A widget that holds a scene to display and modify the transfer function. More...

#include <WTransferFunctionWidget.h>

Inheritance diagram for WTransferFunctionWidget:

Collaboration diagram for WTransferFunctionWidget:

Public Types
typedef QGraphicsView	BaseClass
	type of our base class for easier coding More...

Public Slots
void	dataChanged ()
	Notification that the data changed, i.e., a control point has been moved or a color changed. More...

Public Member Functions
	WTransferFunctionWidget (QWidget qparent=NULL, WTransferFunctionGuiNotificationClass parent=NULL)
	Constructor. More...

virtual	~WTransferFunctionWidget ()
	Destructor. More...

void	setHistogram (const std::vector< double > &histogram)
	Called from external to set histogram. More...

void	forceRedraw ()
	Redraw the widget. More...

void	setCurrent (WTransferFunctionPoint *current)
	Set the current active point => this should be changed to QGraphicsScene object selection. More...

void	setCurrentColor (WTransferFunctionColorPoint *ccurrent)
	Similar to setCurrent but for Color control points. More...

void	sample1DTransferFunction (unsigned char *array, int width)
	Sample the transfer function into a 1D RGBA texture. More...

void	sample1DTransferFunctionForDisplay (unsigned char *array, int width)
	Sample the transfer function into a 1D RGBA, ABGR, ARGB, ... More...

void	insertPoint (const QPointF &position)
	Insert a new alpha control point at scene position position. More...

void	insertPointNormalized (const QPointF &position)
	Same as insertPoint but in normalized coordinates and not in screen space. More...

void	insertColor (const QPointF &pos, QColor const *const color=0)
	Insert a new color control point at scene position pos (only the x-value is relevant) If a color is provided, it is used. More...

void	insertColorNormalized (const QPointF &pos, QColor const *const color=0)
	Same as insertColor but in normalized coordinates, i.e., [ 0...1 ] along x. More...

void	clearTransferFunction ()
	Remove all points from the transfer function widget to be able to insert new points. More...

Protected Member Functions
virtual void	drawBackground (QPainter *painter, const QRectF &rect)
	Draws the background. More...

virtual void	keyPressEvent (QKeyEvent *event)
	Interactions implemented so far: right click: insert new object (Ctrl+left click or two-finger tap on OSX) left click on objects: (handled by individual objects) move control points and select object double click on objects: (handled by individual objects) open parameter dialog, e.g., to change the color "Delete" or "Backspace": delete selected itom. More...

virtual void	mousePressEvent (QMouseEvent *event)
	For a documentation of the implemented actions confer the keyPressEvent documentation. More...

WTransferFunctionPoint *	findPointOnLeft (QPointF position)
	Internal helper function: Find the point to the left of the given point. More...

WTransferFunctionColorPoint *	findCPointOnLeft (QPointF position)
	Internal helper function: Find the point to the left of the given color control point. More...

void	updateTransferFunction ()
	Updates the transfer function. More...

void	setMyBackground ()
	Internal helper function to update the QGraphicsPixmapItem that holds a representation of the current color map and displays it as a background of the widget. More...

Private Attributes
WTransferFunctionGuiNotificationClass *	parent
	the class that receives our update notifications More...

QGraphicsScene *	scene
	our scene More...

WTransferFunctionPoint *	first
	linked list of alpha items More...

WTransferFunctionPoint *	last
	first element More...

WTransferFunctionPoint *	current
	last element in list More...

WTransferFunctionColorPoint *	cfirst
	currently selected/active element More...

WTransferFunctionColorPoint *	clast
	first element More...

WTransferFunctionColorPoint *	ccurrent
	last element More...

WTransferFunctionBackground *	background
	currently selected/active color element More...

WTransferFunctionHistogram *	histogram
	background that displays the color map More...

bool	initialized
	item responsible for displaying histogram data More...

Detailed Description

A widget that holds a scene to display and modify the transfer function.

Currently most data storage is done in this class, which is not a great design. Thus, we should try to split the model and the view a bit more, even though this is not intended by QGraphicsView.

Definition at line 69 of file WTransferFunctionWidget.h.

Member Typedef Documentation

◆ BaseClass

typedef QGraphicsView WTransferFunctionWidget::BaseClass

type of our base class for easier coding

Definition at line 75 of file WTransferFunctionWidget.h.

Constructor & Destructor Documentation

◆ WTransferFunctionWidget()

WTransferFunctionWidget::WTransferFunctionWidget	(	QWidget *	qparent = `NULL`,
		WTransferFunctionGuiNotificationClass *	parent = `NULL`
	)

Constructor.

Create a TF widget with a given parent.

Parameters

qparent	parent widgeet
parent	a class that receives notifications

Definition at line 42 of file WTransferFunctionWidget.cpp.

References background, histogram, initialized, scene, and setMyBackground().

