org.extex.font.format.xtf.tables
Class TtfTableCMAP.Format2

java.lang.Object
  org.extex.font.format.xtf.tables.TtfTableCMAP.Format
      org.extex.font.format.xtf.tables.TtfTableCMAP.Format2

All Implemented Interfaces:

XMLWriterConvertible

Enclosing class:

TtfTableCMAP

public class TtfTableCMAP.Format2
extends TtfTableCMAP.Format

The format 2 mapping subtable type is used for fonts containing Japanese, Chinese, or Korean characters. The code standards used in this table are supported on Macintosh systems in Asia.

These fonts contain a mixed 8/16-bit encoding, in which certain byte values are set aside to signal the first byte of a 2-byte character. These special values are also legal as the second byte of a 2-byte character.

Type	Name	Description
USHORT	format	Format number is set to 2.
USHORT	length	Length in bytes.
USHORT	version	Version number (starts at 0)
USHORT	subHeaderKeys[256]	Array that maps high bytes to subHeaders: value is subHeader index * 8.
4 words struct	subHeaders[ ]	Variable-length array of subHeader structures.
4 words-struct	subHeaders[ ]
USHORT	glyphIndexArray[ ]	Variable-length array containing subarrays used for mapping the low byte of 2-byte characters.

A subHeader is structured as follows:

Type	Name	Description
USHORT	firstCode	First valid low byte for this subHeader.
USHORT	entryCount	Number of valid low bytes for this subHeader.
SHORT	idDelta	See text below.
USHORT	idRangeOffset	The firstCode and entryCount values specify a subrange that begins at firstCode and has a length equal to the value of entryCount. This subrange stays within the 0–255 range of the byte being mapped. Bytes outside of this subrange are mapped to glyph index 0 (missing glyph).The offset of the byte within this subrange is then used as index into a corresponding subarray of glyphIndexArray. This subarray is also of length entryCount. The value of the idRangeOffset is the number of bytes past the actual location of the idRangeOffset word where the glyphIndexArray element corresponding to firstCode appears. Finally, if the value obtained from the subarray is not 0 (which indicates the missing glyph), you should add idDelta to it in order to get the glyphIndex. The value idDelta permits the same subarray to be used for several different subheaders. The idDelta arithmetic is modulo 65536.

Method Summary

int	mapCharCode(int charCode) map char code.
void	writeXML(XMLStreamWriter writer) Write the data to a XMLStreamWriter.

Methods inherited from class org.extex.font.format.xtf.tables.TtfTableCMAP.Format

addAttributes, getFormat, getLength, getVersion, toString

Methods inherited from class java.lang.Object

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

Method Detail

mapCharCode

public int mapCharCode(int charCode)

map char code.

Specified by:

mapCharCode in class TtfTableCMAP.Format

Parameters:

charCode - the charcode

Returns:

Returns the map char code

See Also:

TtfTableCMAP.Format.mapCharCode(int)

writeXML

public void writeXML(XMLStreamWriter writer)
              throws java.io.IOException

Write the data to a XMLStreamWriter.

Parameters:

writer - the XML-Writer

Throws:

java.io.IOException - if an IO-error occurs.

See Also:

XMLWriterConvertible.writeXML( org.extex.util.xml.XMLStreamWriter)