OpenStructure
swap_util.hh
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1 //------------------------------------------------------------------------------
2 // This file is part of the OpenStructure project <www.openstructure.org>
3 //
4 // Copyright (C) 2003-2010 by the IPLT authors
5 // Copyright (C) 2008-2011 by the OpenStructure authors
6 //
7 // This library is free software; you can redistribute it and/or modify it under
8 // the terms of the GNU Lesser General Public License as published by the Free
9 // Software Foundation; either version 3.0 of the License, or (at your option)
10 // any later version.
11 // This library is distributed in the hope that it will be useful, but WITHOUT
12 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 // FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
14 // details.
15 //
16 // You should have received a copy of the GNU Lesser General Public License
17 // along with this library; if not, write to the Free Software Foundation, Inc.,
18 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 //------------------------------------------------------------------------------
20 #ifndef OST_IO_SWAP_UTIL_HH
21 #define OST_IO_SWAP_UTIL_HH
22 
23 
24 /*
25  byte swapping utils, originally copied from IPLT
26 
27  Author: Ansgar Philippsen
28 */
29 
30 #include <cmath>
31 
32 namespace ost { namespace io {
33 
34 // byte swapping stuff
35 
36 template <typename T> void swap_buf(T* p, int n);
37 
38 inline
39 void swap_short(short int *p, short int n) {swap_buf<short int>(p,n);}
40 inline
41 void swap_ushort(unsigned short int *p, short int n) {swap_buf<unsigned short int>(p,n);}
42 inline
43 void swap_int(int *p, int n) {swap_buf<int>(p,n);}
44 inline
45 void swap_uint(uint *p, int n) {swap_buf<uint>(p,n);}
46 inline
47 void swap_float(float *p, int n) {swap_buf<float>(p,n);}
48 inline
49 void swap_double(double *p, int n) {swap_buf<double>(p,n);}
50 inline
51 void swap_long(long *p, int n) {swap_buf<long>(p,n);}
52 
53 //definitions
54 template <typename T>
55 void swap_buf(T* p, int n)
56 {
57  unsigned char *a,tmp;
58 
59  for(int k=0;k<n;k++) {
60  a=reinterpret_cast<unsigned char *>(&p[k]);
61 
62  if(sizeof(T)==2) {
63  tmp=a[0];
64  a[0]=a[1];
65  a[1]=tmp;
66  } else if(sizeof(T)==4) {
67  tmp=a[0];
68  a[0]=a[3];
69  a[3]=tmp;
70  tmp=a[1];
71  a[1]=a[2];
72  a[2]=tmp;
73  } else if(sizeof(T)==8) {
74  tmp = a[0];
75  a[0] = a[7];
76  a[7] = tmp;
77  tmp = a[1];
78  a[1] = a[6];
79  a[6] = tmp;
80  tmp = a[2];
81  a[2] = a[5];
82  a[5] =tmp;
83  tmp = a[3];
84  a[3] = a[4];
85  a[4] = tmp;
86  }
87  }
88 }
89 
90 }} // namespace
91 
92 #endif
93 
94