ogrlayer.cpp

mitab,读取MapInfo的地图文件

/******************************************************************************
 * $Id: ogrlayer.cpp 10646 2007-01-18 02:38:10Z warmerdam $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  The generic portions of the OGRSFLayer class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 1999,  Les Technologies SoftMap Inc.
 *
 * 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.
 ****************************************************************************/

#include "ogrsf_frmts.h"
#include "ogr_api.h"
#include "ogr_p.h"
#include "ogr_attrind.h"

CPL_CVSID("$Id: ogrlayer.cpp 10646 2007-01-18 02:38:10Z warmerdam $");

/************************************************************************/
/*                              OGRLayer()                              */
/************************************************************************/

OGRLayer::OGRLayer()

{
    m_poStyleTable = NULL;
    m_poAttrQuery = NULL;
    m_poAttrIndex = NULL;
    m_nRefCount = 0;

    m_nFeaturesRead = 0;

    m_poFilterGeom = NULL;
    m_bFilterIsEnvelope = FALSE;
}

/************************************************************************/
/*                             ~OGRLayer()                              */
/************************************************************************/

OGRLayer::~OGRLayer()

{
    if ( m_poStyleTable )
    {
        delete m_poStyleTable;
        m_poStyleTable = NULL;
    }

    if( m_poAttrIndex != NULL )
    {
        delete m_poAttrIndex;
        m_poAttrIndex = NULL;
    }

    if( m_poAttrQuery != NULL )
    {
        delete m_poAttrQuery;
        m_poAttrQuery = NULL;
    }

    if( m_poFilterGeom )
    {
        delete m_poFilterGeom;
        m_poFilterGeom = NULL;
    }
}

/************************************************************************/
/*                             Reference()                              */
/************************************************************************/

int OGRLayer::Reference()

{
    return ++m_nRefCount;
}

/************************************************************************/
/*                          OGR_L_Reference()                           */
/************************************************************************/

int OGR_L_Reference( OGRLayerH hLayer )

{
    return ((OGRLayer *) hLayer)->Reference();
}

/************************************************************************/
/*                            Dereference()                             */
/************************************************************************/

int OGRLayer::Dereference()

{
    return --m_nRefCount;
}

/************************************************************************/
/*                         OGR_L_Dereference()                          */
/************************************************************************/

int OGR_L_Dereference( OGRLayerH hLayer )

{
    return ((OGRLayer *) hLayer)->Dereference();
}

/************************************************************************/
/*                            GetRefCount()                             */
/************************************************************************/

int OGRLayer::GetRefCount() const

{
    return m_nRefCount;
}

/************************************************************************/
/*                         OGR_L_GetRefCount()                          */
/************************************************************************/

int OGR_L_GetRefCount( OGRLayerH hLayer )

{
    return ((OGRLayer *) hLayer)->GetRefCount();
}

/************************************************************************/
/*                          GetFeatureCount()                           */
/************************************************************************/

int OGRLayer::GetFeatureCount( int bForce )

{
    OGRFeature     *poFeature;
    int            nFeatureCount = 0;

    if( !bForce )
        return -1;

    ResetReading();
    while( (poFeature = GetNextFeature()) != NULL )
    {
        nFeatureCount++;
        delete poFeature;
    }
    ResetReading();

    return nFeatureCount;
}

/************************************************************************/
/*                       OGR_L_GetFeatureCount()                        */
/************************************************************************/

int OGR_L_GetFeatureCount( OGRLayerH hLayer, int bForce )

{
    return ((OGRLayer *) hLayer)->GetFeatureCount(bForce);
}

/************************************************************************/
/*                             GetExtent()                              */
/************************************************************************/

OGRErr OGRLayer::GetExtent(OGREnvelope *psExtent, int bForce )

{
    OGRFeature  *poFeature;
    OGREnvelope oEnv;
    GBool       bExtentSet = FALSE;

/* -------------------------------------------------------------------- */
/*      If this layer has a none geometry type, then we can             */
/*      reasonably assume there are not extents available.              */
/* -------------------------------------------------------------------- */
    if( GetLayerDefn()->GetGeomType() == wkbNone )
    {
        psExtent->MinX = 0.0;
        psExtent->MaxX = 0.0;
        psExtent->MinY = 0.0;
        psExtent->MaxY = 0.0;
        
        return OGRERR_FAILURE;
    }

/* -------------------------------------------------------------------- */
/*      If not forced, we should avoid having to scan all the           */
/*      features and just return a failure.                             */
/* -------------------------------------------------------------------- */
    if( !bForce )
        return OGRERR_FAILURE;

/* -------------------------------------------------------------------- */
/*      OK, we hate to do this, but go ahead and read through all       */
/*      the features to collect geometries and build extents.           */
/* -------------------------------------------------------------------- */
    ResetReading();
    while( (poFeature = GetNextFeature()) != NULL )
    {
        OGRGeometry *poGeom = poFeature->GetGeometryRef();
        if (poGeom && !bExtentSet)
        {
            poGeom->getEnvelope(psExtent);
            bExtentSet = TRUE;
        }
        else if (poGeom)
        {
            poGeom->getEnvelope(&oEnv);
            if (oEnv.MinX < psExtent->MinX) 
                psExtent->MinX = oEnv.MinX;
            if (oEnv.MinY < psExtent->MinY) 
                psExtent->MinY = oEnv.MinY;
            if (oEnv.MaxX > psExtent->MaxX) 
                psExtent->MaxX = oEnv.MaxX;
            if (oEnv.MaxY > psExtent->MaxY) 
                psExtent->MaxY = oEnv.MaxY;
        }
        delete poFeature;
    }
    ResetReading();

    return (bExtentSet ? OGRERR_NONE : OGRERR_FAILURE);
}

/************************************************************************/
/*                          OGR_L_GetExtent()                           */
/************************************************************************/

OGRErr OGR_L_GetExtent( OGRLayerH hLayer, OGREnvelope *psExtent, int bForce )

{
    return ((OGRLayer *) hLayer)->GetExtent( psExtent, bForce );
}

/************************************************************************/
/*                         SetAttributeFilter()                         */
/************************************************************************/

OGRErr OGRLayer::SetAttributeFilter( const char *pszQuery )

{
/* -------------------------------------------------------------------- */
/*      Are we just clearing any existing query?                        */
/* -------------------------------------------------------------------- */
    if( pszQuery == NULL || strlen(pszQuery) == 0 )
    {
        if( m_poAttrQuery )
        {
            delete m_poAttrQuery;
            m_poAttrQuery = NULL;
            ResetReading();
        }
        return OGRERR_NONE;
    }

/* -------------------------------------------------------------------- */
/*      Or are we installing a new query?                               */
/* -------------------------------------------------------------------- */
    OGRErr      eErr;

    if( !m_poAttrQuery )
        m_poAttrQuery = new OGRFeatureQuery();

    eErr = m_poAttrQuery->Compile( GetLayerDefn(), pszQuery );
    if( eErr != OGRERR_NONE )
    {
        delete m_poAttrQuery;
        m_poAttrQuery = NULL;
    }

    ResetReading();

    return eErr;
}

/************************************************************************/
/*                      OGR_L_SetAttributeFilter()                      */