text: /*
   *
   * WKTRaster - Raster Types for PostGIS
   * http://trac.osgeo.org/postgis/wiki/WKTRaster
   *
   * Copyright (C) 2011-2013 Regents of the University of California
   *   <bkpark@ucdavis.edu>
   * Copyright (C) 2010-2011 Jorge Arevalo <jorge.arevalo@deimos-space.com>
   * Copyright (C) 2010-2011 David Zwarg <dzwarg@azavea.com>
   * Copyright (C) 2009-2011 Pierre Racine <pierre.racine@sbf.ulaval.ca>
   * Copyright (C) 2009-2011 Mateusz Loskot <mateusz@loskot.net>
   * Copyright (C) 2008-2009 Sandro Santilli <strk@keybit.net>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   *
   */
  
  #include <postgres.h> /* for palloc */
  #include <fmgr.h>
  #include <utils/builtins.h>
  
  #include "../../postgis_config.h"
  #include "lwgeom_pg.h"
  
  #include "rtpostgis.h"
  
  Datum RASTER_lib_version(PG_FUNCTION_ARGS);
  Datum RASTER_lib_build_date(PG_FUNCTION_ARGS);
  Datum RASTER_gdal_version(PG_FUNCTION_ARGS);
  Datum RASTER_minPossibleValue(PG_FUNCTION_ARGS);
  
  PG_FUNCTION_INFO_V1(RASTER_lib_version);
  Datum RASTER_lib_version(PG_FUNCTION_ARGS)
  {
      char ver[64];
      text *result;
  
      snprintf(ver, 64, "%s r%d", POSTGIS_LIB_VERSION, POSTGIS_SVN_REVISION);
      ver[63] = '\0';
  
      result = cstring2text(ver);
      PG_RETURN_TEXT_P(result);
  }
  
  PG_FUNCTION_INFO_V1(RASTER_lib_build_date);
  Datum RASTER_lib_build_date(PG_FUNCTION_ARGS)
  {
      char *ver = POSTGIS_BUILD_DATE;
      text *result;
      result = palloc(VARHDRSZ  + strlen(ver));
      SET_VARSIZE(result, VARHDRSZ + strlen(ver));
      memcpy(VARDATA(result), ver, strlen(ver));
      PG_RETURN_POINTER(result);
  }
  
  PG_FUNCTION_INFO_V1(RASTER_gdal_version);
  Datum RASTER_gdal_version(PG_FUNCTION_ARGS)
  {
  	const char *ver = rt_util_gdal_version("--version");
  	text *result;
  
  	/* add indicator if GDAL isn't configured right */
  	if (!rt_util_gdal_configured()) {
  		char *rtn = NULL;
  		rtn = palloc(strlen(ver) + strlen(" GDAL_DATA not found") + 1);
  		if (!rtn)
  			result = cstring2text(ver);
  		else {
  			sprintf(rtn, "%s GDAL_DATA not found", ver);
  			result = cstring2text(rtn);
  			pfree(rtn);
  		}
  	}
  	else
  		result = cstring2text(ver);
  
  	PG_RETURN_POINTER(result);
  }
  
  PG_FUNCTION_INFO_V1(RASTER_minPossibleValue);
  Datum RASTER_minPossibleValue(PG_FUNCTION_ARGS)
  {
  	text *pixeltypetext = NULL;
  	char *pixeltypechar = NULL;
  	rt_pixtype pixtype = PT_END;
  	double pixsize = 0;
  
  	if (PG_ARGISNULL(0))
  		PG_RETURN_NULL();
  
  	pixeltypetext = PG_GETARG_TEXT_P(0);
  	pixeltypechar = text_to_cstring(pixeltypetext);
  
  	pixtype = rt_pixtype_index_from_name(pixeltypechar);
  	if (pixtype == PT_END) {
  		elog(ERROR, "RASTER_minPossibleValue: Invalid pixel type: %s", pixeltypechar);
  		PG_RETURN_NULL();
  	}
  
  	pixsize = rt_pixtype_get_min_value(pixtype);
  
  	/*
  		correct pixsize of unsigned pixel types
  		example: for PT_8BUI, the value is CHAR_MIN but if char is signed, 
  			the value returned is -127 instead of 0.
  	*/
  	switch (pixtype) {
  		case PT_1BB:
  		case PT_2BUI:
  		case PT_4BUI:
  		case PT_8BUI:
  		case PT_16BUI:
  		case PT_32BUI:
  			pixsize = 0;
  			break;
  		default:
  			break;
  	}
  
  	PG_RETURN_FLOAT8(pixsize);
  }
  
  /** find the detoasted size of a value */
  Datum RASTER_memsize(PG_FUNCTION_ARGS);
  PG_FUNCTION_INFO_V1(RASTER_memsize);
  Datum RASTER_memsize(PG_FUNCTION_ARGS)
  {
    void *detoasted = PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
    size_t size = VARSIZE(detoasted);
    PG_FREE_IF_COPY(detoasted,0);
    PG_RETURN_INT32(size);
  }
  
  
  