Geografic-Information-System/lib/ogsf/gsget.c

/*!
   \file lib/ogsf/gsget.c

   \brief OGSF library - get map attribute (lower level functions)

   GRASS OpenGL gsurf OGSF Library 

   (C) 1999-2008 by the GRASS Development Team

   This program is free software under the 
   GNU General Public License (>=v2). 
   Read the file COPYING that comes with GRASS
   for details.

   \author Bill Brown USACERL (January 1993)
   \author Doxygenized by Martin Landa <landa.martin gmail.com> (May 2008)
 */

#include <grass/ogsf.h>

/*!
   \brief Get map attributes

   \param buff
   \param offset
   \param[out] att

   \return 0 on failure
   \return 1 on success
 */
int get_mapatt(typbuff * buff, int offset, float *att)
{
    if (buff->nm) {
	if (BM_get
	    (buff->nm, (offset % buff->nm->cols),
	     (offset / buff->nm->cols))) {
	    return (0);
	}
    }

    *att = (buff->ib ? (float)buff->ib[offset] :
	    buff->sb ? (float)buff->sb[offset] :
	    buff->cb ? (float)buff->cb[offset] :
	    buff->fb ? (float)buff->fb[offset] : buff->k);

    if (buff->tfunc) {
	*att = (buff->tfunc) (*att, offset);
    }

    return (1);
}