QGCMapPolygon.cc

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#include "QGCMapPolygon.h"
#include "QGCGeo.h"
#include "GeoJsonHelper.h"
#include "JsonParsing.h"
#include "QGCQGeoCoordinate.h"
#include "AppMessages.h"
#include "QGCApplication.h"
#include "QGCLoggingCategory.h"
#include "ShapeFileHelper.h"
#include "KMLDomDocument.h"
 
#include <QtCore/QLineF>
#include <QMetaMethod>
 
QGC_LOGGING_CATEGORY(QGCMapPolygonLog, "QMLControls.QGCMapPolygon")
 
QGCMapPolygon::QGCMapPolygon(QObject* parent)
    : QObject               (parent)
    , _dirty                (false)
    , _centerDrag           (false)
    , _ignoreCenterUpdates  (false)
    , _interactive          (false)
{
    _init();
}
 
QGCMapPolygon::QGCMapPolygon(const QGCMapPolygon& other, QObject* parent)
    : QObject               (parent)
    , _dirty                (false)
    , _centerDrag           (false)
    , _ignoreCenterUpdates  (false)
    , _interactive          (false)
{
    *this = other;
 
    _init();
}
 
QGCMapPolygon::~QGCMapPolygon()
{
    qgcApp()->removeCompressedSignal(QMetaMethod::fromSignal(&QGCMapPolygon::pathChanged));
}
 
void QGCMapPolygon::_init(void)
{
    connect(&_polygonModel, &QmlObjectListModel::dirtyChanged, this, &QGCMapPolygon::_polygonModelDirtyChanged);
    connect(&_polygonModel, &QmlObjectListModel::countChanged, this, &QGCMapPolygon::_polygonModelCountChanged);
    connect(&_polygonModel, &QmlObjectListModel::modelReset, this, [this]() {
        emit pathChanged();
        emit centerChanged(_center);
    });
 
    connect(this, &QGCMapPolygon::pathChanged,  this, &QGCMapPolygon::_updateCenter);
    connect(this, &QGCMapPolygon::countChanged, this, &QGCMapPolygon::isValidChanged);
    connect(this, &QGCMapPolygon::countChanged, this, &QGCMapPolygon::isEmptyChanged);
 
}
 
const QGCMapPolygon& QGCMapPolygon::operator=(const QGCMapPolygon& other)
{
    clear();
 
    QVariantList vertices = other.path();
    QList<QGeoCoordinate> rgCoord;
    for (const QVariant& vertexVar: vertices) {
        rgCoord.append(vertexVar.value<QGeoCoordinate>());
    }
    appendVertices(rgCoord);
 
    setDirty(true);
 
    return *this;
}
 
void QGCMapPolygon::clear(void)
{
    // Bug workaround, see below
    while (_polygonPath.count() > 1) {
        _polygonPath.takeLast();
    }
    if (_vertexDrag) {
        emit dragPathChanged();
    } else {
        emit pathChanged();
    }
 
    // Although this code should remove the polygon from the map it doesn't. There appears
    // to be a bug in QGCMapPolygon which causes it to not be redrawn if the list is empty. So
    // we work around it by using the code above to remove all but the last point which in turn
    // will cause the polygon to go away.
    _polygonPath.clear();
 
    _polygonModel.clearAndDeleteContents();
 
    emit cleared();
 
    setDirty(true);
}
 
void QGCMapPolygon::adjustVertex(int vertexIndex, const QGeoCoordinate coordinate)
{
    _polygonPath[vertexIndex] = QVariant::fromValue(coordinate);
    _polygonModel.value<QGCQGeoCoordinate*>(vertexIndex)->setCoordinate(coordinate);
    if (!_centerDrag) {
        if (!_deferredPathChanged) {
            _deferredPathChanged = true;
            if (_vertexDrag) {
                // During vertex drag only emit the lightweight visual signal
                QTimer::singleShot(0, this, [this]() {
                    emit dragPathChanged();
                    _deferredPathChanged = false;
                });
            } else {
                QTimer::singleShot(0, this, [this]() {
                    emit pathChanged();
                    _deferredPathChanged = false;
                });
            }
        }
    }
    setDirty(true);
}
 
void QGCMapPolygon::setDirty(bool dirty)
{
    if (_dirty != dirty) {
        _dirty = dirty;
        if (!dirty) {
            _polygonModel.setDirty(false);
        }
        emit dirtyChanged(dirty);
    }
}
 
