QwtPolarSpectrogram Class Reference

#include <qwt_polar_spectrogram.h>

Inheritance diagram for QwtPolarSpectrogram:

List of all members.

Public Types
enum	PaintAttribute { ApproximatedAtan = 0x01 }
typedef QFlags< PaintAttribute >	PaintAttributes
Public Member Functions
	QwtPolarSpectrogram ()
virtual	~QwtPolarSpectrogram ()
void	setData (QwtRasterData *data)
const QwtRasterData *	data () const
void	setColorMap (QwtColorMap *)
const QwtColorMap *	colorMap () const
void	setPaintAttribute (PaintAttribute, bool on=true)
bool	testPaintAttribute (PaintAttribute) const
void	setRenderThreadCount (uint numThreads)
uint	renderThreadCount () const
virtual int	rtti () const
virtual void	draw (QPainter *painter, const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap, const QPointF &pole, double radius, const QRectF &canvasRect) const
virtual QwtInterval	boundingInterval (int scaleId) const
Protected Member Functions
virtual QImage	renderImage (const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap, const QPointF &pole, const QRect &rect) const
virtual void	renderTile (const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap, const QPointF &pole, const QPoint &imagePos, const QRect &tile, QImage *image) const

---

Detailed Description

An item, which displays a spectrogram.

A spectrogram displays threedimenional data, where the 3rd dimension ( the intensity ) is displayed using colors. The colors are calculated from the values using a color map.

See also:

QwtRasterData, QwtColorMap

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Member Typedef Documentation

typedef QFlags<PaintAttribute> QwtPolarSpectrogram::PaintAttributes

Paint attributes.

---

Member Enumeration Documentation

enum QwtPolarSpectrogram::PaintAttribute

Attributes to modify the drawing algorithm. The default setting disables ApproximatedAtan

See also:

setPaintAttribute(), testPaintAttribute()

Enumerator:

ApproximatedAtan

Use qwtFastAtan2 instead of atan2 for translating widget into polar coordinates.

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Constructor & Destructor Documentation

QwtPolarSpectrogram::QwtPolarSpectrogram

(

)

[explicit]

Constructor.

QwtPolarSpectrogram::~QwtPolarSpectrogram

(

)

[virtual]

Destructor.

---

Member Function Documentation

QwtInterval QwtPolarSpectrogram::boundingInterval

(

int

scaleId

)

const [virtual]

Interval, that is necessary to display the item This interval can be useful for operations like clipping or autoscaling

Parameters:

scaleId

Scale index

Returns:

bounding interval ( == position )

See also:

position()

Reimplemented from QwtPolarItem.

const QwtColorMap * QwtPolarSpectrogram::colorMap

(

)

const

Returns:

Color Map used for mapping the intensity values to colors

See also:

setColorMap()

const QwtRasterData * QwtPolarSpectrogram::data

(

)

const

Returns:

Spectrogram data

See also:

setData()

void QwtPolarSpectrogram::draw	(	QPainter *	painter,
		const QwtScaleMap &	azimuthMap,
		const QwtScaleMap &	radialMap,
		const QPointF &	pole,
		double	radius,
		const QRectF &	canvasRect
	)		const [virtual]

Draw the spectrogram

Parameters:

painter	Painter
azimuthMap	Maps azimuth values to values related to 0.0, M_2PI
radialMap	Maps radius values into painter coordinates.
pole	Position of the pole in painter coordinates
radius	Radius of the complete plot area in painter coordinates
canvasRect	Contents rect of the canvas in painter coordinates

Implements QwtPolarItem.

QImage QwtPolarSpectrogram::renderImage	(	const QwtScaleMap &	azimuthMap,
		const QwtScaleMap &	radialMap,
		const QPointF &	pole,
		const QRect &	rect
	)		const [protected, virtual]

Render an image from the data and color map.

The area is translated into a rect of the paint device. For each pixel of this rect the intensity is mapped into a color.

Parameters:

azimuthMap	Maps azimuth values to values related to 0.0, M_2PI
radialMap	Maps radius values into painter coordinates.
pole	Position of the pole in painter coordinates
rect	Target rectangle of the image in painter coordinates

Returns:

A QImage::Format_Indexed8 or QImage::Format_ARGB32 depending on the color map.

See also:

QwtRasterData::intensity(), QwtColorMap::rgb(), QwtColorMap::colorIndex()

uint QwtPolarSpectrogram::renderThreadCount

(

)

const

Returns:

Number of threads to be used for rendering. If numThreads is set to 0, the system specific ideal thread count is used.

Warning:

Rendering in multiple threads is only supported for Qt >= 4.4

See also:

setRenderThreadCount(), renderImage(), renderTile()

void QwtPolarSpectrogram::renderTile	(	const QwtScaleMap &	azimuthMap,
		const QwtScaleMap &	radialMap,
		const QPointF &	pole,
		const QPoint &	imagePos,
		const QRect &	tile,
		QImage *	image
	)		const [protected, virtual]

Render a sub-rectangle of an image.

renderTile() is called by renderImage() to render different parts of the image by concurrent threads.

Parameters:

azimuthMap	Maps azimuth values to values related to 0.0, M_2PI
radialMap	Maps radius values into painter coordinates.
pole	Position of the pole in painter coordinates
imagePos	Top/left position of the image in painter coordinates
tile	Sub-rectangle of the tile in painter coordinates
image	Image to be rendered

See also:

setRenderThreadCount()

Note:

renderTile needs to be reentrant

int QwtPolarSpectrogram::rtti

(

)

const [virtual]

Returns:

QwtPolarItem::Rtti_PolarSpectrogram

Reimplemented from QwtPolarItem.

void QwtPolarSpectrogram::setColorMap

(

QwtColorMap *

colorMap

)

Change the color map

Often it is useful to display the mapping between intensities and colors as an additional plot axis, showing a color bar.

Parameters:

colorMap

Color Map

See also:

colorMap(), QwtScaleWidget::setColorBarEnabled(), QwtScaleWidget::setColorMap()

void QwtPolarSpectrogram::setData

(

QwtRasterData *

data

)

Set the data to be displayed

Parameters:

data	Spectrogram Data

See also:

data()

Warning:

QwtRasterData::initRaster() is called each time before the image is rendered, but without any useful parameters. Also QwtRasterData::rasterHint() is not used.

void QwtPolarSpectrogram::setPaintAttribute	(	PaintAttribute	attribute,
		bool	on = true
	)

Specify an attribute how to draw the curve

Parameters:

attribute	Paint attribute
on	On/Off

See also:

testPaintAttribute()

void QwtPolarSpectrogram::setRenderThreadCount

(

uint

numThreads

)

Rendering an image from the raster data can often be done parallel on a multicore system.

Parameters:

numThreads

Number of threads to be used for rendering. If numThreads is set to 0, the system specific ideal thread count is used.

The default thread count is 1 ( = no additional threads )

Warning:

Rendering in multiple threads is only supported for Qt >= 4.4

See also:

renderThreadCount(), renderImage(), renderTile()

bool QwtPolarSpectrogram::testPaintAttribute

(

PaintAttribute

attribute

)

const

Parameters:

attribute

Paint attribute

Returns:

True, when attribute has been set

See also:

setPaintAttribute()