GDALDataset *GRASSDataset::Open( GDALOpenInfo * poOpenInfo )
{
char *pszGisdb = NULL, *pszLoc = NULL;
char *pszMapset = NULL, *pszElem = NULL, *pszName = NULL;
char **papszCells = NULL;
char **papszMapsets = NULL;
/* -------------------------------------------------------------------- */
/* Does this even look like a grass file path? */
/* -------------------------------------------------------------------- */
if( strstr(poOpenInfo->pszFilename,"/cellhd/") == NULL
&& strstr(poOpenInfo->pszFilename,"/group/") == NULL )
return NULL;
/* Always init, if no rasters are opened G_no_gisinit resets the projection and
* rasters in different projection may be then opened */
// Don't use GISRC file and read/write GRASS variables (from location G_VAR_GISRC) to memory only.
G_set_gisrc_mode ( G_GISRC_MODE_MEMORY );
// Init GRASS libraries (required)
G_no_gisinit(); // Doesn't check write permissions for mapset compare to G_gisinit
// Set error function
G_set_error_routine ( (GrassErrorHandler) Grass2CPLErrorHook );
// GISBASE is path to the directory where GRASS is installed,
if ( !getenv( "GISBASE" ) ) {
static char* gisbaseEnv = NULL;
const char *gisbase = GRASS_GISBASE;
CPLError( CE_Warning, CPLE_AppDefined, "GRASS warning: GISBASE "
"enviroment variable was not set, using:\n%s", gisbase );
char buf[2000];
snprintf ( buf, sizeof(buf), "GISBASE=%s", gisbase );
buf[sizeof(buf)-1] = '\0';
CPLFree(gisbaseEnv);
gisbaseEnv = CPLStrdup ( buf );
putenv( gisbaseEnv );
}
if ( !SplitPath( poOpenInfo->pszFilename, &pszGisdb, &pszLoc, &pszMapset,
&pszElem, &pszName) ) {
return NULL;
}
/* -------------------------------------------------------------------- */
/* Check element name */
/* -------------------------------------------------------------------- */
if ( strcmp(pszElem,"cellhd") != 0 && strcmp(pszElem,"group") != 0 ) {
G_free(pszGisdb);
G_free(pszLoc);
G_free(pszMapset);
G_free(pszElem);
G_free(pszName);
return NULL;
}
/* -------------------------------------------------------------------- */
/* Set GRASS variables */
/* -------------------------------------------------------------------- */
G__setenv( "GISDBASE", pszGisdb );
G__setenv( "LOCATION_NAME", pszLoc );
G__setenv( "MAPSET", pszMapset); // group is searched only in current mapset
G_reset_mapsets();
G_add_mapset_to_search_path ( pszMapset );
/* -------------------------------------------------------------------- */
/* Check if this is a valid grass cell. */
/* -------------------------------------------------------------------- */
if ( strcmp(pszElem,"cellhd") == 0 ) {
if ( G_find_file2("cell", pszName, pszMapset) == NULL ) {
G_free(pszGisdb); G_free(pszLoc); G_free(pszMapset); G_free(pszElem); G_free(pszName);
return NULL;
}
papszMapsets = CSLAddString( papszMapsets, pszMapset );
papszCells = CSLAddString( papszCells, pszName );
}
/* -------------------------------------------------------------------- */
/* Check if this is a valid GRASS imagery group. */
/* -------------------------------------------------------------------- */
else {
struct Ref ref;
I_init_group_ref( &ref );
if ( I_get_group_ref( pszName, &ref ) == 0 ) {
G_free(pszGisdb); G_free(pszLoc); G_free(pszMapset); G_free(pszElem); G_free(pszName);
return NULL;
}
for( int iRef = 0; iRef < ref.nfiles; iRef++ )
{
papszCells = CSLAddString( papszCells, ref.file[iRef].name );
papszMapsets = CSLAddString( papszMapsets, ref.file[iRef].mapset );
G_add_mapset_to_search_path ( ref.file[iRef].mapset );
}
I_free_group_ref( &ref );
}
G_free( pszMapset );
G_free( pszName );
/* -------------------------------------------------------------------- */
/* Create a corresponding GDALDataset. */
/* -------------------------------------------------------------------- */
GRASSDataset *poDS;
poDS = new GRASSDataset();
/* notdef: should only allow read access to an existing cell, right? */
poDS->eAccess = poOpenInfo->eAccess;
poDS->pszGisdbase = pszGisdb;
poDS->pszLocation = pszLoc;
poDS->pszElement = pszElem;
/* -------------------------------------------------------------------- */
/* Capture some information from the file that is of interest. */
/* -------------------------------------------------------------------- */
#if GRASS_VERSION_MAJOR >= 7
Rast_get_cellhd( papszCells[0], papszMapsets[0], &(poDS->sCellInfo) );
#else
if( G_get_cellhd( papszCells[0], papszMapsets[0], &(poDS->sCellInfo) ) != 0 ) {
CPLError( CE_Warning, CPLE_AppDefined, "GRASS: Cannot open raster header");
delete poDS;
return NULL;
}
#endif
poDS->nRasterXSize = poDS->sCellInfo.cols;
poDS->nRasterYSize = poDS->sCellInfo.rows;
poDS->adfGeoTransform[0] = poDS->sCellInfo.west;
poDS->adfGeoTransform[1] = poDS->sCellInfo.ew_res;
poDS->adfGeoTransform[2] = 0.0;
poDS->adfGeoTransform[3] = poDS->sCellInfo.north;
poDS->adfGeoTransform[4] = 0.0;
poDS->adfGeoTransform[5] = -1 * poDS->sCellInfo.ns_res;
/* -------------------------------------------------------------------- */
/* Try to get a projection definition. */