QGeoCoordinate QGCMapPolygon::_coordFromPointF(const QPointF& point) const
{
    QGeoCoordinate coord;
 
    if (_polygonPath.count() > 0) {
        QGeoCoordinate tangentOrigin = _polygonPath[0].value<QGeoCoordinate>();
        QGCGeo::convertNedToGeo(-point.y(), point.x(), 0, tangentOrigin, coord);
    }
 
    return coord;
}
 
QPointF QGCMapPolygon::_pointFFromCoord(const QGeoCoordinate& coordinate) const
{
    if (_polygonPath.count() > 0) {
        double y, x, down;
        QGeoCoordinate tangentOrigin = _polygonPath[0].value<QGeoCoordinate>();
 
        QGCGeo::convertGeoToNed(coordinate, tangentOrigin, y, x, down);
        return QPointF(x, -y);
    }
 
    return QPointF();
}
 
QPolygonF QGCMapPolygon::_toPolygonF(void) const
{
    QPolygonF polygon;
 
    if (_polygonPath.count() > 2) {
        for (int i=0; i<_polygonPath.count(); i++) {
            polygon.append(_pointFFromCoord(_polygonPath[i].value<QGeoCoordinate>()));
        }
    }
 
    return polygon;
}
 
bool QGCMapPolygon::containsCoordinate(const QGeoCoordinate& coordinate) const
{
    if (_polygonPath.count() > 2) {
        return _toPolygonF().containsPoint(_pointFFromCoord(coordinate), Qt::OddEvenFill);
    } else {
        return false;
    }
}
 
void QGCMapPolygon::setPath(const QList<QGeoCoordinate>& path)
{
    _polygonPath.clear();
    _polygonModel.clearAndDeleteContents();
    for(const QGeoCoordinate& coord: path) {
        _polygonPath.append(QVariant::fromValue(coord));
        _polygonModel.append(new QGCQGeoCoordinate(coord, this));
    }
 
    setDirty(true);
    emit pathChanged();
}
 
void QGCMapPolygon::setPath(const QVariantList& path)
{
    _polygonPath = path;
 
    _polygonModel.clearAndDeleteContents();
    for (int i=0; i<_polygonPath.count(); i++) {
        _polygonModel.append(new QGCQGeoCoordinate(_polygonPath[i].value<QGeoCoordinate>(), this));
    }
 
    setDirty(true);
    emit pathChanged();
}
 
void QGCMapPolygon::saveToJson(QJsonObject& json)
{
    QJsonValue jsonValue;
 
    GeoJsonHelper::saveGeoCoordinateArray(_polygonPath, false /* writeAltitude*/, jsonValue);
    json.insert(jsonPolygonKey, jsonValue);
    setDirty(false);
}
 
bool QGCMapPolygon::loadFromJson(const QJsonObject& json, bool required, QString& errorString)
{
    errorString.clear();
    clear();
 
    if (required) {
        if (!JsonParsing::validateRequiredKeys(json, QStringList(jsonPolygonKey), errorString)) {
            return false;
        }
    } else if (!json.contains(jsonPolygonKey)) {
        return true;
    }
 
    if (!GeoJsonHelper::loadGeoCoordinateArray(json[jsonPolygonKey], false /* altitudeRequired */, _polygonPath, errorString)) {
        return false;
    }
 
    for (int i=0; i<_polygonPath.count(); i++) {
        _polygonModel.append(new QGCQGeoCoordinate(_polygonPath[i].value<QGeoCoordinate>(), this));
    }
 
    setDirty(false);
    emit pathChanged();
 
    return true;
}
 
QList<QGeoCoordinate> QGCMapPolygon::coordinateList(void) const
{
    QList<QGeoCoordinate> coords;
 
    for (int i=0; i<_polygonPath.count(); i++) {
        coords.append(_polygonPath[i].value<QGeoCoordinate>());
    }
 
    return coords;
}
 
void QGCMapPolygon::splitPolygonSegment(int vertexIndex)
{
    int nextIndex = vertexIndex + 1;
    if (nextIndex > _polygonPath.length() - 1) {
        nextIndex = 0;
    }
 
