GXFDataset::~GXFDataset()
{
FlushCache();
if( hGXF != NULL )
GXFClose( hGXF );
CPLFree( pszProjection );
}
GXFHandle GXFOpen( const char * pszFilename )
{
FILE *fp;
GXFInfo_t *psGXF;
char szTitle[71];
char **papszList;
int nHeaderCount = 0;
/* -------------------------------------------------------------------- */
/* We open in binary to ensure that we can efficiently seek() */
/* to any location when reading scanlines randomly. If we */
/* opened as text we might still be able to seek(), but I */
/* believe that on Windows, the C library has to read through */
/* all the data to find the right spot taking into account DOS */
/* CRs. */
/* -------------------------------------------------------------------- */
fp = VSIFOpen( pszFilename, "rb" );
if( fp == NULL )
{
/* how to effectively communicate this error out? */
CPLError( CE_Failure, CPLE_OpenFailed,
"Unable to open file: %s\n", pszFilename );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Create the GXF Information object. */
/* -------------------------------------------------------------------- */
psGXF = (GXFInfo_t *) VSICalloc( sizeof(GXFInfo_t), 1 );
psGXF->fp = fp;
psGXF->dfTransformScale = 1.0;
psGXF->nSense = GXFS_LL_RIGHT;
psGXF->dfXPixelSize = 1.0;
psGXF->dfYPixelSize = 1.0;
psGXF->dfSetDummyTo = -1e12;
psGXF->dfUnitToMeter = 1.0;
psGXF->pszTitle = VSIStrdup("");
/* -------------------------------------------------------------------- */
/* Read the header, one line at a time. */
/* -------------------------------------------------------------------- */
while( (papszList = GXFReadHeaderValue( fp, szTitle)) != NULL && nHeaderCount < MAX_HEADER_COUNT )
{
if( EQUALN(szTitle,"#TITL",5) )
{
CPLFree( psGXF->pszTitle );
psGXF->pszTitle = CPLStrdup( papszList[0] );
}
else if( EQUALN(szTitle,"#POIN",5) )
{
psGXF->nRawXSize = atoi(papszList[0]);
}
else if( EQUALN(szTitle,"#ROWS",5) )
{
psGXF->nRawYSize = atoi(papszList[0]);
}
else if( EQUALN(szTitle,"#PTSE",5) )
{
psGXF->dfXPixelSize = CPLAtof(papszList[0]);
}
else if( EQUALN(szTitle,"#RWSE",5) )
{
psGXF->dfYPixelSize = CPLAtof(papszList[0]);
}
else if( EQUALN(szTitle,"#DUMM",5) )
{
memset( psGXF->szDummy, 0, sizeof(psGXF->szDummy));
strncpy( psGXF->szDummy, papszList[0], sizeof(psGXF->szDummy) - 1);
psGXF->dfSetDummyTo = CPLAtof(papszList[0]);
}
else if( EQUALN(szTitle,"#XORI",5) )
{
psGXF->dfXOrigin = CPLAtof(papszList[0]);
}
else if( EQUALN(szTitle,"#YORI",5) )
{
psGXF->dfYOrigin = CPLAtof(papszList[0]);
}
else if( EQUALN(szTitle,"#ZMIN",5) )
{
psGXF->dfZMinimum = CPLAtof(papszList[0]);
}
else if( EQUALN(szTitle,"#ZMAX",5) )
{
psGXF->dfZMaximum = CPLAtof(papszList[0]);
}
else if( EQUALN(szTitle,"#SENS",5) )
{
psGXF->nSense = atoi(papszList[0]);
}
else if( EQUALN(szTitle,"#MAP_PROJECTION",8) )
{
psGXF->papszMapProjection = papszList;
papszList = NULL;
}
else if( EQUALN(szTitle,"#MAP_D",5) )
{
psGXF->papszMapDatumTransform = papszList;
papszList = NULL;
}
else if( EQUALN(szTitle,"#UNIT",5) )
{
char **papszFields;
papszFields = CSLTokenizeStringComplex( papszList[0], ", ",
TRUE, TRUE );
if( CSLCount(papszFields) > 1 )
{
psGXF->pszUnitName = VSIStrdup( papszFields[0] );
psGXF->dfUnitToMeter = CPLAtof( papszFields[1] );
if( psGXF->dfUnitToMeter == 0.0 )
psGXF->dfUnitToMeter = 1.0;
}
CSLDestroy( papszFields );
