A class that stores a 1D transfer function which consists of a linear interpolation of alpha and color values. More...

#include <WTransferFunction.h>

Collaboration diagram for WTransferFunction:

Classes
struct	AlphaEntry
	Alpha entries represent linearly interpolated transparency values along the isovalue scale. More...

struct	ColorEntry
	Color entries are linearly interpolated colors along isovalues. More...

struct	Entry
	Prototype for a storage element. More...

struct	LessPred
	Templatized comparison predicate for internal searching. More...

Public Member Functions
	WTransferFunction ()
	Default constructor of a meaningless transfer function. More...

	WTransferFunction (const WTransferFunction &rhs)
	Deep copy constructor. More...

WTransferFunction &	operator= (const WTransferFunction &rhs)
	Deep copy operator. More...

bool	operator== (const WTransferFunction &rhs) const
	Check equivalence of two transfer functions. More...

bool	operator!= (const WTransferFunction &rhs) const
	Check equivalence of two transfer functions. More...

	~WTransferFunction ()
	Default destuctor. More...

size_t	numAlphas () const
	Get the number of alphas. More...

size_t	numColors () const
	Get the number of colors. More...

double	getOpacityScale () const
	Get the scaling factor for the opacity. More...

void	setOpacityScale (double factor)
	Set the scaling factor for the opacity. More...

double	getAlphaIsovalue (size_t i) const
	Get the isovalue at a given index in the alpha values. More...

double	getColorIsovalue (size_t i) const
	The isovalue of the color at a given index. More...

double	getAlpha (size_t i) const
	Get alpha at given index. More...

const WColor &	getColor (size_t i) const
	Get color at given index. More...

void	addColor (double iso, const WColor &color)
	Insert a new color point. More...

void	addAlpha (double iso, double alpha)
	Insert a new alpha point. More...

void	setHistogram (std::vector< double > &data)
	Set the histogram going along with the transfer function. More...

void	removeHistogram ()
	Clears the histogram data so the gui won't show any. More...

const std::vector< double > &	getHistogram () const
	Returns the histogram. More...

void	sample1DTransferFunction (unsigned char *array, int width, double min, double max) const
	sample/render the transfer function linearly between min and max in an RGBA texture. More...

Static Public Member Functions
static WTransferFunction	createFromRGBA (unsigned char const *const rgba, size_t size)
	Try to estimate a transfer function from an RGBA image. More...

Private Attributes
std::vector< ColorEntry >	m_colors
	Sorted list of colors. More...

std::vector< AlphaEntry >	m_alphas
	Sorted list of alpha values. More...

double	m_isomin
	The smallest used iso value. More...

double	m_isomax
	The largest used iso value. More...

double	m_opacityScale
	Factor by which the output opacity is scaled to allow for easier specification of very small opacity values. More...

std::vector< double >	m_histogram
	Sores a histogram. More...

Friends
std::ostream &	operator<< (std::ostream &out, const WTransferFunction &tf)
	Default output operator. More...

Detailed Description

A class that stores a 1D transfer function which consists of a linear interpolation of alpha and color values.

Definition at line 37 of file WTransferFunction.h.

Constructor & Destructor Documentation

◆ WTransferFunction() [1/2]

WTransferFunction::WTransferFunction ( )

inline

Default constructor of a meaningless transfer function.

Definition at line 43 of file WTransferFunction.h.

◆ WTransferFunction() [2/2]

WTransferFunction::WTransferFunction ( const WTransferFunction & rhs )

inline

Deep copy constructor.

Parameters

rhs	the value to histogram

Definition at line 52 of file WTransferFunction.h.

◆ ~WTransferFunction()

WTransferFunction::~WTransferFunction ( )

inline

Default destuctor.

Definition at line 95 of file WTransferFunction.h.

Member Function Documentation

◆ addAlpha()

void WTransferFunction::addAlpha	(	double	iso,
		double	alpha
	)

Insert a new alpha point.

Parameters

iso	the new iso value
alpha	the new alpha value at the given iso value

Definition at line 211 of file WTransferFunction.cpp.

References m_alphas, m_colors, m_isomax, and m_isomin.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::create(), createFromRGBA(), WMTransferFunction1D::properties(), WVisualizationPropertyHandler::setColorGradient(), and WTransferFunctionWidget::updateTransferFunction().

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◆ addColor()

void WTransferFunction::addColor	(	double	iso,
		const WColor &	color
	)

Insert a new color point.

Parameters

iso	the new iso value
color	the new color at the given iso value

Definition at line 187 of file WTransferFunction.cpp.

