ogrogdilayer.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

/******************************************************************************
 * $Id: ogrogdilayer.cpp,v 1.9 2005/02/22 13:08:54 fwarmerdam Exp $
 *
 * Project:  OGDI Bridge
 * Purpose:  Implements OGROGDILayer class.
 * Author:   Daniel Morissette, [e-mail]
 *           (Based on some code contributed by Frank Warmerdam :)
 *
 ******************************************************************************
 * Copyright (c) 2000, Daniel Morissette
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ******************************************************************************
 *
 * $Log: ogrogdilayer.cpp,v $
 * Revision 1.9  2005/02/22 13:08:54  fwarmerdam
 * use OGRLayer base spatial filter support
 *
 * Revision 1.8  2005/02/02 20:54:27  fwarmerdam
 * track m_nFeaturesRead
 *
 * Revision 1.7  2003/08/11 14:17:22  warmerda
 * Trim leading spaces from attributes values.  Attributes from OGDI
 * that were quoted (such as { FA001 } from NOAMER/VRF) were exceeding the
 * field width.  I kind of wonder if the VRF driver was behaving improperly
 * in returning the extra quoted spaces, but in any event it seems prudent
 * to trim them.
 *
 * http://bugzilla.remotesensing.org/show_bug.cgi?id=372
 *
 * Revision 1.6  2003/05/21 03:58:49  warmerda
 * expand tabs
 *
 * Revision 1.5  2001/07/18 04:55:16  warmerda
 * added CPL_CSVID
 *
 * Revision 1.4  2001/06/19 15:50:23  warmerda
 * added feature attribute query support
 *
 * Revision 1.3  2001/04/17 21:41:02  warmerda
 * Added use of cln_GetLayerCapabilities() to query list of available layers.
 * Restructured OGROGDIDataSource and OGROGDILayer classes somewhat to
 * avoid passing so much information in the layer creation call.  Added support
 * for preserving text on OGDI text features.
 *
 * Revision 1.2  2000/08/30 01:36:57  danmo
 * Added GetSpatialRef() support
 *
 * Revision 1.1  2000/08/24 04:16:19  danmo
 * Initial revision
 *
 */

#include "ogrogdi.h"
#include "cpl_conv.h"
#include "cpl_string.h"

CPL_CVSID("$Id: ogrogdilayer.cpp,v 1.9 2005/02/22 13:08:54 fwarmerdam Exp $");

/************************************************************************/
/*                           OGROGDILayer()                            */
/************************************************************************/

OGROGDILayer::OGROGDILayer( OGROGDIDataSource *poODS, 
                            const char * pszName, ecs_Family eFamily )

{
    m_poODS = poODS;
    m_nClientID = m_poODS->GetClientID();
    m_eFamily = eFamily;

    m_pszOGDILayerName = CPLStrdup(pszName);

    m_sFilterBounds = *(m_poODS->GetGlobalBounds());

    m_iNextShapeId = 0;
    m_nTotalShapeCount = -1;
    m_poFeatureDefn = NULL;

    // Keep a reference on the SpatialRef (owned by the dataset).
    m_poSpatialRef = m_poODS->GetSpatialRef();

    // Select layer and feature family.
    ResetReading();

    BuildFeatureDefn();
}

/************************************************************************/
/*                           ~OGROGDILayer()                           */
/************************************************************************/

OGROGDILayer::~OGROGDILayer()

{
    if( m_nFeaturesRead > 0 && m_poFeatureDefn != NULL )
    {
        CPLDebug( "OGDI", "%d features read on layer '%s'.",
                  (int) m_nFeaturesRead, 
                  m_poFeatureDefn->GetName() );
    }

    if (m_poFeatureDefn)
        delete m_poFeatureDefn;

    CPLFree(m_pszOGDILayerName);

    // Note: we do not delete m_poSpatialRef since it is owned by the dataset
}

/************************************************************************/
/*                          SetSpatialFilter()                          */
/************************************************************************/

void OGROGDILayer::SetSpatialFilter( OGRGeometry * poGeomIn )

