MercatorProjection.h

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// SPDX-License-Identifier: LGPL-2.1-or-later
//
// SPDX-FileCopyrightText: 2007 Inge Wallin <ingwa@kde.org>
// SPDX-FileCopyrightText: 2007-2012 Torsten Rahn <rahn@kde.org>
//
 
#ifndef MARBLE_MERCATORPROJECTION_H
#define MARBLE_MERCATORPROJECTION_H
 
/** @file
 * This file contains the headers for MercatorProjection.
 *
 * @author Inge Wallin  <inge@lysator.liu.se>
 * @author Torsten Rahn <rahn@kde.org>
 */
 
#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;
    qreal minValidLat() const override;
 
    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:
    mutable qreal m_lastCenterLat;
    mutable qreal m_lastCenterLatInv;
 
    Q_DISABLE_COPY(MercatorProjection)
};
 
}
 
#endif