References m_alphas, m_colors, m_isomax, and m_isomin.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::create(), createFromRGBA(), WMTransferFunction1D::properties(), WVisualizationPropertyHandler::setColorGradient(), and WTransferFunctionWidget::updateTransferFunction().

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◆ createFromRGBA()

WTransferFunction WTransferFunction::createFromRGBA	(	unsigned char const *const	rgba,
		size_t	size
	)

static

Try to estimate a transfer function from an RGBA image.

Parameters

rgba	values between 0 and 255 representing the red, green, and blue channel
size	number of color entries in rgba

Returns: approximated transfer function

the threshold here is larger than for alpha, becuase we compare all colors at once

Definition at line 235 of file WTransferFunction.cpp.

References addAlpha(), and addColor().

Referenced by WTransferFunctionScene::dropEvent().

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◆ getAlpha()

double WTransferFunction::getAlpha ( size_t i ) const

inline

Get alpha at given index.

Parameters

i	the index to query

Returns: the alpha value at index i

Definition at line 166 of file WTransferFunction.h.

References m_alphas, and m_opacityScale.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::asString(), and WPropertyTransferFunctionWidget::update().

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◆ getAlphaIsovalue()

double WTransferFunction::getAlphaIsovalue ( size_t i ) const

inline

Get the isovalue at a given index in the alpha values.

Parameters

i	the index of the point to query

Returns: the alpha values position/isovalue at index i

Definition at line 144 of file WTransferFunction.h.

References m_alphas.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::asString(), and WPropertyTransferFunctionWidget::update().

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◆ getColor()

const WColor& WTransferFunction::getColor ( size_t i ) const

inline

Get color at given index.

Parameters

i	the index to query

Returns: the color at index i

Definition at line 177 of file WTransferFunction.h.

References m_colors.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::asString(), and WPropertyTransferFunctionWidget::update().

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◆ getColorIsovalue()

double WTransferFunction::getColorIsovalue ( size_t i ) const

inline

The isovalue of the color at a given index.

Parameters

i	the index of the point to query.

Returns: the color values position/isovalue at index i

Definition at line 155 of file WTransferFunction.h.

References m_colors.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::asString(), and WPropertyTransferFunctionWidget::update().

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◆ getHistogram()

const std::vector< double >& WTransferFunction::getHistogram ( ) const

inline

Returns the histogram.

Returns: a reference to the internal representation of the histogram

Definition at line 225 of file WTransferFunction.h.

References m_histogram.

Referenced by WPropertyTransferFunctionWidget::update().

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◆ getOpacityScale()

double WTransferFunction::getOpacityScale ( ) const

inline

Get the scaling factor for the opacity.

Returns: scaling factor

Definition at line 124 of file WTransferFunction.h.

References m_opacityScale.

◆ numAlphas()

size_t WTransferFunction::numAlphas ( ) const

inline

Get the number of alphas.

Returns: the number of alpha points

Definition at line 104 of file WTransferFunction.h.

References m_alphas.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::asString(), WMTransferFunction1D::moduleMain(), and WPropertyTransferFunctionWidget::update().

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◆ numColors()

size_t WTransferFunction::numColors ( ) const

inline

Get the number of colors.

Returns: the number of color points

Definition at line 114 of file WTransferFunction.h.

References m_colors.

Referenced by PROPERTY_TYPE_HELPER::WStringConversion< WPVBaseTypes::PV_TRANSFERFUNCTION >::asString(), and WPropertyTransferFunctionWidget::update().

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◆ operator!=()

bool WTransferFunction::operator!= ( const WTransferFunction & rhs ) const

Check equivalence of two transfer functions.

Returns: negated result of operator==

Parameters

rhs	the value to compare with

Definition at line 91 of file WTransferFunction.cpp.

◆ operator=()

WTransferFunction& WTransferFunction::operator= ( const WTransferFunction & rhs )

inline

Deep copy operator.

Parameters

rhs	the value to copy

Returns: reference to current object; reference to current object

Definition at line 65 of file WTransferFunction.h.

References m_alphas, m_colors, m_histogram, m_isomax, and m_isomin.

◆ operator==()

bool WTransferFunction::operator== ( const WTransferFunction & rhs ) const

Check equivalence of two transfer functions.

Returns: true if this object contains exactly the same data as rhs

Parameters

rhs	object to compare with

Definition at line 33 of file WTransferFunction.cpp.

References m_alphas, m_colors, m_histogram, m_isomax, and m_isomin.

◆ removeHistogram()

void WTransferFunction::removeHistogram ( )

inline

Clears the histogram data so the gui won't show any.

Definition at line 215 of file WTransferFunction.h.

References m_histogram.

Referenced by WMTransferFunction1D::moduleMain().