}
else if( EQUALN(szTitle,"#TRAN",5) )
{
char **papszFields;
papszFields = CSLTokenizeStringComplex( papszList[0], ", ",
TRUE, TRUE );
if( CSLCount(papszFields) > 1 )
{
psGXF->dfTransformScale = CPLAtof(papszFields[0]);
psGXF->dfTransformOffset = CPLAtof(papszFields[1]);
}
if( CSLCount(papszFields) > 2 )
psGXF->pszTransformName = CPLStrdup( papszFields[2] );
CSLDestroy( papszFields );
}
else if( EQUALN(szTitle,"#GTYPE",5) )
{
psGXF->nGType = atoi(papszList[0]);
}
CSLDestroy( papszList );
nHeaderCount ++;
}
CSLDestroy( papszList );
/* -------------------------------------------------------------------- */
/* Did we find the #GRID? */
/* -------------------------------------------------------------------- */
if( !EQUALN(szTitle,"#GRID",5) )
{
GXFClose( psGXF );
CPLError( CE_Failure, CPLE_WrongFormat,
"Didn't parse through to #GRID successfully in.\n"
"file `%s'.\n",
pszFilename );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Allocate, and initialize the raw scanline offset array. */
/* -------------------------------------------------------------------- */
if( psGXF->nRawYSize <= 0 )
{
GXFClose( psGXF );
return NULL;
}
psGXF->panRawLineOffset = (long *)
VSICalloc( sizeof(long), psGXF->nRawYSize+1 );
if( psGXF->panRawLineOffset == NULL )
{
GXFClose( psGXF );
return NULL;
}
psGXF->panRawLineOffset[0] = VSIFTell( psGXF->fp );
/* -------------------------------------------------------------------- */
/* Update the zmin/zmax values to take into account #TRANSFORM */
/* information. */
/* -------------------------------------------------------------------- */
if( psGXF->dfZMinimum != 0.0 || psGXF->dfZMaximum != 0.0 )
{
psGXF->dfZMinimum = (psGXF->dfZMinimum * psGXF->dfTransformScale)
+ psGXF->dfTransformOffset;
psGXF->dfZMaximum = (psGXF->dfZMaximum * psGXF->dfTransformScale)
+ psGXF->dfTransformOffset;
}
return( (GXFHandle) psGXF );
}
GDALDataset *GXFDataset::Open( GDALOpenInfo * poOpenInfo )
{
GXFHandle l_hGXF;
int i, bFoundKeyword, bFoundIllegal;
/* -------------------------------------------------------------------- */
/* Before trying GXFOpen() we first verify that there is at */
/* least one "\n#keyword" type signature in the first chunk of */
/* the file. */
/* -------------------------------------------------------------------- */
if( poOpenInfo->nHeaderBytes < 50 )
return NULL;
bFoundKeyword = FALSE;
bFoundIllegal = FALSE;
for( i = 0; i < poOpenInfo->nHeaderBytes-1; i++ )
{
if( (poOpenInfo->pabyHeader[i] == 10
|| poOpenInfo->pabyHeader[i] == 13)
&& poOpenInfo->pabyHeader[i+1] == '#' )
{
if( STARTS_WITH((const char*)poOpenInfo->pabyHeader + i + 2, "include") )
return NULL;
if( STARTS_WITH((const char*)poOpenInfo->pabyHeader + i + 2, "define") )
return NULL;
if( STARTS_WITH((const char*)poOpenInfo->pabyHeader + i + 2, "ifdef") )
return NULL;
bFoundKeyword = TRUE;
}
if( poOpenInfo->pabyHeader[i] == 0 )
{
bFoundIllegal = TRUE;
break;
}
}
if( !bFoundKeyword || bFoundIllegal )
return NULL;
/* -------------------------------------------------------------------- */
/* At this point it is plausible that this is a GXF file, but */
/* we also now verify that there is a #GRID keyword before */
/* passing it off to GXFOpen(). We check in the first 50K. */
/* -------------------------------------------------------------------- */
