Graph Gallery
// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "topographicseries.h"
// Value used to encode height data as RGB value on PNG file
const float packingFactor = 11983.f;
TopographicSeries::TopographicSeries()
{
setDrawMode(QSurface3DSeries::DrawSurface);
setFlatShadingEnabled(true);
setBaseColor(Qt::white);
}
TopographicSeries::~TopographicSeries() = default;
void TopographicSeries::setTopographyFile(const QString file, float width, float height)
{
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);
m_sampleCountX = float(imageWidth);
m_sampleCountZ = float(imageHeight);
}