MapProvider.cpp

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#include "MapProvider.h"
#include <QGCLoggingCategory.h>
 
#include <QtCore/QLocale>
 
QGC_LOGGING_CATEGORY(MapProviderLog, "QtLocationPlugin.MapProvider")
 
// QtLocation expects MapIds to start at 1 and be sequential.
int MapProvider::_mapIdIndex = 1;
 
MapProvider::MapProvider(
    const QString &mapName,
    const QString &referrer,
    const QString &imageFormat,
    quint32 averageSize,
    QGeoMapType::MapStyle mapStyle)
    : _mapName(mapName)
    , _referrer(referrer)
    , _imageFormat(imageFormat)
    , _averageSize(averageSize)
    , _mapStyle(mapStyle)
    , _language(!QLocale::system().uiLanguages().isEmpty() ? QLocale::system().uiLanguages().constFirst() : "en")
    , _mapId(_mapIdIndex++)
{
    // qCDebug(MapProviderLog) << Q_FUNC_INFO << this << _mapId;
}
 
MapProvider::~MapProvider()
{
    // qCDebug(MapProviderLog) << Q_FUNC_INFO << this << _mapId;
}
 
QUrl MapProvider::getTileURL(int x, int y, int zoom) const
{
    return QUrl(_getURL(x, y, zoom));
}
 
QString MapProvider::getImageFormat(QByteArrayView image) const
{
    if (image.size() < 3) {
        return QString();
    }
 
    static constexpr QByteArrayView pngSignature("\x89\x50\x4E\x47\x0D\x0A\x1A\x0A");
    if (image.startsWith(pngSignature)) {
        return QStringLiteral("png");
    }
 
    static constexpr QByteArrayView jpegSignature("\xFF\xD8\xFF");
    if (image.startsWith(jpegSignature)) {
        return QStringLiteral("jpg");
    }
 
    static constexpr QByteArrayView gifSignature("\x47\x49\x46\x38");
    if (image.startsWith(gifSignature)) {
        return QStringLiteral("gif");
    }
 
    return _imageFormat;
}
 
QString MapProvider::_tileXYToQuadKey(int tileX, int tileY, int levelOfDetail) const
{
    QString quadKey;
    for (int i = levelOfDetail; i > 0; i--) {
        char digit = '0';
        const int mask = 1 << (i - 1);
 
        if ((tileX & mask) != 0) {
            digit++;
        }
        if ((tileY & mask) != 0) {
            digit += 2;
        }
 
        (void) quadKey.append(digit);
    }
 
    return quadKey;
}
 
int MapProvider::_getServerNum(int x, int y, int max) const
{
    return (x + 2 * y) % max;
}
 
int MapProvider::long2tileX(double lon, int z) const
{
    return static_cast<int>(floor((lon + 180.0) / 360.0 * pow(2.0, z)));
}
 
int MapProvider::lat2tileY(double lat, int z) const
{
    return static_cast<int>(floor((1.0 - log(tan(lat * M_PI / 180.0) + 1.0 / cos(lat * M_PI / 180.0)) / M_PI) / 2.0 * pow(2.0, z)));
}
 
double MapProvider::tileX2long(int x, int z) const
{
    return x / std::pow(2.0, z) * 360.0 - 180.0;
}
 
double MapProvider::tileY2lat(int y, int z) const
{
    const double n = M_PI - 2.0 * M_PI * y / std::pow(2.0, z);
    return qRadiansToDegrees(std::atan(std::sinh(n)));
}
 
QGCTileSet MapProvider::getTileCount(int zoom, double topleftLon,
                                     double topleftLat, double bottomRightLon,
                                     double bottomRightLat) const
{
    QGCTileSet set;
    set.tileX0 = long2tileX(topleftLon, zoom);
    set.tileY0 = lat2tileY(topleftLat, zoom);
    set.tileX1 = long2tileX(bottomRightLon, zoom);
    set.tileY1 = lat2tileY(bottomRightLat, zoom);
 
    set.tileCount = (static_cast<quint64>(set.tileX1) -
                     static_cast<quint64>(set.tileX0) + 1) *
                    (static_cast<quint64>(set.tileY1) -
                     static_cast<quint64>(set.tileY0) + 1);
 
    set.tileSize = getAverageSize() * set.tileCount;
    return set;
}
 
// Resolution math: https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#Resolution_and_Scale