ogrct.cpp

mitab,读取MapInfo的地图文件

/************************************************************************/
/*                             Initialize()                             */
/************************************************************************/

int OGRProj4CT::Initialize( OGRSpatialReference * poSourceIn, 
                            OGRSpatialReference * poTargetIn )

{
    CPLMutexHolderD( &hPROJMutex );

    if( poSourceIn == NULL || poTargetIn == NULL )
        return FALSE;

    poSRSSource = poSourceIn->Clone();
    poSRSTarget = poTargetIn->Clone();

    bSourceLatLong = poSRSSource->IsGeographic();
    bTargetLatLong = poSRSTarget->IsGeographic();

/* -------------------------------------------------------------------- */
/*      Setup source and target translations to radians for lat/long    */
/*      systems.                                                        */
/* -------------------------------------------------------------------- */
    dfSourceToRadians = DEG_TO_RAD;
    dfSourceFromRadians = RAD_TO_DEG;
    bSourceWrap = FALSE;
    dfSourceWrapLong = 0.0;

    if( bSourceLatLong )
    {
        OGR_SRSNode *poUNITS = poSRSSource->GetAttrNode( "GEOGCS|UNIT" );
        if( poUNITS && poUNITS->GetChildCount() >= 2 )
        {
            dfSourceToRadians = atof(poUNITS->GetChild(1)->GetValue());
            if( dfSourceToRadians == 0.0 )
                dfSourceToRadians = DEG_TO_RAD;
            else
                dfSourceFromRadians = 1 / dfSourceToRadians;
        }
    }

    dfTargetToRadians = DEG_TO_RAD;
    dfTargetFromRadians = RAD_TO_DEG;
    bTargetWrap = FALSE;
    dfTargetWrapLong = 0.0;

    if( bTargetLatLong )
    {
        OGR_SRSNode *poUNITS = poSRSTarget->GetAttrNode( "GEOGCS|UNIT" );
        if( poUNITS && poUNITS->GetChildCount() >= 2 )
        {
            dfTargetToRadians = atof(poUNITS->GetChild(1)->GetValue());
            if( dfTargetToRadians == 0.0 )
                dfTargetToRadians = DEG_TO_RAD;
            else
                dfTargetFromRadians = 1 / dfTargetToRadians;
        }
    }

/* -------------------------------------------------------------------- */
/*      Preliminary logic to setup wrapping.                            */
/* -------------------------------------------------------------------- */
    const char *pszCENTER_LONG;

    if( CPLGetConfigOption( "CENTER_LONG", NULL ) != NULL )
    {
        bSourceWrap = bTargetWrap = TRUE;
        dfSourceWrapLong = dfTargetWrapLong = 
            atof(CPLGetConfigOption( "CENTER_LONG", "" ));
        CPLDebug( "OGRCT", "Wrap at %g.", dfSourceWrapLong );
    }

    pszCENTER_LONG = poSRSSource->GetExtension( "GEOGCS", "CENTER_LONG" );
    if( pszCENTER_LONG != NULL )
    {
        dfSourceWrapLong = atof(pszCENTER_LONG);
        bSourceWrap = TRUE;
        CPLDebug( "OGRCT", "Wrap source at %g.", dfSourceWrapLong );
    }

    pszCENTER_LONG = poSRSTarget->GetExtension( "GEOGCS", "CENTER_LONG" );
    if( pszCENTER_LONG != NULL )
    {
        dfTargetWrapLong = atof(pszCENTER_LONG);
        bTargetWrap = TRUE;
        CPLDebug( "OGRCT", "Wrap target at %g.", dfTargetWrapLong );
    }

/* -------------------------------------------------------------------- */
/*      Establish PROJ.4 handle for source if projection.               */
/* -------------------------------------------------------------------- */
    char        *pszProj4Defn;

    if( poSRSSource->exportToProj4( &pszProj4Defn ) != OGRERR_NONE )
        return FALSE;

    if( strlen(pszProj4Defn) == 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "No PROJ.4 translation for source SRS, coordinate\n"
                  "transformation initialization has failed." );
        return FALSE;
    }

    psPJSource = pfn_pj_init_plus( pszProj4Defn );
    
    if( psPJSource == NULL )
    {
        if( pfn_pj_get_errno_ref != NULL
            && pfn_pj_strerrno != NULL )
        {
            int *p_pj_errno = pfn_pj_get_errno_ref();

            CPLError( CE_Failure, CPLE_NotSupported, 
                      "Failed to initialize PROJ.4 with `%s'.\n%s", 
                      pszProj4Defn, pfn_pj_strerrno(*p_pj_errno) );
        }
        else
        {
            CPLError( CE_Failure, CPLE_NotSupported, 
                      "Failed to initialize PROJ.4 with `%s'.\n", 
                      pszProj4Defn );
        }
    }
    
    CPLFree( pszProj4Defn );
    
    if( psPJSource == NULL )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Establish PROJ.4 handle for target if projection.               */
/* -------------------------------------------------------------------- */
    if( poSRSTarget->exportToProj4( &pszProj4Defn ) != OGRERR_NONE )
        return FALSE;

    if( strlen(pszProj4Defn) == 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "No PROJ.4 translation for destination SRS, coordinate\n"
                  "transformation initialization has failed." );
        return FALSE;
    }

    psPJTarget = pfn_pj_init_plus( pszProj4Defn );
    
    if( psPJTarget == NULL )
        CPLError( CE_Failure, CPLE_NotSupported, 
                  "Failed to initialize PROJ.4 with `%s'.", 
                  pszProj4Defn );
    