    QGeoCoordinate firstVertex = _polygonPath[vertexIndex].value<QGeoCoordinate>();
    QGeoCoordinate nextVertex = _polygonPath[nextIndex].value<QGeoCoordinate>();
 
    double distance = firstVertex.distanceTo(nextVertex);
    double azimuth = firstVertex.azimuthTo(nextVertex);
    QGeoCoordinate newVertex = firstVertex.atDistanceAndAzimuth(distance / 2, azimuth);
 
    if (nextIndex == 0) {
        appendVertex(newVertex);
    } else {
        _polygonModel.insert(nextIndex, new QGCQGeoCoordinate(newVertex, this));
        _polygonPath.insert(nextIndex, QVariant::fromValue(newVertex));
        emit pathChanged();
        if (0 <= _selectedVertexIndex && vertexIndex < _selectedVertexIndex) {
            selectVertex(_selectedVertexIndex+1);
        }
    }
}
 
void QGCMapPolygon::appendVertex(const QGeoCoordinate& coordinate)
{
    _polygonPath.append(QVariant::fromValue(coordinate));
    _polygonModel.append(new QGCQGeoCoordinate(coordinate, this));
    if (!_deferredPathChanged) {
        // Only update the path once per event loop, to prevent lag-spikes
        _deferredPathChanged = true;
        QTimer::singleShot(0, this, [this]() {
            if (_vertexDrag) {
                emit dragPathChanged();
            } else {
                emit pathChanged();
            }
            _deferredPathChanged = false;
        });
    }
}
 
void QGCMapPolygon::appendVertices(const QList<QGeoCoordinate>& coordinates)
{
    QList<QObject*> objects;
 
    beginReset();
    for (const QGeoCoordinate& coordinate: coordinates) {
        objects.append(new QGCQGeoCoordinate(coordinate, this));
        _polygonPath.append(QVariant::fromValue(coordinate));
    }
    _polygonModel.append(objects);
    endReset();
 
    if (_vertexDrag) {
        emit dragPathChanged();
    } else {
        emit pathChanged();
    }
}
 
void QGCMapPolygon::appendVertices(const QVariantList& varCoords)
{
    QList<QGeoCoordinate> rgCoords;
    for (const QVariant& varCoord: varCoords) {
        rgCoords.append(varCoord.value<QGeoCoordinate>());
    }
    appendVertices(rgCoords);
}
 
void QGCMapPolygon::_polygonModelDirtyChanged(bool dirty)
{
    if (dirty) {
        setDirty(true);
    }
}
 
void QGCMapPolygon::removeVertex(int vertexIndex)
{
    if (vertexIndex < 0 || vertexIndex >= _polygonPath.length()) {
        qCWarning(QGCMapPolygonLog) << "Call to removePolygonCoordinate with bad vertexIndex:count" << vertexIndex << _polygonPath.length();
        return;
    }
 
    if (_polygonPath.length() <= 3) {
        // Don't allow the user to trash the polygon
        return;
    }
 
    QObject* coordObj = _polygonModel.removeAt(vertexIndex);
    coordObj->deleteLater();
    if(vertexIndex == _selectedVertexIndex) {
        selectVertex(-1);
    } else if (vertexIndex < _selectedVertexIndex) {
        selectVertex(_selectedVertexIndex - 1);
    } // else do nothing - keep current selected vertex
 
    _polygonPath.removeAt(vertexIndex);
    emit pathChanged();
}
 
void QGCMapPolygon::_polygonModelCountChanged(int count)
{
    emit countChanged(count);
}
 
void QGCMapPolygon::_updateCenter(void)
{
    if (!_ignoreCenterUpdates) {
        QGeoCoordinate center;
 
        if (_polygonPath.count() > 2) {
            QPolygonF polygonF = _toPolygonF();
            const int n = polygonF.count();
 
