com.itextpdf.io.font

Class CFFFontSubset

java.lang.Object

com.itextpdf.io.font.CFFFont

com.itextpdf.io.font.CFFFontSubset

public class CFFFontSubset
extends CFFFont

This Class subsets a CFF Type Font. The subset is preformed for CID fonts and NON CID fonts. The Charstring is subsetted for both types. For CID fonts only the FDArray which are used are embedded. The Lsubroutines of the FDArrays used are subsetted as well. The Subroutine subset supports both Type1 and Type2 formatting although only tested on Type2 Format. For Non CID the Lsubroutines are subsetted. On both types the Gsubroutines is subsetted. A font which was not of CID type is transformed into CID as a part of the subset process. The CID synthetic creation was written by Sivan Toledo (sivan@math.tau.ac.il)

Author:

Oren Manor (manorore@post.tau.ac.il) and Ygal Blum (blumygal@post.tau.ac.il)

Nested Class Summary

Nested classes/interfaces inherited from class com.itextpdf.io.font.CFFFont

CFFFont.DictNumberItem, CFFFont.DictOffsetItem, CFFFont.Font, CFFFont.IndexBaseItem, CFFFont.IndexMarkerItem, CFFFont.IndexOffsetItem, CFFFont.Item, CFFFont.MarkerItem, CFFFont.OffsetItem, CFFFont.RangeItem, CFFFont.StringItem, CFFFont.SubrMarkerItem, CFFFont.UInt16Item, CFFFont.UInt24Item, CFFFont.UInt32Item, CFFFont.UInt8Item

Field Summary

Fields inherited from class com.itextpdf.io.font.CFFFont

arg_count, args, buf, fonts, gsubrIndexOffset, gsubrOffsets, key, nameIndexOffset, nameOffsets, stringIndexOffset, stringOffsets, topdictIndexOffset, topdictOffsets

Constructor Summary

Constructors

Constructor and Description
CFFFontSubset(byte[] cff, Map<Integer,int[]> GlyphsUsed) C'tor for CFFFontSubset

Method Summary

Modifier and Type	Method and Description
protected byte[]	AssembleIndex(int[] NewOffsets, byte[] NewObjects) Function creates the new index, inserting the count,offsetsize,offset array and object array.
protected void	BuildFDArrayUsed(int Font) Function reads the FDSelect and builds the FDArrayUsed Map According to the glyphs used
protected void	BuildFDSubrsOffsets(int Font, int FD) The function finds for the FD array processed the local subr offset and its offset array.
protected void	BuildGSubrsUsed(int Font) Function scans the Glsubr used list to find recursive calls to Gsubrs and adds to Map and list
protected void	BuildIndexHeader(int Count, int Offsize, int First) Function Build the header of an index
protected void	BuildNewCharString(int FontIndex) Function uses BuildNewIndex to create the new index of the subset charstrings
protected byte[]	BuildNewFile(int Font) The function builds the new output stream according to the subset process
protected byte[]	BuildNewIndex(int[] Offsets, Map<Integer,int[]> Used, byte OperatorForUnusedEntries) Function builds the new offset array, object array and assembles the index.
protected byte[]	BuildNewIndexAndCopyAllGSubrs(int[] Offsets, byte OperatorForUnusedEntries) Function builds the new offset array, object array and assembles the index.
protected void	BuildNewLGSubrs(int Font) Function builds the new local and global subsrs indices.
protected void	BuildSubrUsed(int Font, int FD, int SubrOffset, int[] SubrsOffsets, Map<Integer,int[]> hSubr, List<Integer> lSubr) Function uses ReadAsubr on the glyph used to build the LSubr and Gsubr Map.
protected int	CalcBias(int Offset, int Font) Function calcs bias according to the CharString type and the count of the subrs
protected int	CalcHints(int begin, int end, int LBias, int GBias, int[] LSubrsOffsets) The function reads the subroutine and returns the number of the hint in it.
protected void	CopyHeader() Function Copies the header from the original fileto the output list
protected int	countEntireIndexRange(int indexOffset) Function computes the size of an index
protected void	CreateCharset(CFFFont.OffsetItem charsetRef, int nglyphs) Function creates new CharSet for non-CID fonts.
protected void	CreateFDArray(CFFFont.OffsetItem fdarrayRef, CFFFont.OffsetItem privateRef, int Font) Function creates new FDArray for non-CID fonts.
protected void	CreateFDSelect(CFFFont.OffsetItem fdselectRef, int nglyphs) Function creates new FDSelect for non-CID fonts.
protected void	CreateKeys(CFFFont.OffsetItem fdarrayRef, CFFFont.OffsetItem fdselectRef, CFFFont.OffsetItem charsetRef, CFFFont.OffsetItem charstringsRef) Function adds the keys into the TopDict
protected void	CreateNewStringIndex(int Font) Function takes the original string item and adds the new strings to accommodate the CID rules
protected void	EmptyStack() Empty the Type2 Stack
protected void	HandelStack() Function Checks how the current operator effects the run time stack after being run An operator may increase or decrease the stack size
protected void	PopStack() Pop one element from the stack
byte[]	Process(String fontName) The Process function extracts one font out of the CFF file and returns a subset version of the original.
protected void	PushStack() Add an item to the stack
protected void	ReadASubr(int begin, int end, int GBias, int LBias, Map<Integer,int[]> hSubr, List<Integer> lSubr, int[] LSubrsOffsets) The function reads a subrs (glyph info) between begin and end.
protected void	ReadCommand() The function reads the next command after the file pointer is set
protected void	ReadFDArray(int Font) Read the FDArray count, offsize and Offset array
protected void	readFDSelect(int Font) Read the FDSelect of the font and compute the array and its length
protected int	StackOpp() Function checks the key and return the change to the stack after the operator

