gml2ogrgeometry.cpp

用于读取TAB、MIF、SHP文件的类

/************************************************************************/
/*                      GML2OGRGeometry_XMLNode()                       */
/*                                                                      */
/*      Translates the passed XMLnode and it's children into an         */
/*      OGRGeometry.  This is used recursively for geometry             */
/*      collections.                                                    */
/************************************************************************/

static OGRGeometry *GML2OGRGeometry_XMLNode( CPLXMLNode *psNode )

{
    const char *pszBaseGeometry = BareGMLElement( psNode->pszValue );

/* -------------------------------------------------------------------- */
/*      Polygon                                                         */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"Polygon") )
    {
        CPLXMLNode *psChild;
        OGRPolygon *poPolygon = new OGRPolygon();
        OGRLinearRing *poRing;

        // Find outer ring.
        psChild = FindBareXMLChild( psNode, "outerBoundaryIs" );
        if( psChild == NULL || psChild->psChild == NULL )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Missing outerBoundaryIs property on Polygon." );
            delete poPolygon;
            return NULL;
        }

        // Translate outer ring and add to polygon.
        poRing = (OGRLinearRing *) 
            GML2OGRGeometry_XMLNode( psChild->psChild );
        if( poRing == NULL )
        {
            delete poPolygon;
            return NULL;
        }

        if( !EQUAL(poRing->getGeometryName(),"LINEARRING") )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Got %.500s geometry as outerBoundaryIs instead of LINEARRING.",
                      poRing->getGeometryName() );
            delete poPolygon;
            delete poRing;
            return NULL;
        }

        poPolygon->addRingDirectly( poRing );

        // Find all inner rings 
        for( psChild = psNode->psChild; 
             psChild != NULL;
             psChild = psChild->psNext ) 
        {
            if( psChild->eType == CXT_Element
                && EQUAL(BareGMLElement(psChild->pszValue),"innerBoundaryIs") )
            {
                poRing = (OGRLinearRing *) 
                    GML2OGRGeometry_XMLNode( psChild->psChild );
                if( !EQUAL(poRing->getGeometryName(),"LINEARRING") )
                {
                    CPLError( CE_Failure, CPLE_AppDefined, 
                              "Got %.500s geometry as innerBoundaryIs instead of LINEARRING.",
                              poRing->getGeometryName() );
                    delete poPolygon;
                    delete poRing;
                    return NULL;
                }

                poPolygon->addRingDirectly( poRing );
            }
        }

        return poPolygon;
    }

/* -------------------------------------------------------------------- */
/*      LinearRing                                                      */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"LinearRing") )
    {
        OGRLinearRing   *poLinearRing = new OGRLinearRing();
        
        if( !ParseGMLCoordinates( psNode, poLinearRing ) )
        {
            delete poLinearRing;
            return NULL;
        }

        return poLinearRing;
    }

/* -------------------------------------------------------------------- */
/*      LineString                                                      */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"LineString") )
    {
        OGRLineString   *poLine = new OGRLineString();
        
        if( !ParseGMLCoordinates( psNode, poLine ) )
        {
            delete poLine;
            return NULL;
        }

        return poLine;
    }

/* -------------------------------------------------------------------- */
/*      PointType                                                       */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"PointType") 
        || EQUAL(pszBaseGeometry,"Point") )
    {
        OGRPoint *poPoint = new OGRPoint();
        
        if( !ParseGMLCoordinates( psNode, poPoint ) )
        {
            delete poPoint;
            return NULL;
        }

        return poPoint;
    }

/* -------------------------------------------------------------------- */
/*      Box                                                             */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"BoxType") || EQUAL(pszBaseGeometry,"Box") )
    {
        OGRLineString  oPoints;

        if( !ParseGMLCoordinates( psNode, &oPoints ) )
            return NULL;

        if( oPoints.getNumPoints() < 2 )
            return NULL;

        OGRLinearRing *poBoxRing = new OGRLinearRing();
        OGRPolygon *poBoxPoly = new OGRPolygon();

        poBoxRing->setNumPoints( 5 );
        poBoxRing->setPoint( 
            0, oPoints.getX(0), oPoints.getY(0), oPoints.getZ(0) );
        poBoxRing->setPoint( 
            1, oPoints.getX(1), oPoints.getY(0), oPoints.getZ(0) );
        poBoxRing->setPoint( 
            2, oPoints.getX(1), oPoints.getY(1), oPoints.getZ(1) );
        poBoxRing->setPoint( 
            3, oPoints.getX(0), oPoints.getY(1), oPoints.getZ(0) );
        poBoxRing->setPoint( 
            4, oPoints.getX(0), oPoints.getY(0), oPoints.getZ(0) );

        poBoxPoly->addRingDirectly( poBoxRing );

        return poBoxPoly;
    }

/* -------------------------------------------------------------------- */
/*      MultiPolygon                                                    */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"MultiPolygon") )
    {
        CPLXMLNode *psChild;
        OGRMultiPolygon *poMPoly = new OGRMultiPolygon();

