truetypefont.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

     * @throws DocumentException the font is invalid
     * @throws IOException the font file could not be read
     */
    TrueTypeFont(String ttFile, String enc, boolean emb, byte ttfAfm[], boolean justNames) throws DocumentException, IOException {
        this.justNames = justNames;
        String nameBase = getBaseName(ttFile);
        String ttcName = getTTCName(nameBase);
        if (nameBase.length() < ttFile.length()) {
            style = ttFile.substring(nameBase.length());
        }
        encoding = enc;
        embedded = emb;
        fileName = ttcName;
        fontType = FONT_TYPE_TT;
        ttcIndex = "";
        if (ttcName.length() < nameBase.length())
            ttcIndex = nameBase.substring(ttcName.length() + 1);
        if (fileName.toLowerCase().endsWith(".ttf") || fileName.toLowerCase().endsWith(".otf") || fileName.toLowerCase().endsWith(".ttc")) {
            process(ttfAfm);
            if (!justNames && embedded && os_2.fsType == 2)
                throw new DocumentException(fileName + style + " cannot be embedded due to licensing restrictions.");
        }
        else
            throw new DocumentException(fileName + style + " is not a TTF, OTF or TTC font file.");
        if (!encoding.startsWith("#"))
            PdfEncodings.convertToBytes(" ", enc); // check if the encoding exists
        createEncoding();
    }
    
    /** Gets the name from a composed TTC file name.
     * If I have for input "myfont.ttc,2" the return will
     * be "myfont.ttc".
     * @param name the full name
     * @return the simple file name
     */    
    protected static String getTTCName(String name) {
        int idx = name.toLowerCase().indexOf(".ttc,");
        if (idx < 0)
            return name;
        else
            return name.substring(0, idx + 4);
    }
    
    
    /**
     * Reads the tables 'head', 'hhea', 'OS/2' and 'post' filling several variables.
     * @throws DocumentException the font is invalid
     * @throws IOException the font file could not be read
     */
    void fillTables() throws DocumentException, IOException {
        int table_location[];
        table_location = (int[])tables.get("head");
        if (table_location == null)
            throw new DocumentException("Table 'head' does not exist in " + fileName + style);
        rf.seek(table_location[0] + 16);
        head.flags = rf.readUnsignedShort();
        head.unitsPerEm = rf.readUnsignedShort();
        rf.skipBytes(16);
        head.xMin = rf.readShort();
        head.yMin = rf.readShort();
        head.xMax = rf.readShort();
        head.yMax = rf.readShort();
        head.macStyle = rf.readUnsignedShort();
        
        table_location = (int[])tables.get("hhea");
        if (table_location == null)
            throw new DocumentException("Table 'hhea' does not exist " + fileName + style);
        rf.seek(table_location[0] + 4);
        hhea.Ascender = rf.readShort();
        hhea.Descender = rf.readShort();
        hhea.LineGap = rf.readShort();
        hhea.advanceWidthMax = rf.readUnsignedShort();
        hhea.minLeftSideBearing = rf.readShort();
        hhea.minRightSideBearing = rf.readShort();
        hhea.xMaxExtent = rf.readShort();
        hhea.caretSlopeRise = rf.readShort();
        hhea.caretSlopeRun = rf.readShort();
        rf.skipBytes(12);
        hhea.numberOfHMetrics = rf.readUnsignedShort();
        
        table_location = (int[])tables.get("OS/2");
        if (table_location == null)
            throw new DocumentException("Table 'OS/2' does not exist in " + fileName + style);
        rf.seek(table_location[0]);
        int version = rf.readUnsignedShort();
        os_2.xAvgCharWidth = rf.readShort();
        os_2.usWeightClass = rf.readUnsignedShort();
        os_2.usWidthClass = rf.readUnsignedShort();
        os_2.fsType = rf.readShort();
        os_2.ySubscriptXSize = rf.readShort();
        os_2.ySubscriptYSize = rf.readShort();
        os_2.ySubscriptXOffset = rf.readShort();
        os_2.ySubscriptYOffset = rf.readShort();
        os_2.ySuperscriptXSize = rf.readShort();
        os_2.ySuperscriptYSize = rf.readShort();
        os_2.ySuperscriptXOffset = rf.readShort();
        os_2.ySuperscriptYOffset = rf.readShort();
        os_2.yStrikeoutSize = rf.readShort();
        os_2.yStrikeoutPosition = rf.readShort();
        os_2.sFamilyClass = rf.readShort();
        rf.readFully(os_2.panose);
        rf.skipBytes(16);
        rf.readFully(os_2.achVendID);
        os_2.fsSelection = rf.readUnsignedShort();
        os_2.usFirstCharIndex = rf.readUnsignedShort();
        os_2.usLastCharIndex = rf.readUnsignedShort();
        os_2.sTypoAscender = rf.readShort();
        os_2.sTypoDescender = rf.readShort();
        if (os_2.sTypoDescender > 0)
            os_2.sTypoDescender = (short)(-os_2.sTypoDescender);
        os_2.sTypoLineGap = rf.readShort();
        os_2.usWinAscent = rf.readUnsignedShort();
        os_2.usWinDescent = rf.readUnsignedShort();
        os_2.ulCodePageRange1 = 0;
        os_2.ulCodePageRange2 = 0;
        if (version > 0) {
            os_2.ulCodePageRange1 = rf.readInt();
            os_2.ulCodePageRange2 = rf.readInt();
        }
        if (version > 1) {
            rf.skipBytes(2);
            os_2.sCapHeight = rf.readShort();
        }
        else
            os_2.sCapHeight = (int)(0.7 * head.unitsPerEm);
        
