如何根据QT中的地图放置瓷砖

问题描述

我正在尝试在 QT 中做离线地图。我想将我的瓷砖放置到我的地图上。我只是放置了一个图块，它并没有完成地图。它在顶部和底部显示相同的内容。我该怎么做？

我在 qrc 中有所有这些。但是，如果有一种方法可以像 "http://tile.openstreetmap.org/%1/%2/%3.png" 那样针对我想去的地方，我想知道。

这是一个简单的代码脚本

#include "slippymap.h"
#include <math.h>
#include <QtWidgets>
#include <QtNetwork>


#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

uint qHash(const QPoint& p)
{
    return p.x() * 17 ^ p.y();
}

// tile size in pixels
const int tdim = 256;

QPointF tileForCoordinate(qreal lat,qreal lng,int zoom)
{
    qreal zn = static_cast<qreal>(1 << zoom);
    qreal tx = (lng + 180.0) / 360.0;
    qreal ty = (1.0 - log(tan(lat * M_PI / 180.0) +
                          1.0 / cos(lat * M_PI / 180.0)) / M_PI) / 2.0;
    return QPointF(tx * zn,ty * zn);
}

qreal longitudeFromTile(qreal tx,int zoom)
{
    qreal zn = static_cast<qreal>(1 << zoom);
    qreal lat = tx / zn * 360.0 - 180.0;
    return lat;
}

qreal latitudeFromTile(qreal ty,int zoom)
{
    qreal zn = static_cast<qreal>(1 << zoom);
    qreal n = M_PI - 2 * M_PI * ty / zn;
    qreal lng = 180.0 / M_PI * atan(0.5 * (exp(n) - exp(-n)));
    return lng;
}



SlippyMap::SlippyMap(QObject *parent)
    :QObject(parent),width(400),height(300),zoom(10),latitude(12.89542),longitude(77.56534)
{
    m_emptyTile = QPixmap(tdim,tdim);
    m_emptyTile.fill(Qt::lightGray);

    QNetworkDiskCache *cache = new QNetworkDiskCache;
    cache->setCacheDirectory(QStandardPaths::writableLocation(QStandardPaths::CacheLocation));
    m_manager.setCache(cache);
    connect(&m_manager,SIGNAL(finished(QNetworkReply*)),this,SLOT(handleNetworkData(QNetworkReply*)));
}

void SlippyMap::invalidate()
{
    if (width <= 0 || height <= 0)
        return;

    QPointF ct = tileForCoordinate(latitude,longitude,zoom);
    qreal tx = ct.x();
    qreal ty = ct.y();

    // top-left corner of the center tile
    int xp = width / 2 - (tx - floor(tx)) * tdim;
    int yp = height / 2 - (ty - floor(ty)) * tdim;

    // first tile vertical and horizontal
    int xa = (xp + tdim - 1) / tdim;
    int ya = (yp + tdim - 1) / tdim;
    int xs = static_cast<int>(tx) - xa;
    int ys = static_cast<int>(ty) - ya;

    // offset for top-left tile
    m_offset = QPoint(xp - xa * tdim,yp - ya * tdim);

    // last tile vertical and horizontal
    int xe = static_cast<int>(tx) + (width - xp - 1) / tdim;
    int ye = static_cast<int>(ty) + (height - yp - 1) / tdim;

    // build a rect
    m_tilesRect = QRect(xs,ys,xe - xs + 1,ye - ys + 1);

    if (m_url.isEmpty())
        download();

    emit updated(QRect(0,width,height));
}

void SlippyMap::render(QPainter *p,const QRect &rect)
{
    int mx = 0,my = 0; // x and y for marker
    qreal latdiff,lngdiff; // storing reminder
    QPointF center = tileForCoordinate(latitude,zoom); // getting tile points for real gps point
    int cx = qFloor(center.x());
    int cy = qFloor(center.y());

    for (int x = 0; x <= m_tilesRect.width(); ++x)
        for (int y = 0; y <= m_tilesRect.height(); ++y) {
            QPoint tp(x + m_tilesRect.left(),y + m_tilesRect.top());
            QRect box = tileRect(tp);

            if (tp.x() == cx && tp.y() == cy) {
                mx = box.x();
                my = box.y();
                latdiff = qAbs(tp.x() - center.x());
                lngdiff = qAbs(tp.y() - center.y());
            }

            if (rect.intersects(box)) {
                if (m_tilePixmaps.contains(tp))
                    p->drawPixmap(box,m_tilePixmaps.value(tp));
                else
                    p->drawPixmap(box,m_emptyTile);
            }
        }
    // marker
    if (mx != 0 && my != 0) {
        QIcon marker = QIcon(":/icons/map.png");
        // int dx= (mx+(latdiff*256.0)-40);
        // int dy= (my+(lngdiff*256.0)-40);
        //        for(int i=0;i<=100;i++)
        //   {
        p->drawPixmap((mx+(latdiff*256.0)-40),(my+(lngdiff*256.0)-40),marker.pixmap(40,40));
        // p->drawPixmap((dx+100),(dy+100),40));
        // p->drawPixmap((dx+50),(dy+50),40));

        // }
    }
}

void SlippyMap::pan(const QPoint &delta)
{
    QPointF dx = QPointF(delta) / qreal(tdim);
    QPointF center = tileForCoordinate(latitude,zoom) - dx;
    latitude = latitudeFromTile(center.y(),zoom);
    longitude = longitudeFromTile(center.x(),zoom);
    invalidate();
}

void SlippyMap::handleNetworkData(QNetworkReply *reply)
{
    QImage img;
    QPoint tp = reply->request().attribute(QNetworkRequest::User).toPoint();
    QUrl url = reply->url();
    if (!reply->error())
        if (!img.load(reply,0))
            img = QImage();
    reply->deleteLater();
    m_tilePixmaps[tp] = QPixmap::fromImage(img);
    if (img.isNull())
        m_tilePixmaps[tp] = m_emptyTile;
    emit updated(tileRect(tp));

    // purge unused spaces
    QRect bound = m_tilesRect.adjusted(-2,-2,2,2);
    foreach(QPoint tp,m_tilePixmaps.keys())
        if (!bound.contains(tp))
            m_tilePixmaps.remove(tp);

    download();
}

void SlippyMap::download()
{
    QPoint grab(0,0);
    for (int x = 0; x <= m_tilesRect.width(); ++x)
        for (int y = 0; y <= m_tilesRect.height(); ++y) {
            QPoint tp = m_tilesRect.topLeft() + QPoint(x,y);
            if (!m_tilePixmaps.contains(tp)) {
                grab = tp;
                break;
            }
        }
    if (grab == QPoint(0,0)) {
        m_url = QUrl();
        return;
    }

//osm formatında yüklemeyi dene

    QString path = "http://tile.openstreetmap.org/%1/%2/%3.png";
    m_url = QUrl(path.arg(zoom).arg(grab.x()).arg(grab.y()));
    QNetworkRequest request;
    request.setUrl(m_url);
    request.setRawHeader("User-Agent","The Qt Company (Qt Graphics Dojo 1.0");
    request.setAttribute(QNetworkRequest::User,QVariant(grab));
    m_manager.get(request);
}

QRect SlippyMap::tileRect(const QPoint &tp)
{
    QPoint t = tp - m_tilesRect.topLeft();
    int x = t.x() * tdim + m_offset.x();
    int y = t.y() * tdim + m_offset.y();
    return QRect(x,y,tdim,tdim);
}

解决方法

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