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#include <stdlib.h>
#include <qwt_painter.h>
#include <qwt_plot_canvas.h>
#include <qwt_plot_marker.h>
#include <qwt_plot_curve.h>
#include <qwt_scale_widget.h>
#include <qwt_legend.h>
#include <qwt_scale_draw.h>
#include <qwt_math.h>
#include "data_plot.h"
//
// Initialize main window
//
DataPlot::DataPlot(QWidget *parent):
QwtPlot(parent),
d_interval(0),
d_timerId(-1)
{
// Disable polygon clipping
QwtPainter::setDeviceClipping(false);
// We don't need the cache here
canvas()->setPaintAttribute(QwtPlotCanvas::PaintCached, false);
canvas()->setPaintAttribute(QwtPlotCanvas::PaintPacked, false);
#if QT_VERSION >= 0x040000
#ifdef Q_WS_X11
/*
Qt::WA_PaintOnScreen is only supported for X11, but leads
to substantial bugs with Qt 4.2.x/Windows
*/
canvas()->setAttribute(Qt::WA_PaintOnScreen, true);
#endif
#endif
alignScales();
// Initialize data
for (int i = 0; i< PLOT_SIZE; i++)
{
d_x[i] = 0.5 * i; // time axis
d_y[i] = 0;
d_z[i] = 0;
}
// Assign a title
setTitle("A Test for High Refresh Rates");
insertLegend(new QwtLegend(), QwtPlot::BottomLegend);
// Insert new curves
QwtPlotCurve *cRight = new QwtPlotCurve("Data Moving Right");
cRight->attach(this);
QwtPlotCurve *cLeft = new QwtPlotCurve("Data Moving Left");
cLeft->attach(this);
// Set curve styles
cRight->setPen(QPen(Qt::red));
cLeft->setPen(QPen(Qt::blue));
// Attach (don't copy) data. Both curves use the same x array.
cRight->setRawData(d_x, d_y, PLOT_SIZE);
cLeft->setRawData(d_x, d_z, PLOT_SIZE);
#if 0
// Insert zero line at y = 0
QwtPlotMarker *mY = new QwtPlotMarker();
mY->setLabelAlignment(Qt::AlignRight|Qt::AlignTop);
mY->setLineStyle(QwtPlotMarker::HLine);
mY->setYValue(0.0);
mY->attach(this);
#endif
// Axis
setAxisTitle(QwtPlot::xBottom, "Time/seconds");
setAxisScale(QwtPlot::xBottom, 0, 100);
setAxisTitle(QwtPlot::yLeft, "Values");
setAxisScale(QwtPlot::yLeft, -1.5, 1.5);
setTimerInterval(0.0);
}
//
// Set a plain canvas frame and align the scales to it
//
void DataPlot::alignScales()
{
// The code below shows how to align the scales to
// the canvas frame, but is also a good example demonstrating
// why the spreaded API needs polishing.
canvas()->setFrameStyle(QFrame::Box | QFrame::Plain );
canvas()->setLineWidth(1);
for ( int i = 0; i < QwtPlot::axisCnt; i++ )
{
QwtScaleWidget *scaleWidget = (QwtScaleWidget *)axisWidget(i);
if ( scaleWidget )
scaleWidget->setMargin(0);
QwtScaleDraw *scaleDraw = (QwtScaleDraw *)axisScaleDraw(i);
if ( scaleDraw )
scaleDraw->enableComponent(QwtAbstractScaleDraw::Backbone, false);
}
}
void DataPlot::setTimerInterval(double ms)
{
d_interval = qRound(ms);
if ( d_timerId >= 0 )
{
killTimer(d_timerId);
d_timerId = -1;
}
if (d_interval >= 0 )
d_timerId = startTimer(d_interval);
}
// Generate new values
void DataPlot::timerEvent(QTimerEvent *)
{
static double phase = 0.0;
if (phase > (M_PI - 0.0001))
phase = 0.0;
// y moves from left to right:
// Shift y array right and assign new value to y[0].
for ( int i = PLOT_SIZE - 1; i > 0; i-- )
d_y[i] = d_y[i-1];
d_y[0] = sin(phase) * (-1.0 + 2.0 * double(rand()) / double(RAND_MAX));
for ( int j = 0; j < PLOT_SIZE - 1; j++ )
d_z[j] = d_z[j+1];
d_z[PLOT_SIZE - 1] = 0.8 - (2.0 * phase/M_PI) + 0.4 *
double(rand()) / double(RAND_MAX);
// update the display
replot();
phase += M_PI * 0.02;
}
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