Isis::Buffer Class Reference
[Low Level Cube I/O]

Buffer for reading and writing cube data. More...

#include <Buffer.h>

Inherited by Isis::BufferManager, and Isis::Portal.

Public Member Functions
	Buffer ()
	Default constructor for proper initialization purposes.
	Buffer (const int nsamps, const int nlines, const int nbands, const Isis::PixelType type)
	Creates a Buffer object.
	~Buffer ()
	Destroys the Buffer object and frees shape buffer.
	Buffer (const Buffer &)
	The copy constructor.
Buffer &	operator= (const double &d)
	Assign the entire buffer to a constant double value.
int	SampleDimension () const
	Returns the number of samples in the shape buffer.
int	LineDimension () const
	Returns the number of lines in the shape buffer.
int	BandDimension () const
	Returns the number of bands in the shape buffer.
int	size () const
	Returns the total number of pixels in the shape buffer.
int	Sample (const int index=0) const
	Returns the sample position associated with a shape buffer index.
int	Line (const int index=0) const
	Returns the line position associated with a shape buffer index.
int	Band (const int index=0) const
	Returns the band position associated with a shape buffer index.
void	Position (const int index, int &i_samp, int &i_line, int &i_band) const
	Returns the sample, line, and band position associated with a shape buffer index.
int	Index (const int i_samp, const int i_line, const int i_band) const
	Given a sample, line, and band position, this returns the appropriate index in the shape buffer.
double	at (const int index) const
	Returns the value in the shape buffer at the given index.
double &	operator[] (const int index)
	Returns the value in the shape buffer at given index.
const double &	operator[] (const int index) const
	Returns the value in the shape buffer at given index.
double *	DoubleBuffer () const
	Returns the value of the shape buffer.
void	Copy (const Buffer &in, bool includeRawBuf=true)
	Allows copying of the buffer contents to another Buffer.
bool	CopyOverlapFrom (const Buffer &in)
	Allows copying of the buffer contents of a larger buffer to another same size or smaller Buffer, using their base positions to relate data.
void *	RawBuffer () const
	Returns a void pointer to the raw buffer.
Isis::PixelType	PixelType () const
	Returns the raw buffer pixel type.
Protected Member Functions
void	SetBasePosition (const int start_sample, const int start_line, const int start_band)
	This method is used to set the base position of the shape buffer.
void	SetBaseSample (const int start_samp)
	This method is used to set the base sample position of the shape buffer.
void	SetBaseLine (const int start_line)
	This method is used to set the base line position of the shape buffer.
void	SetBaseBand (const int start_band)
	This method is used to set the base band position of the shape buffer.
void	Allocate ()
	Size or resize the memory buffer.
Buffer &	operator= (const Buffer &rvalue)
	Copy operator.
Protected Attributes
int	p_sample
	Starting sample to read/write.
int	p_nsamps
	Number of samples to read/write.
int	p_line
	Starting line to read/write.
int	p_nlines
	Number of lines to read/write.
int	p_band
	Starting band to read/write.
int	p_nbands
	Number of bands to read/write.
int	p_npixels
	Number of pixels (nsamps * nlines * nbands).
double *	p_buf
	Shape buffer allocated to the size of npixels for handling reads/writes.
const Isis::PixelType	p_pixelType
	The pixel type of the raw buffer.
void *	p_rawbuf
	The raw dm read from the disk.

Detailed Description

Buffer for reading and writing cube data.

This is the base class for I/O on buffers of data from cubes. The programmer can define an arbitrary shape using this object and then read or write that shape from a cube. Some example shapes are lines, tiles, columns, cublets, and spectral pencils. Data which is read or written to a cube will always be contained within an internal buffer of type double. There are methods for querying the sample/line/band position based upon the buffer index. Note that this class does not read/write data but is used in conjunction with the class to read/write data. Even more powerful are the BufferManager classes which inherit this object and can step through cubes by line, tile, boxcar, column, etc.

If you would like to see Buffer being used in implementation, see circle.cpp

Author:: 2002-04-09 Kris Becker & Jeff Anderson

Constructor & Destructor Documentation

Isis::Buffer::Buffer ( )

Default constructor for proper initialization purposes.

This constructor is mostly useless but is needed so that it protects against improper usage.

Isis::Buffer::Buffer	(	const int	nsamps,
		const int	nlines,
		const int	nbands,
		const Isis::PixelType	type
	)

Creates a Buffer object.

Note that the number of pixels in the buffer can not exceed 2GB.

Parameters:

	nsamps	Number of samples in shape.
	nlines	Number of lines in shape.
	nbands	Number of bands in shape.
	type	Raw buffer pixel type

Exceptions:

Isis::iException::Programmer

- Invalid value for a dimension

References _FILEINFO_, Allocate(), p_band, p_line, p_nbands, p_nlines, p_npixels, p_nsamps, p_sample, and Isis::IException::Programmer.