{
    if( !InstallFilter( poGeomIn ) )
        return;

    if( m_poFilterGeom != NULL )
    {
        OGREnvelope     oEnv;
        ecs_Result     *psResult;

        m_poFilterGeom->getEnvelope(&oEnv);

        m_sFilterBounds.north = oEnv.MaxY;
        m_sFilterBounds.south = oEnv.MinY;
        m_sFilterBounds.east  = oEnv.MinX;
        m_sFilterBounds.west  = oEnv.MaxX;

        psResult = cln_SelectRegion( m_nClientID, &m_sFilterBounds);
        if( ECSERROR(psResult) )
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "%s", psResult->message );
            return;
        }
    }

    m_iNextShapeId = 0;
    m_nTotalShapeCount = -1;
}

/************************************************************************/
/*                            ResetReading()                            */
/************************************************************************/

void OGROGDILayer::ResetReading()

{
    ecs_Result *psResult;
    ecs_LayerSelection sSelectionLayer;

    sSelectionLayer.Select = m_pszOGDILayerName;
    sSelectionLayer.F = m_eFamily;

    psResult = cln_SelectLayer(m_nClientID, &sSelectionLayer);
    if( ECSERROR( psResult ) )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Access to layer '%s' Failed: \n",
                  m_pszOGDILayerName, psResult->message );
        return;
    }

    m_iNextShapeId = 0;

}

/************************************************************************/
/*                           GetNextFeature()                           */
/************************************************************************/

OGRFeature *OGROGDILayer::GetNextFeature()

{
    OGRFeature  *poFeature=NULL;
    ecs_Result  *psResult;
    int         i;

  TryAgain:
    if (m_nTotalShapeCount != -1 && m_iNextShapeId >= m_nTotalShapeCount )
        return NULL;
        
/* -------------------------------------------------------------------- */
/*      Retrieve object from OGDI server and create new feature         */
/* -------------------------------------------------------------------- */
    psResult = cln_GetNextObject(m_nClientID);
    if (! ECSSUCCESS(psResult))
    {
        // We probably reached EOF... keep track of shape count.
        m_nTotalShapeCount = m_iNextShapeId;
        return NULL;
    }
   
    poFeature = new OGRFeature(m_poFeatureDefn);

    poFeature->SetFID( m_iNextShapeId++ );
    m_nFeaturesRead++;

/* -------------------------------------------------------------------- */
/*      Process geometry                                                */
/* -------------------------------------------------------------------- */
    if (m_eFamily == Point)
    {
        ecs_Point       *psPoint = &(ECSGEOM(psResult).point);
        OGRPoint        *poOGRPoint = new OGRPoint(psPoint->c.x, psPoint->c.y);

        poFeature->SetGeometryDirectly(poOGRPoint);
    }
    else if (m_eFamily == Line)
    {
        ecs_Line        *psLine = &(ECSGEOM(psResult).line);
        OGRLineString   *poOGRLine = new OGRLineString();

        poOGRLine->setNumPoints( psLine->c.c_len );

        for( i=0; i < (int) psLine->c.c_len; i++ ) 
        {
            poOGRLine->setPoint(i, psLine->c.c_val[i].x, psLine->c.c_val[i].y);
        }

        poFeature->SetGeometryDirectly(poOGRLine);
    }
    else if (m_eFamily == Area)
    {
        ecs_Area        *psArea = &(ECSGEOM(psResult).area);
        OGRPolygon      *poOGRPolygon = new OGRPolygon();

        for(int iRing=0; iRing < (int) psArea->ring.ring_len; iRing++)
        {
            ecs_FeatureRing     *psRing = &(psArea->ring.ring_val[iRing]);
            OGRLinearRing       *poOGRRing = new OGRLinearRing();

            poOGRRing->setNumPoints( psRing->c.c_len );

            for( i=0; i < (int) psRing->c.c_len; i++ ) 
            {
                poOGRRing->setPoint(i, psRing->c.c_val[i].x, 
                                    psRing->c.c_val[i].y);
            }
            poOGRPolygon->addRingDirectly(poOGRRing);
        }

        // __TODO__
        // When OGR supports polygon centroids then we should carry them here

        poFeature->SetGeometryDirectly(poOGRPolygon);
    }
    else if (m_eFamily == Text)
    {
        // __TODO__
        // For now text is treated as a point and string is lost
        //
        ecs_Text       *psText = &(ECSGEOM(psResult).text);
        OGRPoint        *poOGRPoint = new OGRPoint(psText->c.x, psText->c.y);

        poFeature->SetGeometryDirectly(poOGRPoint);
    }
    else
    {
        CPLAssert(FALSE);