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◆ ~WTransferFunctionWidget()

WTransferFunctionWidget::~WTransferFunctionWidget ( )

virtual

Destructor.

Definition at line 218 of file WTransferFunctionWidget.cpp.

Member Function Documentation

◆ clearTransferFunction()

void WTransferFunctionWidget::clearTransferFunction ( )

Remove all points from the transfer function widget to be able to insert new points.

Definition at line 291 of file WTransferFunctionWidget.cpp.

References ccurrent, cfirst, clast, current, first, WTransferFunctionPoint::getLine(), WTransferFunctionColorPoint::getRight(), WTransferFunctionPoint::getRight(), and last.

Referenced by WPropertyTransferFunctionWidget::update().

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◆ dataChanged

void WTransferFunctionWidget::dataChanged ( )

slot

Notification that the data changed, i.e., a control point has been moved or a color changed.

Definition at line 269 of file WTransferFunctionWidget.cpp.

References forceRedraw(), initialized, setMyBackground(), and updateTransferFunction().

Referenced by WTransferFunctionColorPoint::colorSelected(), WTransferFunctionColorPoint::dropEvent(), WTransferFunctionColorPoint::itemChange(), WTransferFunctionPoint::itemChange(), and keyPressEvent().

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◆ drawBackground()

void WTransferFunctionWidget::drawBackground	(	QPainter *	painter,
		const QRectF &	rect
	)

protectedvirtual

Draws the background.

Parameters

painter	the painter to use
rect	the QRectF to repaint

Definition at line 253 of file WTransferFunctionWidget.cpp.

◆ findCPointOnLeft()

WTransferFunctionColorPoint * WTransferFunctionWidget::findCPointOnLeft ( QPointF position )

protected

Internal helper function: Find the point to the left of the given color control point.

Parameters

position a position

Returns: a color point left of the given position, i.e., with return.x < x_position

Definition at line 556 of file WTransferFunctionWidget.cpp.

References cfirst, current, and WTransferFunctionPoint::getRight().

Referenced by insertColor().

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◆ findPointOnLeft()

WTransferFunctionPoint * WTransferFunctionWidget::findPointOnLeft ( QPointF position )

protected

Internal helper function: Find the point to the left of the given point.

Parameters

position in the widget

Returns: an alpha point left of the given position, i.e., with return.x < x_position

Definition at line 538 of file WTransferFunctionWidget.cpp.

References current, first, and WTransferFunctionPoint::getRight().

Referenced by insertPoint().

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◆ forceRedraw()

void WTransferFunctionWidget::forceRedraw ( )

Redraw the widget.

Definition at line 280 of file WTransferFunctionWidget.cpp.

References initialized, and scene.

Referenced by dataChanged(), mousePressEvent(), and setHistogram().

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◆ insertColor()

void WTransferFunctionWidget::insertColor	(	const QPointF &	pos,
		QColor const *const	color = `0`
	)

Insert a new color control point at scene position pos (only the x-value is relevant) If a color is provided, it is used.

Otherwise, a new color is used interpolating the current color map.

Parameters

pos	the clicked position where pos.x = iso and pos.y is ignored
color	the color of the new point. If color = 0, a new color is created by interpolating the neighbors.

Definition at line 374 of file WTransferFunctionWidget.cpp.

References cfirst, clast, WTransferFunctionColorPoint::colorSelected(), findCPointOnLeft(), WTransferFunctionColorPoint::getColor(), WTransferFunctionColorPoint::getRight(), scene, WTransferFunctionColorPoint::setLeft(), and WTransferFunctionColorPoint::setRight().

Referenced by WTransferFunctionScene::dropEvent(), insertColorNormalized(), and mousePressEvent().

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◆ insertColorNormalized()

void WTransferFunctionWidget::insertColorNormalized	(	const QPointF &	pos,
		QColor const *const	color = `0`
	)

Same as insertColor but in normalized coordinates, i.e., [ 0...1 ] along x.

Parameters

pos	the position
color	the new color ( my be 0 and will then be interpolated linearly )

Definition at line 369 of file WTransferFunctionWidget.cpp.

References insertColor(), and scene.

Referenced by WPropertyTransferFunctionWidget::update().

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◆ insertPoint()

void WTransferFunctionWidget::insertPoint ( const QPointF & position )

Insert a new alpha control point at scene position position.

Parameters

position the position of the point with position.x = iso and position.y = alpha in window coordinates.

Definition at line 445 of file WTransferFunctionWidget.cpp.

References cfirst, clast, findPointOnLeft(), first, WTransferFunctionPoint::getLine(), WTransferFunctionPoint::getRight(), scene, WTransferFunctionLine::setLeft(), WTransferFunctionPoint::setLeft(), WTransferFunctionPoint::setLine(), WTransferFunctionPoint::setPos(), WTransferFunctionLine::setRight(), and WTransferFunctionPoint::setRight().

Referenced by insertPointNormalized(), and mousePressEvent().

