datasource.cpp Example File

openglseries/datasource.cpp
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#include "datasource.h" #include <QtCore/QtMath> QT_CHARTS_USE_NAMESPACE DataSource::DataSource(QObject *parent) : QObject(parent), m_index(-1) { generateData(0, 0, 0); } void DataSource::update(QAbstractSeries *series, int seriesIndex) { if (series) { QXYSeries *xySeries = static_cast<QXYSeries *>(series); const QVector<QVector<QPointF> > &seriesData = m_data.at(seriesIndex); if (seriesIndex == 0) m_index++; if (m_index > seriesData.count() - 1) m_index = 0; QVector<QPointF> points = seriesData.at(m_index); // Use replace instead of clear + append, it's optimized for performance xySeries->replace(points); } } void DataSource::handleSceneChanged() { m_dataUpdater.start(); } void DataSource::updateAllSeries() { static int frameCount = 0; static QString labelText = QStringLiteral("FPS: %1"); for (int i = 0; i < m_seriesList.size(); i++) update(m_seriesList[i], i); frameCount++; int elapsed = m_fpsTimer.elapsed(); if (elapsed >= 1000) { elapsed = m_fpsTimer.restart(); qreal fps = qreal(0.1 * int(10000.0 * (qreal(frameCount) / qreal(elapsed)))); m_fpsLabel->setText(labelText.arg(QString::number(fps, 'f', 1))); m_fpsLabel->adjustSize(); frameCount = 0; } } void DataSource::startUpdates(const QList<QXYSeries *> &seriesList, QLabel *fpsLabel) { m_seriesList = seriesList; m_fpsLabel = fpsLabel; m_dataUpdater.setInterval(0); m_dataUpdater.setSingleShot(true); QObject::connect(&m_dataUpdater, &QTimer::timeout, this, &DataSource::updateAllSeries); m_fpsTimer.start(); updateAllSeries(); } void DataSource::generateData(int seriesCount, int rowCount, int colCount) { m_data.clear(); qreal xAdjustment = 20.0 / (colCount * rowCount); qreal yMultiplier = 3.0 / qreal(seriesCount); // Append the new data depending on the type for (int k(0); k < seriesCount; k++) { QVector<QVector<QPointF> > seriesData; qreal height = qreal(k) * (10.0 / qreal(seriesCount)) + 0.3; for (int i(0); i < rowCount; i++) { QVector<QPointF> points; points.reserve(colCount); for (int j(0); j < colCount; j++) { qreal x(0); qreal y(0); // data with sin + random component y = height + (yMultiplier * qSin(3.14159265358979 / 50 * j) + (yMultiplier * (qreal) rand() / (qreal) RAND_MAX)); // 0.000001 added to make values logaxis compatible x = 0.000001 + 20.0 * (qreal(j) / qreal(colCount)) + (xAdjustment * qreal(i)); points.append(QPointF(x, y)); } seriesData.append(points); } m_data.append(seriesData); } }