Isis::Buffer::~Buffer ( )

Destroys the Buffer object and frees shape buffer.

References p_buf, and p_rawbuf.

Isis::Buffer::Buffer ( const Buffer & rhs )

The copy constructor.

Allows a new Buffer object to be created using an existing Buffer object.

Parameters:

rhs

The Buffer to be used to create the new buffer

References Allocate(), Copy(), p_band, p_line, p_npixels, and p_sample.

Member Function Documentation

void Isis::Buffer::Allocate ( ) [protected]

Size or resize the memory buffer.

Exceptions:

Isis::iException::System

- Memory allocation failed

References _FILEINFO_, Isis::Message::MemoryAllocationFailed(), p_buf, p_npixels, p_pixelType, p_rawbuf, Isis::SizeOf(), and Isis::IException::Unknown.

Referenced by Buffer(), and Isis::Brick::Resize().

double Isis::Buffer::at ( const int index ) const

Returns the value in the shape buffer at the given index.

Parameters:

index

Index position in buffer. Out of bounds index is trapped.

Returns:: double Buffer value at index

Exceptions:

Isis::iException::Programmer

- Array Subscript not in range

References _FILEINFO_, Isis::Message::ArraySubscriptNotInRange(), p_buf, p_npixels, and Isis::IException::Programmer.

Referenced by Isis::CubeDataThreadTester::BrickChanged(), Isis::ViewportBuffer::DataReady(), Isis::ViewportBuffer::fillBuffer(), Isis::CubeDataThreadTester::ReadBrick(), and Isis::CubeDataThreadTester::ReadWriteBrick().

int Isis::Buffer::Band ( const int index = 0 ) const

Returns the band position associated with a shape buffer index.

The shape buffer is one dimensional. Let us assume a nsamps=2, nlines=3, and nbands=2. Therefore the total size of the shape buffer is 12 and valid index values are 0-11. Indexes 0-5 will return band 1 and 6-11 will return band 2.

Parameters:

index

Shape buffer index to map to a band position. Defaults to 0.

Returns:: int The absolute band number based on the buffer index.

References p_band, p_nlines, and p_nsamps.

Referenced by CopyOverlapFrom(), Isis::IndependentCubeViewport::cubeDataChanged(), Isis::SpectralDefinition2D::operator()(), Isis::Average::operator()(), Isis::ImageImporter::operator()(), Isis::Equalization::ApplyFunctor::operator()(), Position(), Isis::CubeIoHandler::read(), and Isis::ProcessRubberSheet::StartProcess().

int Isis::Buffer::BandDimension ( ) const [inline]

Returns the number of bands in the shape buffer.

Returns:: int

References p_nbands.

Referenced by Isis::IndependentCubeViewport::cubeDataChanged(), Isis::CubeIoHandler::read(), Isis::RegionalCachingAlgorithm::recommendChunksToFree(), and Isis::Hillshade::shadedValue().

void Isis::Buffer::Copy	(	const Buffer &	in,
		bool	includeRawBuf = `true`
	)

Allows copying of the buffer contents to another Buffer.

Parameters:

in

The Buffer to be copied.

Exceptions:

Isis::iException::Programmer

- Input and Output buffers are not the same size

References _FILEINFO_, p_buf, p_npixels, p_pixelType, p_rawbuf, PixelType(), Isis::IException::Programmer, size(), and Isis::SizeOf().

Referenced by Buffer().

bool Isis::Buffer::CopyOverlapFrom ( const Buffer & in )

Allows copying of the buffer contents of a larger buffer to another same size or smaller Buffer, using their base positions to relate data.

This does not copy the raw buffer.

Parameters:

in

The Buffer to be copied.

Returns:: The operation was successful (the buffers overlapped)

References Band(), Index(), Line(), p_band, p_line, p_nbands, p_nlines, p_npixels, p_nsamps, p_sample, Sample(), and size().

double* Isis::Buffer::DoubleBuffer ( ) const [inline]

Returns the value of the shape buffer.

Returns:: double* The shape buffer

References p_buf.

Referenced by Isis::Process::CalculateStatistics(), Isis::IndependentCubeViewport::cubeDataChanged(), Isis::Cube::histogram(), Isis::DemShape::localRadius(), Isis::HistogramTool::refreshPlot(), and Isis::Cube::statistics().

int Isis::Buffer::Index	(	const int	i_samp,
		const int	i_line,
		const int	i_band
	)			const

Given a sample, line, and band position, this returns the appropriate index in the shape buffer.

Parameters:

	i_samp	Sample position.
	i_line	Line position.
	i_band	Band position.

