ogrpolygon.cpp

来自「在linux环境下」· C++ 代码 · 共 837 行 · 第 1/2 页

    if( eByteOrder == wkbNDR )
        b3D = pabyData[4] & 0x80 || pabyData[2] & 0x80;
    else
        b3D = pabyData[1] & 0x80 || pabyData[3] & 0x80;

/* -------------------------------------------------------------------- */
/*      Do we already have some rings?                                  */
/* -------------------------------------------------------------------- */
    if( nRingCount != 0 )
    {
        for( int iRing = 0; iRing < nRingCount; iRing++ )
            delete papoRings[iRing];

        OGRFree( papoRings );
        papoRings = NULL;
    }
    
/* -------------------------------------------------------------------- */
/*      Get the ring count.                                             */
/* -------------------------------------------------------------------- */
    memcpy( &nRingCount, pabyData + 5, 4 );
    
    if( OGR_SWAP( eByteOrder ) )
        nRingCount = CPL_SWAP32(nRingCount);

    papoRings = (OGRLinearRing **) OGRMalloc(sizeof(void*) * nRingCount);

    nDataOffset = 9;
    if( nSize != -1 )
        nSize -= nDataOffset;

/* -------------------------------------------------------------------- */
/*      Get the rings.                                                  */
/* -------------------------------------------------------------------- */
    for( int iRing = 0; iRing < nRingCount; iRing++ )
    {
        OGRErr  eErr;
        
        papoRings[iRing] = new OGRLinearRing();
        eErr = papoRings[iRing]->_importFromWkb( eByteOrder, b3D,
                                                 pabyData + nDataOffset,
                                                 nSize );
        if( eErr != OGRERR_NONE )
        {
            nRingCount = iRing;
            return eErr;
        }

        if( nSize != -1 )
            nSize -= papoRings[iRing]->_WkbSize( b3D );

        nDataOffset += papoRings[iRing]->_WkbSize( b3D );
    }
    
    return OGRERR_NONE;
}

/************************************************************************/
/*                            exportToWkb()                             */
/*                                                                      */
/*      Build a well known binary representation of this object.        */
/************************************************************************/

OGRErr  OGRPolygon::exportToWkb( OGRwkbByteOrder eByteOrder,
                                 unsigned char * pabyData )

{
    int         nOffset;
    int         b3D = getCoordinateDimension() == 3;
    
/* -------------------------------------------------------------------- */
/*      Set the byte order.                                             */
/* -------------------------------------------------------------------- */
    pabyData[0] = (unsigned char) eByteOrder;

/* -------------------------------------------------------------------- */
/*      Set the geometry feature type.                                  */
/* -------------------------------------------------------------------- */
    GUInt32 nGType = getGeometryType();
    
    if( eByteOrder == wkbNDR )
        nGType = CPL_LSBWORD32( nGType );
    else
        nGType = CPL_MSBWORD32( nGType );

    memcpy( pabyData + 1, &nGType, 4 );
    
/* -------------------------------------------------------------------- */
/*      Copy in the raw data.                                           */
/* -------------------------------------------------------------------- */
    if( OGR_SWAP( eByteOrder ) )
    {
        int     nCount;

        nCount = CPL_SWAP32( nRingCount );
        memcpy( pabyData+5, &nCount, 4 );
    }
    else
    {
        memcpy( pabyData+5, &nRingCount, 4 );
    }
    
    nOffset = 9;
    
/* ==================================================================== */
/*      Serialize each of the rings.                                    */
/* ==================================================================== */
    for( int iRing = 0; iRing < nRingCount; iRing++ )
    {
        papoRings[iRing]->_exportToWkb( eByteOrder, b3D,
                                        pabyData + nOffset );

        nOffset += papoRings[iRing]->_WkbSize(b3D);
    }
    
    return OGRERR_NONE;
}

/************************************************************************/
/*                           importFromWkt()                            */
/*                                                                      */
/*      Instantiate from well known text format.  Currently this is     */
/*      `POLYGON ((x y, x y, ...),(x y, ...),...)'.                     */
/************************************************************************/

OGRErr OGRPolygon::importFromWkt( char ** ppszInput )

{
    char        szToken[OGR_WKT_TOKEN_MAX];
    const char  *pszInput = *ppszInput;
    int         iRing;

