示例#1
0
GDALDataset *NWT_GRDDataset::Open( GDALOpenInfo * poOpenInfo )
{
    if( !Identify(poOpenInfo) )
        return NULL;

/* -------------------------------------------------------------------- */
/*      Create a corresponding GDALDataset.                             */
/* -------------------------------------------------------------------- */
    NWT_GRDDataset *poDS;

    poDS = new NWT_GRDDataset();

    poDS->fp = VSIFOpenL(poOpenInfo->pszFilename, "rb");
    if (poDS->fp == NULL)
    {
        delete poDS;
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Read the header.                                                */
/* -------------------------------------------------------------------- */
    VSIFSeekL( poDS->fp, 0, SEEK_SET );
    VSIFReadL( poDS->abyHeader, 1, 1024, poDS->fp );
    poDS->pGrd = (NWT_GRID *) malloc(sizeof(NWT_GRID));
    if (!nwt_ParseHeader( poDS->pGrd, (char *) poDS->abyHeader ) ||
        !GDALCheckDatasetDimensions(poDS->pGrd->nXSide, poDS->pGrd->nYSide) )
    {
        delete poDS;
        return NULL;
    }

    poDS->nRasterXSize = poDS->pGrd->nXSide;
    poDS->nRasterYSize = poDS->pGrd->nYSide;

// create a colorTable
  // if( poDS->pGrd->iNumColorInflections > 0 )
  //   poDS->CreateColorTable();
  nwt_LoadColors( poDS->ColorMap, 4096, poDS->pGrd );
/* -------------------------------------------------------------------- */
/*      Create band information objects.                                */
/* -------------------------------------------------------------------- */
    poDS->SetBand( 1, new NWT_GRDRasterBand( poDS, 1 ) );    //r
    poDS->SetBand( 2, new NWT_GRDRasterBand( poDS, 2 ) );    //g
    poDS->SetBand( 3, new NWT_GRDRasterBand( poDS, 3 ) );    //b
    poDS->SetBand( 4, new NWT_GRDRasterBand( poDS, 4 ) );    //z

/* -------------------------------------------------------------------- */
/*      Initialize any PAM information.                                 */
/* -------------------------------------------------------------------- */
    poDS->SetDescription( poOpenInfo->pszFilename );
    poDS->TryLoadXML();

/* -------------------------------------------------------------------- */
/*      Check for external overviews.                                   */
/* -------------------------------------------------------------------- */
    poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename, poOpenInfo->papszSiblingFiles );

    return (poDS);
}
GDALDataset *NWT_GRDDataset::Open( GDALOpenInfo * poOpenInfo )
{
/* -------------------------------------------------------------------- */
/*  Look for the header                                                 */
/* -------------------------------------------------------------------- */
    if( poOpenInfo->fp == NULL || poOpenInfo->nHeaderBytes < 50 )
        return NULL;

    if( poOpenInfo->pabyHeader[0] != 'H' ||
        poOpenInfo->pabyHeader[1] != 'G' ||
        poOpenInfo->pabyHeader[2] != 'P' ||
        poOpenInfo->pabyHeader[3] != 'C' || poOpenInfo->pabyHeader[4] != '1' )
    return NULL;

/* -------------------------------------------------------------------- */
/*      Create a corresponding GDALDataset.                             */
/* -------------------------------------------------------------------- */
    NWT_GRDDataset *poDS;

    poDS = new NWT_GRDDataset();

    poDS->fp = poOpenInfo->fp;
    poOpenInfo->fp = NULL;

/* -------------------------------------------------------------------- */
/*      Read the header.                                                */
/* -------------------------------------------------------------------- */
    VSIFSeek( poDS->fp, 0, SEEK_SET );
    VSIFRead( poDS->abyHeader, 1, 1024, poDS->fp );
    poDS->pGrd = (NWT_GRID *) malloc(sizeof(NWT_GRID));
    if (!nwt_ParseHeader( poDS->pGrd, (char *) poDS->abyHeader ) ||
        !GDALCheckDatasetDimensions(poDS->pGrd->nXSide, poDS->pGrd->nYSide) )
    {
        delete poDS;
        return NULL;
    }

    poDS->nRasterXSize = poDS->pGrd->nXSide;
    poDS->nRasterYSize = poDS->pGrd->nYSide;

// create a colorTable
  // if( poDS->pGrd->iNumColorInflections > 0 )
  //   poDS->CreateColorTable();
  nwt_LoadColors( poDS->ColorMap, 4096, poDS->pGrd );
/* -------------------------------------------------------------------- */
/*      Create band information objects.                                */
/* -------------------------------------------------------------------- */
    poDS->SetBand( 1, new NWT_GRDRasterBand( poDS, 1 ) );    //r
    poDS->SetBand( 2, new NWT_GRDRasterBand( poDS, 2 ) );    //g
    poDS->SetBand( 3, new NWT_GRDRasterBand( poDS, 3 ) );    //b
    poDS->SetBand( 4, new NWT_GRDRasterBand( poDS, 4 ) );    //z

/* -------------------------------------------------------------------- */
/*      Initialize any PAM information.                                 */
/* -------------------------------------------------------------------- */
    poDS->SetDescription( poOpenInfo->pszFilename );
    poDS->TryLoadXML();

    return (poDS);
}