/* -------------------------------------------------------------------- */
struct Key_Value *projinfo, *projunits;
projinfo = G_get_projinfo();
projunits = G_get_projunits();
poDS->pszProjection = GPJ_grass_to_wkt ( projinfo, projunits, 0, 0);
if (projinfo) G_free_key_value(projinfo);
if (projunits) G_free_key_value(projunits);
/* -------------------------------------------------------------------- */
/* Create band information objects. */
/* -------------------------------------------------------------------- */
for( int iBand = 0; papszCells[iBand] != NULL; iBand++ )
{
GRASSRasterBand *rb = new GRASSRasterBand( poDS, iBand+1, papszMapsets[iBand],
papszCells[iBand] );
if ( !rb->valid ) {
CPLError( CE_Warning, CPLE_AppDefined, "GRASS: Cannot open raster band %d", iBand);
delete rb;
delete poDS;
return NULL;
}
poDS->SetBand( iBand+1, rb );
}
CSLDestroy(papszCells);
CSLDestroy(papszMapsets);
/* -------------------------------------------------------------------- */
/* Confirm the requested access is supported. */
/* -------------------------------------------------------------------- */
if( poOpenInfo->eAccess == GA_Update )
{
delete poDS;
CPLError( CE_Failure, CPLE_NotSupported,
"The GRASS driver does not support update access to existing"
" datasets.\n" );
return NULL;
}
return poDS;
}
GDALDataset *GRASSDataset::Open( GDALOpenInfo * poOpenInfo )
{
static int bDoneGISInit = FALSE;
char *pszMapset = NULL, *pszCell = NULL;
char **papszCells = NULL;
char **papszMapsets = NULL;
if( !bDoneGISInit )
{
G_set_error_routine( (GrassErrorHandler) Grass2CPLErrorHook );
G_gisinit_2( "GDAL", NULL, NULL, NULL );
}
/* -------------------------------------------------------------------- */
/* Check if this is a valid grass cell. */
/* -------------------------------------------------------------------- */
if( G_check_cell( poOpenInfo->pszFilename, &pszMapset, &pszCell ) )
{
papszCells = CSLAddString( papszCells, pszCell );
papszMapsets = CSLAddString( papszMapsets, pszMapset );
G_free( pszMapset );
G_free( pszCell );
}
/* -------------------------------------------------------------------- */
/* Check if this is a valid GRASS imagery group. */
/* -------------------------------------------------------------------- */
else if( I_check_group( poOpenInfo->pszFilename, &pszMapset, &pszCell ) )
{
struct Ref ref;
I_init_group_ref( &ref );
I_get_group_ref( pszCell, &ref );
for( int iRef = 0; iRef < ref.nfiles; iRef++ )
{
papszCells = CSLAddString( papszCells, ref.file[iRef].name );
papszMapsets = CSLAddString( papszMapsets, ref.file[iRef].mapset );
}
I_free_group_ref( &ref );
G_free( pszMapset );
G_free( pszCell );
}
else
return NULL;
/* -------------------------------------------------------------------- */
/* Create a corresponding GDALDataset. */
/* -------------------------------------------------------------------- */
GRASSDataset *poDS;
poDS = new GRASSDataset();
/* notdef: should only allow read access to an existing cell, right? */
poDS->eAccess = poOpenInfo->eAccess;
/* -------------------------------------------------------------------- */
/* Capture some information from the file that is of interest. */
/* -------------------------------------------------------------------- */
struct Cell_head sCellInfo;
if( G_get_cellhd( papszCells[0], papszMapsets[0], &sCellInfo ) != 0 )
{
/* notdef: report failure. */
return NULL;
}
poDS->nRasterXSize = sCellInfo.cols;
poDS->nRasterYSize = sCellInfo.rows;
G_set_window( &sCellInfo );
poDS->adfGeoTransform[0] = sCellInfo.west;
poDS->adfGeoTransform[1] = sCellInfo.ew_res;
poDS->adfGeoTransform[2] = 0.0;
poDS->adfGeoTransform[3] = sCellInfo.north;
poDS->adfGeoTransform[4] = 0.0;
poDS->adfGeoTransform[5] = -1 * sCellInfo.ns_res;
/* -------------------------------------------------------------------- */
/* Try to get a projection definition. */
/* -------------------------------------------------------------------- */
char *pszProj4;
pszProj4 = G_get_cell_as_proj4( papszCells[0], papszMapsets[0] );
if( pszProj4 != NULL )
{
OGRSpatialReference oSRS;
if( oSRS.importFromProj4( pszProj4 ) == OGRERR_NONE )
{
oSRS.exportToWkt( &(poDS->pszProjection) );
}
G_free( pszProj4 );
}
/* -------------------------------------------------------------------- */
/* Create band information objects. */
/* -------------------------------------------------------------------- */
for( int iBand = 0; papszCells[iBand] != NULL; iBand++ )
{
poDS->SetBand( iBand+1,
new GRASSRasterBand( poDS, iBand+1,
papszMapsets[iBand],
papszCells[iBand] ) );
}
/* -------------------------------------------------------------------- */
/* Confirm the requested access is supported. */
/* -------------------------------------------------------------------- */
if( poOpenInfo->eAccess == GA_Update )
{
delete poDS;
CPLError( CE_Failure, CPLE_NotSupported,
"The GRASS driver does not support update access to existing"
" datasets.\n" );
return NULL;
}
return poDS;
}