Esempio n. 1
0
GDALRasterBand *VRTRasterBand::GetOverview( int iOverview )

{
    // First: overviews declared in <Overview> element
    if( !m_apoOverviews.empty() )
    {
        if( iOverview < 0
            || iOverview >= static_cast<int>( m_apoOverviews.size() ) )
            return NULL;

        if( m_apoOverviews[iOverview].poBand == NULL
            && !m_apoOverviews[iOverview].bTriedToOpen )
        {
            m_apoOverviews[iOverview].bTriedToOpen = TRUE;

            GDALDataset *poSrcDS = reinterpret_cast<GDALDataset *>(
                GDALOpenShared( m_apoOverviews[iOverview].osFilename,
                                GA_ReadOnly ) );

            if( poSrcDS == NULL )
                return NULL;

            m_apoOverviews[iOverview].poBand = poSrcDS->GetRasterBand(
                m_apoOverviews[iOverview].nBand );

            if (m_apoOverviews[iOverview].poBand == NULL)
            {
                GDALClose( (GDALDatasetH)poSrcDS );
            }
        }

        return m_apoOverviews[iOverview].poBand;
    }

    // If not found, external .ovr overviews
    GDALRasterBand* poRet = GDALRasterBand::GetOverview( iOverview );
    if( poRet )
        return poRet;

    // If not found, implicit virtual overviews
    VRTDataset* poVRTDS = reinterpret_cast<VRTDataset *>( poDS );
    poVRTDS->BuildVirtualOverviews();
    if( !poVRTDS->m_apoOverviews.empty() && poVRTDS->m_apoOverviews[0] )
    {
        if( iOverview < 0
            || iOverview >= static_cast<int>( poVRTDS->m_apoOverviews.size() ) )
            return NULL;

        return poVRTDS->m_apoOverviews[iOverview]->GetRasterBand(nBand);
    }

    return NULL;
}
Esempio n. 2
0
GDALRasterBand *VRTRasterBand::GetOverview( int iOverview )

{
    // First: overviews declared in <Overview> element
    if( apoOverviews.size() > 0 )
    {
        if( iOverview < 0 || iOverview >= (int) apoOverviews.size() )
            return NULL;

        if( apoOverviews[iOverview].poBand == NULL 
            && !apoOverviews[iOverview].bTriedToOpen )
        {
            apoOverviews[iOverview].bTriedToOpen = TRUE;

            GDALDataset *poSrcDS = (GDALDataset *)
                GDALOpenShared( apoOverviews[iOverview].osFilename, GA_ReadOnly );
            
            if( poSrcDS == NULL )
                return NULL;

            apoOverviews[iOverview].poBand = poSrcDS->GetRasterBand( 
                apoOverviews[iOverview].nBand );

            if (apoOverviews[iOverview].poBand == NULL)
            {
                GDALClose( (GDALDatasetH)poSrcDS );
            }
        }

        return apoOverviews[iOverview].poBand;
    }
    
    // If not found, external .ovr overviews
    GDALRasterBand* poRet = GDALRasterBand::GetOverview( iOverview );
    if( poRet )
        return poRet;
    
    // If not found, implicit virtual overviews
    VRTDataset* poVRTDS = ((VRTDataset *)poDS);
    poVRTDS->BuildVirtualOverviews();
    if( poVRTDS->apoOverviews.size() && poVRTDS->apoOverviews[0] )
    {
        if( iOverview < 0 || iOverview >= (int) poVRTDS->apoOverviews.size() )
            return NULL;
        return poVRTDS->apoOverviews[iOverview]->GetRasterBand(nBand);
    }
    
    return NULL;
}
Esempio n. 3
0
int VRTRasterBand::GetOverviewCount()

{
    // First: overviews declared in <Overview> element
    if( !m_apoOverviews.empty() )
        return static_cast<int>(m_apoOverviews.size());

    // If not found, external .ovr overviews
    const int nOverviewCount = GDALRasterBand::GetOverviewCount();
    if( nOverviewCount )
        return nOverviewCount;

    // If not found, implicit virtual overviews
    VRTDataset* poVRTDS = reinterpret_cast<VRTDataset *>( poDS );
    poVRTDS->BuildVirtualOverviews();
    if( !poVRTDS->m_apoOverviews.empty() && poVRTDS->m_apoOverviews[0] )
        return static_cast<int>( poVRTDS->m_apoOverviews.size() );

    return 0;
}
Esempio n. 4
0
int VRTRasterBand::GetOverviewCount()

{
    // First: overviews declared in <Overview> element
    if( apoOverviews.size() > 0 )
        return apoOverviews.size();

    // If not found, external .ovr overviews
    int nOverviewCount = GDALRasterBand::GetOverviewCount();
    if( nOverviewCount )
        return nOverviewCount;

    // If not found, implicit virtual overviews
    VRTDataset* poVRTDS = ((VRTDataset *)poDS);
    poVRTDS->BuildVirtualOverviews();
    if( poVRTDS->apoOverviews.size() && poVRTDS->apoOverviews[0] )
        return (int)poVRTDS->apoOverviews.size();

    return 0;
}