Methods inherited from class com.itextpdf.io.font.CFFFont

exists, getCID, getDictItem, getEntireIndexRange, getNames, getString, isCID

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CFFFontSubset

public CFFFontSubset(byte[] cff,
                     Map<Integer,int[]> GlyphsUsed)

C'tor for CFFFontSubset

Parameters:

cff - - The font file

GlyphsUsed - - a Map that contains the glyph used in the subset

Method Detail

readFDSelect

protected void readFDSelect(int Font)

Read the FDSelect of the font and compute the array and its length

Parameters:

Font - The index of the font being processed

BuildFDArrayUsed

protected void BuildFDArrayUsed(int Font)

Function reads the FDSelect and builds the FDArrayUsed Map According to the glyphs used

Parameters:

Font - the Number of font being processed

ReadFDArray

protected void ReadFDArray(int Font)

Read the FDArray count, offsize and Offset array

Parameters:

Font -

Process

public byte[] Process(String fontName)

The Process function extracts one font out of the CFF file and returns a subset version of the original.

Parameters:

fontName - - The name of the font to be taken out of the CFF

Returns:

The new font stream

CalcBias

protected int CalcBias(int Offset,
                       int Font)

Function calcs bias according to the CharString type and the count of the subrs

Parameters:

Offset - The offset to the relevant subrs index

Font - the font

Returns:

The calculated Bias

BuildNewCharString

protected void BuildNewCharString(int FontIndex)
                           throws IOException

Function uses BuildNewIndex to create the new index of the subset charstrings

Parameters:

FontIndex - the font

Throws:

IOException

BuildNewLGSubrs

protected void BuildNewLGSubrs(int Font)
                        throws IOException

Function builds the new local and global subsrs indices. IF CID then All of the FD Array lsubrs will be subsetted.

Parameters:

Font - the font

Throws:

IOException

BuildFDSubrsOffsets

protected void BuildFDSubrsOffsets(int Font,
                                   int FD)

The function finds for the FD array processed the local subr offset and its offset array.

Parameters:

Font - the font

FD - The FDARRAY processed

BuildSubrUsed

protected void BuildSubrUsed(int Font,
                             int FD,
                             int SubrOffset,
                             int[] SubrsOffsets,
                             Map<Integer,int[]> hSubr,
                             List<Integer> lSubr)

Function uses ReadAsubr on the glyph used to build the LSubr and Gsubr Map. The Map (of the lsubr only) is then scanned recursively for Lsubr and Gsubrs calls.

Parameters:

Font - the font

FD - FD array processed. 0 indicates function was called by non CID font

SubrOffset - the offset to the subr index to calc the bias

SubrsOffsets - the offset array of the subr index

hSubr - Map of the subrs used

lSubr - list of the subrs used

BuildGSubrsUsed

protected void BuildGSubrsUsed(int Font)

Function scans the Glsubr used list to find recursive calls to Gsubrs and adds to Map and list

Parameters:

Font - the font

ReadASubr

protected void ReadASubr(int begin,
                         int end,
                         int GBias,
                         int LBias,
                         Map<Integer,int[]> hSubr,
                         List<Integer> lSubr,
                         int[] LSubrsOffsets)

The function reads a subrs (glyph info) between begin and end. Adds calls to a Lsubr to the hSubr and lSubrs. Adds calls to a Gsubr to the hGSubr and lGSubrs.

