qwt_polar_curve.cpp

Go to the documentation of this file.

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * QwtPolar Widget Library
 * Copyright (C) 2008   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
 *****************************************************************************/

#include "qwt_polar_curve.h"
#include "qwt_polar.h"
#include "qwt_painter.h"
#include "qwt_scale_map.h"
#include "qwt_math.h"
#include "qwt_symbol.h"
#include "qwt_legend.h"
#include "qwt_curve_fitter.h"
#include "qwt_clipper.h"

#include <qpainter.h>

static inline bool qwtInsidePole( const QwtScaleMap &map, double radius )
{
    return map.isInverting() ? ( radius > map.s1() ) : ( radius < map.s1() );
}

static int qwtVerifyRange( int size, int &i1, int &i2 )
{
    if ( size < 1 )
        return 0;

    i1 = qBound( 0, i1, size - 1 );
    i2 = qBound( 0, i2, size - 1 );

    if ( i1 > i2 )
        qSwap( i1, i2 );

    return ( i2 - i1 + 1 );
}

class QwtPolarCurve::PrivateData
{
public:
    PrivateData():
        style( QwtPolarCurve::Lines ),
        curveFitter( NULL )
    {
        symbol = new QwtSymbol();
        pen = QPen( Qt::black );
    }

    ~PrivateData()
    {
        delete symbol;
        delete curveFitter;
    }

    QwtPolarCurve::CurveStyle style;
    const QwtSymbol *symbol;
    QPen pen;
    QwtCurveFitter *curveFitter;

    QwtPolarCurve::LegendAttributes legendAttributes;
};

QwtPolarCurve::QwtPolarCurve():
    QwtPolarItem( QwtText() )
{
    init();
}

QwtPolarCurve::QwtPolarCurve( const QwtText &title ):
    QwtPolarItem( title )
{
    init();
}

QwtPolarCurve::QwtPolarCurve( const QString &title ):
    QwtPolarItem( QwtText( title ) )
{
    init();
}

QwtPolarCurve::~QwtPolarCurve()
{
    delete d_series;
    delete d_data;
}

void QwtPolarCurve::init()
{
    d_data = new PrivateData;
    d_series = NULL;

    setItemAttribute( QwtPolarItem::AutoScale );
    setItemAttribute( QwtPolarItem::Legend );
    setZ( 20.0 );

    setRenderHint( RenderAntialiased, true );
}

int QwtPolarCurve::rtti() const
{
    return QwtPolarItem::Rtti_PolarCurve;
}

void QwtPolarCurve::setLegendAttribute( LegendAttribute attribute, bool on )
{
    if ( on )
        d_data->legendAttributes |= attribute;
    else
        d_data->legendAttributes &= ~attribute;
}

bool QwtPolarCurve::testLegendAttribute( LegendAttribute attribute ) const
{
    return ( d_data->legendAttributes & attribute );
}

void QwtPolarCurve::setStyle( CurveStyle style )
{
    if ( style != d_data->style )
    {
        d_data->style = style;
        itemChanged();
    }
}

QwtPolarCurve::CurveStyle QwtPolarCurve::style() const
{
    return d_data->style;
}

void QwtPolarCurve::setSymbol( QwtSymbol *symbol )
{
    if ( symbol != d_data->symbol )
    {
        delete d_data->symbol;
        d_data->symbol = symbol;
        itemChanged();
    }
}

const QwtSymbol *QwtPolarCurve::symbol() const
{
    return d_data->symbol;
}

void QwtPolarCurve::setPen( const QPen &pen )
{
    if ( pen != d_data->pen )
    {
        d_data->pen = pen;
        itemChanged();
    }
}

const QPen& QwtPolarCurve::pen() const
{
    return d_data->pen;
}

void QwtPolarCurve::setData( QwtSeriesData<QwtPointPolar> *data )
{
    if ( d_series != data )
    {
        delete d_series;
        d_series = data;
        itemChanged();
    }
}

void QwtPolarCurve::setCurveFitter( QwtCurveFitter *curveFitter )
{
    if ( curveFitter != d_data->curveFitter )
    {
        delete d_data->curveFitter;
        d_data->curveFitter = curveFitter;

        itemChanged();
    }
}

QwtCurveFitter *QwtPolarCurve::curveFitter() const
{
    return d_data->curveFitter;
}

void QwtPolarCurve::draw( QPainter *painter,
    const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap,
    const QPointF &pole, double radius,
    const QRectF &canvasRect ) const
{
    Q_UNUSED( radius );
    Q_UNUSED( canvasRect );

    draw( painter, azimuthMap, radialMap, pole, 0, -1 );
}

void QwtPolarCurve::draw( QPainter *painter,
    const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap,
    const QPointF &pole, int from, int to ) const
{
    if ( !painter || dataSize() <= 0 )
        return;

    if ( to < 0 )
        to = dataSize() - 1;

    if ( qwtVerifyRange( dataSize(), from, to ) > 0 )
    {
        painter->save();
        painter->setPen( d_data->pen );

        drawCurve( painter, d_data->style,
            azimuthMap, radialMap, pole, from, to );

        painter->restore();

        if ( d_data->symbol->style() != QwtSymbol::NoSymbol )
        {
            painter->save();
            drawSymbols( painter, *d_data->symbol,
                azimuthMap, radialMap, pole, from, to );
            painter->restore();
        }
    }
}

void QwtPolarCurve::drawCurve( QPainter *painter, int style,
    const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap,
    const QPointF &pole, int from, int to ) const
{
    switch ( style )
    {
        case Lines:
            drawLines( painter, azimuthMap, radialMap, pole, from, to );
            break;
        case NoCurve:
        default:
            break;
    }
}

void QwtPolarCurve::drawLines( QPainter *painter,
    const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap,
    const QPointF &pole, int from, int to ) const
{
    int size = to - from + 1;
    if ( size <= 0 )
        return;

