mirror of https://github.com/qt/qtgraphs.git
56 lines
1.6 KiB
C++
56 lines
1.6 KiB
C++
// Copyright (C) 2023 The Qt Company Ltd.
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// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
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#include "topographicseries.h"
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//! [0]
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// Value used to encode height data as RGB value on PNG file
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const float packingFactor = 11983.f;
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//! [0]
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TopographicSeries::TopographicSeries()
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{
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setDrawMode(QSurface3DSeries::DrawSurface);
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setShading(QSurface3DSeries::Shading::Flat);
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setBaseColor(Qt::white);
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}
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TopographicSeries::~TopographicSeries() = default;
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void TopographicSeries::setTopographyFile(const QString &file, float width, float height)
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{
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//! [1]
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QImage heightMapImage(file);
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uchar *bits = heightMapImage.bits();
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int imageHeight = heightMapImage.height();
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int imageWidth = heightMapImage.width();
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int widthBits = imageWidth * 4;
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float stepX = width / float(imageWidth);
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float stepZ = height / float(imageHeight);
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QSurfaceDataArray dataArray;
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dataArray.reserve(imageHeight);
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for (int i = 0; i < imageHeight; ++i) {
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int p = i * widthBits;
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float z = height - float(i) * stepZ;
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QSurfaceDataRow newRow;
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newRow.reserve(imageWidth);
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for (int j = 0; j < imageWidth; ++j) {
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uchar aa = bits[p + 0];
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uchar rr = bits[p + 1];
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uchar gg = bits[p + 2];
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uint color = uint((gg << 16) + (rr << 8) + aa);
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float y = float(color) / packingFactor;
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newRow.append(QSurfaceDataItem(float(j) * stepX, y, z));
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p += 4;
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}
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dataArray.append(newRow);
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}
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dataProxy()->resetArray(dataArray);
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//! [1]
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m_sampleCountX = float(imageWidth);
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m_sampleCountZ = float(imageHeight);
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}
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