Add some comments

ExampleViewOpenGL/src/ExampleGLWidget.cpp

@@ -42,9 +42,9 @@ ExampleGLWidget::ExampleGLWidget() :
 
 }
 
-bool ExampleGLWidget::isInitialized()
+ExampleGLWidget::~ExampleGLWidget()
 {
-    return _isInitialized;
+    cleanup();
 }
 
 void ExampleGLWidget::setData(const std::vector<hdps::Vector2f>& points, float pointSize, float pointOpacity)
@@ -74,14 +74,15 @@ void ExampleGLWidget::setData(const std::vector<hdps::Vector2f>& points, float p
     _bounds.makeSquare();
     _bounds.expand(0.1f);
 
-    makeCurrent();
+    // Send the data to the renderer
     _pointRenderer.setBounds(_bounds);
     _pointRenderer.setData(_points);
     _pointRenderer.setColors(_colors);
 
     _pointRenderer.setPointSize(pointSize);
     _pointRenderer.setAlpha(pointOpacity);
 
+    // Calls paintGL()
     update();
 }
 

ExampleViewOpenGL/src/ExampleGLWidget.h

@@ -19,13 +19,16 @@ class ExampleGLWidget : public QOpenGLWidget, protected QOpenGLFunctions
 
 public:
     ExampleGLWidget();
-
+    ~ExampleGLWidget();
+
     /** Returns true when the widget was initialized and is ready to be used. */
-    bool isInitialized();
+    bool isInitialized() const { return _isInitialized;};
 
+    /** Sets 2D point positions and visual properties in the renderer */
     void setData(const std::vector<hdps::Vector2f>& points, float pointSize, float pointOpacity);
 
 protected:
+    // We have to override some QOpenGLWidget functions that handle the actual drawing
     void initializeGL()         override;
     void resizeGL(int w, int h) override;
     void paintGL()              override;
@@ -35,11 +38,11 @@ class ExampleGLWidget : public QOpenGLWidget, protected QOpenGLFunctions
     void initialized();
 
 private:
-    bool                    _isInitialized;
-    QColor                  _backgroundColor;
-    PointRenderer           _pointRenderer;
-    float                   _pixelRatio;
-    std::vector<Vector2f>   _points;
-    std::vector<Vector3f>   _colors;
-    Bounds                  _bounds;
+    PointRenderer           _pointRenderer;     /* ManiVault OpenGL point renderer implementation */
+    float                   _pixelRatio;        /* device pixel ratio */
+    std::vector<Vector2f>   _points;            /* 2D coordinates of points */
+    std::vector<Vector3f>   _colors;            /* Color of points - here we use a constant color for simplicity */
+    Bounds                  _bounds;            /* Min and max point coordinates for camera placement */
+    QColor                  _backgroundColor;   /* Background color */
+    bool                    _isInitialized;     /* Whether OpenGL is initialized */
 };

ExampleViewOpenGL/src/ExampleViewGLPlugin.cpp

@@ -77,8 +77,9 @@ ExampleViewGLPlugin::ExampleViewGLPlugin(const PluginFactory* factory) :
     });
 
     // update data when data set changed
-    connect(&_currentDataSet, &Dataset<Points>::dataChanged, this, &ExampleViewGLPlugin::updateData);
+    connect(&_currentDataSet, &Dataset<Points>::dataChanged, this, &ExampleViewGLPlugin::updatePlot);
 
+    // update settings UI when data set changed
     connect(&_currentDataSet, &Dataset<Points>::changed, this, [this]() {
         const auto enabled = _currentDataSet.isValid();
 
@@ -129,7 +130,7 @@ void ExampleViewGLPlugin::init()
 
 }
 
-void ExampleViewGLPlugin::updateData()
+void ExampleViewGLPlugin::updatePlot()
 {
     if (!_currentDataSet.isValid())
     {
@@ -143,8 +144,7 @@ void ExampleViewGLPlugin::updateData()
         return;
     }
 
-    std::vector<hdps::Vector2f> data;
-
+    // Retrieve the data that is to be shown from the core
     auto newDimX = _settingsAction.getXDimensionPickerAction().getCurrentDimensionIndex();
     auto newDimY = _settingsAction.getYDimensionPickerAction().getCurrentDimensionIndex();
 
@@ -154,7 +154,10 @@ void ExampleViewGLPlugin::updateData()
     if (newDimY >= 0)
         _currentDimensions[1] = static_cast<unsigned int>(newDimY);
 
+    std::vector<hdps::Vector2f> data;
     _currentDataSet->extractDataForDimensions(data, _currentDimensions[0], _currentDimensions[1]);
+
+    // Set data in OpenGL widget
     _exampleGLWidget->setData(data, _settingsAction.getPointSizeAction().getValue(), _settingsAction.getPointOpacityAction().getValue());
 }
 
