DataBuffer
Class DataBuffer
- java.lang.Object
-
- java.awt.image.DataBuffer
- Direct Known Subclasses:
- DataBufferByte, DataBufferDouble, DataBufferFloat, DataBufferInt, DataBufferShort, DataBufferUShort
public abstract class DataBuffer extends Object
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:
-
Raster
,SampleModel
Fields
TYPE_BYTE
@Native public static final int TYPE_BYTE
Tag for unsigned byte data.
TYPE_USHORT
@Native public static final int TYPE_USHORT
Tag for unsigned short data.
TYPE_SHORT
@Native public static final int TYPE_SHORT
Tag for signed short data. Placeholder for future use.
TYPE_INT
@Native public static final int TYPE_INT
Tag for int data.
TYPE_FLOAT
@Native public static final int TYPE_FLOAT
Tag for float data. Placeholder for future use.
TYPE_DOUBLE
@Native public static final int TYPE_DOUBLE
Tag for double data. Placeholder for future use.
TYPE_UNDEFINED
@Native public static final int TYPE_UNDEFINED
Tag for undefined data.
dataType
protected int dataType
The data type of this DataBuffer.
banks
protected int banks
The number of banks in this DataBuffer.
offset
protected int offset
Offset into default (first) bank from which to get the first element.
size
protected int size
Usable size of all banks.
offsets
protected int[] offsets
Offsets into all banks.
Constructors
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
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 banks -
numBanks
- the number of banks in thisDataBuffer
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 banks -
numBanks
- the number of banks in thisDataBuffer
-
offset
- the offset for each bank
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 banks -
numBanks
- the number of banks in thisDataBuffer
-
offsets
- an array containing an offset for each bank. - Throws:
-
ArrayIndexOutOfBoundsException
- ifnumBanks
does not equal the length ofoffsets
Methods
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
getDataType
public int getDataType()
Returns the data type of this DataBuffer.
- Returns:
- the data type of this
DataBuffer
.
getSize
public int getSize()
Returns the size (in array elements) of all banks.
- Returns:
- the size of all banks.
getOffset
public int getOffset()
Returns the offset of the default bank in array elements.
- Returns:
- the offset of the default bank.
getOffsets
public int[] getOffsets()
Returns the offsets (in array elements) of all the banks.
- Returns:
- the offsets of all banks.
getNumBanks
public int getNumBanks()
Returns the number of banks in this DataBuffer.
- Returns:
- the number of banks.
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:
-
setElem(int, int)
,setElem(int, int, int)
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 bank -
i
- 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:
-
setElem(int, int)
,setElem(int, int, int)
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 array -
val
- the data to set the element at the specified index in the data array - See Also:
-
getElem(int)
,getElem(int, int)
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 bank -
i
- the specified index into the data array -
val
- the data to set the element in the specified bank at the specified index in the data array - See Also:
-
getElem(int)
,getElem(int, int)
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:
-
setElemFloat(int, float)
,setElemFloat(int, int, float)
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 cast getElem(int, int)
to a float. Subclasses can override this method if another implementation is needed.
- Parameters:
-
bank
- the specified bank -
i
- 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:
-
setElemFloat(int, float)
,setElemFloat(int, int, float)
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 call setElem(int, int)
. Subclasses can override this method if another implementation is needed.
- Parameters:
-
i
- the specified index -
val
- the value to set the element at the specified index in the data array - See Also:
-
getElemFloat(int)
,getElemFloat(int, int)
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 call setElem(int, int)
. Subclasses can override this method if another implementation is needed.
- Parameters:
-
bank
- the specified bank -
i
- the specified index -
val
- the value to set the element in the specified bank at the specified index in the data array - See Also:
-
getElemFloat(int)
,getElemFloat(int, int)
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 cast getElem(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:
-
setElemDouble(int, double)
,setElemDouble(int, int, double)
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 bank -
i
- the specified index - Returns:
- a double value representing the element from the specified bank at the specified index in the data array.
- See Also:
-
setElemDouble(int, double)
,setElemDouble(int, int, double)
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 call setElem(int, int)
. Subclasses can override this method if another implementation is needed.
- Parameters:
-
i
- the specified index -
val
- the value to set the element at the specified index in the data array - See Also:
-
getElemDouble(int)
,getElemDouble(int, int)
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 call setElem(int, int)
. Subclasses can override this method if another implementation is needed.
- Parameters:
-
bank
- the specified bank -
i
- the specified index -
val
- the value to set the element in the specified bank at the specified index of the data array - See Also:
-
getElemDouble(int)
,getElemDouble(int, int)
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