Class 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)
    • Constructor Detail

      • CFFFontSubset

        public CFFFontSubset​(RandomAccessFileOrArray rf,
                             HashMap<Integer,​int[]> GlyphsUsed)
        C'tor for CFFFontSubset
        Parameters:
        rf - - The font file
        GlyphsUsed - - a HashMap 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 HashMap 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)
                       throws IOException
        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
        Throws:
        IOException
      • 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 & 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,
                                     HashMap<Integer,​int[]> hSubr,
                                     ArrayList<Integer> lSubr)
        Function uses ReadAsubr on the glyph used to build the LSubr & Gsubr HashMap. The HashMap (of the lsubr only) is then scanned recursively for Lsubr & 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 - HashMap of the subrs used
        lSubr - ArrayList of the subrs used
      • BuildGSubrsUsed

        protected void BuildGSubrsUsed​(int Font)
        Function scans the Glsubr used ArrayList to find recursive calls to Gsubrs and adds to Hashmap & ArrayList
        Parameters:
        Font - the font
      • ReadASubr

        protected void ReadASubr​(int begin,
                                 int end,
                                 int GBias,
                                 int LBias,
                                 HashMap<Integer,​int[]> hSubr,
                                 ArrayList<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 HashMap for the lSubrs
        lSubr - the ArrayList 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,
                                       HashMap<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 hashmap 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