Combine 3 more widget examples into graph gallery

Combine the remaining 3 surface graph examples into graph gallery
example.

Pick-to: 6.5
Task-number: QTBUG-110698
Change-Id: Ia324189e10f781f9822db220def72b7b15d37a49
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>

1 files changed, 56 insertions, 0 deletions

diff --git a/examples/datavisualization/graphgallery/topographicseries.cpp b/examples/datavisualization/graphgallery/topographicseries.cpp
new file mode 100644
index 00000000..d33fa6bd
--- /dev/null
+++ b/examples/datavisualization/graphgallery/topographicseries.cpp
@@ -0,0 +1,56 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#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()
+{
+}
+
+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);
+
+    QSurfaceDataArray *dataArray = new QSurfaceDataArray;
+    dataArray->reserve(imageHeight);
+    for (int i = 0; i < imageHeight; i++) {
+        int p = i * widthBits;
+        float z = height - float(i) * stepZ;
+        QSurfaceDataRow *newRow = new QSurfaceDataRow(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)[j].setPosition(QVector3D(float(j) * stepX, y, z));
+            p = p + 4;
+        }
+        *dataArray << newRow;
+    }
+
+    dataProxy()->resetArray(dataArray);
+    //! [1]
+
+    m_sampleCountX = float(imageWidth);
+    m_sampleCountZ = float(imageHeight);
+}