Added a Base Histogram class, that allows colorcoding for each bar.

libs_required/ACG/CMakeLists.txt

@@ -93,6 +93,7 @@ set ( headers
     Math/QuaternionT.hh
     Math/VectorT.hh
     QtWidgets/QtApplication.hh
+    QtWidgets/QtChartHistogram.hh
     QtWidgets/QtClippingDialog.hh
     QtWidgets/QtColorChooserButton.hh
     QtWidgets/QtColorTranslator.hh
@@ -209,6 +210,7 @@ set (sources
     GL/stipple_alpha.cc
     Math/BSplineBasis.cc
     QtWidgets/QtApplication.cc
+    QtWidgets/QtChartHistogram.cc
     QtWidgets/QtClippingDialog.cc
     QtWidgets/QtColorChooserButton.cc
     QtWidgets/QtColorTranslator.cc

libs_required/ACG/QtWidgets/QtChartHistogram.cc

+/*===========================================================================*\
+ *                                                                           *
+ *                              OpenFlipper                                  *
+ *           Copyright (c) 2001-2024, RWTH-Aachen University                 *
+ *           Department of Computer Graphics and Multimedia                  *
+ *                          All rights reserved.                             *
+ *                            www.openflipper.org                            *
+ *                                                                           *
+ *---------------------------------------------------------------------------*
+ * This file is part of OpenFlipper.                                         *
+ *---------------------------------------------------------------------------*
+ *                                                                           *
+ * Redistribution and use in source and binary forms, with or without        *
+ * modification, are permitted provided that the following conditions        *
+ * are met:                                                                  *
+ *                                                                           *
+ * 1. Redistributions of source code must retain the above copyright notice, *
+ *    this list of conditions and the following disclaimer.                  *
+ *                                                                           *
+ * 2. Redistributions in binary form must reproduce the above copyright      *
+ *    notice, this list of conditions and the following disclaimer in the    *
+ *    documentation and/or other materials provided with the distribution.   *
+ *                                                                           *
+ * 3. Neither the name of the copyright holder nor the names of its          *
+ *    contributors may be used to endorse or promote products derived from   *
+ *    this software without specific prior written permission.               *
+ *                                                                           *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS       *
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED *
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A           *
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER *
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,  *
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,       *
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR        *
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF    *
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING      *
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS        *
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.              *
+ *                                                                           *
+\*===========================================================================*/
+
+
+//=============================================================================
+//
+//  CLASS QtChart - IMPLEMENTATION
+//
+//=============================================================================
+
+//== INCLUDES =================================================================
+
+#include "QtChartHistogram.hh"
+#include <QChart>
+#include <QValueAxis>
+#include <QBarSeries>
+#include <QLineSeries>
+#include <QStackedBarSeries>
+#include <QBarCategoryAxis>
+#include <QBarSet>
+#include <QChartView>
+#include <QRubberBand>
+
+#include <cfloat>
+
+#include <Utils/ColorCoder.hh>
+//== NAMESPACES ===============================================================
+
+namespace ACG {
+namespace QtWidgets {
+
+//This class creates a Histogram in a QChartView. The Histogram can be zoomed in and out by using a rubberband. 
+//The x-axis values are updated when the rubberband is moved. The y-axis values are updated automatically.
+//The Histogram can be color coded.
+//!!!!!IMPORTANT!!!! This class allows for colored bars in the Histogram, which is not possible with QCharts alone. 
+//In order to achieve that we have to create a new QBarSet for each bar. And "stack" them on top of each other.
+//This is not very efficient and should be avoided if possible. In addition to that, the x-axis is detached in order to allow 
+//a correct zoom behavior. (This is also very hacky and should be avoided but I didnt see any other way to make it work)
+//However I think there is a bug in the QCharts library and as soon as it is fixed, the workaround is not needed anymore..
+QtChartHistogram::QtChartHistogram(QString title_X, QString title_Y, const std::vector<double>& _values, QWidget* _parent) : QChartView(_parent)
+{
+    //create chart
+    chart_ = new QChart();
+  
+    //create x-axis 
+    axisX = new QValueAxis();
+    axisX->setTitleText(title_X);
+    axisX->setRange(0, 100);
+    chart_->addAxis(axisX, Qt::AlignBottom);
+
+    // Create y-axis
+    axisY = new QValueAxis();
+    axisY->setTitleText(title_Y);
+    axisY->setRange(0, 500);
+    chart_->addAxis(axisY, Qt::AlignLeft);
+
+    // Set the chart to the chartView(this widget)
+    setChart(chart_);
+    setRubberBand(QChartView::RectangleRubberBand);
+
+    // Create the series and attach it to the chart
+    series = new QStackedBarSeries();
+    chart_->addSeries(series);
+    series->attachAxis(axisY);
+
+    // Set the values
+    setValues(_values);
+
+    // Get the rubberband from the chartView
