ViewportParams.cpp

// SPDX-License-Identifier: LGPL-2.1-or-later
//
// SPDX-FileCopyrightText: 2007 Inge Wallin <ingwa@kde.org>
// SPDX-FileCopyrightText: 2008 Jens-Michael Hoffmann <jensmh@gmx.de>
// SPDX-FileCopyrightText: 2010-2013 Bernhard Beschow <bbeschow@cs.tu-berlin.de>
//
 
#include "ViewportParams.h"
 
#include <QRect>
 
#include <QPainterPath>
#include <QRegion>
 
#include "AzimuthalEquidistantProjection.h"
#include "EquirectProjection.h"
#include "GeoDataLatLonAltBox.h"
#include "GnomonicProjection.h"
#include "LambertAzimuthalProjection.h"
#include "MarbleDebug.h"
#include "MercatorProjection.h"
#include "SphericalProjection.h"
#include "StereographicProjection.h"
#include "VerticalPerspectiveProjection.h"
 
namespace Marble
{
 
class ViewportParamsPrivate
{
public:
    ViewportParamsPrivate(Projection projection, qreal centerLongitude, qreal centerLatitude, int radius, const QSize &size);
 
    static const AbstractProjection *abstractProjection(Projection projection);
 
    // These two go together.  m_currentProjection points to one of
    // the static Projection classes at the bottom.
    Projection m_projection;
    const AbstractProjection *m_currentProjection;
 
    // Parameters that determine the painting
    qreal m_centerLongitude;
    qreal m_centerLatitude;
    qreal m_heading;
    Quaternion m_planetAxis; // Position, coded in a quaternion
    matrix m_planetAxisMatrix;
    int m_radius; // Zoom level (pixels / globe radius)
    qreal m_angularResolution;
 
    QSize m_size; // width, height
 
    bool m_dirtyBox;
    GeoDataLatLonAltBox m_viewLatLonAltBox;
 
    static const SphericalProjection s_sphericalProjection;
    static const EquirectProjection s_equirectProjection;
    static const MercatorProjection s_mercatorProjection;
    static const GnomonicProjection s_gnomonicProjection;
    static const StereographicProjection s_stereographicProjection;
    static const LambertAzimuthalProjection s_lambertAzimuthalProjection;
    static const AzimuthalEquidistantProjection s_azimuthalEquidistantProjection;
    static const VerticalPerspectiveProjection s_verticalPerspectiveProjection;
 
    GeoDataCoordinates m_focusPoint;
};
 
const SphericalProjection ViewportParamsPrivate::s_sphericalProjection;
const EquirectProjection ViewportParamsPrivate::s_equirectProjection;
const MercatorProjection ViewportParamsPrivate::s_mercatorProjection;
const GnomonicProjection ViewportParamsPrivate::s_gnomonicProjection;
const StereographicProjection ViewportParamsPrivate::s_stereographicProjection;
const LambertAzimuthalProjection ViewportParamsPrivate::s_lambertAzimuthalProjection;
const AzimuthalEquidistantProjection ViewportParamsPrivate::s_azimuthalEquidistantProjection;
const VerticalPerspectiveProjection ViewportParamsPrivate::s_verticalPerspectiveProjection;
 
ViewportParamsPrivate::ViewportParamsPrivate(Projection projection, qreal centerLongitude, qreal centerLatitude, int radius, const QSize &size)
    : m_projection(projection)
    , m_currentProjection(abstractProjection(projection))
    , m_centerLongitude(centerLongitude)
    , m_centerLatitude(centerLatitude)
    , m_heading(0)
    , m_planetAxis()
    , m_planetAxisMatrix()
    , m_radius(radius)
    , m_angularResolution(4.0 / abs(m_radius))
    , m_size(size)
    , m_dirtyBox(true)
    , m_viewLatLonAltBox()
{
}
 
const AbstractProjection *ViewportParamsPrivate::abstractProjection(Projection projection)
{
    switch (projection) {
    case Spherical:
        return &s_sphericalProjection;
    case Equirectangular:
        return &s_equirectProjection;
    case Mercator:
        return &s_mercatorProjection;
    case Gnomonic:
        return &s_gnomonicProjection;
    case Stereographic:
        return &s_stereographicProjection;
    case LambertAzimuthal:
        return &s_lambertAzimuthalProjection;
    case AzimuthalEquidistant:
        return &s_azimuthalEquidistantProjection;
    case VerticalPerspective:
        return &s_verticalPerspectiveProjection;
    }
 
    return nullptr;
}
 
ViewportParams::ViewportParams()
    : d(new ViewportParamsPrivate(Spherical, 0, 0, 2000, QSize(100, 100)))
{
    centerOn(d->m_centerLongitude, d->m_centerLatitude);
}
 