Parameters:

begin - the start point of the subr

end - the end point of the subr

GBias - the bias of the Global Subrs

LBias - the bias of the Local Subrs

hSubr - the Map for the lSubrs

lSubr - the list for the lSubrs

HandelStack

protected void HandelStack()

Function Checks how the current operator effects the run time stack after being run An operator may increase or decrease the stack size

StackOpp

protected int StackOpp()

Function checks the key and return the change to the stack after the operator

Returns:

The change in the stack. 2-> flush the stack

EmptyStack

protected void EmptyStack()

Empty the Type2 Stack

PopStack

protected void PopStack()

Pop one element from the stack

PushStack

protected void PushStack()

Add an item to the stack

ReadCommand

protected void ReadCommand()

The function reads the next command after the file pointer is set

CalcHints

protected int CalcHints(int begin,
                        int end,
                        int LBias,
                        int GBias,
                        int[] LSubrsOffsets)

The function reads the subroutine and returns the number of the hint in it. If a call to another subroutine is found the function calls recursively.

Parameters:

begin - the start point of the subr

end - the end point of the subr

LBias - the bias of the Local Subrs

GBias - the bias of the Global Subrs

LSubrsOffsets - The Offsets array of the subroutines

Returns:

The number of hints in the subroutine read.

BuildNewIndex

protected byte[] BuildNewIndex(int[] Offsets,
                               Map<Integer,int[]> Used,
                               byte OperatorForUnusedEntries)
                        throws IOException

Function builds the new offset array, object array and assembles the index. used for creating the glyph and subrs subsetted index

Parameters:

Offsets - the offset array of the original index

Used - the Map of the used objects

OperatorForUnusedEntries - the operator inserted into the data stream for unused entries

Returns:

the new index subset version

Throws:

IOException

BuildNewIndexAndCopyAllGSubrs

protected byte[] BuildNewIndexAndCopyAllGSubrs(int[] Offsets,
                                               byte OperatorForUnusedEntries)
                                        throws IOException

Function builds the new offset array, object array and assembles the index. used for creating the glyph and subrs subsetted index

Parameters:

Offsets - the offset array of the original index

OperatorForUnusedEntries - the operator inserted into the data stream for unused entries

Returns:

the new index subset version

Throws:

IOException

AssembleIndex

protected byte[] AssembleIndex(int[] NewOffsets,
                               byte[] NewObjects)

Function creates the new index, inserting the count,offsetsize,offset array and object array.

Parameters:

NewOffsets - the subsetted offset array

NewObjects - the subsetted object array

Returns:

the new index created

BuildNewFile

protected byte[] BuildNewFile(int Font)

The function builds the new output stream according to the subset process

Parameters:

Font - the font

Returns:

the subsetted font stream

CopyHeader

protected void CopyHeader()

Function Copies the header from the original fileto the output list

BuildIndexHeader

protected void BuildIndexHeader(int Count,
                                int Offsize,
                                int First)

Function Build the header of an index

Parameters:

Count - the count field of the index

Offsize - the offsize field of the index

First - the first offset of the index

CreateKeys

protected void CreateKeys(CFFFont.OffsetItem fdarrayRef,
                          CFFFont.OffsetItem fdselectRef,
                          CFFFont.OffsetItem charsetRef,
                          CFFFont.OffsetItem charstringsRef)

Function adds the keys into the TopDict

Parameters:

fdarrayRef - OffsetItem for the FDArray

fdselectRef - OffsetItem for the FDSelect

charsetRef - OffsetItem for the CharSet

charstringsRef - OffsetItem for the CharString

CreateNewStringIndex

protected void CreateNewStringIndex(int Font)

Function takes the original string item and adds the new strings to accommodate the CID rules

Parameters:

Font - the font

CreateFDSelect

protected void CreateFDSelect(CFFFont.OffsetItem fdselectRef,
                              int nglyphs)

Function creates new FDSelect for non-CID fonts. The FDSelect built uses a single range for all glyphs

Parameters:

fdselectRef - OffsetItem for the FDSelect

nglyphs - the number of glyphs in the font

CreateCharset

protected void CreateCharset(CFFFont.OffsetItem charsetRef,
                             int nglyphs)

Function creates new CharSet for non-CID fonts. The CharSet built uses a single range for all glyphs

Parameters:

charsetRef - OffsetItem for the CharSet

nglyphs - the number of glyphs in the font

CreateFDArray

protected void CreateFDArray(CFFFont.OffsetItem fdarrayRef,
                             CFFFont.OffsetItem privateRef,
                             int Font)

Function creates new FDArray for non-CID fonts. The FDArray built has only the "Private" operator that points to the font's original private dict

Parameters:

fdarrayRef - OffsetItem for the FDArray

privateRef - OffsetItem for the Private Dict

Font - the font

countEntireIndexRange

protected int countEntireIndexRange(int indexOffset)

Function computes the size of an index

Parameters:

indexOffset - The offset for the computed index

Returns:

The size of the index