        table_location = (int[])tables.get("post");
        if (table_location == null) {
            italicAngle = -Math.atan2(hhea.caretSlopeRun, hhea.caretSlopeRise) * 180 / Math.PI;
            return;
        }
        rf.seek(table_location[0] + 4);
        short mantissa = rf.readShort();
        int fraction = rf.readUnsignedShort();
        italicAngle = (double)mantissa + (double)fraction / 16384.0;
        rf.skipBytes(4);
        isFixedPitch = rf.readInt() != 0;
    }
    
    /**
     * Gets the Postscript font name.
     * @throws DocumentException the font is invalid
     * @throws IOException the font file could not be read
     * @return the Postscript font name
     */
    String getBaseFont() throws DocumentException, IOException {
        int table_location[];
        table_location = (int[])tables.get("name");
        if (table_location == null)
            throw new DocumentException("Table 'name' does not exist in " + fileName + style);
        rf.seek(table_location[0] + 2);
        int numRecords = rf.readUnsignedShort();
        int startOfStorage = rf.readUnsignedShort();
        for (int k = 0; k < numRecords; ++k) {
            int platformID = rf.readUnsignedShort();
            int platformEncodingID = rf.readUnsignedShort();
            int languageID = rf.readUnsignedShort();
            int nameID = rf.readUnsignedShort();
            int length = rf.readUnsignedShort();
            int offset = rf.readUnsignedShort();
            if (nameID == 6) {
                rf.seek(table_location[0] + startOfStorage + offset);
                if (platformID == 0 || platformID == 3)
                    return readUnicodeString(length);
                else
                    return readStandardString(length);
            }
        }
        File file = new File(fileName);
        return file.getName().replace(' ', '-');
    }
    
    /** Extracts the names of the font in all the languages available.
     * @param id the name id to retrieve
     * @throws DocumentException on error
     * @throws IOException on error
     */    
    String[][] getNames(int id) throws DocumentException, IOException {
        int table_location[];
        table_location = (int[])tables.get("name");
        if (table_location == null)
            throw new DocumentException("Table 'name' does not exist in " + fileName + style);
        rf.seek(table_location[0] + 2);
        int numRecords = rf.readUnsignedShort();
        int startOfStorage = rf.readUnsignedShort();
        ArrayList names = new ArrayList();
        for (int k = 0; k < numRecords; ++k) {
            int platformID = rf.readUnsignedShort();
            int platformEncodingID = rf.readUnsignedShort();
            int languageID = rf.readUnsignedShort();
            int nameID = rf.readUnsignedShort();
            int length = rf.readUnsignedShort();
            int offset = rf.readUnsignedShort();
            if (nameID == id) {
                int pos = rf.getFilePointer();
                rf.seek(table_location[0] + startOfStorage + offset);
                String name;
                if (platformID == 0 || platformID == 3 || (platformID == 2 && platformEncodingID == 1)){
                    name = readUnicodeString(length);
                }
                else {
                    name = readStandardString(length);
                }
                names.add(new String[]{String.valueOf(platformID),
                    String.valueOf(platformEncodingID), String.valueOf(languageID), name});
                rf.seek(pos);
            }
        }
        String thisName[][] = new String[names.size()][];
        for (int k = 0; k < names.size(); ++k)
            thisName[k] = (String[])names.get(k);
        return thisName;
    }
    
    void checkCff() {
        int table_location[];
        table_location = (int[])tables.get("CFF ");
        if (table_location != null) {
            cff = true;
            cffOffset = table_location[0];
            cffLength = table_location[1];
        }
    }