        // Find all inner rings 
        for( psChild = psNode->psChild; 
             psChild != NULL;
             psChild = psChild->psNext ) 
        {
            if( psChild->eType == CXT_Element
                && EQUAL(BareGMLElement(psChild->pszValue),"polygonMember") )
            {
                OGRPolygon *poPolygon;

                poPolygon = (OGRPolygon *) 
                    GML2OGRGeometry_XMLNode( psChild->psChild );

                if( poPolygon == NULL )
                {
                    delete poMPoly;
                    return NULL;
                }

                if( !EQUAL(poPolygon->getGeometryName(),"POLYGON") )
                {
                    CPLError( CE_Failure, CPLE_AppDefined, 
                              "Got %.500s geometry as polygonMember instead of MULTIPOLYGON.",
                              poPolygon->getGeometryName() );
                    delete poPolygon;
                    delete poMPoly;
                    return NULL;
                }

                poMPoly->addGeometryDirectly( poPolygon );
            }
        }

        return poMPoly;
    }

/* -------------------------------------------------------------------- */
/*      MultiPoint                                                      */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"MultiPoint") )
    {
        CPLXMLNode *psChild;
        OGRMultiPoint *poMP = new OGRMultiPoint();

        // collect points.
        for( psChild = psNode->psChild; 
             psChild != NULL;
             psChild = psChild->psNext ) 
        {
            if( psChild->eType == CXT_Element
                && EQUAL(BareGMLElement(psChild->pszValue),"pointMember") )
            {
                OGRPoint *poPoint;

                poPoint = (OGRPoint *) 
                    GML2OGRGeometry_XMLNode( psChild->psChild );
                if( poPoint == NULL 
                    || wkbFlatten(poPoint->getGeometryType()) != wkbPoint )
                {
                    CPLError( CE_Failure, CPLE_AppDefined, 
                              "Got %.500s geometry as pointMember instead of MULTIPOINT",
                              poPoint ? poPoint->getGeometryName() : "NULL" );
                    delete poPoint;
                    delete poMP;
                    return NULL;
                }

                poMP->addGeometryDirectly( poPoint );
            }
        }

        return poMP;
    }

/* -------------------------------------------------------------------- */
/*      MultiLineString                                                 */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"MultiLineString") )
    {
        CPLXMLNode *psChild;
        OGRMultiLineString *poMP = new OGRMultiLineString();

        // collect lines
        for( psChild = psNode->psChild; 
             psChild != NULL;
             psChild = psChild->psNext ) 
        {
            if( psChild->eType == CXT_Element
                && EQUAL(BareGMLElement(psChild->pszValue),"lineStringMember") )
            {
                OGRGeometry *poGeom;

                poGeom = GML2OGRGeometry_XMLNode( psChild->psChild );
                if( poGeom == NULL 
                    || wkbFlatten(poGeom->getGeometryType()) != wkbLineString )
                {
                    CPLError( CE_Failure, CPLE_AppDefined, 
                              "Got %.500s geometry as Member instead of LINESTRING.",
                              poGeom ? poGeom->getGeometryName() : "NULL" );
                    delete poGeom;
                    delete poMP;
                    return NULL;
                }

                poMP->addGeometryDirectly( poGeom );
            }
        }

        return poMP;
    }

/* -------------------------------------------------------------------- */
/*      GeometryCollection                                              */
/* -------------------------------------------------------------------- */
    if( EQUAL(pszBaseGeometry,"GeometryCollection") )
    {
        CPLXMLNode *psChild;
        OGRGeometryCollection *poGC = new OGRGeometryCollection();

        // collect geoms
        for( psChild = psNode->psChild; 
             psChild != NULL;
             psChild = psChild->psNext ) 
        {
            if( psChild->eType == CXT_Element
                && EQUAL(BareGMLElement(psChild->pszValue),"geometryMember") )
            {
                OGRGeometry *poGeom;

                poGeom = GML2OGRGeometry_XMLNode( psChild->psChild );
                if( poGeom == NULL )
                {
                    CPLError( CE_Failure, CPLE_AppDefined, 
                              "Failed to get geometry in geometryMember" );
                    delete poGeom;
                    delete poGC;
                    return NULL;
                }

                poGC->addGeometryDirectly( poGeom );
            }
        }

        return poGC;
    }

    CPLError( CE_Failure, CPLE_AppDefined, 
              "Unrecognised geometry type <%.500s>.", 
              pszBaseGeometry );

    return NULL;
}

/************************************************************************/
/*                      OGR_G_CreateFromGMLTree()                       */
/************************************************************************/

OGRGeometryH OGR_G_CreateFromGMLTree( const CPLXMLNode *psTree )

{
    return (OGRGeometryH) GML2OGRGeometry_XMLNode( (CPLXMLNode *) psTree );
}

/************************************************************************/
/*                        OGR_G_CreateFromGML()                         */
/************************************************************************/

OGRGeometryH OGR_G_CreateFromGML( const char *pszGML )

{
    if( pszGML == NULL || strlen(pszGML) == 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "GML Geometry is empty in GML2OGRGeometry()." );
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Try to parse the XML snippet using the MiniXML API.  If this    */
/*      fails, we assume the minixml api has already posted a CPL       */
/*      error, and just return NULL.                                    */
/* -------------------------------------------------------------------- */
    CPLXMLNode *psGML = CPLParseXMLString( pszGML );

    if( psGML == NULL )
        return NULL;

/* -------------------------------------------------------------------- */
/*      Convert geometry recursively.                                   */
/* -------------------------------------------------------------------- */
    OGRGeometry *poGeometry;

    poGeometry = GML2OGRGeometry_XMLNode( psGML );

    CPLDestroyXMLNode( psGML );
    
    return (OGRGeometryH) poGeometry;
}