C++ QgsVector类代码示例

bool QgsClockwiseAngleComparer::operator()( const QgsPointXY &a, const QgsPointXY &b ) const
{
  const bool aIsLeft = a.x() < mVertex.x();
  const bool bIsLeft = b.x() < mVertex.x();
  if ( aIsLeft != bIsLeft )
    return bIsLeft;

  if ( qgsDoubleNear( a.x(), mVertex.x() ) && qgsDoubleNear( b.x(), mVertex.x() ) )
  {
    if ( a.y() >= mVertex.y() || b.y() >= mVertex.y() )
    {
      return b.y() < a.y();
    }
    else
    {
      return a.y() < b.y();
    }
  }
  else
  {
    const QgsVector oa = a - mVertex;
    const QgsVector ob = b - mVertex;
    const double det = oa.crossProduct( ob );
    if ( qgsDoubleNear( det, 0.0 ) )
    {
      return oa.lengthSquared() < ob.lengthSquared();
    }
    else
    {
      return det < 0;
    }
  }
}

void QgsSelectedFeature::moveSelectedVertexes( QgsVector v )
{
  int nUpdates = 0;
  Q_FOREACH ( QgsVertexEntry *entry, mVertexMap )
  {
    if ( entry->isSelected() )
      nUpdates++;
  }

  if ( nUpdates == 0 )
    return;

  mVlayer->beginEditCommand( QObject::tr( "Moved vertices" ) );
  int topologicalEditing = QgsProject::instance()->readNumEntry( "Digitizing", "/TopologicalEditing", 0 );

  beginGeometryChange();

  QMultiMap<double, QgsSnappingResult> currentResultList;
  for ( int i = mVertexMap.size() - 1; i > -1 && nUpdates > 0; i-- )
  {
    QgsVertexEntry *entry = mVertexMap.value( i, nullptr );
    if ( !entry || !entry->isSelected() )
      continue;

    if ( topologicalEditing )
    {
      // snap from current vertex
      currentResultList.clear();
      mVlayer->snapWithContext( entry->pointV1(), ZERO_TOLERANCE, currentResultList, QgsSnapper::SnapToVertex );
    }

    // only last update should trigger the geometry update
    // as vertex selection gets lost on the update
    if ( --nUpdates == 0 )
      endGeometryChange();

    QgsPointV2 p = entry->point();
    p.setX( p.x() + v.x() );
    p.setY( p.y() + v.y() );
    mVlayer->moveVertex( p, mFeatureId, i );

    if ( topologicalEditing )
    {
      QMultiMap<double, QgsSnappingResult>::iterator resultIt =  currentResultList.begin();

      for ( ; resultIt != currentResultList.end(); ++resultIt )
      {
        // move all other
        if ( mFeatureId !=  resultIt.value().snappedAtGeometry )
          mVlayer->moveVertex( p, resultIt.value().snappedAtGeometry, resultIt.value().snappedVertexNr );
      }
    }
  }

  if ( nUpdates > 0 )
    endGeometryChange();

  mVlayer->endEditCommand();
}

//
// distance of point q from line through p in direction v
// return >0  => q lies left of the line
//        <0  => q lies right of the line
//
double QgsGeometryValidator::distLine2Point( const QgsPoint& p, QgsVector v, const QgsPoint& q )
{
  if ( qgsDoubleNear( v.length(), 0 ) )
  {
    throw QgsException( QObject::tr( "invalid line" ) );
  }

  return ( v.x()*( q.y() - p.y() ) - v.y()*( q.x() - p.x() ) ) / v.length();
}

QgsVector calcMotion( const QgsPoint &a, const QgsPoint &b, const QgsPoint &c,
                      double lowerThreshold, double upperThreshold )
{
  QgsVector p = a - b;
  QgsVector q = c - b;

  if ( qgsDoubleNear( p.length(), 0.0 ) || qgsDoubleNear( q.length(), 0.0 ) )
    return QgsVector( 0, 0 );

  // 2.0 is a magic number from the original JOSM source code
  double scale = 2.0 * std::min( p.length(), q.length() );

  p = p.normalized();
  q = q.normalized();
  double dotProduct = p * q;

  if ( !dotProductWithinAngleTolerance( dotProduct, lowerThreshold, upperThreshold ) )
  {
    return QgsVector( 0, 0 );
  }

  // wonderful nasty hack which has survived through JOSM -> id -> QGIS
  // to deal with almost-straight segments (angle is closer to 180 than to 90/270).
  if ( dotProduct < -M_SQRT1_2 )
    dotProduct += 1.0;