    /** Reads the font data.
     * @param ttfAfm the font as a <CODE>byte</CODE> array, possibly <CODE>null</CODE>
     * @throws DocumentException the font is invalid
     * @throws IOException the font file could not be read
     */
    void process(byte ttfAfm[]) throws DocumentException, IOException {
        tables = new HashMap();
        
        try {
            if (ttfAfm == null)
                rf = new RandomAccessFileOrArray(fileName);
            else
                rf = new RandomAccessFileOrArray(ttfAfm);
            if (ttcIndex.length() > 0) {
                int dirIdx = Integer.parseInt(ttcIndex);
                if (dirIdx < 0)
                    throw new DocumentException("The font index for " + fileName + " must be positive.");
                String mainTag = readStandardString(4);
                if (!mainTag.equals("ttcf"))
                    throw new DocumentException(fileName + " is not a valid TTC file.");
                rf.skipBytes(4);
                int dirCount = rf.readInt();
                if (dirIdx >= dirCount)
                    throw new DocumentException("The font index for " + fileName + " must be between 0 and " + (dirCount - 1) + ". It was " + dirIdx + ".");
                rf.skipBytes(dirIdx * 4);
                directoryOffset = rf.readInt();
            }
            rf.seek(directoryOffset);
            int ttId = rf.readInt();
            if (ttId != 0x00010000 && ttId != 0x4F54544F)
                throw new DocumentException(fileName + " is not a valid TTF or OTF file.");
            int num_tables = rf.readUnsignedShort();
            rf.skipBytes(6);
            for (int k = 0; k < num_tables; ++k) {
                String tag = readStandardString(4);
                rf.skipBytes(4);
                int table_location[] = new int[2];
                table_location[0] = rf.readInt();
                table_location[1] = rf.readInt();
                tables.put(tag, table_location);
            }
            checkCff();
            fontName = getBaseFont();
            fullName = getNames(4); //full name
            familyName = getNames(1); //family name
            if (!justNames) {
                fillTables();
                readGlyphWidths();
                readCMaps();
                readKerning();
                readBbox();
                GlyphWidths = null;
            }
        }
        finally {
            if (rf != null) {
                rf.close();
                if (!embedded)
                    rf = null;
            }
        }
    }
    
    /** Reads a <CODE>String</CODE> from the font file as bytes using the Cp1252
     *  encoding.
     * @param length the length of bytes to read
     * @return the <CODE>String</CODE> read
     * @throws IOException the font file could not be read
     */
    protected String readStandardString(int length) throws IOException {
        byte buf[] = new byte[length];
        rf.readFully(buf);
        try {
            return new String(buf, WINANSI);
        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
    }
    
    /** Reads a Unicode <CODE>String</CODE> from the font file. Each character is
     *  represented by two bytes.
     * @param length the length of bytes to read. The <CODE>String</CODE> will have <CODE>length</CODE>/2
     * characters
     * @return the <CODE>String</CODE> read
     * @throws IOException the font file could not be read
     */
    protected String readUnicodeString(int length) throws IOException {
        StringBuffer buf = new StringBuffer();
        length /= 2;
        for (int k = 0; k < length; ++k) {
            buf.append(rf.readChar());
        }
        return buf.toString();
    }
    
    /** Reads the glyphs widths. The widths are extracted from the table 'hmtx'.
     *  The glyphs are normalized to 1000 units.
     * @throws DocumentException the font is invalid
     * @throws IOException the font file could not be read
     */
    protected void readGlyphWidths() throws DocumentException, IOException {
        int table_location[];
        table_location = (int[])tables.get("hmtx");
        if (table_location == null)
            throw new DocumentException("Table 'hmtx' does not exist in " + fileName + style);
        rf.seek(table_location[0]);
        GlyphWidths = new int[hhea.numberOfHMetrics];
        for (int k = 0; k < hhea.numberOfHMetrics; ++k) {
            GlyphWidths[k] = (rf.readUnsignedShort() * 1000) / head.unitsPerEm;
            rf.readUnsignedShort();
        }
    }
    
    /** Gets a glyph width.
     * @param glyph the glyph to get the width of
     * @return the width of the glyph in normalized 1000 units
     */
    protected int getGlyphWidth(int glyph) {
        if (glyph >= GlyphWidths.length)
            glyph = GlyphWidths.length - 1;
        return GlyphWidths[glyph];
    }