Returns:: int Index at the specified sample, line and band.

Exceptions:

Isis::iException::Programmer

- Array Subscript not in range

References _FILEINFO_, Isis::Message::ArraySubscriptNotInRange(), p_band, p_line, p_nbands, p_nlines, p_nsamps, p_sample, and Isis::IException::Programmer.

Referenced by CopyOverlapFrom(), and Isis::ViewportBuffer::fillBuffer().

int Isis::Buffer::Line ( const int index = 0 ) const

Returns the line position associated with a shape buffer index.

The shape buffer is one dimensional. Let us assume a nsamps=2, nlines=3, and nbands=2. Therefore the total size of the shape buffer is 12 and valid index values are 0-11. Line(0), Line(1), Line(6) and Line(7), will return a 1, Line(2), Line(3), Line(8) and Line(9) will return a 2, and Line(4), Line(5), Line(10), and Line(11) will return a 3.

Parameters:

index

Shape buffer index to map to a line position. Defaults to 0

Returns:: int The absolute line number based on the buffer index

References p_line, p_nlines, and p_nsamps.

Referenced by CopyOverlapFrom(), Isis::IndependentCubeViewport::cubeDataChanged(), Isis::CubeViewport::cubeDataChanged(), Isis::ViewportBuffer::DataReady(), Isis::ViewportBuffer::fillBuffer(), Isis::Average::operator()(), Isis::Nearest::operator()(), Isis::ImageImporter::operator()(), Isis::Equalization::CalculateFunctor::operator()(), Position(), Isis::CubeIoHandler::read(), Isis::StreamExporter::writeGrayscale(), Isis::QtExporter::writeGrayscale(), Isis::StreamExporter::writeRgb(), Isis::QtExporter::writeRgb(), Isis::StreamExporter::writeRgba(), and Isis::QtExporter::writeRgba().

int Isis::Buffer::LineDimension ( ) const [inline]

Returns the number of lines in the shape buffer.

Returns:: int

References p_nlines.

Referenced by Isis::IndependentCubeViewport::cubeDataChanged(), Isis::CubeViewport::cubeDataChanged(), Isis::ViewportBuffer::fillBuffer(), Isis::Equalization::CalculateFunctor::operator()(), Isis::CubeIoHandler::read(), Isis::RegionalCachingAlgorithm::recommendChunksToFree(), and Isis::Hillshade::shadedValue().

Buffer& Isis::Buffer::operator= ( const Buffer & rvalue ) [inline, protected]

Copy operator.

We will make it private since copies of these buffers do not need to occur.

Parameters:

rvalue

Right hand side

Returns:: Buffer&

Reimplemented in Isis::BufferManager.

Buffer & Isis::Buffer::operator= ( const double & d )

Assign the entire buffer to a constant double value.

Parameters:

d

Value to assign to the buffer

Returns:: the current Buffer

References p_buf, and p_npixels.

const double& Isis::Buffer::operator[] ( const int index ) const [inline]

Returns the value in the shape buffer at given index.

Parameters:

index

Index position in buffer. No out of bounds index is checked

Returns:: double

References p_buf.

double& Isis::Buffer::operator[] ( const int index ) [inline]

Returns the value in the shape buffer at given index.

Parameters:

index

Index position in buffer. No out of bounds index is checked

Returns:: double&

References p_buf.

Isis::PixelType Isis::Buffer::PixelType ( ) const [inline]

Returns the raw buffer pixel type.

Returns:: Isis::PixelType

References p_pixelType.

Referenced by Copy().

void Isis::Buffer::Position	(	const int	index,
		int &	i_samp,
		int &	i_line,
		int &	i_band
	)			const

Returns the sample, line, and band position associated with a shape buffer index.

Performs the same function as the Sample, Line, and Band methods.

Parameters:

	index	Shape buffer index to map to a band position.
	i_samp	Sample position in shape buffer at index.
	i_line	Line position in shape buffer at index
	i_band	Band position in shape buffer at index.

References Band(), Line(), and Sample().

void* Isis::Buffer::RawBuffer ( ) const [inline]

Returns a void pointer to the raw buffer.

Cast this void pointer using information from the PixelType() method

Returns:: void* Pointer to the raw buffer

References p_rawbuf.

int Isis::Buffer::Sample ( const int index = 0 ) const

Returns the sample position associated with a shape buffer index.

The shape buffer is one dimensional. Let us assume a nsamps=2, nlines=3, and nbands=2. Therefore the total size of the shape buffer is 12 and valid index values are 0-11. Sample(0), Sample(2), Sample(4), etc will return a 1 while Sample(1), Sample(3), Sample(5), etc will return a 2.

Parameters:

index

Shape buffer index to map to a sample position. Defaults to 0.