            // Surveyor's (shoelace) formula for polygon centroid
            double signedArea = 0;
            double cx = 0;
            double cy = 0;
 
            for (int i = 0; i < n; i++) {
                const int j = (i + 1) % n;
                const double cross = polygonF[i].x() * polygonF[j].y() - polygonF[j].x() * polygonF[i].y();
                signedArea += cross;
                cx += (polygonF[i].x() + polygonF[j].x()) * cross;
                cy += (polygonF[i].y() + polygonF[j].y()) * cross;
            }
 
            if (qAbs(signedArea) < 1e-6) {
                // Degenerate or near-degenerate polygon (area < 0.5e-6 m²) — fall back to vertex average
                QPointF avg(0, 0);
                for (int i = 0; i < n; i++) {
                    avg += polygonF[i];
                }
                center = _coordFromPointF(QPointF(avg.x() / n, avg.y() / n));
            } else {
                signedArea *= 0.5;
                cx /= (6.0 * signedArea);
                cy /= (6.0 * signedArea);
                center = _coordFromPointF(QPointF(cx, cy));
            }
        }
        if (_center != center) {
            _center = center;
            emit centerChanged(center);
        }
    }
}
 
void QGCMapPolygon::setCenter(QGeoCoordinate newCenter)
{
    if (newCenter != _center) {
        _ignoreCenterUpdates = true;
 
        // Adjust polygon vertices to new center
        double distance = _center.distanceTo(newCenter);
        double azimuth = _center.azimuthTo(newCenter);
 
        for (int i=0; i<count(); i++) {
            QGeoCoordinate oldVertex = _polygonPath[i].value<QGeoCoordinate>();
            QGeoCoordinate newVertex = oldVertex.atDistanceAndAzimuth(distance, azimuth);
            adjustVertex(i, newVertex);
        }
 
        _ignoreCenterUpdates = false;
        _center = newCenter;
 
        if (_centerDrag) {
            // During center drag emit lightweight visual signals only
            if (!_deferredPathChanged) {
                _deferredPathChanged = true;
                QTimer::singleShot(0, this, [this]() {
                    emit dragPathChanged();
                    emit dragCenterChanged(_center);
                    _deferredPathChanged = false;
                });
            }
        } else {
            if (!_deferredPathChanged) {
                _deferredPathChanged = true;
                QTimer::singleShot(0, this, [this]() {
                    emit pathChanged();
                    emit centerChanged(_center);
                    _deferredPathChanged = false;
                });
            }
        }
    }
}
 
void QGCMapPolygon::setCenterDrag(bool centerDrag)
{
    if (centerDrag != _centerDrag) {
        _centerDrag = centerDrag;
        if (!centerDrag) {
            // Drag ended. Center edits do not use vertexDrag, so emit pathChanged here.
            // For interactive center drag, setVertexDrag(false) emits pathChanged.
            if (!_vertexDrag) {
                emit pathChanged();
            }
            emit centerChanged(_center);
        }
        emit centerDragChanged(centerDrag);
    }
}
 
void QGCMapPolygon::setVertexDrag(bool vertexDrag)
{
    if (_vertexDrag != vertexDrag) {
        _vertexDrag = vertexDrag;
        if (!vertexDrag) {
            // Drag ended - signal path changed so downstream can recalculate
            emit pathChanged();
        }
        emit vertexDragChanged(vertexDrag);
    }
}
 
void QGCMapPolygon::setInteractive(bool interactive)
{
    if (_interactive != interactive) {
        _interactive = interactive;
        emit interactiveChanged(interactive);
    }
}
 
QGeoCoordinate QGCMapPolygon::vertexCoordinate(int vertex) const
{
    if (vertex >= 0 && vertex < _polygonPath.count()) {
        return _polygonPath[vertex].value<QGeoCoordinate>();
    } else {
        qCWarning(QGCMapPolygonLog) << "QGCMapPolygon::vertexCoordinate bad vertex requested:count" << vertex << _polygonPath.count();
        return QGeoCoordinate();
    }
}
 
