org.zmpp.base
Class MemorySection

java.lang.Object
  org.zmpp.base.MemorySection

All Implemented Interfaces:

MemoryAccess, MemoryReadAccess

public class MemorySection
extends Object
implements MemoryAccess

A MemorySection object wraps a reference to a MemoryAccess object, a length and a start to support subsections within memory. All access functions will be relative to the initialized start offset within the global memory.

Version:

1.0

Author:

Wei-ju Wu

Constructor Summary

MemorySection(MemoryAccess memaccess, int start, int length)

Method Summary

int	getLength() Returns the length of this object in bytes.
byte	readByte(int address) Returns the signed 8 bit value at specified address.
short	readShort(int address) Returns the signed 16 bit word at the specified address.
long	readUnsigned32(int address) Reads the unsigned 32 bit word at the specified address.
short	readUnsignedByte(int address) Returns the unsigned 8 bit value at the specified address.
int	readUnsignedShort(int address) Reads the unsigned 16 bit word at the specified address.
void	writeByte(int address, byte value) Writes a byte value to the specified address.
void	writeShort(int address, short value) Writes a short value to the memory.
void	writeUnsigned32(int address, long value) Writes an unsigned 32 bit value to the specified address.
void	writeUnsignedByte(int address, short value) Writes an unsigned byte value to the specified address.
void	writeUnsignedShort(int address, int value) Writes an unsigned 16 bit value to the specified address.

Methods inherited from class java.lang.Object

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

Constructor Detail

MemorySection

public MemorySection(MemoryAccess memaccess,
                     int start,
                     int length)

Method Detail

getLength

public int getLength()

Returns the length of this object in bytes.

Returns:

the length in bytes

writeUnsignedShort

public void writeUnsignedShort(int address,
                               int value)

Writes an unsigned 16 bit value to the specified address.

Specified by:

writeUnsignedShort in interface MemoryAccess

Parameters:

address - the address to write to

value - the value to write

writeShort

public void writeShort(int address,
                       short value)

Writes a short value to the memory.

Specified by:

writeShort in interface MemoryAccess

Parameters:

address - the address

value - the value

writeUnsignedByte

public void writeUnsignedByte(int address,
                              short value)

Writes an unsigned byte value to the specified address.

Specified by:

writeUnsignedByte in interface MemoryAccess

Parameters:

address - the address to write to

value - the value to write

writeByte

public void writeByte(int address,
                      byte value)

Writes a byte value to the specified address.

Specified by:

writeByte in interface MemoryAccess

Parameters:

address - the address

value - the value

writeUnsigned32

public void writeUnsigned32(int address,
                            long value)

Writes an unsigned 32 bit value to the specified address.

Specified by:

writeUnsigned32 in interface MemoryAccess

Parameters:

address - the address to write to

value - the value to write

readUnsigned32

public long readUnsigned32(int address)

Reads the unsigned 32 bit word at the specified address.

Specified by:

readUnsigned32 in interface MemoryReadAccess

Parameters:

address - the address

Returns:

the 32 bit unsigned value as long

readUnsignedShort

public int readUnsignedShort(int address)

Reads the unsigned 16 bit word at the specified address.

Specified by:

readUnsignedShort in interface MemoryReadAccess

Parameters:

address - the address

Returns:

the 16 bit unsigned value as int

readShort

public short readShort(int address)

Returns the signed 16 bit word at the specified address.

Specified by:

readShort in interface MemoryReadAccess

Parameters:

address - the address

Returns:

the 16 bit signed value

readUnsignedByte

public short readUnsignedByte(int address)

Returns the unsigned 8 bit value at the specified address.

Specified by:

readUnsignedByte in interface MemoryReadAccess

Parameters:

address - the address

Returns:

the 8 bit unsigned value

readByte

public byte readByte(int address)

Returns the signed 8 bit value at specified address.

Specified by:

readByte in interface MemoryReadAccess

Parameters:

address - the byte address

Returns:

the 8 bit signed value