1 files changed, 55 insertions, 0 deletions
diff --git a/examples/datavisualization/graphgallery/topographicseries.cpp b/examples/datavisualization/graphgallery/topographicseries.cpp
new file mode 100644
index 00000000..201a275e
--- /dev/null
+++ b/examples/datavisualization/graphgallery/topographicseries.cpp
@@ -0,0 +1,55 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "topographicseries.h"
+
+//! [0]
+// Value used to encode height data as RGB value on PNG file
+const float packingFactor = 11983.f;
+//! [0]
+
+TopographicSeries::TopographicSeries()
+{
+    setDrawMode(QSurface3DSeries::DrawSurface);
+    setFlatShadingEnabled(true);
+    setBaseColor(Qt::white);
+}
+
+TopographicSeries::~TopographicSeries() = default;
+
+void TopographicSeries::setTopographyFile(const QString file, float width, float height)
+{
+    //! [1]
+    QImage heightMapImage(file);
+    uchar *bits = heightMapImage.bits();
+    int imageHeight = heightMapImage.height();
+    int imageWidth = heightMapImage.width();
+    int widthBits = imageWidth * 4;
+    float stepX = width / float(imageWidth);
+    float stepZ = height / float(imageHeight);
+
+    auto *dataArray = new QSurfaceDataArray;
+    dataArray->reserve(imageHeight);
+    for (int i = 0; i < imageHeight; ++i) {
+        int p = i * widthBits;
+        float z = height - float(i) * stepZ;
+        auto *newRow = new QSurfaceDataRow;
+        newRow->reserve(imageWidth);
+        for (int j = 0; j < imageWidth; ++j) {
+            uchar aa = bits[p + 0];
+            uchar rr = bits[p + 1];
+            uchar gg = bits[p + 2];
+            uint color = uint((gg << 16) + (rr << 8) + aa);
+            float y = float(color) / packingFactor;
+            newRow->append(QSurfaceDataItem({float(j) * stepX, y, z}));
+            p += 4;
+        }
+        dataArray->append(newRow);
+    }
+
+    dataProxy()->resetArray(dataArray);
+    //! [1]
+
+    m_sampleCountX = float(imageWidth);
+    m_sampleCountZ = float(imageHeight);
+}