/* -------------------------------------------------------------------- */
/*      Clear existing rings.                                           */
/* -------------------------------------------------------------------- */
    if( nRingCount > 0 )
    {
        for( iRing = 0; iRing < nRingCount; iRing++ )
            delete papoRings[iRing];
        
        nRingCount = 0;
        CPLFree( papoRings );
    }

/* -------------------------------------------------------------------- */
/*      Read and verify the ``POLYGON'' keyword token.                  */
/* -------------------------------------------------------------------- */
    pszInput = OGRWktReadToken( pszInput, szToken );

    if( !EQUAL(szToken,"POLYGON") )
        return OGRERR_CORRUPT_DATA;

/* -------------------------------------------------------------------- */
/*      The next character should be a ( indicating the start of the    */
/*      list of rings.                                                  */
/* -------------------------------------------------------------------- */
    pszInput = OGRWktReadToken( pszInput, szToken );
    if( szToken[0] != '(' )
        return OGRERR_CORRUPT_DATA;

/* ==================================================================== */
/*      Read each ring in turn.  Note that we try to reuse the same     */
/*      point list buffer from ring to ring to cut down on              */
/*      allocate/deallocate overhead.                                   */
/* ==================================================================== */
    OGRRawPoint *paoPoints = NULL;
    int         nMaxPoints = 0, nMaxRings = 0;
    double      *padfZ = NULL;
    
    do
    {
        int     nPoints = 0;

/* -------------------------------------------------------------------- */
/*      Read points for one ring from input.                            */
/* -------------------------------------------------------------------- */
        pszInput = OGRWktReadPoints( pszInput, &paoPoints, &padfZ, &nMaxPoints,
                                     &nPoints );

        if( pszInput == NULL )
        {
            CPLFree( paoPoints );
            return OGRERR_CORRUPT_DATA;
        }
        
/* -------------------------------------------------------------------- */
/*      Do we need to grow the ring array?                              */
/* -------------------------------------------------------------------- */
        if( nRingCount == nMaxRings )
        {
            nMaxRings = nMaxRings * 2 + 1;
            papoRings = (OGRLinearRing **)
                CPLRealloc(papoRings, nMaxRings * sizeof(OGRLinearRing*));
        }

/* -------------------------------------------------------------------- */
/*      Create the new ring, and assign to ring list.                   */
/* -------------------------------------------------------------------- */
        papoRings[nRingCount] = new OGRLinearRing();
        papoRings[nRingCount]->setPoints( nPoints, paoPoints, padfZ );

        nRingCount++;

/* -------------------------------------------------------------------- */
/*      Read the delimeter following the ring.                          */
/* -------------------------------------------------------------------- */
        
        pszInput = OGRWktReadToken( pszInput, szToken );
    } while( szToken[0] == ',' );

/* -------------------------------------------------------------------- */
/*      freak if we don't get a closing bracket.                        */
/* -------------------------------------------------------------------- */
    CPLFree( paoPoints );
    CPLFree( padfZ );
   
    if( szToken[0] != ')' )
        return OGRERR_CORRUPT_DATA;
    
    *ppszInput = (char *) pszInput;
    return OGRERR_NONE;
}

/************************************************************************/
/*                            exportToWkt()                             */
/*                                                                      */
/*      Translate this structure into it's well known text format       */
/*      equivelent.  This could be made alot more CPU efficient!        */
/************************************************************************/

OGRErr OGRPolygon::exportToWkt( char ** ppszDstText )

{
    char        **papszRings;
    int         iRing, nCumulativeLength = 0;
    OGRErr      eErr;

/* -------------------------------------------------------------------- */
/*      Build a list of strings containing the stuff for each ring.     */
/* -------------------------------------------------------------------- */
    papszRings = (char **) CPLCalloc(sizeof(char *),nRingCount);

    for( iRing = 0; iRing < nRingCount; iRing++ )
    {
        eErr = papoRings[iRing]->exportToWkt( &(papszRings[iRing]) );
        if( eErr != OGRERR_NONE )
            return eErr;

        CPLAssert( EQUALN(papszRings[iRing],"LINEARRING (", 12) );
        nCumulativeLength += strlen(papszRings[iRing] + 11);
    }
    