+    rubberBand_ = findChild<QRubberBand *>();
+    rubberBand_->installEventFilter(this);
+
+    // Install eventfilter for the chartView, so we can update the cursor type if inside the chart 
+    this->installEventFilter(this);
+
+    // Connect the rubberband signal to the slot
+    connect(this, &QtChartHistogram::rubberBandChanged, this, &QtChartHistogram::rubberBandChangedSlot);
+    
+    // Set the render hint to antialiasing, so the chart looks nicer
+    setRenderHint(QPainter::Antialiasing);
+
+    // Hide the legend
+    chart_->legend()->setVisible(false);
+
+    replot();
+
+}
+
+//destructor 
+QtChartHistogram::~QtChartHistogram()
+{}
+
+//------------------------------------------------------------------------------
+
+// Override the mouseReleaseEvent to emit a signal when the right mouse button is released 
+void QtChartHistogram::mouseReleaseEvent(QMouseEvent *event)
+{
+    if (event->button() == Qt::RightButton) {
+       // There might be a more elegant way to reset the zoom, but this is simple and works well
+       replot();
+    }
+    else {
+       QChartView::mouseReleaseEvent(event);
+    }
+}
+
+//------------------------------------------------------------------------------
+
+// Event filter
+bool QtChartHistogram::eventFilter(QObject *obj, QEvent *event)
+{
+    if (obj == this && event->type() == QEvent::Enter){
+        // if we are inside the chart, we wanna change the cursor to a cross
+        setCursor(Qt::CrossCursor);
+    }
+    else if (obj == chart_ && event->type() == QEvent::Leave){
+        // if we leave the chart, we wanna change the cursor back to the default
+        setCursor(Qt::ArrowCursor);
+    }
+
+    // if we use rubberband on the chartView, we wanna update the x-axis values (as the x-axis is detached from the series)
+    if (obj == rubberBand_ && (event->type() == QEvent::HideToParent)){
+        //transform the rubberband coordinates to the x-axis values
+        auto rubberminX = rubberBand_->geometry().x() - chart_->plotArea().x();
+        auto rubbermaxX = rubberBand_->geometry().x() - chart_->plotArea().x() + rubberBand_->geometry().width();
+        
+        emit rubberBandChanged(rubberminX, rubbermaxX);
+    } 
+    return false;
+
+}
+
+//------------------------------------------------------------------------------
+
+void QtChartHistogram::rubberBandChangedSlot(double rubberminX, double rubbermaxX)
+{
+
+  //get the x values of the chart
+  qreal minX = static_cast<const QValueAxis*>(chart_->axes(Qt::Horizontal).back())->min();
+  qreal maxX = static_cast<const QValueAxis*>(chart_->axes(Qt::Horizontal).back())->max();
+  
+  //compute the new x-axis values
+  double newMin = minX + ((rubberminX)/ chart_->plotArea().width()) * (maxX - minX);
+  double newMax = minX + (rubbermaxX / chart_->plotArea().width()) * (maxX - minX);
+
+  //set the new x-axis values
+  dynamic_cast<QValueAxis*>(chart_->axes(Qt::Horizontal).back())->setRange(newMin, newMax);
+
+}
+
+//------------------------------------------------------------------------------
+
+// Set the values
+void QtChartHistogram::setValues(const std::vector<double>& _values)
+{
+  values_ = _values;
+}
+
+//------------------------------------------------------------------------------
+
+// Replot the chart
+void QtChartHistogram::replot()
+{
+    // Create intervals
+    const int intervalCount = 101;
+
+    std::vector<int> intervals(intervalCount, 0);
+
+    double realMin = FLT_MAX;
+    double realMax = -FLT_MAX;
+
+    // Compute realMin and realMax
+    for (const auto& value : values_) {
+        if (!std::isnan(value)) { // Check for NaN
+            realMin = std::min(realMin, value);
+            realMax = std::max(realMax, value);
+        }
+    }
+
+    // Check for the edge case where realMin equals realMax
+    // In this case we have only one value and we want to create some margins around the value
+    // In order to display the value correctly in the histogram
+    if (realMin == realMax) {
+        realMax = realMin + 50;
+        realMin = realMin - 50;
+    }
+
+    float width = (realMax - realMin) / intervalCount;
+
+    // Populate the intervals
+    for (const auto& value : values_) {
+        if (!std::isnan(value)) { // Check for NaN
+            int index = std::min(intervalCount - 1, static_cast<int>((value - realMin) / width));
+            intervals[index]++;
+        }
+    }
+    
+    std::vector<QColor> colors;
+
+    // If we want to color code the histogram
+    if (colorCoding_){
+        // Create Colors for the intervals
+        ACG::ColorCoder cCoder(realMin,realMax);
+        for (int i = 0; i < intervalCount; i++) {
+            const double intervalCenter = realMin + (i + 0.5) * width;
+            colors.push_back(cCoder.color_qcolor(intervalCenter));
+        }
+    } 
+    else {
+        // Use just one color
+        for (int i = 0; i < intervalCount; i++) {
+            const double intervalCenter = realMin + (i + 0.5) * width;
+            colors.push_back(Qt::black);
+        }
+    } 
+    
+    // Remove the old series and create a new one. For some reason you have to remove the series. Simply clearing the series and appending new values does not work.
+    chart_->removeSeries(series);
+
+    // Clear the series
+    series = new QStackedBarSeries();
+    
+    // Set the axes range
+    axisX->setRange(realMin, realMax);
+    axisY->setRange(0, *std::max_element(intervals.begin(), intervals.end()));
+
+    // Create for each Bar a new set. This is needed to add different colors to each bar.
+    for (int i = 0; i < intervalCount; i++) {
+        QBarSet* set = new QBarSet("Values");
+        for (int j = 0; j < intervalCount; j++){
+            if (j == i){
+            *set << intervals[j];
+            set->setColor(colors[j]);
+            }
+            else{
+            *set << 0;
+            }
+        }
+        set->setColor(colors[i]);
+        series->append(set);
+    }
+    chart_->addSeries(series);
+    series->attachAxis(axisY);
+}
+
+void QtChartHistogram::setColorCoding(bool _colorCoding)
+{
+    colorCoding_ = _colorCoding;
+}
+
+} // namespace QtWidgets
+
+} // namespace ACG
+
+