ViewportParams::ViewportParams(Projection projection, qreal centerLongitude, qreal centerLatitude, int radius, const QSize &size)
    : d(new ViewportParamsPrivate(projection, centerLongitude, centerLatitude, radius, size))
{
    centerOn(d->m_centerLongitude, d->m_centerLatitude);
}
 
ViewportParams::~ViewportParams()
{
    delete d;
}
 
// ================================================================
//                    Getters and setters
 
Projection ViewportParams::projection() const
{
    return d->m_projection;
}
 
const AbstractProjection *ViewportParams::currentProjection() const
{
    return d->m_currentProjection;
}
 
void ViewportParams::setProjection(Projection newProjection)
{
    d->m_projection = newProjection;
    d->m_currentProjection = ViewportParamsPrivate::abstractProjection(newProjection);
 
    // We now need to reset the planetAxis to make sure
    // that it's a valid axis orientation!
    // So this line is important (although it might look odd) ! :
    centerOn(d->m_centerLongitude, d->m_centerLatitude);
}
 
int ViewportParams::polarity() const
{
    // For mercator this just gives the extreme latitudes
    // instead of the actual poles but it works fine as well:
    GeoDataCoordinates northPole(0.0, +currentProjection()->maxLat());
    GeoDataCoordinates southPole(0.0, -currentProjection()->maxLat());
 
    bool globeHidesN, globeHidesS;
    qreal x;
    qreal yN, yS;
 
    currentProjection()->screenCoordinates(northPole, this, x, yN, globeHidesN);
    currentProjection()->screenCoordinates(southPole, this, x, yS, globeHidesS);
 
    int polarity = 0;
 
    // case of the flat map:
    if (!globeHidesN && !globeHidesS) {
        if (yN < yS) {
            polarity = +1;
        }
        if (yS < yN) {
            polarity = -1;
        }
    } else {
        if (!globeHidesN && yN < height() / 2) {
            polarity = +1;
        }
        if (!globeHidesN && yN > height() / 2) {
            polarity = -1;
        }
        if (!globeHidesS && yS > height() / 2) {
            polarity = +1;
        }
        if (!globeHidesS && yS < height() / 2) {
            polarity = -1;
        }
    }
 
    return polarity;
}
 
int ViewportParams::radius() const
{
    return d->m_radius;
}
 
void ViewportParams::setRadius(int newRadius)
{
    if (newRadius > 0) {
        d->m_dirtyBox = true;
 
        d->m_radius = newRadius;
        d->m_angularResolution = 4.0 / d->m_radius;
    }
}
 
void ViewportParams::centerOn(qreal lon, qreal lat)
{
    if (!d->m_currentProjection->traversablePoles()) {
        if (lat > d->m_currentProjection->maxLat())
            lat = d->m_currentProjection->maxLat();
 
        if (lat < d->m_currentProjection->minLat())
            lat = d->m_currentProjection->minLat();
    } else {
        while (lat > M_PI)
            lat -= 2 * M_PI;
        while (lat < -M_PI)
            lat += 2 * M_PI;
    }
 
    while (lon > M_PI)
        lon -= 2 * M_PI;
    while (lon < -M_PI)
        lon += 2 * M_PI;
 
    d->m_centerLongitude = lon;
    d->m_centerLatitude = lat;
 
    const Quaternion roll = Quaternion::fromEuler(0, 0, d->m_heading);
    const Quaternion quat = Quaternion::fromEuler(-lat, lon, 0.0);
 
    d->m_planetAxis = quat * roll;
    d->m_planetAxis.normalize();
 
    d->m_dirtyBox = true;
    d->m_planetAxis.inverse().toMatrix(d->m_planetAxisMatrix);
    d->m_planetAxis.normalize();
}
 
void ViewportParams::setHeading(qreal heading)
{
    d->m_heading = heading;
 
    const Quaternion roll = Quaternion::fromEuler(0, 0, heading);
 
    const qreal centerLat = centerLatitude();
    const qreal centerLon = centerLongitude();
 
    const Quaternion quat = Quaternion::fromEuler(-centerLat, centerLon, 0);
 
    d->m_planetAxis = quat * roll;
    d->m_planetAxis.normalize();
 
    d->m_dirtyBox = true;
    d->m_planetAxis.inverse().toMatrix(d->m_planetAxisMatrix);
    d->m_planetAxis.normalize();
}
 
qreal ViewportParams::heading() const
{
    return d->m_heading;
}
 
Quaternion ViewportParams::planetAxis() const
{
    return d->m_planetAxis;
}
 
const matrix &ViewportParams::planetAxisMatrix() const
{
    return d->m_planetAxisMatrix;
}
 
int ViewportParams::width() const
{
    return d->m_size.width();
}
 
int ViewportParams::height() const
{
    return d->m_size.height();
}
 
QSize ViewportParams::size() const
{
    return d->m_size;
}
 
void ViewportParams::setWidth(int newWidth)
{
    setSize(QSize(newWidth, height()));
}
 
void ViewportParams::setHeight(int newHeight)
{
    setSize(QSize(width(), newHeight));
}
 
