C++ (Cpp) OGRGeometryCollection::getEnvelope Examples

Example #1

File: ogrdxf_hatch.cpp Project: liyq0307/gdal

OGRDXFFeature *OGRDXFLayer::TranslateHATCH()

{
    char szLineBuf[257];
    int nCode = 0;
    OGRDXFFeature *poFeature = new OGRDXFFeature( poFeatureDefn );

    CPLString osHatchPattern;
    double dfElevation = 0.0;  // Z value to be used for EVERY point
    /* int nFillFlag = 0; */
    OGRGeometryCollection oGC;

    while( (nCode = poDS->ReadValue(szLineBuf,sizeof(szLineBuf))) > 0 )
    {
        switch( nCode )
        {
          case 30:
            // Constant elevation.
            dfElevation = CPLAtof( szLineBuf );
            break;

          case 70:
            /* nFillFlag = atoi(szLineBuf); */
            break;

          case 2:
            osHatchPattern = szLineBuf;
            poFeature->SetField( "Text", osHatchPattern.c_str() );
            break;

          case 91:
          {
              int nBoundaryPathCount = atoi(szLineBuf);

              for( int iBoundary = 0;
                   iBoundary < nBoundaryPathCount;
                   iBoundary++ )
              {
                  if (CollectBoundaryPath( &oGC, dfElevation ) != OGRERR_NONE)
                      break;
              }
          }
          break;

          default:
            TranslateGenericProperty( poFeature, nCode, szLineBuf );
            break;
        }
    }
    if( nCode < 0 )
    {
        DXF_LAYER_READER_ERROR();
        delete poFeature;
        return nullptr;
    }

    if( nCode == 0 )
        poDS->UnreadValue();
   
/* -------------------------------------------------------------------- */
/*      Obtain a tolerance value used when building the polygon.        */
/* -------------------------------------------------------------------- */
   double dfTolerance = atof( CPLGetConfigOption( "DXF_HATCH_TOLERANCE", "-1" ) );
   if( dfTolerance < 0 )
   {
       // If the configuration variable isn't set, compute the bounding box
       // and work out a tolerance from that
       OGREnvelope oEnvelope;
       oGC.getEnvelope( &oEnvelope );
       dfTolerance = std::max( oEnvelope.MaxX - oEnvelope.MinX,
           oEnvelope.MaxY - oEnvelope.MinY ) * 1e-7;
   }

/* -------------------------------------------------------------------- */
/*      Try to turn the set of lines into something useful.             */
/* -------------------------------------------------------------------- */
    OGRErr eErr;

    OGRGeometry* poFinalGeom = (OGRGeometry *)
        OGRBuildPolygonFromEdges( (OGRGeometryH) &oGC,
                                  TRUE, TRUE, dfTolerance, &eErr );
    if( eErr != OGRERR_NONE )
    {
        delete poFinalGeom;
        OGRMultiLineString* poMLS = new OGRMultiLineString();
        for(int i=0;i<oGC.getNumGeometries();i++)
            poMLS->addGeometry(oGC.getGeometryRef(i));
        poFinalGeom = poMLS;
    }

    poFeature->ApplyOCSTransformer( poFinalGeom );
    poFeature->SetGeometryDirectly( poFinalGeom );

    PrepareBrushStyle( poFeature );

    return poFeature;
}