libs_required/ACG/QtWidgets/QtChartHistogram.hh

+/*===========================================================================*\
+ *                                                                           *
+ *                              OpenFlipper                                  *
+ *           Copyright (c) 2001-2024, RWTH-Aachen University                 *
+ *           Department of Computer Graphics and Multimedia                  *
+ *                          All rights reserved.                             *
+ *                            www.openflipper.org                            *
+ *                                                                           *
+ *---------------------------------------------------------------------------*
+ * This file is part of OpenFlipper.                                         *
+ *---------------------------------------------------------------------------*
+ *                                                                           *
+ * Redistribution and use in source and binary forms, with or without        *
+ * modification, are permitted provided that the following conditions        *
+ * are met:                                                                  *
+ *                                                                           *
+ * 1. Redistributions of source code must retain the above copyright notice, *
+ *    this list of conditions and the following disclaimer.                  *
+ *                                                                           *
+ * 2. Redistributions in binary form must reproduce the above copyright      *
+ *    notice, this list of conditions and the following disclaimer in the    *
+ *    documentation and/or other materials provided with the distribution.   *
+ *                                                                           *
+ * 3. Neither the name of the copyright holder nor the names of its          *
+ *    contributors may be used to endorse or promote products derived from   *
+ *    this software without specific prior written permission.               *
+ *                                                                           *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS       *
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED *
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A           *
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER *
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,  *
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,       *
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR        *
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF    *
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING      *
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS        *
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.              *
+ *                                                                           *
+\*===========================================================================*/
+
+
+//=============================================================================
+//
+//  CLASS QtChart - IMPLEMENTATION
+//
+//=============================================================================
+
+//== INCLUDES =================================================================
+#include <QChart>
+#include <QBarSeries>
+#include <QLineSeries>
+#include <QStackedBarSeries>
+#include <QChartView>
+#include <QRubberBand>
+#include <cfloat>
+#include <QValueAxis>
+
+
+#include <QBarSet>
+
+
+
+//== NAMESPACES ===============================================================
+namespace ACG {
+namespace QtWidgets {
+
+//This class creates a Histogram in a QChartView. The Histogram can be zoomed in and out by using a rubberband. 
+//The x-axis values are updated when the rubberband is moved. The y-axis values are updated automatically.
+//The Histogram can be color coded.
+//!!!!!IMPORTANT!!!! This class allows for colored bars in the Histogram, which is not possible with QCharts alone. 
+//In order to achieve that we have to create a new QBarSet for each bar. And "stack" them on top of each other.
+//This is not very efficient and should be avoided if possible. In addition to that, the x-axis is detached in order to allow 
+//a correct zoom behavior. (This is also very hacky and should be avoided but I didnt see any other way to make it work)
+//However I think there is a bug in the QCharts library and as soon as it is fixed, the workaround is not needed anymore.
+class QtChartHistogram : public QChartView {
+    Q_OBJECT
+
+public:
+
+    /// Default constructor
+    explicit QtChartHistogram(QString title_X, QString title_Y, const std::vector<double>& _values, QWidget* _parent = 0);
+
+    /// Destructor
+    ~QtChartHistogram();
+
+    void setColorCoding(bool _colorCoding);
+
+    void setValues(const std::vector<double>& _values);
+
+    void replot();
+
+public slots:
+
+  void rubberBandChangedSlot(double rubber_min, double rubber_max);
+
+signals:  
+
+  void rubberBandChanged(double rubber_min, double rubber_max);
+
+private:
+
+    //variables
+    QChart* chart_;
+    QValueAxis* axisX;
+    QValueAxis* axisY;
+    QStackedBarSeries* series;
+    QRubberBand* rubberBand_;
+    bool colorCoding_;
+    std::vector<double> values_;
+
+protected:
+
+    bool eventFilter(QObject *obj, QEvent *event) override;
+    void mouseReleaseEvent(QMouseEvent *event) override;
+
+};
+
+} // namespace QtWidgets
+} // namespace ACG
+
+
+
+
+