@@ -170,7 +173,7 @@ void ExampleViewGLPlugin::loadData(const hdps::Datasets& datasets)
 
     // Load the first dataset, changes to _currentDataSet are connected with convertDataAndUpdateChart
     _currentDataSet = datasets.first();
-    updateData();
+    updatePlot();
 }
 
 QString ExampleViewGLPlugin::getCurrentDataSetID() const
@@ -181,11 +184,6 @@ QString ExampleViewGLPlugin::getCurrentDataSetID() const
         return QString{};
 }
 
-hdps::Dataset<Points>& ExampleViewGLPlugin::getDataset()
-{ 
-    return _currentDataSet; 
-}
-
 void ExampleViewGLPlugin::createData()
 {
     // Here, we create a random data set, so that we do not need 

ExampleViewOpenGL/src/ExampleViewGLPlugin.h

@@ -23,14 +23,14 @@ class ExampleGLWidget;
 /**
  * Example view plugin class
  *
- * This view plugin class provides skeleton code that shows how to develop
- * a OpenGL view plugin in ManiVault. It shows how to use the built-in drag and drop
- * behavior.
- *
- * To see the plugin in action, please follow the steps below:
- *
- * 1. Go to the visualization menu in ManiVault
- * 2. Choose the Example view menu item, the view will be added to the layout
+ * This plugin showcases how a OpenGL-based visualization can be included in ManiVault.
+ * We are implemented a bare-bone scatterplot using ManiVault's point renderer.
+ * 
+ * This project:
+ *  - Sets up a QOpenGLWidget, which is used to render OpenGL graphics
+ *  - Uses ManiVault's DropWidget to drag&drop data sets into the view
+ * 
+ * To keep this example concise this projects does not implement selections.
  *
  * @authors J. Thijssen & T. Kroes & A. Vieth
  */
@@ -55,9 +55,8 @@ class ExampleViewGLPlugin : public ViewPlugin
     /** Store a private reference to the data set that should be displayed */
     void loadData(const hdps::Datasets& datasets) override;
 
-    hdps::Dataset<Points>& getDataset();
-
-    void updateData();
+    /** Retrieves data to be shown and updates the OpenGL plot */
+    void updatePlot();
 
 private:
     /** We create and publish some data in order to provide an self-contained example project */
@@ -66,11 +65,11 @@ class ExampleViewGLPlugin : public ViewPlugin
     QString getCurrentDataSetID() const;
 
 protected:
-    DropWidget*             _dropWidget;                /** Widget for drag and drop behavior */
-    ExampleGLWidget*        _exampleGLWidget;           /** The visualization widget */
-    SettingsAction         _settingsAction;            /** Settings action */
-    hdps::Dataset<Points>   _currentDataSet;            /** Points smart pointer */
-    std::vector<unsigned int> _currentDimensions;
+    DropWidget*                 _dropWidget;            /** Widget for drag and drop behavior */
+    ExampleGLWidget*            _exampleGLWidget;       /** The OpenGL widget */
+    SettingsAction              _settingsAction;        /** Settings action */
+    hdps::Dataset<Points>       _currentDataSet;        /** Points smart pointer */
+    std::vector<unsigned int>   _currentDimensions;     /** Stores which dimensions of the current data are shown */
 };
 
 /**

ExampleViewOpenGL/src/SettingsAction.cpp

@@ -28,19 +28,19 @@ SettingsAction::SettingsAction(QObject* parent, const QString& title) :
     _datasetNameAction.setString(" (No data loaded yet)");
 
     connect(&_xDimensionPickerAction, &DimensionPickerAction::currentDimensionIndexChanged, [this](const std::uint32_t& currentDimensionIndex) {
-        _exampleViewGLPlugin->updateData();
+        _exampleViewGLPlugin->updatePlot();
     });
 
     connect(&_yDimensionPickerAction, &DimensionPickerAction::currentDimensionIndexChanged, [this](const std::uint32_t& currentDimensionIndex) {
-        _exampleViewGLPlugin->updateData();
+        _exampleViewGLPlugin->updatePlot();
     });
 
     connect(&_pointSizeAction, &DecimalAction::valueChanged, [this](float val) {
-        _exampleViewGLPlugin->updateData();
+        _exampleViewGLPlugin->updatePlot();
     });
 
     connect(&_pointOpacityAction, &DecimalAction::valueChanged, [this](float val) {
-        _exampleViewGLPlugin->updateData();
+        _exampleViewGLPlugin->updatePlot();
     });
 
 }