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◆ sample1DTransferFunction()

void WTransferFunction::sample1DTransferFunction	(	unsigned char *	array,
		int	width,
		double	min,
		double	max
	)		const

sample/render the transfer function linearly between min and max in an RGBA texture.

Parameters

array	pointer to an allocated data structure
width	is the number of RGBA samples.
min	the lowest value to be sampled
max	the hightes value to be sampled

Postcondition: array contains the sampled data

Precondition: array is allocated and has space for width elements

Definition at line 115 of file WTransferFunction.cpp.

References m_alphas, m_colors, m_isomax, m_isomin, and m_opacityScale.

Referenced by WMTransferFunction1D::moduleMain(), and WCsvConverter::sampleTransferFunction().

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◆ setHistogram()

void WTransferFunction::setHistogram ( std::vector< double > & data )

inline

Set the histogram going along with the transfer function.

This should be changed in the future to be handled in a different way. A good option would be to introduce an object encapsulating a transfer function and histogram information.

Parameters

data	the histogram data between m_isomin and m_isomax

Definition at line 207 of file WTransferFunction.h.

References m_histogram.

Referenced by WMTransferFunction1D::moduleMain(), and WTransferFunctionWidget::updateTransferFunction().

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◆ setOpacityScale()

void WTransferFunction::setOpacityScale ( double factor )

inline

Set the scaling factor for the opacity.

Parameters

factor scaling factor of opacity values

Definition at line 133 of file WTransferFunction.h.

References m_opacityScale.

Referenced by WMTransferFunction1D::moduleMain().

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Friends And Related Function Documentation

◆ operator<<

std::ostream& operator<<	(	std::ostream &	out,
		const WTransferFunction &	tf
	)

friend

Default output operator.

Currently stores values the same way as it is done in the properties. This code should only be used for debugging and you should not rely on the interface.

Parameters

tf	The transfer function to output
out	The stream to which we write

Returns: reference to out

Definition at line 355 of file WTransferFunction.cpp.

Member Data Documentation

◆ m_alphas

std::vector<AlphaEntry> WTransferFunction::m_alphas

private

Sorted list of alpha values.

Definition at line 368 of file WTransferFunction.h.

Referenced by addAlpha(), addColor(), getAlpha(), getAlphaIsovalue(), numAlphas(), operator=(), operator==(), and sample1DTransferFunction().

◆ m_colors

std::vector<ColorEntry> WTransferFunction::m_colors

private

Sorted list of colors.

Definition at line 363 of file WTransferFunction.h.

Referenced by addAlpha(), addColor(), getColor(), getColorIsovalue(), numColors(), operator=(), operator==(), and sample1DTransferFunction().

◆ m_histogram

std::vector< double > WTransferFunction::m_histogram

private

Sores a histogram.

This is used for property-handling only and does not change the transfer function at all.

Definition at line 391 of file WTransferFunction.h.

Referenced by getHistogram(), operator=(), operator==(), removeHistogram(), and setHistogram().

◆ m_isomax

double WTransferFunction::m_isomax

private

The largest used iso value.

Definition at line 378 of file WTransferFunction.h.

Referenced by addAlpha(), addColor(), operator=(), operator==(), and sample1DTransferFunction().

◆ m_isomin

double WTransferFunction::m_isomin

private

The smallest used iso value.

Definition at line 373 of file WTransferFunction.h.

Referenced by addAlpha(), addColor(), operator=(), operator==(), and sample1DTransferFunction().

◆ m_opacityScale

double WTransferFunction::m_opacityScale

private

Factor by which the output opacity is scaled to allow for easier specification of very small opacity values.

Definition at line 385 of file WTransferFunction.h.

Referenced by getAlpha(), getOpacityScale(), sample1DTransferFunction(), and setOpacityScale().

The documentation for this class was generated from the following files:

Classes

Public Member Functions

Static Public Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ WTransferFunction() [1/2]

◆ WTransferFunction() [2/2]

◆ ~WTransferFunction()

Member Function Documentation

◆ addAlpha()

◆ addColor()

◆ createFromRGBA()

◆ getAlpha()

◆ getAlphaIsovalue()

◆ getColor()

◆ getColorIsovalue()

◆ getHistogram()

◆ getOpacityScale()

◆ numAlphas()

◆ numColors()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ removeHistogram()

◆ sample1DTransferFunction()

◆ setHistogram()

◆ setOpacityScale()

Friends And Related Function Documentation

◆ operator<<

Member Data Documentation

◆ m_alphas

◆ m_colors

◆ m_histogram

◆ m_isomax

◆ m_isomin

◆ m_opacityScale