- Qt 6.7
- Qt Graphs
- Graph Gallery
- Qt Graphs | Commercial or GPLv3

# Graph Gallery

     // Copyright (C) 2023 The Qt Company Ltd.
     // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

     #include "highlightseries.h"

     const float darkRedPos = 1.f;
     const float redPos = 0.8f;
     const float yellowPos = 0.6f;
     const float greenPos = 0.4f;
     const float darkGreenPos = 0.2f;

     HighlightSeries::HighlightSeries()
     {
         setDrawMode(QSurface3DSeries::DrawSurface);
         setFlatShadingEnabled(true);
         setVisible(false);
     }

     HighlightSeries::~HighlightSeries() {}

     void HighlightSeries::setTopographicSeries(TopographicSeries *series)
     {
         m_topographicSeries = series;
         m_srcWidth = m_topographicSeries->dataProxy()->array().at(0).size();
         m_srcHeight = m_topographicSeries->dataProxy()->array().size();

         QObject::connect(m_topographicSeries,
                          &QSurface3DSeries::selectedPointChanged,
                          this,
                          &HighlightSeries::handlePositionChange);
     }

     void HighlightSeries::handlePositionChange(const QPoint &position)
     {
         m_position = position;

         if (position == invalidSelectionPosition()) {
             setVisible(false);
             return;
         }

         int halfWidth = m_width / 2;
         int halfHeight = m_height / 2;

         int startX = position.x() - halfWidth;
         if (startX < 0)
             startX = 0;
         int endX = position.x() + halfWidth;
         if (endX > (m_srcWidth - 1))
             endX = m_srcWidth - 1;
         int startZ = position.y() - halfHeight;
         if (startZ < 0)
             startZ = 0;
         int endZ = position.y() + halfHeight;
         if (endZ > (m_srcHeight - 1))
             endZ = m_srcHeight - 1;

         QSurfaceDataProxy *srcProxy = m_topographicSeries->dataProxy();
         const QSurfaceDataArray &srcArray = srcProxy->array();

         QSurfaceDataArray dataArray;
         dataArray.reserve(endZ - startZ);
         for (int i = startZ; i < endZ; ++i) {
             QSurfaceDataRow newRow;
             newRow.reserve(endX - startX);
             QSurfaceDataRow srcRow = srcArray.at(i);
             for (int j = startX; j < endX; ++j) {
                 QVector3D pos = srcRow.at(j).position();
                 pos.setY(pos.y() + m_heightAdjustment);
                 newRow.append(QSurfaceDataItem(pos));
             }
             dataArray.append(newRow);
         }

         dataProxy()->resetArray(dataArray);
         setVisible(true);
     }

     void HighlightSeries::handleGradientChange(float value)
     {
         float ratio = m_minHeight / value;

         QLinearGradient gr;
         gr.setColorAt(0.f, Qt::black);
         gr.setColorAt(darkGreenPos * ratio, Qt::darkGreen);
         gr.setColorAt(greenPos * ratio, Qt::green);
         gr.setColorAt(yellowPos * ratio, Qt::yellow);
         gr.setColorAt(redPos * ratio, Qt::red);
         gr.setColorAt(darkRedPos * ratio, Qt::darkRed);

         setBaseGradient(gr);
         setColorStyle(Q3DTheme::ColorStyle::RangeGradient);

         handleZoomChange(ratio);
     }

     void HighlightSeries::handleZoomChange(float zoom)
     {
         m_heightAdjustment = (1.2f - zoom) * 10.f;
     }