#define BIGBUFSIZE 50000
int nBytesRead, bGotGrid = FALSE;
FILE *fp;
fp = VSIFOpen( poOpenInfo->pszFilename, "rb" );
if( fp == NULL )
return NULL;
char *pszBigBuf = (char *) CPLMalloc(BIGBUFSIZE);
nBytesRead = static_cast<int>(VSIFRead( pszBigBuf, 1, BIGBUFSIZE, fp ));
VSIFClose( fp );
for( i = 0; i < nBytesRead - 5 && !bGotGrid; i++ )
{
if( pszBigBuf[i] == '#' && STARTS_WITH_CI(pszBigBuf+i+1, "GRID") )
bGotGrid = TRUE;
}
CPLFree( pszBigBuf );
if( !bGotGrid )
return NULL;
/* -------------------------------------------------------------------- */
/* Try opening the dataset. */
/* -------------------------------------------------------------------- */
l_hGXF = GXFOpen( poOpenInfo->pszFilename );
if( l_hGXF == NULL )
return( NULL );
/* -------------------------------------------------------------------- */
/* Confirm the requested access is supported. */
/* -------------------------------------------------------------------- */
if( poOpenInfo->eAccess == GA_Update )
{
GXFClose(l_hGXF);
CPLError( CE_Failure, CPLE_NotSupported,
"The GXF driver does not support update access to existing"
" datasets.\n" );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Create a corresponding GDALDataset. */
/* -------------------------------------------------------------------- */
GXFDataset *poDS;
poDS = new GXFDataset();
const char* pszGXFDataType = CPLGetConfigOption("GXF_DATATYPE", "Float32");
GDALDataType eDT = GDALGetDataTypeByName(pszGXFDataType);
if (!(eDT == GDT_Float32 || eDT == GDT_Float64))
{
CPLError(CE_Warning, CPLE_NotSupported,
"Unsupported value for GXF_DATATYPE : %s", pszGXFDataType);
eDT = GDT_Float32;
}
poDS->hGXF = l_hGXF;
poDS->eDataType = eDT;
/* -------------------------------------------------------------------- */
/* Establish the projection. */
/* -------------------------------------------------------------------- */
poDS->pszProjection = GXFGetMapProjectionAsOGCWKT( l_hGXF );
/* -------------------------------------------------------------------- */
/* Capture some information from the file that is of interest. */
/* -------------------------------------------------------------------- */
GXFGetRawInfo( l_hGXF, &(poDS->nRasterXSize), &(poDS->nRasterYSize), NULL,
NULL, NULL, &(poDS->dfNoDataValue) );
if (poDS->nRasterXSize <= 0 || poDS->nRasterYSize <= 0)
{
CPLError( CE_Failure, CPLE_AppDefined,
"Invalid dimensions : %d x %d",
poDS->nRasterXSize, poDS->nRasterYSize);
delete poDS;
return NULL;
}
/* -------------------------------------------------------------------- */
/* Create band information objects. */
/* -------------------------------------------------------------------- */
poDS->nBands = 1;
poDS->SetBand( 1, new GXFRasterBand( poDS, 1 ));
/* -------------------------------------------------------------------- */
/* Initialize any PAM information. */
/* -------------------------------------------------------------------- */
poDS->SetDescription( poOpenInfo->pszFilename );
poDS->TryLoadXML();
/* -------------------------------------------------------------------- */
/* Check for external overviews. */
/* -------------------------------------------------------------------- */
poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename, poOpenInfo->GetSiblingFiles() );
return( poDS );
}