    QPolygonF polyline;

    if ( d_data->curveFitter )
    {
        QPolygonF points( size );
        for ( int j = from; j <= to; j++ )
        {
            const QwtPointPolar point = sample( j );
            points[j - from] = QPointF( point.azimuth(), point.radius() );
        }

        points = d_data->curveFitter->fitCurve( points );

        polyline.resize( points.size() );

        QPointF *polylineData = polyline.data();
        QPointF *pointsData = points.data();

        for ( int i = 0; i < points.size(); i++ )
        {
            const QwtPointPolar point( pointsData[i].x(), pointsData[i].y() );

            double r = radialMap.transform( point.radius() );
            const double a = azimuthMap.transform( point.azimuth() );

            polylineData[i] = qwtPolar2Pos( pole, r, a );
        }
    }
    else
    {
        polyline.resize( size );
        QPointF *polylineData = polyline.data();

        for ( int i = from; i <= to; i++ )
        {
            QwtPointPolar point = sample( i );
            if ( !qwtInsidePole( radialMap, point.radius() ) )
            {
                double r = radialMap.transform( point.radius() );
                const double a = azimuthMap.transform( point.azimuth() );
                polylineData[i - from] = qwtPolar2Pos( pole, r, a );
            }
            else
            {
                polylineData[i - from] = pole;
            }
        }
    }

    QRectF clipRect;
    if ( painter->hasClipping() )
    {
        clipRect = painter->clipRegion().boundingRect();
    }
    else
    {
        clipRect = painter->window();
        if ( !clipRect.isEmpty() )
            clipRect = painter->transform().inverted().mapRect( clipRect );
    }

    if ( !clipRect.isEmpty() )
    {
        double off = qCeil( qMax( qreal( 1.0 ), painter->pen().widthF() ) );
        clipRect = clipRect.toRect().adjusted( -off, -off, off, off );
        QwtClipper::clipPolygonF( clipRect, polyline );
    }

    QwtPainter::drawPolyline( painter, polyline );
}

void QwtPolarCurve::drawSymbols( QPainter *painter, const QwtSymbol &symbol,
    const QwtScaleMap &azimuthMap, const QwtScaleMap &radialMap,
    const QPointF &pole, int from, int to ) const
{
    painter->setBrush( symbol.brush() );
    painter->setPen( symbol.pen() );

    const int chunkSize = 500;

    for ( int i = from; i <= to; i += chunkSize )
    {
        const int n = qMin( chunkSize, to - i + 1 );

        QPolygonF points;
        for ( int j = 0; j < n; j++ )
        {
            const QwtPointPolar point = sample( i + j );

            if ( !qwtInsidePole( radialMap, point.radius() ) )
            {
                const double r = radialMap.transform( point.radius() );
                const double a = azimuthMap.transform( point.azimuth() );

                points += qwtPolar2Pos( pole, r, a );
            }
            else
            {
                points += pole;
            }
        }

        if ( points.size() > 0 )
            symbol.drawSymbols( painter, points );
    }
}

size_t QwtPolarCurve::dataSize() const
{
    return d_series->size();
}

QwtGraphic QwtPolarCurve::legendIcon( int index,
    const QSizeF &size ) const
{
    Q_UNUSED( index );

    if ( size.isEmpty() )
        return QwtGraphic();

    QwtGraphic graphic;
    graphic.setDefaultSize( size );
    graphic.setRenderHint( QwtGraphic::RenderPensUnscaled, true );

    QPainter painter( &graphic );
    painter.setRenderHint( QPainter::Antialiasing,
        testRenderHint( QwtPolarItem::RenderAntialiased ) );

    if ( d_data->legendAttributes == 0 )
    {
        QBrush brush;

        if ( style() != QwtPolarCurve::NoCurve )
        {
            brush = QBrush( pen().color() );
        }
        else if ( d_data->symbol &&
            ( d_data->symbol->style() != QwtSymbol::NoSymbol ) )
        {
            brush = QBrush( d_data->symbol->pen().color() );
        }

        if ( brush.style() != Qt::NoBrush )
        {
            QRectF r( 0, 0, size.width(), size.height() );
            painter.fillRect( r, brush );
        }
    }

    if ( d_data->legendAttributes & QwtPolarCurve::LegendShowLine )
    {
        if ( pen() != Qt::NoPen )
        {
            QPen pn = pen();
            pn.setCapStyle( Qt::FlatCap );

            painter.setPen( pn );

            const double y = 0.5 * size.height();
            QwtPainter::drawLine( &painter, 0.0, y, size.width(), y );
        }
    }

    if ( d_data->legendAttributes & QwtPolarCurve::LegendShowSymbol )
    {
        if ( d_data->symbol )
        {
            QRectF r( 0, 0, size.width(), size.height() );
            d_data->symbol->drawSymbol( &painter, r );
        }
    }

    return graphic;
}

QwtInterval QwtPolarCurve::boundingInterval( int scaleId ) const
{
    const QRectF boundingRect = d_series->boundingRect();

    if ( scaleId == QwtPolar::ScaleAzimuth )
        return QwtInterval( boundingRect.left(), boundingRect.right() );

    if ( scaleId == QwtPolar::ScaleRadius )
        return QwtInterval( boundingRect.top(), boundingRect.bottom() );

    return QwtInterval();
}