Class DataBuffer
java.lang.Object
java.awt.image.DataBuffer
- Direct Known Subclasses:
DataBufferByte
,DataBufferDouble
,DataBufferFloat
,DataBufferInt
,DataBufferShort
,DataBufferUShort
This class exists to wrap one or more data arrays. Each data array in
the DataBuffer is referred to as a bank. Accessor methods for getting
and setting elements of the DataBuffer's banks exist with and without
a bank specifier. The methods without a bank specifier use the default 0th
bank. The DataBuffer can optionally take an offset per bank, so that
data in an existing array can be used even if the interesting data
doesn't start at array location zero. Getting or setting the 0th
element of a bank, uses the (0+offset)th element of the array. The
size field specifies how much of the data array is available for
use. Size + offset for a given bank should never be greater
than the length of the associated data array. The data type of
a data buffer indicates the type of the data array(s) and may also
indicate additional semantics, e.g. storing unsigned 8-bit data
in elements of a byte array. The data type may be TYPE_UNDEFINED
or one of the types defined below. Other types may be added in
the future. Generally, an object of class DataBuffer will be cast down
to one of its data type specific subclasses to access data type specific
methods for improved performance. Currently, the Java 2D(tm) API
image classes use TYPE_BYTE, TYPE_USHORT, TYPE_INT, TYPE_SHORT,
TYPE_FLOAT, and TYPE_DOUBLE DataBuffers to store image data.
- See Also:
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Field Summary
Modifier and TypeFieldDescriptionprotected int
The number of banks in this DataBuffer.protected int
The data type of this DataBuffer.protected int
Offset into default (first) bank from which to get the first element.protected int[]
Offsets into all banks.protected int
Usable size of all banks.static final int
Tag for unsigned byte data.static final int
Tag for double data.static final int
Tag for float data.static final int
Tag for int data.static final int
Tag for signed short data.static final int
Tag for undefined data.static final int
Tag for unsigned short data. -
Constructor Summary
ModifierConstructorDescriptionprotected
DataBuffer
(int dataType, int size) Constructs a DataBuffer containing one bank of the specified data type and size.protected
DataBuffer
(int dataType, int size, int numBanks) Constructs a DataBuffer containing the specified number of banks.protected
DataBuffer
(int dataType, int size, int numBanks, int offset) Constructs a DataBuffer that contains the specified number of banks.protected
DataBuffer
(int dataType, int size, int numBanks, int[] offsets) Constructs a DataBuffer which contains the specified number of banks. -
Method Summary
Modifier and TypeMethodDescriptionint
Returns the data type of this DataBuffer.static int
getDataTypeSize
(int type) Returns the size (in bits) of the data type, given a datatype tag.int
getElem
(int i) Returns the requested data array element from the first (default) bank as an integer.abstract int
getElem
(int bank, int i) Returns the requested data array element from the specified bank as an integer.double
getElemDouble
(int i) Returns the requested data array element from the first (default) bank as a double.double
getElemDouble
(int bank, int i) Returns the requested data array element from the specified bank as a double.float
getElemFloat
(int i) Returns the requested data array element from the first (default) bank as a float.float
getElemFloat
(int bank, int i) Returns the requested data array element from the specified bank as a float.int
Returns the number of banks in this DataBuffer.int
Returns the offset of the default bank in array elements.int[]
Returns the offsets (in array elements) of all the banks.int
getSize()
Returns the size (in array elements) of all banks.void
setElem
(int i, int val) Sets the requested data array element in the first (default) bank from the given integer.abstract void
setElem
(int bank, int i, int val) Sets the requested data array element in the specified bank from the given integer.void
setElemDouble
(int i, double val) Sets the requested data array element in the first (default) bank from the given double.void
setElemDouble
(int bank, int i, double val) Sets the requested data array element in the specified bank from the given double.void
setElemFloat
(int i, float val) Sets the requested data array element in the first (default) bank from the given float.void
setElemFloat
(int bank, int i, float val) Sets the requested data array element in the specified bank from the given float.
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Field Details
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TYPE_BYTE
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TYPE_USHORT
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TYPE_SHORT
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TYPE_INT
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TYPE_FLOAT
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TYPE_DOUBLE
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TYPE_UNDEFINED
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dataType
protected int dataTypeThe data type of this DataBuffer. -
banks
protected int banksThe number of banks in this DataBuffer. -
offset
protected int offsetOffset into default (first) bank from which to get the first element. -
size
protected int sizeUsable size of all banks. -
offsets
protected int[] offsetsOffsets into all banks.
