main.cpp Example File | Qt Charts 5.12.8

- Qt 5.12
- Qt Charts
- OpenGL Accelerated Series Example
- main.cpp Example File
- Qt Charts | Commercial or GPLv3

# main.cpp Example File

openglseries/main.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2016 The Qt Company Ltd.
     ** Contact: https://www.qt.io/licensing/
     **
     ** This file is part of the Qt Charts module of the Qt Toolkit.
     **
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     ** the Free Software Foundation and appearing in the file LICENSE.GPL3
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     #include "datasource.h"
     #include <QtWidgets/QApplication>
     #include <QtWidgets/QMainWindow>
     #include <QtCharts/QChartView>
     #include <QtCharts/QLineSeries>
     #include <QtCharts/QScatterSeries>
     #include <QtCharts/QValueAxis>
     #include <QtCharts/QLogValueAxis>
     #include <QtWidgets/QLabel>

     // Uncomment to use logarithmic axes instead of regular value axes
     //#define USE_LOG_AXIS

     // Uncomment to use regular series instead of OpenGL accelerated series
     //#define DONT_USE_GL_SERIES

     // Uncomment to add a simple regular series (thick line) and a matching OpenGL series (thinner line)
     // to verify the series have same visible geometry.
     //#define ADD_SIMPLE_SERIES

     QT_CHARTS_USE_NAMESPACE

     int main(int argc, char *argv[])
     {
         QApplication a(argc, argv);
         QStringList colors;
         colors << "red" << "blue" << "green" << "black";

         QChart *chart = new QChart();
         chart->legend()->hide();

     #ifdef USE_LOG_AXIS
         QLogValueAxis *axisX = new QLogValueAxis;
         QLogValueAxis *axisY = new QLogValueAxis;
     #else
         QValueAxis *axisX = new QValueAxis;
         QValueAxis *axisY = new QValueAxis;
     #endif

         chart->addAxis(axisX, Qt::AlignBottom);
         chart->addAxis(axisY, Qt::AlignLeft);

         const int seriesCount = 10;
     #ifdef DONT_USE_GL_SERIES
         const int pointCount = 100;
         chart->setTitle("Unaccelerated Series");
     #else
         const int pointCount = 10000;
         chart->setTitle("OpenGL Accelerated Series");
     #endif

         QList<QXYSeries *> seriesList;
         for (int i = 0; i < seriesCount; i++) {
             QXYSeries *series = 0;
             int colorIndex = i % colors.size();
             if (i % 2) {
                 series = new QScatterSeries;
                 QScatterSeries *scatter = static_cast<QScatterSeries *>(series);
                 scatter->setColor(QColor(colors.at(colorIndex)));
                 scatter->setMarkerSize(qreal(colorIndex + 2) / 2.0);
                 // Scatter pen doesn't have affect in OpenGL drawing, but if you disable OpenGL drawing
                 // this makes the marker border visible and gives comparable marker size to OpenGL
                 // scatter points.
                 scatter->setPen(QPen("black"));
             } else {
                 series = new QLineSeries;
                 series->setPen(QPen(QBrush(QColor(colors.at(colorIndex))),
                                     qreal(colorIndex + 2) / 2.0));
             }
             seriesList.append(series);
     #ifdef DONT_USE_GL_SERIES
             series->setUseOpenGL(false);
     #else
             series->setUseOpenGL(true);
     #endif
             chart->addSeries(series);
             series->attachAxis(axisX);
             series->attachAxis(axisY);
         }

         if (axisX->type() == QAbstractAxis::AxisTypeLogValue)
             axisX->setRange(0.1, 20.0);
         else
             axisX->setRange(0, 20.0);

         if (axisY->type() == QAbstractAxis::AxisTypeLogValue)
             axisY->setRange(0.1, 10.0);
         else
             axisY->setRange(0, 10.0);

     #ifdef ADD_SIMPLE_SERIES
         QLineSeries *simpleRasterSeries = new QLineSeries;
         *simpleRasterSeries << QPointF(0.001, 0.001)
                      << QPointF(2.5, 8.0)
                      << QPointF(5.0, 4.0)
                      << QPointF(7.5, 9.0)
                      << QPointF(10.0, 0.001)
                      << QPointF(12.5, 2.0)
                      << QPointF(15.0, 1.0)
                      << QPointF(17.5, 6.0)
                      << QPointF(20.0, 10.0);
         simpleRasterSeries->setUseOpenGL(false);
         simpleRasterSeries->setPen(QPen(QBrush("magenta"), 8));
         chart->addSeries(simpleRasterSeries);
         simpleRasterSeries->attachAxis(axisX);
         simpleRasterSeries->attachAxis(axisY);

         QLineSeries *simpleGLSeries = new QLineSeries;
         simpleGLSeries->setUseOpenGL(true);
         simpleGLSeries->setPen(QPen(QBrush("black"), 2));
         simpleGLSeries->replace(simpleRasterSeries->points());
         chart->addSeries(simpleGLSeries);
         simpleGLSeries->attachAxis(axisX);
         simpleGLSeries->attachAxis(axisY);
     #endif

         QChartView *chartView = new QChartView(chart);

         QMainWindow window;
         window.setCentralWidget(chartView);
         window.resize(600, 400);
         window.show();

         DataSource dataSource;
         dataSource.generateData(seriesCount, 10, pointCount);

         QLabel *fpsLabel = new QLabel(&window);
         QLabel *countLabel = new QLabel(&window);
         QString countText = QStringLiteral("Total point count: %1");
         countLabel->setText(countText.arg(pointCount * seriesCount));
         countLabel->adjustSize();
         fpsLabel->move(10, 2);
         fpsLabel->adjustSize();
         fpsLabel->raise();
         fpsLabel->show();
         countLabel->move(10, fpsLabel->height());
         fpsLabel->raise();
         countLabel->show();

         // We can get more than one changed event per frame, so do async update.
         // This also allows the application to be responsive.
         QObject::connect(chart->scene(), &QGraphicsScene::changed,
                          &dataSource, &DataSource::handleSceneChanged);

         dataSource.startUpdates(seriesList, fpsLabel);

         return a.exec();
     }