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++ // Copyright (C) 2023 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
++
++ #include "scatterdatamodifier.h"
++ #include <QtGraphs/qscatterdataproxy.h>
++ #include <QtGraphs/qvalue3daxis.h>
++ #include <QtGraphs/q3dscene.h>
++ #include <QtGraphs/qscatter3dseries.h>
++ #include <QtGraphs/QCustom3DItem>
++
++ #include <QtGui/qquaternion.h>
++
++ #include <QtCore/qmath.h>
++
++ static const float verticalRange = 8.0f;
++ static const float horizontalRange = verticalRange;
++ static const float ellipse_a = horizontalRange / 3.0f;
++ static const float ellipse_b = verticalRange;
++ static const float doublePi = float(M_PI) * 2.0f;
++ static const float radiansToDegrees = 360.0f / doublePi;
++ static const float animationFrames = 30.0f;
++
++ ScatterDataModifier::ScatterDataModifier(Q3DScatterWidgetItem *scatter)
++ : m_graph(scatter),
++ m_fieldLines(12),
++ m_arrowsPerLine(16),
++ m_magneticField(new QScatter3DSeries),
++ m_sun(new QCustom3DItem),
++ m_angleOffset(0.0f),
++ m_angleStep(doublePi / m_arrowsPerLine / animationFrames)
++ {
++ m_graph->setShadowQuality(QtGraphs3D::ShadowQuality::None);
++ m_graph->setCameraPreset(QtGraphs3D::CameraPreset::Front);
++
++ // Magnetic field lines use custom narrow arrow
++ m_magneticField->setItemSize(0.2f);
++ //! [3]
++ m_magneticField->setMesh(QAbstract3DSeries::Mesh::UserDefined);
++ m_magneticField->setUserDefinedMesh(QStringLiteral(":/mesh/narrowarrow.mesh"));
++ //! [3]
++ //! [4]
++ QLinearGradient fieldGradient(0, 0, 16, 1024);
++ fieldGradient.setColorAt(0.0, Qt::black);
++ fieldGradient.setColorAt(1.0, Qt::white);
++ m_magneticField->setBaseGradient(fieldGradient);
++ m_magneticField->setColorStyle(QGraphsTheme::ColorStyle::RangeGradient);
++ //! [4]
++
++ // For 'sun' we use a custom large sphere
++ m_sun->setScaling(QVector3D(0.07f, 0.07f, 0.07f));
++ m_sun->setMeshFile(QStringLiteral(":/mesh/largesphere.mesh"));
++ QImage sunColor = QImage(2, 2, QImage::Format_RGB32);
++ sunColor.fill(QColor(0xff, 0xbb, 0x00));
++ m_sun->setTextureImage(sunColor);
++
++ m_graph->addSeries(m_magneticField);
++ m_graph->addCustomItem(m_sun);
++
++ // Configure the axes according to the data
++ m_graph->axisX()->setRange(-horizontalRange, horizontalRange);
++ m_graph->axisY()->setRange(-verticalRange, verticalRange);
++ m_graph->axisZ()->setRange(-horizontalRange, horizontalRange);
++ m_graph->axisX()->setSegmentCount(int(horizontalRange));
++ m_graph->axisZ()->setSegmentCount(int(horizontalRange));
++
++ QObject::connect(&m_rotationTimer, &QTimer::timeout, this,
++ &ScatterDataModifier::triggerRotation);
++
++ toggleRotation();
++ generateData();
++ }
++
++ ScatterDataModifier::~ScatterDataModifier()
++ {
++ delete m_graph;
++ }
++
++ void ScatterDataModifier::generateData()
++ {
++ int arraySize = m_fieldLines * m_arrowsPerLine;
++ if (arraySize != m_magneticFieldArray.size())
++ m_magneticFieldArray.resize(arraySize);
++
++ QScatterDataItem *ptrToDataArray = &m_magneticFieldArray.first();
++
++ for (float i = 0; i < m_fieldLines; i++) {
++ float horizontalAngle = (doublePi * i) / m_fieldLines;
++ float xCenter = ellipse_a * qCos(horizontalAngle);
++ float zCenter = ellipse_a * qSin(horizontalAngle);
++
++ // Rotate - arrow always tangential to origin
++ //! [0]
++ QQuaternion yRotation = QQuaternion::fromAxisAndAngle(0.0f, 1.0f, 0.0f, horizontalAngle * radiansToDegrees);
++ //! [0]
++
++ for (float j = 0; j < m_arrowsPerLine; j++) {
++ // Calculate point on ellipse centered on origin and parallel to x-axis
++ float verticalAngle = ((doublePi * j) / m_arrowsPerLine) + m_angleOffset;
++ float xUnrotated = ellipse_a * qCos(verticalAngle);
++ float y = ellipse_b * qSin(verticalAngle);
++
++ // Rotate the ellipse around y-axis
++ float xRotated = xUnrotated * qCos(horizontalAngle);
++ float zRotated = xUnrotated * qSin(horizontalAngle);
++
++ // Add offset
++ float x = xCenter + xRotated;
++ float z = zCenter + zRotated;
++
++ //! [1]
++ QQuaternion zRotation = QQuaternion::fromAxisAndAngle(0.0f, 0.0f, 1.0f, verticalAngle * radiansToDegrees);
++ QQuaternion totalRotation = yRotation * zRotation;
++ //! [1]
++
++ ptrToDataArray->setPosition(QVector3D(x, y, z));
++ //! [2]
++ ptrToDataArray->setRotation(totalRotation);
++ //! [2]
++ ptrToDataArray++;
++ }
++ }
++
++ if (m_graph->selectedSeries() == m_magneticField)
++ m_graph->clearSelection();
++
++ m_magneticField->dataProxy()->resetArray(m_magneticFieldArray);
++ }
++
++ void ScatterDataModifier::setFieldLines(int lines)
++ {
++ m_fieldLines = lines;
++ generateData();
++ }
++
++ void ScatterDataModifier::setArrowsPerLine(int arrows)
++ {
++ m_angleOffset = 0.0f;
++ m_angleStep = doublePi / m_arrowsPerLine / animationFrames;
++ m_arrowsPerLine = arrows;
++ generateData();
++ }
++
++ void ScatterDataModifier::triggerRotation()
++ {
++ m_angleOffset += m_angleStep;
++ generateData();
++ }
++
++ void ScatterDataModifier::toggleSun()
++ {
++ m_sun->setVisible(!m_sun->isVisible());
++ }
++
++ void ScatterDataModifier::toggleRotation()
++ {
++ if (m_rotationTimer.isActive())
++ m_rotationTimer.stop();
++ else
++ m_rotationTimer.start(15);
++ }