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◆ insertPointNormalized()

void WTransferFunctionWidget::insertPointNormalized ( const QPointF & position )

Same as insertPoint but in normalized coordinates and not in screen space.

Parameters

position same as in insertPoint, but scaled to [ 0..1 ]x[ 0..1 ]

Definition at line 440 of file WTransferFunctionWidget.cpp.

References insertPoint(), and scene.

Referenced by WPropertyTransferFunctionWidget::update().

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◆ keyPressEvent()

void WTransferFunctionWidget::keyPressEvent ( QKeyEvent * event )

protectedvirtual

Interactions implemented so far: right click: insert new object (Ctrl+left click or two-finger tap on OSX) left click on objects: (handled by individual objects) move control points and select object double click on objects: (handled by individual objects) open parameter dialog, e.g., to change the color "Delete" or "Backspace": delete selected itom.

Parameters

event the event to handle

Definition at line 316 of file WTransferFunctionWidget.cpp.

References ccurrent, current, dataChanged(), WTransferFunctionColorPoint::getLeft(), WTransferFunctionPoint::getLeft(), WTransferFunctionPoint::getLine(), WTransferFunctionColorPoint::getRight(), WTransferFunctionPoint::getRight(), WTransferFunctionColorPoint::setLeft(), WTransferFunctionPoint::setLeft(), WTransferFunctionColorPoint::setRight(), WTransferFunctionLine::setRight(), and WTransferFunctionPoint::setRight().

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◆ mousePressEvent()

void WTransferFunctionWidget::mousePressEvent ( QMouseEvent * event )

protectedvirtual

For a documentation of the implemented actions confer the keyPressEvent documentation.

Parameters

event the event to handle

Definition at line 516 of file WTransferFunctionWidget.cpp.

References forceRedraw(), insertColor(), and insertPoint().

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◆ sample1DTransferFunction()

void WTransferFunctionWidget::sample1DTransferFunction	(	unsigned char *	array,
		int	width
	)

Sample the transfer function into a 1D RGBA texture.

Parameters

array	target byte array of RGBA values
width	width of array in number of color values

Definition at line 137 of file WTransferFunctionWidget.cpp.

References ccurrent, cfirst, first, WTransferFunctionColorPoint::getColor(), WTransferFunctionColorPoint::getRight(), WTransferFunctionPoint::getRight(), and scene.

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◆ sample1DTransferFunctionForDisplay()

void WTransferFunctionWidget::sample1DTransferFunctionForDisplay	(	unsigned char *	array,
		int	width
	)

Sample the transfer function into a 1D RGBA, ABGR, ARGB, ...

inaternal representation needs ARGB, but we do not display alpha component, so set it to 255

whatever... This function should work on the graphics native system, but I did not find the function to get information about the alignment, yet. (X11 Linux, little endian: ABRG. OSX: ARGB, X11 on OSX from Linux host->???)

Parameters

array	target byte array of RGBA values
width	width of array in number of color values

Definition at line 185 of file WTransferFunctionWidget.cpp.

References ccurrent, cfirst, WTransferFunctionColorPoint::getColor(), WTransferFunctionColorPoint::getRight(), and scene.

Referenced by setMyBackground().

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◆ setCurrent()

void WTransferFunctionWidget::setCurrent ( WTransferFunctionPoint * current )

inline

Set the current active point => this should be changed to QGraphicsScene object selection.

Parameters

current the new selection

Definition at line 108 of file WTransferFunctionWidget.h.

References ccurrent, and current.

Referenced by WTransferFunctionPoint::mousePressEvent().

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◆ setCurrentColor()

void WTransferFunctionWidget::setCurrentColor ( WTransferFunctionColorPoint * ccurrent )

inline

Similar to setCurrent but for Color control points.

Parameters

ccurrent the new seelection

Definition at line 119 of file WTransferFunctionWidget.h.

References ccurrent, and current.

Referenced by WTransferFunctionColorPoint::mousePressEvent().

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◆ setHistogram()

void WTransferFunctionWidget::setHistogram ( const std::vector< double > & histogram )

Called from external to set histogram.

Parameters

histogram The histogram data

Definition at line 262 of file WTransferFunctionWidget.cpp.

References forceRedraw(), WTransferFunctionHistogram::getData(), and histogram.

Referenced by WPropertyTransferFunctionWidget::update().

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◆ setMyBackground()

void WTransferFunctionWidget::setMyBackground ( )

protected

Internal helper function to update the QGraphicsPixmapItem that holds a representation of the current color map and displays it as a background of the widget.

This function samples the texture into a QPixmap and updates the QGraphicsPixmapItem.

Definition at line 229 of file WTransferFunctionWidget.cpp.

References background, sample1DTransferFunctionForDisplay(), and WTransferFunctionBackground::setMyPixmap().

Referenced by dataChanged(), and WTransferFunctionWidget().

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