org.zmpp.vmutil
Class ZsciiConverter

java.lang.Object
  org.zmpp.vmutil.ZsciiConverter

public class ZsciiConverter
extends Object

This class provides conversion for the ZSCII character encoding into the Java character system.

Version:

1.0

Author:

Wei-ju Wu

Nested Class Summary

static interface	ZsciiConverter.AbbreviationsTable This interface defines the abstract access to an abbreviations table in memory, this will be used for decoding if needed.
static class	ZsciiConverter.Alphabet Defines the possible alphabets here.

Field Summary

static String	A0CHARS
static String	A1CHARS
static String	A2CHARS
static byte	CHAR_0
static byte	CHAR_1
static byte	CHAR_6
static byte	SHIFT_2
static byte	SHIFT_3
static byte	SHIFT_4
static byte	SHIFT_5

Constructor Summary

ZsciiConverter(int version, ZsciiConverter.AbbreviationsTable abbreviations)
Constructor.

Method Summary

String	convert(MemoryReadAccess memaccess, int address) Performs a ZSCII to Unicode conversion at the specified position of the given memory object.
static char	decode(ZsciiConverter.Alphabet alphabet, short zchar) Decodes a printable character to a unicode character.
static void	decodeZchar(StringBuilder builder, ZsciiConverter.Alphabet alphabet, byte b) Decodes the given byte value to the specified buffer using the working alphabet.
ZsciiConverter.Alphabet	getInitialAlphabet() Returns the initial alphabet of this converter.
int	getVersion() Returns the story file version.
static ZsciiConverter.Alphabet	shiftFrom(ZsciiConverter.Alphabet alphabet, byte shiftChar) Returns a new alphabet for a given shift character.

Methods inherited from class java.lang.Object

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

Field Detail

CHAR_0

public static final byte CHAR_0

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Constant Field Values

CHAR_1

public static final byte CHAR_1

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Constant Field Values

SHIFT_2

public static final byte SHIFT_2

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Constant Field Values

SHIFT_3

public static final byte SHIFT_3

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Constant Field Values

SHIFT_4

public static final byte SHIFT_4

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Constant Field Values

SHIFT_5

public static final byte SHIFT_5

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Constant Field Values

CHAR_6

public static final byte CHAR_6

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Constant Field Values

A0CHARS

public static final String A0CHARS

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Constant Field Values

A1CHARS

public static final String A1CHARS

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Constant Field Values

A2CHARS

public static final String A2CHARS

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Constant Field Values

Constructor Detail

ZsciiConverter

public ZsciiConverter(int version,
                      ZsciiConverter.AbbreviationsTable abbreviations)

Constructor.

Parameters:

version - Story file version

abbreviations - the abbreviations table used for decoding

Method Detail

getInitialAlphabet

public ZsciiConverter.Alphabet getInitialAlphabet()

Returns the initial alphabet of this converter.

Returns:

the initial alphabet

getVersion

public int getVersion()

Returns the story file version.

Returns:

the story file version

convert

public String convert(MemoryReadAccess memaccess,
                      int address)

Performs a ZSCII to Unicode conversion at the specified position of the given memory object.

Parameters:

memaccess - a MemoryReadAccess object

address - the address of a ZSCII string

Returns:

a converted Unicode string

decodeZchar

public static void decodeZchar(StringBuilder builder,
                               ZsciiConverter.Alphabet alphabet,
                               byte b)

Decodes the given byte value to the specified buffer using the working alphabet.

Parameters:

builder - the buffer to print into

alphabet - the working alphabet

b - a z character, needs to be a non-shift character

decode

public static char decode(ZsciiConverter.Alphabet alphabet,
                          short zchar)

Decodes a printable character to a unicode character.

Parameters:

alphabet - the work alphabet

zchar - the ZSCII character to decode

Returns:

the Unicode character

shiftFrom

public static ZsciiConverter.Alphabet shiftFrom(ZsciiConverter.Alphabet alphabet,
                                                byte shiftChar)

Returns a new alphabet for a given shift character. If the character is not a shift character, the old alphabet is returned.

Parameters:

alphabet - the start alphabet

shiftChar - the shift character

Returns:

the shifted alphabet