src/gmxlib/xtcio.c

   1 /*
   2  * $Id$
   3  *
   4  *                This source code is part of
   5  *
   6  *                 G   R   O   M   A   C   S
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   8  *          GROningen MAchine for Chemical Simulations
   9  *
  10  *                        VERSION 3.1
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  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
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  32
  33 #include <string.h>
  34 #include "typedefs.h"
  35 #include "xdrf.h"
  36 #include "gmxfio.h"
  37 #include "xtcio.h"
  38 #include "smalloc.h"
  39 #include "vec.h"
  40 #include "futil.h"
  41 #include "fatal.h"
  42
  43 #define XTC_MAGIC 1995
  44
  45 int open_xtc(char *fn,char *mode)
  46 {
  47   return fio_open(fn,mode);
  48 }
  49
  50 void close_xtc(int fp)
  51 {
  52   fio_close(fp);
  53 }
  54
  55 static void check_xtc_magic(int magic)
  56 {
  57   if (magic != XTC_MAGIC)
  58     fatal_error(0,"Magic Number Error in XTC file (read %d, should be %d)",
  59                 magic,XTC_MAGIC);
  60 }
  61
  62 int xtc_check(char *str,bool bResult,char *file,int line)
  63 {
  64   if (!bResult) {
  65     if (debug)
  66       fprintf(debug,"\nXTC error: read/write of %s failed, "
  67               "source file %s, line %d\n",str,file,line);
  68     return 0;
  69   }
  70   return 1;
  71 }
  72
  73 void xtc_check_fat_err(char *str,bool bResult,char *file,int line)
  74 {
  75   if (!bResult) {
  76     fatal_error(0,"XTC read/write of %s failed, "
  77                 "source file %s, line %d\n",str,file,line);
  78   }
  79 }
  80
  81 static int xtc_header(XDR *xd,int *magic,int *natoms,int *step,real *time,
  82                       bool *bOK)
  83 {
  84   int result;
  85
  86   if (xdr_int(xd,magic) == 0)
  87     return 0;
  88   result=XTC_CHECK("natoms", xdr_int(xd,natoms));  /* number of atoms */
  89   if (result)
  90     result=XTC_CHECK("step",   xdr_int(xd,step));    /* frame number    */
  91   if (result)
  92     result=XTC_CHECK("time",   xdr_real(xd,time));   /* time            */
  93   *bOK=(result!=0);
  94
  95   return result;
  96 }
  97
  98 static int xtc_coord(XDR *xd,int *natoms,matrix box,rvec *x,real *prec)
  99 {
 100   int i,j,result;
 101
 102   /* box */
 103   result=1;
 104   for(i=0; ((i<DIM) && result); i++)
 105     for(j=0; ((j<DIM) && result); j++)
 106       result=XTC_CHECK("box",xdr_real(xd,&(box[i][j])));
 107
 108   if (result)
 109     /* coordinates     */
 110     result=XTC_CHECK("x",xdr3drcoord(xd,x[0],natoms,prec));
 111
 112   return result;
 113 }
 114
 115 static int xtc_io(XDR *xd,int *magic,
 116                   int *natoms,int *step,real *time,
 117                   matrix box,rvec *x,real *prec,bool *bOK)
 118 {
 119   if (!xtc_header(xd,magic,natoms,step,time,bOK))
 120     return 0;
 121   return xtc_coord(xd,natoms,box,x,prec);
 122 }
 123
 124 int write_xtc(int fp,
 125               int natoms,int step,real time,
 126               matrix box,rvec *x,real prec)
 127 {
 128   int magic_number = XTC_MAGIC;
 129   XDR *xd;
 130   bool bDum;
 131
 132   xd = fio_getxdr(fp);
 133   /* write magic number and xtc identidier */
 134   if (!xtc_header(xd,&magic_number,&natoms,&step,&time,&bDum))
 135     return 0;
 136
 137   /* write data */
 138   return xtc_coord(xd,&natoms,box,x,&prec);
 139 }
 140
 141 int read_first_xtc(int fp,int *natoms,int *step,real *time,
 142                    matrix box,rvec **x,real *prec,bool *bOK)
 143 {
 144   int magic;
 145   XDR *xd;
 146
 147   *bOK=TRUE;
 148   xd = fio_getxdr(fp);
 149
 150   /* read header and malloc x */
 151   if ( !xtc_header(xd,&magic,natoms,step,time,bOK))
 152     return 0;
 153
 154   /* Check magic number */
 155   check_xtc_magic(magic);
 156
 157   snew(*x,*natoms);
 158
 159   *bOK=xtc_coord(xd,natoms,box,*x,prec);
 160
 161   return *bOK;
 162 }
 163
 164 int read_next_xtc(int fp,
 165                   int natoms,int *step,real *time,
 166                   matrix box,rvec *x,real *prec,bool *bOK)
 167 {
 168   int magic;
 169   int n;
 170   XDR *xd;
 171
 172   *bOK=TRUE;
 173   xd = fio_getxdr(fp);
 174
 175   /* read header */
 176   if (!xtc_header(xd,&magic,&n,step,time,bOK))
 177     return 0;
 178   if (n>natoms)
 179     fatal_error(0, "Frame contains more atoms (%d) than expected (%d)",
 180                 n, natoms);
 181
 182   /* Check magic number */
 183   check_xtc_magic(magic);
 184
 185   *bOK=xtc_coord(xd,&natoms,box,x,prec);
 186
 187   return *bOK;
 188 }
 189