QList<QPointF> QGCMapPolygon::nedPolygon(void) const
{
    QList<QPointF>  nedPolygon;
 
    if (count() > 0) {
        QGeoCoordinate  tangentOrigin = vertexCoordinate(0);
 
        for (int i=0; i<_polygonModel.count(); i++) {
            double y, x, down;
            QGeoCoordinate vertex = vertexCoordinate(i);
            if (i == 0) {
                // This avoids a nan calculation that comes out of convertGeoToNed
                x = y = 0;
            } else {
                QGCGeo::convertGeoToNed(vertex, tangentOrigin, y, x, down);
            }
            nedPolygon += QPointF(x, y);
        }
    }
 
    return nedPolygon;
}
 
 
void QGCMapPolygon::offset(double distance)
{
    QList<QGeoCoordinate> rgNewPolygon;
 
    // I'm sure there is some beautiful famous algorithm to do this, but here is a brute force method
 
    if (count() > 2) {
        // Convert the polygon to NED
        QList<QPointF> rgNedVertices = nedPolygon();
 
        // Walk the edges, offsetting by the specified distance
        QList<QLineF> rgOffsetEdges;
        for (int i=0; i<rgNedVertices.count(); i++) {
            int     lastIndex = i == rgNedVertices.count() - 1 ? 0 : i + 1;
            QLineF  offsetEdge;
            QLineF  originalEdge(rgNedVertices[i], rgNedVertices[lastIndex]);
 
            QLineF workerLine = originalEdge;
            workerLine.setLength(distance);
            workerLine.setAngle(workerLine.angle() - 90.0);
            offsetEdge.setP1(workerLine.p2());
 
            workerLine.setPoints(originalEdge.p2(), originalEdge.p1());
            workerLine.setLength(distance);
            workerLine.setAngle(workerLine.angle() + 90.0);
            offsetEdge.setP2(workerLine.p2());
 
            rgOffsetEdges.append(offsetEdge);
        }
 
        // Intersect the offset edges to generate new vertices
        QPointF         newVertex;
        QGeoCoordinate  tangentOrigin = vertexCoordinate(0);
        for (int i=0; i<rgOffsetEdges.count(); i++) {
            int prevIndex = i == 0 ? rgOffsetEdges.count() - 1 : i - 1;
            auto intersect = rgOffsetEdges[prevIndex].intersects(rgOffsetEdges[i], &newVertex);
            if (intersect == QLineF::NoIntersection) {
                // FIXME: Better error handling?
                qCWarning(QGCMapPolygonLog, "Intersection failed");
                return;
            }
            QGeoCoordinate coord;
            QGCGeo::convertNedToGeo(newVertex.y(), newVertex.x(), 0, tangentOrigin, coord);
            rgNewPolygon.append(coord);
        }
    }
 
    // Update internals
    beginReset();
    clear();
    appendVertices(rgNewPolygon);
    endReset();
}
 
bool QGCMapPolygon::loadKMLOrSHPFile(const QString& file)
{
    QString errorString;
    QList<QList<QGeoCoordinate>> polygons;
    if (!ShapeFileHelper::loadPolygonsFromFile(file, polygons, errorString)) {
        QGC::showAppMessage(errorString);
        return false;
    }
    if (polygons.isEmpty()) {
        QGC::showAppMessage(tr("No polygons found in file"));
        return false;
    }
    const QList<QGeoCoordinate>& rgCoords = polygons.first();
 
    beginReset();
    clear();
    appendVertices(rgCoords);
    endReset();
 
    return true;
}
 
double QGCMapPolygon::area(void) const
{
    // https://www.mathopenref.com/coordpolygonarea2.html
 
    if (_polygonPath.count() < 3) {
        return 0;
    }
 
    double coveredArea = 0.0;
    QList<QPointF> nedVertices = nedPolygon();
    for (int i=0; i<nedVertices.count(); i++) {
        if (i != 0) {
            coveredArea += nedVertices[i - 1].x() * nedVertices[i].y() - nedVertices[i].x() * nedVertices[i -1].y();
        } else {
            coveredArea += nedVertices.last().x() * nedVertices[i].y() - nedVertices[i].x() * nedVertices.last().y();
        }
    }
    return 0.5 * fabs(coveredArea);
}
 