  QgsVector new_v = p + q;
  // 0.1 magic number from JOSM implementation - think this is to limit each iterative step
  return new_v.normalized() * ( 0.1 * dotProduct * scale );
}

bool QgsRay2D::intersects( const QgsLineSegment2D &segment, QgsPointXY &intersectPoint ) const
{
  const QgsVector ao = origin - segment.start();
  const QgsVector ab = segment.end() - segment.start();
  const double det = ab.crossProduct( direction );
  if ( qgsDoubleNear( det, 0.0 ) )
  {
    const int abo = segment.pointLeftOfLine( origin );
    if ( abo != 0 )
    {
      return false;
    }
    else
    {
      const double distA = ao * direction;
      const double distB = ( origin - segment.end() ) * direction;

      if ( distA > 0 && distB > 0 )
      {
        return false;
      }
      else
      {
        if ( ( distA > 0 ) != ( distB > 0 ) )
          intersectPoint = origin;
        else if ( distA > distB ) // at this point, both distances are negative
          intersectPoint = segment.start(); // hence the nearest point is A
        else
          intersectPoint = segment.end();
        return true;
      }
    }
  }
  else
  {
    const double u = ao.crossProduct( direction ) / det;
    if ( u < 0.0 || 1.0 < u )
    {
      return false;
    }
    else
    {
      const double t = -ab.crossProduct( ao ) / det;
      intersectPoint = origin + direction * t;
      return qgsDoubleNear( t, 0.0 ) || t > 0;
    }
  }
}

bool QgsGeometryUtils::lineIntersection( const QgsPointV2& p1, const QgsVector& v, const QgsPointV2& q1, const QgsVector& w, QgsPointV2& inter )
{
  double d = v.y() * w.x() - v.x() * w.y();

  if ( d == 0 )
    return false;

  double dx = q1.x() - p1.x();
  double dy = q1.y() - p1.y();
  double k = ( dy * w.x() - dx * w.y() ) / d;

  inter = QgsPointV2( p1.x() + v.x() * k, p1.y() + v.y() * k );

  return true;
}

double normalizedDotProduct( const QgsPoint &a, const QgsPoint &b, const QgsPoint &c )
{
  QgsVector p = a - b;
  QgsVector q = c - b;

  if ( p.length() > 0 )
    p = p.normalized();
  if ( q.length() > 0 )
    q = q.normalized();

  return p * q;
}

bool QgsGeometryValidator::intersectLines( const QgsPoint& p, QgsVector v, const QgsPoint& q, QgsVector w, QgsPoint &s )
{
  double d = v.y() * w.x() - v.x() * w.y();

  if ( qgsDoubleNear( d, 0 ) )
    return false;

  double dx = q.x() - p.x();
  double dy = q.y() - p.y();
  double k = ( dy * w.x() - dx * w.y() ) / d;

  s = p + v * k;

  return true;
}

void QgsGeometryValidator::checkRingIntersections(
  int p0, int i0, const QgsPolyline &ring0,
  int p1, int i1, const QgsPolyline &ring1 )
{
  for ( int i = 0; !mStop && i < ring0.size() - 1; i++ )
  {
    QgsVector v = ring0[i+1] - ring0[i];

    for ( int j = 0; !mStop && j < ring1.size() - 1; j++ )
    {
      QgsVector w = ring1[j+1] - ring1[j];

      QgsPoint s;
      if ( intersectLines( ring0[i], v, ring1[j], w, s ) )
      {
        double d = -distLine2Point( ring0[i], v.perpVector(), s );

        if ( d >= 0 && d <= v.length() )
        {
          d = -distLine2Point( ring1[j], w.perpVector(), s );
          if ( d > 0 && d < w.length() &&
               ring0[i+1] != ring1[j+1] && ring0[i+1] != ring1[j] &&
               ring0[i+0] != ring1[j+1] && ring0[i+0] != ring1[j] )
          {
            QString msg = QObject::tr( "segment %1 of ring %2 of polygon %3 intersects segment %4 of ring %5 of polygon %6 at %7" )
                          .arg( i0 ).arg( i ).arg( p0 )
                          .arg( i1 ).arg( j ).arg( p1 )
                          .arg( s.toString() );
            QgsDebugMsg( msg );
            emit errorFound( QgsGeometry::Error( msg, s ) );
            mErrorCount++;
          }
        }
      }
    }
  }
}

double QgsVector::angle( QgsVector v ) const
{
  return v.angle() - angle();
}

void QgsGeometryValidator::validatePolyline( int i, QgsPolyline line, bool ring )
{
  if ( ring )
  {
    if ( line.size() < 4 )
    {
      QString msg = QObject::tr( "ring %1 with less than four points" ).arg( i );
      QgsDebugMsg( msg );
      emit errorFound( QgsGeometry::Error( msg ) );
      mErrorCount++;
      return;
    }

    if ( line[0] != line[ line.size()-1 ] )
    {
      QString msg = QObject::tr( "ring %1 not closed" ).arg( i );
      QgsDebugMsg( msg );
      emit errorFound( QgsGeometry::Error( msg ) );
      mErrorCount++;
      return;
    }
  }
  else if ( line.size() < 2 )
  {
    QString msg = QObject::tr( "line %1 with less than two points" ).arg( i );
    QgsDebugMsg( msg );
    emit errorFound( QgsGeometry::Error( msg ) );
    mErrorCount++;
    return;
  }

  int j = 0;
  while ( j < line.size() - 1 )
  {
    int n = 0;
    while ( j < line.size() - 1 && line[j] == line[j+1] )
    {
      line.remove( j );
      n++;
    }

    if ( n > 0 )
    {
      QString msg = QObject::tr( "line %1 contains %n duplicate node(s) at %2", "number of duplicate nodes", n ).arg( i ).arg( j );
      QgsDebugMsg( msg );
      emit errorFound( QgsGeometry::Error( msg, line[j] ) );
      mErrorCount++;
    }

    j++;
  }

  for ( j = 0; !mStop && j < line.size() - 3; j++ )
  {
    QgsVector v = line[j+1] - line[j];
    double vl = v.length();

    int n = ( j == 0 && ring ) ? line.size() - 2 : line.size() - 1;

    for ( int k = j + 2; !mStop && k < n; k++ )
    {
      QgsVector w = line[k+1] - line[k];

