Qwt User's Guide
QwtPixelMatrix Class Reference

A bit field corresponding to the pixels of a rectangle. More...

#include <qwt_pixel_matrix.h>

Public Member Functions

 QwtPixelMatrix (const QRect &rect)
 Constructor.
 ~QwtPixelMatrix ()
 Destructor.
void setRect (const QRect &rect)
QRect rect () const
bool testPixel (int x, int y) const
 Test if a pixel has been set.
bool testAndSetPixel (int x, int y, bool on)
 Set a pixel and test if a pixel has been set before.
int index (int x, int y) const
 Calculate the index in the bit field corresponding to a position.

Detailed Description

A bit field corresponding to the pixels of a rectangle.

QwtPixelMatrix is intended to filter out duplicates in an unsorted array of points.


Constructor & Destructor Documentation

QwtPixelMatrix::QwtPixelMatrix ( const QRect &  rect)

Constructor.

Parameters:
rectBounding rectangle for the matrix

Member Function Documentation

int QwtPixelMatrix::index ( int  x,
int  y 
) const [inline]

Calculate the index in the bit field corresponding to a position.

Parameters:
xX-coordinate
yY-coordinate
Returns:
Index, when rect() contains pos - otherwise -1.
QRect QwtPixelMatrix::rect ( ) const
Returns:
Bounding rectangle
void QwtPixelMatrix::setRect ( const QRect &  rect)

Set the bounding rectangle of the matrix

Parameters:
rectBounding rectangle
Note:
All bits are cleared
bool QwtPixelMatrix::testAndSetPixel ( int  x,
int  y,
bool  on 
) [inline]

Set a pixel and test if a pixel has been set before.

Parameters:
xX-coordinate
yY-coordinate
onSet/Clear the pixel
Returns:
true, when pos is outside of rect(), or when the pixel was set before.
bool QwtPixelMatrix::testPixel ( int  x,
int  y 
) const [inline]

Test if a pixel has been set.

Parameters:
xX-coordinate
yY-coordinate
Returns:
true, when pos is outside of rect(), or when the pixel has already been set.

List of all members.

 All Classes Functions Variables Typedefs Enumerations Enumerator