    CPLFree( pszProj4Defn );
    
    if( psPJTarget == NULL )
        return FALSE;

    return TRUE;
}

/************************************************************************/
/*                            GetSourceCS()                             */
/************************************************************************/

OGRSpatialReference *OGRProj4CT::GetSourceCS()

{
    return poSRSSource;
}

/************************************************************************/
/*                            GetTargetCS()                             */
/************************************************************************/

OGRSpatialReference *OGRProj4CT::GetTargetCS()

{
    return poSRSTarget;
}

/************************************************************************/
/*                             Transform()                              */
/*                                                                      */
/*      This is a small wrapper for the extended transform version.     */
/************************************************************************/

int OGRProj4CT::Transform( int nCount, double *x, double *y, double *z )

{
    int *pabSuccess = (int *) CPLMalloc(sizeof(int) * nCount );
    int bOverallSuccess, i;

    bOverallSuccess = TransformEx( nCount, x, y, z, pabSuccess );

    for( i = 0; i < nCount; i++ )
    {
        if( !pabSuccess[i] )
        {
            bOverallSuccess = FALSE;
            break;
        }
    }

    CPLFree( pabSuccess );

    return bOverallSuccess;
}

/************************************************************************/
/*                            OCTTransform()                            */
/************************************************************************/

int CPL_STDCALL OCTTransform( OGRCoordinateTransformationH hTransform,
                              int nCount, double *x, double *y, double *z )

{
    return ((OGRCoordinateTransformation*) hTransform)->
        Transform( nCount, x, y,z );
}

/************************************************************************/
/*                            TransformEx()                             */
/************************************************************************/

int OGRProj4CT::TransformEx( int nCount, double *x, double *y, double *z,
                             int *pabSuccess )

{
    int   err, i;

/* -------------------------------------------------------------------- */
/*      Potentially transform to radians.                               */
/* -------------------------------------------------------------------- */
    if( bSourceLatLong )
    {
        if( bSourceWrap )
        {
            for( i = 0; i < nCount; i++ )
            {
                if( x[i] != HUGE_VAL && y[i] != HUGE_VAL )
                {
                    if( x[i] < dfSourceWrapLong - 180.0 )
                        x[i] += 360.0;
                    else if( x[i] > dfSourceWrapLong + 180 )
                        x[i] -= 360.0;
                }
            }
        }

        for( i = 0; i < nCount; i++ )
        {
            if( x[i] != HUGE_VAL )
            {
                x[i] *= dfSourceToRadians;
                y[i] *= dfSourceToRadians;
            }
        }
    }

/* -------------------------------------------------------------------- */
/*      Do the transformation using PROJ.4.                             */
/* -------------------------------------------------------------------- */
    CPLMutexHolderD( &hPROJMutex );
    err = pfn_pj_transform( psPJSource, psPJTarget, nCount, 1, x, y, z );

/* -------------------------------------------------------------------- */
/*      Try to report an error through CPL.  Get proj.4 error string    */
/*      if possible.  Try to avoid reporting thousands of error         */
/*      ... supress further error reporting on this OGRProj4CT if we    */
/*      have already reported 20 errors.                                */
/* -------------------------------------------------------------------- */
    if( err != 0 )
    {
        if( pabSuccess )
            memset( pabSuccess, 0, sizeof(int) * nCount );

        if( ++nErrorCount < 20 )
        {
            const char *pszError = NULL;
            if( pfn_pj_strerrno != NULL )
                pszError = pfn_pj_strerrno( err );
            
            if( pszError == NULL )
                CPLError( CE_Failure, CPLE_AppDefined, 
                          "Reprojection failed, err = %d", 
                          err );
            else
                CPLError( CE_Failure, CPLE_AppDefined, "%s", pszError );
        }
        else if( nErrorCount == 20 )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Reprojection failed, err = %d, further errors will be supressed on the transform object.", 
                      err );
        }

        return FALSE;
    }

/* -------------------------------------------------------------------- */
/*      Potentially transform back to degrees.                          */
/* -------------------------------------------------------------------- */
    if( bTargetLatLong )
    {
        for( i = 0; i < nCount; i++ )
        {
            if( x[i] != HUGE_VAL && y[i] != HUGE_VAL )
            {
                x[i] *= dfTargetFromRadians;
                y[i] *= dfTargetFromRadians;
            }
        }

        if( bTargetWrap )
        {
            for( i = 0; i < nCount; i++ )
            {
                if( x[i] != HUGE_VAL && y[i] != HUGE_VAL )
                {
                    if( x[i] < dfTargetWrapLong - 180.0 )
                        x[i] += 360.0;
                    else if( x[i] > dfTargetWrapLong + 180 )
                        x[i] -= 360.0;
                }
            }
        }
    }

/* -------------------------------------------------------------------- */
/*      Establish error information if pabSuccess provided.             */
/* -------------------------------------------------------------------- */
    if( pabSuccess )
    {
        for( i = 0; i < nCount; i++ )
        {
            if( x[i] == HUGE_VAL || y[i] == HUGE_VAL )
                pabSuccess[i] = FALSE;
            else
                pabSuccess[i] = TRUE;
        }
    }

    return TRUE;
}

/************************************************************************/
/*                           OCTTransformEx()                           */
/************************************************************************/

int CPL_STDCALL OCTTransformEx( OGRCoordinateTransformationH hTransform,
                                int nCount, double *x, double *y, double *z,
                                int *pabSuccess )

{
    return ((OGRCoordinateTransformation*) hTransform)->
        TransformEx( nCount, x, y, z, pabSuccess );
}