      QgsPoint s;
      if ( !intersectLines( line[j], v, line[k], w, s ) )
        continue;

      double d = 0.0;
      try
      {
        d = -distLine2Point( line[j], v.perpVector(), s );
      }
      catch ( QgsException & e )
      {
        Q_UNUSED( e );
        QgsDebugMsg( "Error validating: " + e.what() );
        continue;
      }
      if ( d < 0 || d > vl )
        continue;

      try
      {
        d = -distLine2Point( line[k], w.perpVector(), s );
      }
      catch ( QgsException & e )
      {
        Q_UNUSED( e );
        QgsDebugMsg( "Error validating: " + e.what() );
        continue;
      }

      if ( d <= 0 || d >= w.length() )
        continue;

      QString msg = QObject::tr( "segments %1 and %2 of line %3 intersect at %4" ).arg( j ).arg( k ).arg( i ).arg( s.toString() );
      QgsDebugMsg( msg );
      emit errorFound( QgsGeometry::Error( msg, s ) );
      mErrorCount++;
    }
//.........这里部分代码省略.........

void QgsMapToolNodeTool::canvasMoveEvent( QMouseEvent * e )
{
  if ( !mSelectedFeature || !mClicked )
    return;

  QgsVectorLayer* vlayer = mSelectedFeature->vlayer();
  Q_ASSERT( vlayer );

  mSelectAnother = false;

  if ( mMoving )
  {
    // create rubberband, if none exists
    if ( mRubberBands.empty() )
    {
      if ( mIsPoint )
      {
        QList<QgsVertexEntry*> &vertexMap = mSelectedFeature->vertexMap();
        for ( int i = 0; i < vertexMap.size(); i++ )
        {
          if ( vertexMap[i]->isSelected() )
          {
            QgsRubberBand* rb = createRubberBandMarker( vertexMap[i]->point(), vlayer );
            mRubberBands.append( rb );
          }
        }
      }
      createMovingRubberBands();

      QList<QgsSnappingResult> snapResults;
      QgsPoint posMapCoord = snapPointFromResults( snapResults, e->pos() );
      mPosMapCoordBackup = posMapCoord;
    }
    else
    {
      // move rubberband
      QList<QgsSnappingResult> snapResults;
      mSnapper.snapToBackgroundLayers( e->pos(), snapResults, QList<QgsPoint>() << mClosestMapVertex );

      // get correct coordinates to move to
      QgsPoint posMapCoord = snapPointFromResults( snapResults, e->pos() );

      QgsPoint pressMapCoords;
      if ( snapResults.size() > 0 )
      {
        pressMapCoords = mClosestMapVertex;
      }
      else
      {
        pressMapCoords = toMapCoordinates( mPressCoordinates );
      }

      QgsVector offset = posMapCoord - pressMapCoords;

      // handle points
      if ( mIsPoint )
      {
        for ( int i = 0; i < mRubberBands.size(); i++ )
        {
          mRubberBands[i]->setTranslationOffset( offset.x(), offset.y() );
        }
        return;
      }

      // move points
      QList<QgsVertexEntry*> &vertexMap = mSelectedFeature->vertexMap();
      for ( int i = 0; i < vertexMap.size(); i++ )
      {
        if ( !vertexMap[i]->isSelected() )
          continue;

        QgsPoint p = toMapCoordinates( vlayer, vertexMap[i]->point() ) + offset;

        mRubberBands[vertexMap[i]->rubberBandNr()]->movePoint( vertexMap[i]->rubberBandIndex(), p );

        if ( vertexMap[i]->rubberBandIndex() == 0 )
        {
          mRubberBands[vertexMap[i]->rubberBandNr()]->movePoint( 0, p );
        }
      }

      // topological editing
      offset = posMapCoord - mPosMapCoordBackup;
      for ( int i = 0; i < mTopologyRubberBand.size(); i++ )
      {
        for ( int pointIndex = 0; pointIndex < mTopologyRubberBand[i]->numberOfVertices(); pointIndex++ )
        {
          if ( mTopologyRubberBandVertexes[i]->contains( pointIndex ) )
          {
            const QgsPoint* point = mTopologyRubberBand[i]->getPoint( 0, pointIndex );
            if ( point == 0 )
            {
              break;
            }
            mTopologyRubberBand[i]->movePoint( pointIndex, *point + offset );
          }
        }
      }

      mPosMapCoordBackup = posMapCoord;
//.........这里部分代码省略.........