREE( old_base ); } FT_LOCAL_DEF void PS_Table_Release( PS_Table* table ) { FT_Memory memory = table->memory; if ( (FT_ULong)table->init == 0xDEADBEEFUL ) { FREE( table->block ); FREE( table->elements ); FREE( table->lengths ); table->init = 0; } } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** T1 PARSER *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ #define IS_T1_WHITESPACE( c ) ( (c) == ' ' || (c) == '\t' ) #define IS_T1_LINESPACE( c ) ( (c) == '\r' || (c) == '\n' ) #define IS_T1_SPACE( c ) ( IS_T1_WHITESPACE( c ) || IS_T1_LINESPACE( c ) ) FT_LOCAL_DEF void T1_Skip_Spaces( T1_Parser* parser ) { FT_Byte* cur = parser->cursor; FT_Byte* limit = parser->limit; while ( cur < limit ) { FT_Byte c = *cur; if ( !IS_T1_SPACE( c ) ) break; cur++; } parser->cursor = cur; } FT_LOCAL_DEF void T1_Skip_Alpha( T1_Parser* parser ) { FT_Byte* cur = parser->cursor; FT_Byte* limit = parser->limit; while ( cur < limit ) { FT_Byte c = *cur; if ( IS_T1_SPACE( c ) ) break; cur++; } parser->cursor = cur; } FT_LOCAL_DEF void T1_ToToken( T1_Parser* parser, T1_Token* token ) { FT_Byte* cur; FT_Byte* limit; FT_Byte starter, ender; FT_Int embed; token->type = t1_token_none; token->start = 0; token->limit = 0; /* first of all, skip space */ T1_Skip_Spaces( parser ); cur = parser->cursor; limit = parser->limit; if ( cur < limit ) { switch ( *cur ) { /************* check for strings ***********************/ case '(': token->type = t1_token_string; ender = ')'; goto Lookup_Ender; /************* check for programs/array ****************/ case '{': token->type = t1_token_array; ender = '}'; goto Lookup_Ender; /************* check for table/array ******************/ case '[': token->type = t1_token_array; ender = ']'; Lookup_Ender: embed = 1; starter = *cur++; token->start = cur; while ( cur < limit ) { if ( *cur == starter ) embed++; else if ( *cur == ender ) { embed--; if ( embed <= 0 ) { token->limit = cur++; break; } } cur++; } break; /* **************** otherwise, it's any token **********/ default: token->start = cur++; token->type = t1_token_any; while ( cur < limit && !IS_T1_SPACE( *cur ) ) cur++; token->limit = cur; } if ( !token->limit ) { token->start = 0; token->type = t1_token_none; } parser->cursor = cur; } } FT_LOCAL_DEF void T1_ToTokenArray( T1_Parser* parser, T1_Token* tokens, FT_UInt max_tokens, FT_Int* pnum_tokens ) { T1_Token master; *pnum_tokens = -1; T1_ToToken( parser, &master ); if ( master.type == t1_token_array ) { FT_Byte* old_cursor = parser->cursor; FT_Byte* old_limit = parser->limit; T1_Token* cur = tokens; T1_Token* limit = cur + max_tokens; parser->cursor = master.start; parser->limit = master.limit; while ( parser->cursor < parser->limit ) { T1_Token token; T1_ToToken( parser, &token ); if ( !token.type ) break; if ( cur < limit ) *cur = token; cur++; } *pnum_tokens = (FT_Int)( cur - tokens ); parser->cursor = old_cursor; parser->limit = old_limit; } } static FT_Long t1_toint( FT_Byte** cursor, FT_Byte* limit ) { FT_Long result = 0; FT_Byte* cur = *cursor; FT_Byte c = '\0', d; for ( ; cur < limit; cur++ ) { c = *cur; d = (FT_Byte)( c - '0' ); if ( d < 10 ) break; if ( c == '-' ) { cur++; break; } } if ( cur < limit ) { do { d = (FT_Byte)( cur[0] - '0' ); if ( d >= 10 ) break; result = result * 10 + d; cur++; } while ( cur < limit ); if ( c == '-' ) result = -result; } *cursor = cur; return result; } static FT_Long