/* -------------------------------------------------------------------- */
/*      Allocate exactly the right amount of space for the              */
/*      aggregated string.                                              */
/* -------------------------------------------------------------------- */
    *ppszDstText = (char *) VSIMalloc(nCumulativeLength + nRingCount + 11);

    if( *ppszDstText == NULL )
        return OGRERR_NOT_ENOUGH_MEMORY;

/* -------------------------------------------------------------------- */
/*      Build up the string, freeing temporary strings as we go.        */
/* -------------------------------------------------------------------- */
    strcpy( *ppszDstText, "POLYGON (" );

    for( iRing = 0; iRing < nRingCount; iRing++ )
    {                                                           
        if( iRing > 0 )
            strcat( *ppszDstText, "," );
        
        strcat( *ppszDstText, papszRings[iRing] + 11 );
        VSIFree( papszRings[iRing] );
    }

    strcat( *ppszDstText, ")" );

    CPLFree( papszRings );

    return OGRERR_NONE;
}

/************************************************************************/
/*                              get_Area()                              */
/************************************************************************/

double OGRPolygon::get_Area()

{
    // notdef ... correct later.
    
    return 0.0;
}

/************************************************************************/
/*                              Centroid()                              */
/************************************************************************/

int OGRPolygon::Centroid( OGRPoint * )

{
    // notdef ... not implemented yet.
    
    return OGRERR_FAILURE;
}

/************************************************************************/
/*                           PointOnSurface()                           */
/************************************************************************/

int OGRPolygon::PointOnSurface( OGRPoint * )

{
    // notdef ... not implemented yet.
    
    return OGRERR_FAILURE;
}

/************************************************************************/
/*                            getEnvelope()                             */
/************************************************************************/

void OGRPolygon::getEnvelope( OGREnvelope * psEnvelope )

{
    OGREnvelope         oRingEnv;
    
    if( nRingCount == 0 )
        return;

    papoRings[0]->getEnvelope( psEnvelope );

    for( int iRing = 1; iRing < nRingCount; iRing++ )
    {
        papoRings[iRing]->getEnvelope( &oRingEnv );

        if( psEnvelope->MinX > oRingEnv.MinX )
            psEnvelope->MinX = oRingEnv.MinX;
        if( psEnvelope->MinY > oRingEnv.MinY )
            psEnvelope->MinY = oRingEnv.MinY;
        if( psEnvelope->MaxX < oRingEnv.MaxX )
            psEnvelope->MaxX = oRingEnv.MaxX;
        if( psEnvelope->MaxY < oRingEnv.MaxY )
            psEnvelope->MaxY = oRingEnv.MaxY;
    }
}

/************************************************************************/
/*                               Equal()                                */
/************************************************************************/

OGRBoolean OGRPolygon::Equal( OGRGeometry * poOther )

{
    OGRPolygon *poOPoly = (OGRPolygon *) poOther;

    if( poOther == this )
        return TRUE;
    
    if( poOther->getGeometryType() != getGeometryType() )
        return FALSE;

    if( getNumInteriorRings() != poOPoly->getNumInteriorRings() )
        return FALSE;

    if( !getExteriorRing()->Equal( poOPoly->getExteriorRing() ) )
        return FALSE;
    
    // we should eventually test the SRS.

    for( int iRing = 0; iRing < getNumInteriorRings(); iRing++ )
    {
        if( !getInteriorRing(iRing)->Equal(poOPoly->getInteriorRing(iRing)) )
            return FALSE;
    }

    return TRUE;
}

/************************************************************************/
/*                             transform()                              */
/************************************************************************/

OGRErr OGRPolygon::transform( OGRCoordinateTransformation *poCT )

{
#ifdef DISABLE_OGRGEOM_TRANSFORM
    return OGRERR_FAILURE;
#else
    for( int iRing = 0; iRing < nRingCount; iRing++ )
    {
        OGRErr  eErr;

        eErr = papoRings[iRing]->transform( poCT );
        if( eErr != OGRERR_NONE )
        {
            if( iRing != 0 )
            {
                CPLDebug("OGR", 
                         "OGRPolygon::transform() failed for a ring other\n"
                         "than the first, meaning some rings are transformed\n"
                         "and some are not!\n" );

                return OGRERR_FAILURE;
            }

            return eErr;
        }
    }

    assignSpatialReference( poCT->GetTargetCS() );

    return OGRERR_NONE;
#endif
}