void ViewportParams::setSize(const QSize &newSize)
{
    if (newSize == d->m_size)
        return;
 
    d->m_dirtyBox = true;
 
    d->m_size = newSize;
}
 
// ================================================================
//                        Other functions
 
qreal ViewportParams::centerLongitude() const
{
    return d->m_centerLongitude;
}
 
qreal ViewportParams::centerLatitude() const
{
    return d->m_centerLatitude;
}
 
const GeoDataLatLonAltBox &ViewportParams::viewLatLonAltBox() const
{
    if (d->m_dirtyBox) {
        d->m_viewLatLonAltBox = d->m_currentProjection->latLonAltBox(QRect(QPoint(0, 0), d->m_size), this);
        d->m_dirtyBox = false;
    }
 
    return d->m_viewLatLonAltBox;
}
 
GeoDataLatLonAltBox ViewportParams::latLonAltBox(const QRect &screenRect) const
{
    return d->m_currentProjection->latLonAltBox(screenRect, this);
}
 
qreal ViewportParams::angularResolution() const
{
    // We essentially divide the diameter by 180 deg and
    // take half of the result as a guess for the angle per pixel resolution.
    // d->m_angularResolution = 0.25 * M_PI / fabs( (qreal)(d->m_radius);
    return d->m_angularResolution;
}
 
bool ViewportParams::resolves(const GeoDataLatLonBox &latLonBox, qreal pixel) const
{
    return latLonBox.width() + latLonBox.height() > pixel * d->m_angularResolution;
}
 
bool ViewportParams::resolves(const GeoDataLatLonAltBox &latLonAltBox, qreal pixel, qreal altitude) const
{
    return latLonAltBox.width() + latLonAltBox.height() > pixel * d->m_angularResolution || latLonAltBox.maxAltitude() - latLonAltBox.minAltitude() > altitude;
}
 
bool ViewportParams::resolves(const GeoDataCoordinates &coord1, const GeoDataCoordinates &coord2) const
{
    qreal lon1, lat1;
    coord1.geoCoordinates(lon1, lat1);
 
    qreal lon2, lat2;
    coord2.geoCoordinates(lon2, lat2);
 
    // We take the manhattan length as an approximation for the distance
    return (fabs(lon2 - lon1) + fabs(lat2 - lat1) > d->m_angularResolution);
}
 
bool ViewportParams::screenCoordinates(const qreal lon, const qreal lat, qreal &x, qreal &y) const
{
    return d->m_currentProjection->screenCoordinates(lon, lat, this, x, y);
}
 
bool ViewportParams::screenCoordinates(const GeoDataCoordinates &geopoint, qreal &x, qreal &y, bool &globeHidesPoint) const
{
    return d->m_currentProjection->screenCoordinates(geopoint, this, x, y, globeHidesPoint);
}
 
bool ViewportParams::screenCoordinates(const GeoDataCoordinates &geopoint, qreal &x, qreal &y) const
{
    return d->m_currentProjection->screenCoordinates(geopoint, this, x, y);
}
 
bool ViewportParams::screenCoordinates(const GeoDataCoordinates &coordinates,
                                       qreal *x,
                                       qreal &y,
                                       int &pointRepeatNum,
                                       const QSizeF &size,
                                       bool &globeHidesPoint) const
{
    return d->m_currentProjection->screenCoordinates(coordinates, this, x, y, pointRepeatNum, size, globeHidesPoint);
}
 
bool ViewportParams::screenCoordinates(const GeoDataLineString &lineString, QList<QPolygonF *> &polygons) const
{
    return d->m_currentProjection->screenCoordinates(lineString, this, polygons);
}
 
bool ViewportParams::geoCoordinates(const int x, const int y, qreal &lon, qreal &lat, GeoDataCoordinates::Unit unit) const
{
    return d->m_currentProjection->geoCoordinates(x, y, this, lon, lat, unit);
}
 
bool ViewportParams::mapCoversViewport() const
{
    return d->m_currentProjection->mapCoversViewport(this);
}
 
QPainterPath ViewportParams::mapShape() const
{
    return d->m_currentProjection->mapShape(this);
}
 
QRegion ViewportParams::mapRegion() const
{
    return d->m_currentProjection->mapRegion(this);
}
 
GeoDataCoordinates ViewportParams::focusPoint() const
{
    if (d->m_focusPoint.isValid()) {
        return d->m_focusPoint;
    } else {
        const qreal lon = d->m_centerLongitude;
        const qreal lat = d->m_centerLatitude;
 
        return {lon, lat, 0.0, GeoDataCoordinates::Radian};
    }
}
 
void ViewportParams::setFocusPoint(const GeoDataCoordinates &focusPoint)
{
    d->m_focusPoint = focusPoint;
}
 
void ViewportParams::resetFocusPoint()
{
    d->m_focusPoint = GeoDataCoordinates();
}
 
}