t1_tofixed( FT_Byte** cursor, FT_Byte* limit, FT_Long power_ten ) { FT_Byte* cur = *cursor; FT_Long num, divider, result; FT_Int sign = 0; FT_Byte d; if ( cur >= limit ) return 0; /* first of all, check the sign */ if ( *cur == '-' ) { sign = 1; cur++; } /* then, read the integer part, if any */ if ( *cur != '.' ) result = t1_toint( &cur, limit ) << 16; else result = 0; num = 0; divider = 1; if ( cur >= limit ) goto Exit; /* read decimal part, if any */ if ( *cur == '.' && cur + 1 < limit ) { cur++; for (;;) { d = (FT_Byte)( *cur - '0' ); if ( d >= 10 ) break; if ( divider < 10000000L ) { num = num * 10 + d; divider *= 10; } cur++; if ( cur >= limit ) break; } } /* read exponent, if any */ if ( cur + 1 < limit && ( *cur == 'e' || *cur == 'E' ) ) { cur++; power_ten += t1_toint( &cur, limit ); } Exit: /* raise to power of ten if needed */ while ( power_ten > 0 ) { result = result * 10; num = num * 10; power_ten--; } while ( power_ten < 0 ) { result = result / 10; divider = divider * 10; power_ten++; } if ( num ) result += FT_DivFix( num, divider ); if ( sign ) result = -result; *cursor = cur; return result; } static FT_Int t1_tocoordarray( FT_Byte** cursor, FT_Byte* limit, FT_Int max_coords, FT_Short* coords ) { FT_Byte* cur = *cursor; FT_Int count = 0; FT_Byte c, ender; if ( cur >= limit ) goto Exit; /* check for the beginning of an array; if not, only one number will */ /* be read */ c = *cur; ender = 0; if ( c == '[' ) ender = ']'; if ( c == '{' ) ender = '}'; if ( ender ) cur++; /* now, read the coordinates */ for ( ; cur < limit; ) { /* skip whitespace in front of data */ for (;;) { c = *cur; if ( c != ' ' && c != '\t' ) break; cur++; if ( cur >= limit ) goto Exit; } if ( count >= max_coords || c == ender ) break; coords[count] = (FT_Short)( t1_tofixed( &cur, limit, 0 ) >> 16 ); count++; if ( !ender ) break; } Exit: *cursor = cur; return count; } static FT_Int t1_tofixedarray( FT_Byte** cursor, FT_Byte* limit, FT_Int max_values, FT_Fixed* values, FT_Int power_ten ) { FT_Byte* cur = *cursor; FT_Int count = 0; FT_Byte c, ender; if ( cur >= limit ) goto Exit; /* check for the beginning of an array. If not, only one number will */ /* be read */ c = *cur; ender = 0; if ( c == '[' ) ender = ']'; if ( c == '{' ) ender = '}'; if ( ender ) cur++; /* now, read the values */ for ( ; cur < limit; ) { /* skip whitespace in front of data */ for (;;) { c = *cur; if ( c != ' ' && c != '\t' ) break; cur++; if ( cur >= limit ) goto Exit; } if ( count >= max_values || c == ender ) break; values[count] = t1_tofixed( &cur, limit, power_ten ); count++; if ( !ender ) break; } Exit: *cursor = cur; return count; } #if 0 static FT_String* t1_tostring( FT_Byte** cursor, FT_Byte* limit, FT_Memory memory ) { FT_Byte* cur = *cursor; FT_Int len = 0; FT_Int count; FT_String* result; FT_Error error; /* XXX: some stupid fonts have a `Notice' or `Copyright' string */ /* that simply doesn't begin with an opening parenthesis, even */ /* though they have a closing one! E.g. "amuncial.pfb" */ /* */ /* We must deal with these ill-fated cases there. Note that */ /* these fonts didn't work with the old Type 1 driver as the */ /* notice/copyright was not recognized as a valid string token */ /* and made the old token parser commit errors. */ while ( cur < limit && ( *cur == ' ' || *cur == '\t' ) ) cur++; if ( cur + 1 >= limit ) return 0; if ( *cur == '(' ) cur++; /* skip the opening parenthesis, if there is