datasource.cpp Example File

qmloscilloscope/datasource.cpp
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#include "datasource.h" #include <QtCore/qmath.h> using namespace QtDataVisualization; Q_DECLARE_METATYPE(QSurface3DSeries *) DataSource::DataSource(QObject *parent) : QObject(parent), m_index(-1), m_resetArray(nullptr) { qRegisterMetaType<QSurface3DSeries *>(); } DataSource::~DataSource() { clearData(); } void DataSource::generateData(int cacheCount, int rowCount, int columnCount, float xMin, float xMax, float yMin, float yMax, float zMin, float zMax) { if (!cacheCount || !rowCount || !columnCount) return; clearData(); // Re-create the cache array m_data.resize(cacheCount); for (int i(0); i < cacheCount; i++) { QSurfaceDataArray &array = m_data[i]; array.reserve(rowCount); for (int j(0); j < rowCount; j++) array.append(new QSurfaceDataRow(columnCount)); } float xRange = xMax - xMin; float yRange = yMax - yMin; float zRange = zMax - zMin; int cacheIndexStep = columnCount / cacheCount; float cacheStep = float(cacheIndexStep) * xRange / float(columnCount); // Populate caches for (int i(0); i < cacheCount; i++) { QSurfaceDataArray &cache = m_data[i]; float cacheXAdjustment = cacheStep * i; float cacheIndexAdjustment = cacheIndexStep * i; for (int j(0); j < rowCount; j++) { QSurfaceDataRow &row = *(cache[j]); float rowMod = (float(j)) / float(rowCount); float yRangeMod = yRange * rowMod; float zRangeMod = zRange * rowMod; float z = zRangeMod + zMin; qreal rowColWaveAngleMul = M_PI * M_PI * rowMod; float rowColWaveMul = yRangeMod * 0.2f; for (int k(0); k < columnCount; k++) { float colMod = (float(k)) / float(columnCount); float xRangeMod = xRange * colMod; float x = xRangeMod + xMin + cacheXAdjustment; float colWave = float(qSin((2.0 * M_PI * colMod) - (1.0 / 2.0 * M_PI)) + 1.0); float y = (colWave * ((float(qSin(rowColWaveAngleMul * colMod) + 1.0)))) * rowColWaveMul + (0.15f * float(qrand()) / float(RAND_MAX)) * yRangeMod; int index = k + cacheIndexAdjustment; if (index >= columnCount) { // Wrap over index -= columnCount; x -= xRange; } row[index] = QVector3D(x, y, z); } } } } void DataSource::update(QSurface3DSeries *series) { if (series && m_data.size()) { // Each iteration uses data from a different cached array m_index++; if (m_index > m_data.count() - 1) m_index = 0; QSurfaceDataArray array = m_data.at(m_index); int newRowCount = array.size(); int newColumnCount = array.at(0)->size(); // If the first time or the dimensions of the cache array have changed, // reconstruct the reset array if (!m_resetArray || series->dataProxy()->rowCount() != newRowCount || series->dataProxy()->columnCount() != newColumnCount) { m_resetArray = new QSurfaceDataArray(); m_resetArray->reserve(newRowCount); for (int i(0); i < newRowCount; i++) m_resetArray->append(new QSurfaceDataRow(newColumnCount)); } // Copy items from our cache to the reset array for (int i(0); i < newRowCount; i++) { const QSurfaceDataRow &sourceRow = *(array.at(i)); QSurfaceDataRow &row = *(*m_resetArray)[i]; for (int j(0); j < newColumnCount; j++) row[j].setPosition(sourceRow.at(j).position()); } // Notify the proxy that data has changed series->dataProxy()->resetArray(m_resetArray); } } void DataSource::clearData() { for (int i(0); i < m_data.size(); i++) { QSurfaceDataArray &array = m_data[i]; for (int j(0); j < array.size(); j++) delete array[j]; array.clear(); } }