Ejemplo n.º 1
0
double QgsDistanceArea::measurePerimeter( const QgsGeometry* geometry ) const
{
  if ( !geometry )
    return 0.0;

  const QgsAbstractGeometryV2* geomV2 = geometry->geometry();
  if ( !geomV2 || geomV2->dimension() < 2 )
  {
    return 0.0;
  }

  if ( !mEllipsoidalMode || mEllipsoid == GEO_NONE )
  {
    return geomV2->perimeter();
  }

  //create list with (single) surfaces
  QList< const QgsSurfaceV2* > surfaces;
  const QgsSurfaceV2* surf = dynamic_cast<const QgsSurfaceV2*>( geomV2 );
  if ( surf )
  {
    surfaces.append( surf );
  }
  const QgsMultiSurfaceV2* multiSurf = dynamic_cast<const QgsMultiSurfaceV2*>( geomV2 );
  if ( multiSurf )
  {
    surfaces.reserve(( surf ? 1 : 0 ) + multiSurf->numGeometries() );
    for ( int i = 0; i  < multiSurf->numGeometries(); ++i )
    {
      surfaces.append( static_cast<const QgsSurfaceV2*>( multiSurf->geometryN( i ) ) );
    }
  }

  double length = 0;
  QList<const QgsSurfaceV2*>::const_iterator surfaceIt = surfaces.constBegin();
  for ( ; surfaceIt != surfaces.constEnd(); ++surfaceIt )
  {
    if ( !*surfaceIt )
    {
      continue;
    }

    QgsPolygonV2* poly = ( *surfaceIt )->surfaceToPolygon();
    const QgsCurveV2* outerRing = poly->exteriorRing();
    if ( outerRing )
    {
      length += measure( outerRing );
    }
    int nInnerRings = poly->numInteriorRings();
    for ( int i = 0; i < nInnerRings; ++i )
    {
      length += measure( poly->interiorRing( i ) );
    }
    delete poly;
  }
  return length;
}
Ejemplo n.º 2
0
// Make sure all rings are closed and have > 3 points.
static bool lwpoly_make_geos_friendly( QgsPolygonV2 &poly )
{
  // If the polygon has no rings there's nothing to do
  // TODO: in qgis representation there always is exterior ring
  //if ( ! poly->nrings ) return true;

  // All rings must be closed and have > 3 points
  for ( int i = 0; i < poly.numInteriorRings(); i++ )
  {
    if ( !ring_make_geos_friendly( *const_cast<QgsCurve *>( poly.interiorRing( i ) ) ) )
      return false;
  }

  return true;
}
Ejemplo n.º 3
0
QString QgsMultiSurface::asJSON( int precision ) const
{
  // GeoJSON does not support curves
  QString json = QStringLiteral( "{\"type\": \"MultiPolygon\", \"coordinates\": [" );
  Q_FOREACH ( const QgsAbstractGeometry *geom, mGeometries )
  {
    if ( dynamic_cast<const QgsSurface*>( geom ) )
    {
      json += '[';

      QgsPolygonV2* polygon = static_cast<const QgsSurface*>( geom )->surfaceToPolygon();

      QgsLineString* exteriorLineString = polygon->exteriorRing()->curveToLine();
      QgsPointSequence exteriorPts;
      exteriorLineString->points( exteriorPts );
      json += QgsGeometryUtils::pointsToJSON( exteriorPts, precision ) + ", ";
      delete exteriorLineString;

      for ( int i = 0, n = polygon->numInteriorRings(); i < n; ++i )
      {
        QgsLineString* interiorLineString = polygon->interiorRing( i )->curveToLine();
        QgsPointSequence interiorPts;
        interiorLineString->points( interiorPts );
        json += QgsGeometryUtils::pointsToJSON( interiorPts, precision ) + ", ";
        delete interiorLineString;
      }
      if ( json.endsWith( QLatin1String( ", " ) ) )
      {
        json.chop( 2 ); // Remove last ", "
      }

      delete polygon;

      json += QLatin1String( "], " );
    }
  }
  if ( json.endsWith( QLatin1String( ", " ) ) )
  {
    json.chop( 2 ); // Remove last ", "
  }
  json += QLatin1String( "] }" );
  return json;
}
Ejemplo n.º 4
0
double QgsDistanceArea::measure( const QgsAbstractGeometryV2* geomV2, MeasureType type ) const
{
  if ( !geomV2 )
  {
    return 0.0;
  }

  int geomDimension = geomV2->dimension();
  if ( geomDimension <= 0 )
  {
    return 0.0;
  }

  MeasureType measureType = type;
  if ( measureType == Default )
  {
    measureType = ( geomDimension == 1 ? Length : Area );
  }

  if ( !mEllipsoidalMode || mEllipsoid == GEO_NONE )
  {
    //no transform required
    if ( measureType == Length )
    {
      return geomV2->length();
    }
    else
    {
      return geomV2->area();
    }
  }
  else
  {
    //multigeom is sum of measured parts
    const QgsGeometryCollectionV2* collection = dynamic_cast<const QgsGeometryCollectionV2*>( geomV2 );
    if ( collection )
    {
      double sum = 0;
      for ( int i = 0; i < collection->numGeometries(); ++i )
      {
        sum += measure( collection->geometryN( i ), measureType );
      }
      return sum;
    }

    if ( measureType == Length )
    {
      const QgsCurveV2* curve = dynamic_cast<const QgsCurveV2*>( geomV2 );
      if ( !curve )
      {
        return 0.0;
      }

      QgsLineStringV2* lineString = curve->curveToLine();
      double length = measureLine( lineString );
      delete lineString;
      return length;
    }
    else
    {
      const QgsSurfaceV2* surface = dynamic_cast<const QgsSurfaceV2*>( geomV2 );
      if ( !surface )
        return 0.0;

      QgsPolygonV2* polygon = surface->surfaceToPolygon();

      double area = 0;
      const QgsCurveV2* outerRing = polygon->exteriorRing();
      area += measurePolygon( outerRing );

      for ( int i = 0; i < polygon->numInteriorRings(); ++i )
      {
        const QgsCurveV2* innerRing = polygon->interiorRing( i );
        area -= measurePolygon( innerRing );
      }
      delete polygon;
      return area;
    }
  }
}