EMAN2
byteorder.cpp
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00001 
00005 /*
00006  * Author: Steven Ludtke, 04/10/2003 (sludtke@bcm.edu)
00007  * Copyright (c) 2000-2006 Baylor College of Medicine
00008  * 
00009  * This software is issued under a joint BSD/GNU license. You may use the
00010  * source code in this file under either license. However, note that the
00011  * complete EMAN2 and SPARX software packages have some GPL dependencies,
00012  * so you are responsible for compliance with the licenses of these packages
00013  * if you opt to use BSD licensing. The warranty disclaimer below holds
00014  * in either instance.
00015  * 
00016  * This complete copyright notice must be included in any revised version of the
00017  * source code. Additional authorship citations may be added, but existing
00018  * author citations must be preserved.
00019  * 
00020  * This program is free software; you can redistribute it and/or modify
00021  * it under the terms of the GNU General Public License as published by
00022  * the Free Software Foundation; either version 2 of the License, or
00023  * (at your option) any later version.
00024  * 
00025  * This program is distributed in the hope that it will be useful,
00026  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00027  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
00028  * GNU General Public License for more details.
00029  * 
00030  * You should have received a copy of the GNU General Public License
00031  * along with this program; if not, write to the Free Software
00032  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
00033  * 
00034  * */
00035  
00036 #include "byteorder.h"
00037 #include "util.h"
00038 
00039 using namespace EMAN;
00040 
00041 bool ByteOrder::is_host_endian_checked = false;
00042 bool ByteOrder::host_big_endian = false;
00043 
00044 bool ByteOrder::is_host_big_endian()
00045 {
00046         if (!is_host_endian_checked) {
00047                 int one = 1;
00048                 char *p_one = (char *) (&one);
00049 
00050                 if (p_one[0] == 1 && p_one[1] == 0 && p_one[2] == 0 && p_one[3] == 0) {
00051                         host_big_endian = false;
00052                 }
00053                 else {
00054                         host_big_endian = true;
00055                 }
00056 
00057                 is_host_endian_checked = true;
00058         }
00059 
00060         return host_big_endian;
00061 }
00062 
00063 bool ByteOrder::is_float_big_endian(float f)
00064 {
00065         bool is_big = false;
00066         
00067         if (Util::goodf(&f) && f > 0 && f < 65535.0 && f == floor(f)) {
00068                 is_big = is_host_big_endian();
00069         }
00070         else {
00071                 is_big = !is_host_big_endian();
00072         }
00073 
00074         return is_big;
00075 }