void QGCMapPolygon::verifyClockwiseWinding(void)
{
    if (_polygonPath.count() <= 2) {
        return;
    }
 
    double sum = 0;
    for (int i=0; i<_polygonPath.count(); i++) {
        QGeoCoordinate coord1 = _polygonPath[i].value<QGeoCoordinate>();
        QGeoCoordinate coord2 = (i == _polygonPath.count() - 1) ? _polygonPath[0].value<QGeoCoordinate>() : _polygonPath[i+1].value<QGeoCoordinate>();
 
        sum += (coord2.longitude() - coord1.longitude()) * (coord2.latitude() + coord1.latitude());
    }
 
    if (sum < 0.0) {
        // Winding is counter-clockwise and needs reversal
 
        QList<QGeoCoordinate> rgReversed;
        for (const QVariant& varCoord: _polygonPath) {
            rgReversed.prepend(varCoord.value<QGeoCoordinate>());
        }
 
        beginReset();
        clear();
        appendVertices(rgReversed);
        endReset();
    }
}
 
void QGCMapPolygon::beginReset(void)
{
    _polygonModel.beginResetModel();
}
 
void QGCMapPolygon::endReset(void)
{
    _polygonModel.endResetModel();
}
 
QDomElement QGCMapPolygon::kmlPolygonElement(KMLDomDocument& domDocument)
{
#if 0
    <Polygon id="ID">
      <!-- specific to Polygon -->
      <extrude>0</extrude>                       <!-- boolean -->
      <tessellate>0</tessellate>                 <!-- boolean -->
      <altitudeMode>clampToGround</altitudeMode>
            <!-- kml:altitudeModeEnum: clampToGround, relativeToGround, or absolute -->
            <!-- or, substitute gx:altitudeMode: clampToSeaFloor, relativeToSeaFloor -->
      <outerBoundaryIs>
        <LinearRing>
          <coordinates>...</coordinates>         <!-- lon,lat[,alt] -->
        </LinearRing>
      </outerBoundaryIs>
      <innerBoundaryIs>
        <LinearRing>
          <coordinates>...</coordinates>         <!-- lon,lat[,alt] -->
        </LinearRing>
      </innerBoundaryIs>
    </Polygon>
#endif
 
    QDomElement polygonElement = domDocument.createElement("Polygon");
 
    domDocument.addTextElement(polygonElement, "altitudeMode", "clampToGround");
 
    QDomElement outerBoundaryIsElement = domDocument.createElement("outerBoundaryIs");
    QDomElement linearRingElement = domDocument.createElement("LinearRing");
 
    outerBoundaryIsElement.appendChild(linearRingElement);
    polygonElement.appendChild(outerBoundaryIsElement);
 
    QString coordString;
    for (const QVariant& varCoord : _polygonPath) {
        coordString += QStringLiteral("%1\n").arg(domDocument.kmlCoordString(varCoord.value<QGeoCoordinate>()));
    }
    coordString += QStringLiteral("%1\n").arg(domDocument.kmlCoordString(_polygonPath.first().value<QGeoCoordinate>()));
    domDocument.addTextElement(linearRingElement, "coordinates", coordString);
 
    return polygonElement;
}
 
void QGCMapPolygon::setTraceMode(bool traceMode)
{
    if (traceMode != _traceMode) {
        _traceMode = traceMode;
        emit traceModeChanged(traceMode);
    }
}
 
void QGCMapPolygon::setShowAltColor(bool showAltColor){
    if (showAltColor != _showAltColor) {
        _showAltColor = showAltColor;
        emit showAltColorChanged(showAltColor);
    }
}
 
void QGCMapPolygon::selectVertex(int index)
{
    if(index == _selectedVertexIndex) return;   // do nothing
 
    if(-1 <= index && index < count()) {
        _selectedVertexIndex = index;
    } else {
        qCWarning(QGCMapPolygonLog) << QString("QGCMapPolygon: Selected vertex index (%1) is out of bounds! "
                              "Polygon vertices indexes range is [%2..%3].").arg(index).arg(0).arg(count()-1);
        _selectedVertexIndex = -1;   // deselect vertex
    }
 
    emit selectedVertexChanged(_selectedVertexIndex);
}