one */ *cursor = cur; count = 0; /* then, count its length */ for ( ; cur < limit; cur++ ) { if ( *cur == '(' ) count++; else if ( *cur == ')' ) { count--; if ( count < 0 ) break; } } len = cur - *cursor; if ( cur >= limit || ALLOC( result, len + 1 ) ) return 0; /* now copy the string */ MEM_Copy( result, *cursor, len ); result[len] = '\0'; *cursor = cur; return result; } #endif /* 0 */ static int t1_tobool( FT_Byte** cursor, FT_Byte* limit ) { FT_Byte* cur = *cursor; FT_Bool result = 0; /* return 1 if we find `true', 0 otherwise */ if ( cur + 3 < limit && cur[0] == 't' && cur[1] == 'r' && cur[2] == 'u' && cur[3] == 'e' ) { result = 1; cur += 5; } else if ( cur + 4 < limit && cur[0] == 'f' && cur[1] == 'a' && cur[2] == 'l' && cur[3] == 's' && cur[4] == 'e' ) { result = 0; cur += 6; } *cursor = cur; return result; } /* Load a simple field (i.e. non-table) into the current list of objects */ FT_LOCAL_DEF FT_Error T1_Load_Field( T1_Parser* parser, const T1_Field* field, void** objects, FT_UInt max_objects, FT_ULong* pflags ) { T1_Token token; FT_Byte* cur; FT_Byte* limit; FT_UInt count; FT_UInt index; FT_Error error; T1_ToToken( parser, &token ); if ( !token.type ) goto Fail; count = 1; index = 0; cur = token.start; limit = token.limit; if ( token.type == t1_token_array ) { /* if this is an array, and we have no blend, an error occurs */ if ( max_objects == 0 ) goto Fail; count = max_objects; index = 1; } for ( ; count > 0; count--, index++ ) { FT_Byte* q = (FT_Byte*)objects[index] + field->offset; FT_Long val; FT_String* string; switch ( field->type ) { case t1_field_bool: val = t1_tobool( &cur, limit ); goto Store_Integer; case t1_field_fixed: val = t1_tofixed( &cur, limit, 3 ); goto Store_Integer; case t1_field_integer: val = t1_toint( &cur, limit ); Store_Integer: switch ( field->size ) { case 1: *(FT_Byte*)q = (FT_Byte)val; break; case 2: *(FT_UShort*)q = (FT_UShort)val; break; case 4: *(FT_UInt32*)q = (FT_UInt32)val; break; default: /* for 64-bit systems */ *(FT_Long*)q = val; } break; case t1_field_string: { FT_Memory memory = parser->memory; FT_UInt len = (FT_UInt)( limit - cur ); if ( *(FT_String**)q ) /* with synthetic fonts, it's possible to find a field twice */ break; if ( ALLOC( string, len + 1 ) ) goto Exit; MEM_Copy( string, cur, len ); string[len] = 0; *(FT_String**)q = string; } break; default: /* an error occured */ goto Fail; } } #if 0 /* obsolete - keep for reference */ if ( pflags ) *pflags |= 1L << field->flag_bit; #else FT_UNUSED( pflags ); #endif error = PSaux_Err_Ok; Exit: return error; Fail: error = PSaux_Err_Invalid_File_Format; goto Exit; } #define T1_MAX_TABLE_ELEMENTS 32 FT_LOCAL_DEF FT_Error T1_Load_Field_Table( T1_Parser* parser, const T1_Field* field, void** objects, FT_UInt max_objects, FT_ULong* pflags ) { T1_Token elements[T1_MAX_TABLE_ELEMENTS]; T1_Token* token; FT_Int num_elements; FT_Error error = 0; FT_Byte* old_cursor; FT_Byte* old_limit; T1_Field fieldrec = *(T1_Field*)field; #if 1 fieldrec.type = t1_field_integer; if ( field->type == t1_field_fixed_array ) fieldrec.type = t1_field_fixed; #endif T1_ToTokenArray( parser, elements, 32, &num_elements ); if ( num_elements < 0 ) goto Fail; if ( num_elements > T1_MAX_TABLE_ELEMENTS ) num_elements = T1_MAX_TABLE_ELEMENTS; old_cursor = parser->cursor; old_limit = parser->limit; /* we store the elements count */ *(FT_Byte*)( (FT_Byte*)objects[0] + field->count_offset ) = (FT_Byte)num_elements; /* we now load each element, adjusting the field.offset on each one */ token = elements; for ( ; num_elements > 0; num_elements--, token++ ) { parser->cursor = token->start; parser->limit = token->limit; T1_Load_Field( parser, &fieldrec, objects, max_objects, 0 ); fieldrec.offset += fieldrec.size; } #if 0 /* obsolete -- keep for reference */ if ( pflags ) *pflags |= 1L << field->flag_bit; #else FT_UNUSED( pflags ); #endif parser->cursor = old_cursor; parser->limit = old_limit; Exit: return error; Fail: error = PSaux_Err_Invalid_File_Format; goto Exit; } FT_LOCAL_DEF FT_Long T1_ToInt( T1_Parser* parser ) { return t1_toint( &parser->cursor, parser->limit ); } FT_LOCAL_DEF FT_Fixed T1_ToFixed( T1_Parser* parser, FT_Int power_ten ) { return t1_tofixed( &parser->cursor, parser->limit, power_ten ); } FT_LOCAL_DEF FT_Int T1_ToCoordArray( T1_Parser* parser, FT_Int max_coords, FT_Short* coords ) { return t1_tocoordarray( &parser->cursor, parser->limit, max_coords, coords ); } FT_LOCAL_DEF FT_Int T1_ToFixedArray( T1_Parser* parser, FT_Int max_values, FT_Fixed* values, FT_Int power_ten ) { return t1_tofixedarray( &parser->cursor, parser->limit, max_values, values, power_ten ); } #if 0 FT_LOCAL_DEF FT_String* T1_ToString( T1_Parser* parser ) { return t1_tostring( &parser->cursor, parser->limit, parser->memory ); } FT_LOCAL_DEF FT_Bool T1_ToBool( T1_Parser* parser ) { return t1_tobool( &parser->cursor, parser->limit ); } #endif /* 0 */ FT_LOCAL_DEF void T1_Init_Parser( T1_Parser* parser, FT_Byte* base, FT_Byte* limit, FT_Memory memory ) { parser->error = 0; parser->base = base; parser->limit = limit; parser->cursor = base; parser->memory = memory; parser->funcs = t1_parser_funcs; } FT_LOCAL_DEF void T1_Done_Parser( T1_Parser* parser ) { FT_UNUSED( parser ); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** T1 BUILDER *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /* */ /* */ /* T1_Builder_Init */ /* */ /* */ /* Initializes a given glyph builder. */ /* */ /* */ /* builder :: A pointer to the glyph builder to initialize. */ /* */ /* */ /* face :: The current face object. */ /* */ /* size :: The current size object. */ /* */ /* glyph :: The current glyph object. */ /* */ FT_LOCAL_DEF void T1_Builder_Init( T1_Builder* builder, FT_Face face, FT_Size size, FT_GlyphSlot glyph, FT_Bool hinting ) { builder->path_begun = 0; builder->load_points = 1; builder->face = face; builder->glyph = glyph; builder->memory = face->memory; if ( glyph ) { FT_GlyphLoader* loader = glyph->internal->loader; builder->loader = loader; builder->base = &loader->base.outline; builder->current = &loader->current.outline; FT_GlyphLoader_Rewind( loader ); builder->hints_globals = size->internal; builder->hints_funcs = 0; if (hinting) builder->hints_funcs = glyph->internal->glyph_hints; } if ( size ) { builder->scale_x = size->metrics.x_scale; builder->scale_y = size->metrics.y_scale; } builder->pos_x = 0; builder->pos_y = 0; builder->left_bearing.x = 0; builder->left_bearing.y = 0; builder->advance.x = 0; builder->advance.y = 0; builder->funcs = t1_builder_funcs; } /*************************************************************************/ /* */ /* */ /* T1_Builder_Done */ /* */ /* */ /* Finalizes a given glyph builder. Its contents can still be used */ /* after the call, but the function saves important information */ /* within the corresponding glyph slot. */ /* */ /* */ /* builder :: A pointer to the glyph builder to finalize. */ /* */ FT_LOCAL_DEF void T1_Builder_Done( T1_Builder* builder ) { FT_GlyphSlot glyph = builder->glyph; if ( glyph ) glyph->outline = *builder->base; } /* check that there is enough room for `count' more points */ FT_LOCAL_DEF FT_Error T1_Builder_Check_Points( T1_Builder* builder, FT_Int count ) { return FT_GlyphLoader_Check_Points( builder->loader, count, 0 ); } /* add a new point, do not check space */ FT_LOCAL_DEF void T1_Builder_Add_Point( T1_Builder* builder, FT_Pos x, FT_Pos y, FT_Byte flag ) { FT_Outline* outline = builder->current; if ( builder->load_points ) { FT_Vector* point = outline->points + outline->n_points; FT_Byte* control = (FT_Byte*)outline->tags + outline->n_points; if ( builder->shift ) { x >>= 16; y >>= 16; } point->x = x; point->y = y; *control = (FT_Byte)( flag ? FT_Curve_Tag_On : FT_Curve_Tag_Cubic ); builder->last = *point; } outline->n_points++; } /* check space for a new on-curve point, then add it */ FT_LOCAL_DEF FT_Error T1_Builder_Add_Point1( T1_Builder* builder, FT_Pos x, FT_Pos y ) { FT_Error error; error = T1_Builder_Check_Points( builder, 1 ); if ( !error ) T1_Builder_Add_Point( builder, x, y, 1 ); return error; } /* check room for a new contour, then add it */ FT_LOCAL_DEF FT_Error T1_Builder_Add_Contour( T1_Builder* builder ) { FT_Outline* outline = builder->current; FT_Error error; if ( !builder->load_points ) { outline->n_contours++; return PSaux_Err_Ok; } error = FT_GlyphLoader_Check_Points( builder->loader, 0, 1 ); if ( !error ) { if ( outline->n_contours > 0 ) outline->contours[outline->n_contours - 1] = (short)( outline->n_points - 1 ); outline->n_contours++; } return error; } /* if a path was begun, add its first on-curve point */ FT_LOCAL_DEF FT_Error T1_Builder_Start_Point( T1_Builder* builder, FT_Pos x, FT_Pos y ) { FT_Error error = 0; /* test whether we are building a new contour */ if ( !builder->path_begun ) { builder->path_begun = 1; error = T1_Builder_Add_Contour( builder ); if ( !error ) error = T1_Builder_Add_Point1( builder, x, y ); } return error; } /* close the current contour */ FT_LOCAL_DEF void T1_Builder_Close_Contour( T1_Builder* builder ) { FT_Outline* outline = builder->current; /* XXXX: We must not include the last point in the path if it */ /* is located on the first point. */ if ( outline->n_points > 1 ) { FT_Int first = 0; FT_Vector* p1 = outline->points + first; FT_Vector* p2 = outline->points + outline->n_points - 1; FT_Byte* control = (FT_Byte*)outline->tags + outline->n_points - 1; if ( outline->n_contours > 1 ) { first = outline->contours[outline->n_contours - 2] + 1; p1 = outline->points + first; } /* `delete' last point only if it coincides with the first */ /* point and it is not a control point (which can happen). */ if ( p1->x == p2->x && p1->y == p2->y ) if ( *control == FT_Curve_Tag_On ) outline->n_points--; } if ( outline->n_contours > 0 ) outline->contours[outline->n_contours - 1] = (short)( outline->n_points - 1 ); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** OTHER *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_LOCAL_DEF void T1_Decrypt( FT_Byte* buffer, FT_Offset length, FT_UShort seed ) { while ( length > 0 ) { FT_Byte plain; plain = (FT_Byte)( *buffer ^ ( seed >> 8 ) ); seed = (FT_UShort)( ( *buffer + seed ) * 52845U + 22719 ); *buffer++ = plain; length--; } } /* END */