I have a map view in my application, and i want to draw an area of actuation based on the coordinates, for example: point A(x1,y1) to point B(x2,y2) to point C(x3, y3) to point D(x4, y4) and close on point A. I need to convert the distance between the points to meters, because each row and column of the matrix must have a distance of 1 meter on the world map scale between each one. If the X Y of the matrix is inside the drawn area on the map, get value = 1, else, get value = 0.

In this code I set an approximate value of 1 meter in real life, but this makes the result inaccurate, i have to fix it.

    if (selectedCoordinates.isEmpty()) {
        return;
    }

    // Get the bounding box of the selected area
    double minLat = std::numeric_limits<double>::max();
    double maxLat = std::numeric_limits<double>::lowest();
    double minLon = std::numeric_limits<double>::max();
    double maxLon = std::numeric_limits<double>::lowest();

    for (const QVariant &point : selectedCoordinates) {
        QVariantMap pointMap = point.toMap();
        double lat = pointMap["latitude"].toDouble();
        double lon = pointMap["longitude"].toDouble();
        if (lat < minLat) minLat = lat;
        if (lat > maxLat) maxLat = lat;
        if (lon < minLon) minLon = lon;
        if (lon > maxLon) maxLon = lon;
    }

    // Initialize the matrix
    QVector<QVector<int>> matrix;

    // Calculate the matrix of 1x1 meter squares within the bounding box
    double latStep = 1.0 / 111320.0; // Approx. 1 meter per degree latitude
    double lonStep = 1.0 / (111320.0 * std::cos(minLat * M_PI / 180.0)); // Approx. 1 meter per degree longitude

    for (double lat = minLat; lat <= maxLat; lat += latStep) {
        QVector<int> row;
        QVariantList rowV;
        for (double lon = minLon; lon <= maxLon; lon += lonStep) {
            QGeoCoordinate center(lat + latStep / 2, lon + lonStep / 2);

            // Check if the center is inside the selection polygon
            bool insidePolygon = isInsidePolygon(center);

            // Store 1 for inside, 0 for outside
            if (insidePolygon) {
                row.append(1);
            } else {
                row.append(0);
            }

            // Store the coordinates of the center of each square in the matrix
            QVariantMap point;
            point["latitude"] = center.latitude();
            point["longitude"] = center.longitude();
            point["inside"] = insidePolygon;
            rowV.append(point);

            // Draw the square on the map
            auto Obje = ui->quickWidget_MapView->rootObject();
            if (Obje) {
                QVariant returnedValue;
                QMetaObject::invokeMethod(Obje, "drawSquare", Q_RETURN_ARG(QVariant, returnedValue),
                                          Q_ARG(QVariant, QVariant::fromValue(center)),
                                          Q_ARG(QVariant, 1.0),
                                          Q_ARG(QVariant, insidePolygon));
            }
        }
        matrixV.append(rowV);
        matrix.append(row);
    }

    // Print the matrix in a visually organized format
    qDebug() << "Matrix of 1x1 meter squares:";
    for (const QVector<int> &row : matrix) {
        QString rowStr;
        for (int value : row) {
            if (value == 1) {
                rowStr += QString(YELLOW "[1]" RESET " ");
            } else {
                rowStr += "[0] ";
            }
        }
        qDebug().noquote() << rowStr.trimmed();
    }

In a simple polygon, this works fine:

But in a more complex polygon, this occurs: