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C++ OGRGeometryCollection::flattenTo2D方法代码示例

本文整理汇总了C++中OGRGeometryCollection::flattenTo2D方法的典型用法代码示例。如果您正苦于以下问题:C++ OGRGeometryCollection::flattenTo2D方法的具体用法?C++ OGRGeometryCollection::flattenTo2D怎么用?C++ OGRGeometryCollection::flattenTo2D使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在OGRGeometryCollection的用法示例。


在下文中一共展示了OGRGeometryCollection::flattenTo2D方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: simplifyOgrGeometry

//! Simplifies the OGR-geometry (Removing duplicated points) when is applied the specified map2pixel context
bool QgsOgrMapToPixelSimplifier::simplifyOgrGeometry( OGRGeometry* geometry, bool isaLinearRing )
{
  OGRwkbGeometryType wkbGeometryType = wkbFlatten( geometry->getGeometryType() );

  // Simplify the geometry rewriting temporally its WKB-stream for saving calloc's.
  if ( wkbGeometryType == wkbLineString )
  {
    OGRLineString* lineString = ( OGRLineString* )geometry;

    int numPoints = lineString->getNumPoints();
    if (( isaLinearRing && numPoints <= 5 ) || ( !isaLinearRing && numPoints <= 2 ) ) return false;

    OGREnvelope env;
    geometry->getEnvelope( &env );
    QgsRectangle envelope( env.MinX, env.MinY, env.MaxX, env.MaxY );

    // Can replace the geometry by its BBOX ?
    if (( mSimplifyFlags & QgsMapToPixelSimplifier::SimplifyEnvelope ) && canbeGeneralizedByMapBoundingBox( envelope ) )
    {
      OGRRawPoint* points = NULL;
      int numPoints = 0;

      double x1 = envelope.xMinimum();
      double y1 = envelope.yMinimum();
      double x2 = envelope.xMaximum();
      double y2 = envelope.yMaximum();

      if ( isaLinearRing )
      {
        numPoints = 5;
        points = mallocPoints( numPoints );
        points[0].x = x1; points[0].y = y1;
        points[1].x = x2; points[1].y = y1;
        points[2].x = x2; points[2].y = y2;
        points[3].x = x1; points[3].y = y2;
        points[4].x = x1; points[4].y = y1;
      }
      else
      {
        numPoints = 2;
        points = mallocPoints( numPoints );
        points[0].x = x1; points[0].y = y1;
        points[1].x = x2; points[1].y = y2;
      }
      lineString->setPoints( numPoints, points );
      lineString->flattenTo2D();
      return true;
    }
    else
      if ( mSimplifyFlags & QgsMapToPixelSimplifier::SimplifyGeometry )
      {
        QGis::GeometryType geometryType = isaLinearRing ? QGis::Polygon : QGis::Line;
        int numSimplifiedPoints = 0;

        OGRRawPoint* points = mallocPoints( numPoints );
        double* xptr = ( double* )points;
        double* yptr = xptr + 1;
        lineString->getPoints( points );

        if ( simplifyOgrGeometry( geometryType, envelope, xptr, 16, yptr, 16, numPoints, numSimplifiedPoints ) )
        {
          lineString->setPoints( numSimplifiedPoints, points );
          lineString->flattenTo2D();
        }
        return numSimplifiedPoints != numPoints;
      }
  }
  else
    if ( wkbGeometryType == wkbPolygon )
    {
      OGRPolygon* polygon = ( OGRPolygon* )geometry;
      bool result = simplifyOgrGeometry( polygon->getExteriorRing(), true );

      for ( int i = 0, numInteriorRings = polygon->getNumInteriorRings(); i < numInteriorRings; ++i )
      {
        result |= simplifyOgrGeometry( polygon->getInteriorRing( i ), true );
      }
      if ( result ) polygon->flattenTo2D();
      return result;
    }
    else
      if ( wkbGeometryType == wkbMultiLineString || wkbGeometryType == wkbMultiPolygon )
      {
        OGRGeometryCollection* collection = ( OGRGeometryCollection* )geometry;
        bool result = false;

        for ( int i = 0, numGeometries = collection->getNumGeometries(); i < numGeometries; ++i )
        {
          result |= simplifyOgrGeometry( collection->getGeometryRef( i ), wkbGeometryType == wkbMultiPolygon );
        }
        if ( result ) collection->flattenTo2D();
        return result;
      }
  return false;
}
开发者ID:maggi,项目名称:QGIS,代码行数:96,代码来源:qgsogrmaptopixelgeometrysimplifier.cpp


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