C++ QPointArray::makeEllipse方法代码示例

QRegion::QRegion( const QRect &r, RegionType t )
{
    QRect rr = r.normalize();
    data = new QRegionData;
    CHECK_PTR( data );
    data->is_null = FALSE;
    if ( t == Rectangle ) {			// rectangular region
	data->rgn = XCreateRegion();
	XRectangle xr;
	xr.x = rr.x();
	xr.y = rr.y();
	xr.width  = rr.width();
	xr.height = rr.height();
	XUnionRectWithRegion( &xr, data->rgn, data->rgn );
    } else if ( t == Ellipse ) {		// elliptic region
	QPointArray a;
	a.makeEllipse( rr.x(), rr.y(), rr.width(), rr.height() );
	data->rgn = XPolygonRegion( (XPoint*)a.data(), a.size(), EvenOddRule );
    }
}

/**
  Internal method that draws one of the pies in a pie chart.

  \param painter the QPainter to draw in
  \param dataset the dataset to draw the pie for
  \param pie the pie to draw
  \param the chart to draw the pie in
  \param regions a pointer to a list of regions that will be filled
  with regions representing the data segments, if not null
  */
void KDChartPiePainter::drawOnePie( QPainter* painter,
        KDChartTableDataBase* /*data*/,
        uint dataset, uint pie, uint chart,
        uint threeDPieHeight,
        KDChartDataRegionList* regions )
{
    // Is there anything to draw at all?
    int angleLen = _angleLens[ ( int ) pie ];
    if ( angleLen ) {
        int startAngle = _startAngles[ ( int ) pie ];

        KDChartDataRegion* datReg = 0;
        QRegion* region = 0;
        bool mustDeleteRegion = false;
        if ( regions ){
            region = new QRegion();
            mustDeleteRegion = true;
        }

        QRect drawPosition = _position;
        if ( params()->explode() ) {
            // need to compute a new position for each or some of the pie
            QValueList<int> explodeList = params()->explodeValues();
            if( explodeList.count() == 0 || // nothing on list, explode all
                    explodeList.find( pie ) != explodeList.end() ) {
                double explodeAngle = ( startAngle + angleLen / 2 ) / 16;
                double explodeAngleRad = DEGTORAD( explodeAngle );
                double cosAngle = cos( explodeAngleRad );
                double sinAngle = -sin( explodeAngleRad );

                // find the explode factor for this particular pie
                double explodeFactor = 0.0;
                QMap<int,double> explodeFactors = params()->explodeFactors();
                if( !explodeFactors.contains( pie ) ) // not on factors list, use default
                    explodeFactor = params()->explodeFactor();
                else // on factors list, use segment-specific value
                    explodeFactor = explodeFactors[pie];

                double explodeX = explodeFactor * _size * cosAngle;
                double explodeY = explodeFactor * _size * sinAngle;
                drawPosition.moveBy( static_cast<int>( explodeX ), static_cast<int>( explodeY ) );
            } else
                drawPosition = _position;
        } else
            drawPosition = _position;

        // The 3D effect needs to be drawn first because it could
        // otherwise partly hide the pie itself.
        if ( params()->threeDPies() ) {
            draw3DEffect( painter, drawPosition, dataset, pie, chart,
                          threeDPieHeight,
                          params()->explode(), region );
        }

        painter->setBrush( params()->dataColor( pie ) );
        if ( angleLen == 5760 ) {
            // full circle, avoid nasty line in the middle
            painter->drawEllipse( drawPosition );
            if ( regions ) {
                QPointArray hitregion;
                hitregion.makeEllipse( drawPosition.x(), drawPosition.y(),
                                       drawPosition.width(),
                                       drawPosition.height() );
                datReg = new KDChartDataRegion( region->unite( QRegion( hitregion ) ),
                                                dataset,
                                                pie,
                                                chart );
                datReg->points[ KDChartEnums::PosCenter ]
                    = drawPosition.center();
                datReg->points[ KDChartEnums::PosCenterRight ]
                    = pointOnCircle( drawPosition,    0 );
                datReg->points[ KDChartEnums::PosTopRight ]
                    = pointOnCircle( drawPosition,  720 );
                datReg->points[ KDChartEnums::PosTopCenter ]
                    = pointOnCircle( drawPosition, 1440 );
                datReg->points[ KDChartEnums::PosTopLeft ]
                    = pointOnCircle( drawPosition, 2160 );
                datReg->points[ KDChartEnums::PosCenterLeft ]
                    = pointOnCircle( drawPosition, 2880 );
                datReg->points[ KDChartEnums::PosBottomLeft ]
                    = pointOnCircle( drawPosition, 3600 );
                datReg->points[ KDChartEnums::PosBottomCenter ]
                    = pointOnCircle( drawPosition, 4320 );
                datReg->points[ KDChartEnums::PosBottomRight ]
                    = pointOnCircle( drawPosition, 5040 );
                datReg->startAngle = 2880;
                datReg->angleLen   = 5760;
                regions->append( datReg );
            }
        } else {
//.........这里部分代码省略.........