incrementalplot.cpp

QWT5.01用于Qt开发的二维图形库程序

#include <qwt_plot.h>
#include <qwt_plot_canvas.h>
#include <qwt_plot_curve.h>
#include <qwt_symbol.h>
#include "incrementalplot.h"

CurveData::CurveData():
    d_count(0)
{
}

void CurveData::append(double *x, double *y, int count)
{
    int newSize = ( (d_count + count) / 1000 + 1 ) * 1000;
    if ( newSize > size() )
    {
        d_x.resize(newSize);
        d_y.resize(newSize);
    }

    for ( register int i = 0; i < count; i++ )
    {
        d_x[d_count + i] = x[i];
        d_y[d_count + i] = y[i];
    }
    d_count += count;
}

int CurveData::count() const
{
    return d_count;
}

int CurveData::size() const
{
    return d_x.size();
}

const double *CurveData::x() const
{
    return d_x.data();
}

const double *CurveData::y() const
{
    return d_y.data();
}

IncrementalPlot::IncrementalPlot(QWidget *parent): 
    QwtPlot(parent),
    d_data(NULL),
    d_curve(NULL)
{
    setAutoReplot(false);
}

IncrementalPlot::~IncrementalPlot()
{
    delete d_data;
}

void IncrementalPlot::appendData(double x, double y)
{
    appendData(&x, &y, 1);
}

void IncrementalPlot::appendData(double *x, double *y, int size)
{
    if ( d_data == NULL )
        d_data = new CurveData;

    if ( d_curve == NULL )
    {
        d_curve = new QwtPlotCurve("Test Curve");
        d_curve->setStyle(QwtPlotCurve::NoCurve);
        d_curve->setPaintAttribute(QwtPlotCurve::PaintFiltered);
    
        const QColor &c = Qt::white;
        d_curve->setSymbol(QwtSymbol(QwtSymbol::XCross,
            QBrush(c), QPen(c), QSize(5, 5)) );

        d_curve->attach(this);
    }

    d_data->append(x, y, size);
    d_curve->setRawData(d_data->x(), d_data->y(), d_data->count());
#ifdef __GNUC__
#endif

    const bool cacheMode = 
        canvas()->testPaintAttribute(QwtPlotCanvas::PaintCached);

    canvas()->setPaintAttribute(QwtPlotCanvas::PaintCached, false);
    d_curve->draw(d_curve->dataSize() - size, d_curve->dataSize() - 1);
    canvas()->setPaintAttribute(QwtPlotCanvas::PaintCached, cacheMode);
}

void IncrementalPlot::removeData()
{
    delete d_curve;
    d_curve = NULL;

    delete d_data;
    d_data = NULL;

    replot();
}