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Constructor Details
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DataBuffer
protected DataBuffer(int dataType, int size) Constructs a DataBuffer containing one bank of the specified data type and size.- Parameters:
dataType
- the data type of thisDataBuffer
size
- the size of the banks
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DataBuffer
protected DataBuffer(int dataType, int size, int numBanks) Constructs a DataBuffer containing the specified number of banks. Each bank has the specified size and an offset of 0.- Parameters:
dataType
- the data type of thisDataBuffer
size
- the size of the banksnumBanks
- the number of banks in thisDataBuffer
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DataBuffer
protected DataBuffer(int dataType, int size, int numBanks, int offset) Constructs a DataBuffer that contains the specified number of banks. Each bank has the specified datatype, size and offset.- Parameters:
dataType
- the data type of thisDataBuffer
size
- the size of the banksnumBanks
- the number of banks in thisDataBuffer
offset
- the offset for each bank
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DataBuffer
protected DataBuffer(int dataType, int size, int numBanks, int[] offsets) Constructs a DataBuffer which contains the specified number of banks. Each bank has the specified datatype and size. The offset for each bank is specified by its respective entry in the offsets array.- Parameters:
dataType
- the data type of thisDataBuffer
size
- the size of the banksnumBanks
- the number of banks in thisDataBuffer
offsets
- an array containing an offset for each bank.- Throws:
ArrayIndexOutOfBoundsException
- ifnumBanks
does not equal the length ofoffsets
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Method Details
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getDataTypeSize
public static int getDataTypeSize(int type) Returns the size (in bits) of the data type, given a datatype tag.- Parameters:
type
- the value of one of the defined datatype tags- Returns:
- the size of the data type
- Throws:
IllegalArgumentException
- iftype
is less than zero or greater thanTYPE_DOUBLE
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getDataType
public int getDataType()Returns the data type of this DataBuffer.- Returns:
- the data type of this
DataBuffer
.
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getSize
public int getSize()Returns the size (in array elements) of all banks.- Returns:
- the size of all banks.
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getOffset
public int getOffset()Returns the offset of the default bank in array elements.- Returns:
- the offset of the default bank.
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getOffsets
public int[] getOffsets()Returns the offsets (in array elements) of all the banks.- Returns:
- the offsets of all banks.
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getNumBanks
public int getNumBanks()Returns the number of banks in this DataBuffer.- Returns:
- the number of banks.
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getElem
public int getElem(int i) Returns the requested data array element from the first (default) bank as an integer.- Parameters:
i
- the index of the requested data array element- Returns:
- the data array element at the specified index.
- See Also:
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getElem
public abstract int getElem(int bank, int i) Returns the requested data array element from the specified bank as an integer.- Parameters:
bank
- the specified banki
- the index of the requested data array element- Returns:
- the data array element at the specified index from the specified bank at the specified index.
- See Also:
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setElem
public void setElem(int i, int val) Sets the requested data array element in the first (default) bank from the given integer.- Parameters:
i
- the specified index into the data arrayval
- the data to set the element at the specified index in the data array- See Also:
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setElem
public abstract void setElem(int bank, int i, int val) Sets the requested data array element in the specified bank from the given integer.- Parameters:
bank
- the specified banki
- the specified index into the data arrayval
- the data to set the element in the specified bank at the specified index in the data array- See Also:
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getElemFloat
public float getElemFloat(int i) Returns the requested data array element from the first (default) bank as a float. The implementation in this class is to cast getElem(i) to a float. Subclasses may override this method if another implementation is needed.- Parameters:
i
- the index of the requested data array element- Returns:
- a float value representing the data array element at the specified index.
- See Also:
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getElemFloat
public float getElemFloat(int bank, int i) Returns the requested data array element from the specified bank as a float. The implementation in this class is to castgetElem(int, int)
to a float. Subclasses can override this method if another implementation is needed.- Parameters:
bank
- the specified banki
- the index of the requested data array element- Returns:
- a float value representing the data array element from the specified bank at the specified index.
- See Also:
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setElemFloat
public void setElemFloat(int i, float val) Sets the requested data array element in the first (default) bank from the given float. The implementation in this class is to cast val to an int and callsetElem(int, int)
. Subclasses can override this method if another implementation is needed.- Parameters:
i
- the specified indexval
- the value to set the element at the specified index in the data array- See Also:
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setElemFloat
public void setElemFloat(int bank, int i, float val) Sets the requested data array element in the specified bank from the given float. The implementation in this class is to cast val to an int and callsetElem(int, int)
. Subclasses can override this method if another implementation is needed.- Parameters:
bank
- the specified banki
- the specified indexval
- the value to set the element in the specified bank at the specified index in the data array- See Also:
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getElemDouble
public double getElemDouble(int i) Returns the requested data array element from the first (default) bank as a double. The implementation in this class is to castgetElem(int)
to a double. Subclasses can override this method if another implementation is needed.- Parameters:
i
- the specified index- Returns:
- a double value representing the element at the specified index in the data array.
- See Also:
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getElemDouble
public double getElemDouble(int bank, int i) Returns the requested data array element from the specified bank as a double. The implementation in this class is to cast getElem(bank, i) to a double. Subclasses may override this method if another implementation is needed.- Parameters:
bank
- the specified banki
- the specified index- Returns:
- a double value representing the element from the specified bank at the specified index in the data array.
- See Also:
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setElemDouble
public void setElemDouble(int i, double val) Sets the requested data array element in the first (default) bank from the given double. The implementation in this class is to cast val to an int and callsetElem(int, int)
. Subclasses can override this method if another implementation is needed.- Parameters:
i
- the specified indexval
- the value to set the element at the specified index in the data array- See Also:
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setElemDouble
public void setElemDouble(int bank, int i, double val) Sets the requested data array element in the specified bank from the given double. The implementation in this class is to cast val to an int and callsetElem(int, int)
. Subclasses can override this method if another implementation is needed.- Parameters:
bank
- the specified banki
- the specified indexval
- the value to set the element in the specified bank at the specified index of the data array- See Also:
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