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/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
* Qwt Widget Library
* Copyright (C) 1997 Josef Wilgen
* Copyright (C) 2003 Uwe Rathmann
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the Qwt License, Version 1.0
*****************************************************************************/
#ifndef QWT_PIXEL_MATRIX_H
#define QWT_PIXEL_MATRIX_H
#include "qwt_global.h"
#include <qbitarray.h>
#include <qrect.h>
/*!
\brief A bit field corresponding to the pixels of a rectangle
QwtPixelMatrix is intended to filter out duplicates in an
unsorted array of points.
*/
class QWT_EXPORT QwtPixelMatrix: public QBitArray
{
public:
QwtPixelMatrix( const QRect& rect );
~QwtPixelMatrix();
void setRect( const QRect& rect );
QRect rect() const;
bool testPixel( int x, int y ) const;
bool testAndSetPixel( int x, int y, bool on );
int index( int x, int y ) const;
private:
QRect d_rect;
};
/*!
\brief Test if a pixel has been set
\param x X-coordinate
\param y Y-coordinate
\return true, when pos is outside of rect(), or when the pixel
has already been set.
*/
inline bool QwtPixelMatrix::testPixel( int x, int y ) const
{
const int idx = index( x, y );
return ( idx >= 0 ) ? testBit( idx ) : true;
}
/*!
\brief Set a pixel and test if a pixel has been set before
\param x X-coordinate
\param y Y-coordinate
\param on Set/Clear the pixel
\return true, when pos is outside of rect(), or when the pixel
was set before.
*/
inline bool QwtPixelMatrix::testAndSetPixel( int x, int y, bool on )
{
const int idx = index( x, y );
if ( idx < 0 )
return true;
const bool onBefore = testBit( idx );
setBit( idx, on );
return onBefore;
}
/*!
\brief Calculate the index in the bit field corresponding to a position
\param x X-coordinate
\param y Y-coordinate
\return Index, when rect() contains pos - otherwise -1.
*/
inline int QwtPixelMatrix::index( int x, int y ) const
{
const int dx = x - d_rect.x();
if ( dx < 0 || dx >= d_rect.width() )
return -1;
const int dy = y - d_rect.y();
if ( dy < 0 || dy >= d_rect.height() )
return -1;
return dy * d_rect.width() + dx;
}
#endif