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128 | /* ============================================================
*
* This file is a part of digiKam project
* https://www.digikam.org
*
* Date : 2023-05-15
* Description : geolocation engine based on Marble.
* (c) 2007-2022 Marble Team
* https://invent.kde.org/education/marble/-/raw/master/data/credits_authors.html
*
* SPDX-FileCopyrightText: 2023-2024 by Gilles Caulier <caulier dot gilles at gmail dot com>
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* ============================================================ */
/**
* This file contains the headers for MercatorProjection.
*/
#pragma once
// Local includes
#include "CylindricalProjection.h"
namespace Marble
{
/**
* @short A class to implement the Mercator projection.
*/
class MercatorProjection : public CylindricalProjection
{
// Not a QObject so far because we don't need to send signals.
public:
/**
* @brief Construct a new MercatorProjection.
*/
MercatorProjection();
~MercatorProjection() override;
/**
* @brief Returns the user-visible name of the projection.
*/
QString name() const override;
/**
* @brief Returns a short user description of the projection
* that can be used in tooltips or dialogs.
*/
QString description() const override;
/**
* @brief Returns an icon for the projection.
*/
QIcon icon() const override;
qreal maxValidLat() const override;<--- maxValidLat is a virtual function
qreal minValidLat() const override;<--- minValidLat is a virtual function
PreservationType preservationType() const override
{
return Conformal;
}
/**
* @brief Get the screen coordinates corresponding to geographical coordinates in the map.
* @param coordinates the coordinates of the requested pixel position
* @param params the viewport parameters
* @param x the x coordinate of the pixel is returned through this parameter
* @param y the y coordinate of the pixel is returned through this parameter
* @param globeHidesPoint whether the globe hides the point
* @return @c true if the geographical coordinates are visible on the screen
* @c false if the geographical coordinates are not visible on the screen
*/
bool screenCoordinates(const GeoDataCoordinates& coordinates,
const ViewportParams* params,
qreal& x, qreal& y, bool& globeHidesPoint) const override;
bool screenCoordinates(const GeoDataCoordinates& coordinates,
const ViewportParams* viewport,
qreal* x, qreal& y, int& pointRepeatNum,
const QSizeF& size,
bool& globeHidesPoint) const override;
using CylindricalProjection::screenCoordinates;
/**
* @brief Get the earth coordinates corresponding to a pixel in the map.
*
* If the pixel (x, y) is outside the globe, only @p lon will be calculated,
* and lat will be unchanged.
*
* @param x the x coordinate of the pixel
* @param y the y coordinate of the pixel
* @param params the viewport parameters
* @param lon the longitude angle is returned through this parameter
* @param lat the latitude angle is returned through this parameter
* @param unit the unit
* @return @c true if the pixel (x, y) is within the globe
* @c false if the pixel (x, y) is outside the globe, i.e. in space.
*/
bool geoCoordinates(const int x, const int y,
const ViewportParams* params,
qreal& lon, qreal& lat,
GeoDataCoordinates::Unit = GeoDataCoordinates::Degree) const override;
GeoDataLatLonAltBox latLonAltBox(const QRect& screenRect,
const ViewportParams* viewport) const override;
bool mapCoversViewport(const ViewportParams* viewport) const override;
private:
Q_DISABLE_COPY(MercatorProjection)
private:
mutable qreal m_lastCenterLat;
mutable qreal m_lastCenterLatInv;
};
} // namespace Marble
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