QwtPixelMatrix (3) Linux Manual Page
QwtPixelMatrix –
A bit field corresponding to the pixels of a rectangle.
Synopsis
#include <qwt_pixel_matrix.h> Inherits QBitArray.
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:
- rect Bounding rectangle for the matrix
Member Function Documentation
int QwtPixelMatrix::index (intx, inty) const [inline]
Calculate the index in the bit field corresponding to a position. Parameters:
- x X-coordinate
y Y-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:
- rect Bounding rectangle
Note:
- All bits are cleared
bool QwtPixelMatrix::testAndSetPixel (intx, inty, boolon) [inline]
Set a pixel and test if a pixel has been set before. Parameters:
- x X-coordinate
y Y-coordinate
on Set/Clear the pixel
Returns:
- true, when pos is outside of rect(), or when the pixel was set before.
bool QwtPixelMatrix::testPixel (intx, inty) const [inline]
Test if a pixel has been set. Parameters:
- x X-coordinate
y Y-coordinate
Returns:
- true, when pos is outside of rect(), or when the pixel has already been set.