1 files changed, 137 insertions, 0 deletions
diff --git a/src/positioning/qwebmercator.cpp b/src/positioning/qwebmercator.cpp
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+++ b/src/positioning/qwebmercator.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtPositioning module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "qwebmercator_p.h"
+
+#include "qgeocoordinate.h"
+
+#include <qnumeric.h>
+
+#include <cmath>
+
+#include "qdoublevector2d_p.h"
+#include "qdoublevector3d_p.h"
+
+QT_BEGIN_NAMESPACE
+
+QDoubleVector2D QWebMercator::coordToMercator(const QGeoCoordinate &coord)
+{
+    const double pi = M_PI;
+
+    double lon = coord.longitude() / 360.0 + 0.5;
+
+    double lat = coord.latitude();
+    lat = 0.5 - (std::log(std::tan((pi / 4.0) + (pi / 2.0) * lat / 180.0)) / pi) / 2.0;
+    lat = qBound(0.0, lat, 1.0);
+
+    return QDoubleVector2D(lon, lat);
+}
+
+double QWebMercator::realmod(const double a, const double b)
+{
+    quint64 div = static_cast<quint64>(a / b);
+    return a - static_cast<double>(div) * b;
+}
+
+QGeoCoordinate QWebMercator::mercatorToCoord(const QDoubleVector2D &mercator)
+{
+    const double pi = M_PI;
+
+    double fx = mercator.x();
+    double fy = mercator.y();
+
+    if (fy < 0.0)
+        fy = 0.0;
+    else if (fy > 1.0)
+        fy = 1.0;
+
+    double lat;
+
+    if (fy == 0.0)
+        lat = 90.0;
+    else if (fy == 1.0)
+        lat = -90.0;
+    else
+        lat = (180.0 / pi) * (2.0 * std::atan(std::exp(pi * (1.0 - 2.0 * fy))) - (pi / 2.0));
+
+    double lng;
+    if (fx >= 0) {
+        lng = realmod(fx, 1.0);
+    } else {
+        lng = realmod(1.0 - realmod(-1.0 * fx, 1.0), 1.0);
+    }
+
+    lng = lng * 360.0 - 180.0;
+
+    return QGeoCoordinate(lat, lng, 0.0);
+}
+
+QGeoCoordinate QWebMercator::coordinateInterpolation(const QGeoCoordinate &from, const QGeoCoordinate &to, qreal progress)
+{
+    QDoubleVector2D s = QWebMercator::coordToMercator(from);
+    QDoubleVector2D e = QWebMercator::coordToMercator(to);
+
+    double x = s.x();
+
+    if (0.5 < qAbs(e.x() - s.x())) {
+        // handle dateline crossing
+        double ex = e.x();
+        double sx = s.x();
+        if (ex < sx)
+            sx -= 1.0;
+        else if (sx < ex)
+            ex -= 1.0;
+
+        x = (1.0 - progress) * sx + progress * ex;
+
+        if (!qFuzzyIsNull(x) && (x < 0.0))
+            x += 1.0;
+
+    } else {
+        x = (1.0 - progress) * s.x() + progress * e.x();
+    }
+
+    double y = (1.0 - progress) * s.y() + progress * e.y();
+
+    QGeoCoordinate result = QWebMercator::mercatorToCoord(QDoubleVector2D(x, y));
+    result.setAltitude((1.0 - progress) * from.altitude() + progress * to.altitude());
+
+    return result;
+}
+
+QT_END_NAMESPACE