LCOV - code coverage report
Current view: top level - molfile - Gromacs.h (source / functions) Hit Total Coverage
Test: plumed test coverage (other modules) Lines: 342 750 45.6 %
Date: 2024-10-18 13:59:33 Functions: 22 36 61.1 %

          Line data    Source code
       1             : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       2             : University of Illinois Open Source License
       3             : Copyright 2003 Theoretical and Computational Biophysics Group, 
       4             : All rights reserved.
       5             : 
       6             : Developed by:           Theoretical and Computational Biophysics Group
       7             :                         University of Illinois at Urbana-Champaign
       8             :                         http://www.ks.uiuc.edu/
       9             : 
      10             : Permission is hereby granted, free of charge, to any person obtaining a copy of
      11             : this software and associated documentation files (the Software), to deal with 
      12             : the Software without restriction, including without limitation the rights to 
      13             : use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
      14             : of the Software, and to permit persons to whom the Software is furnished to 
      15             : do so, subject to the following conditions:
      16             : 
      17             : Redistributions of source code must retain the above copyright notice, 
      18             : this list of conditions and the following disclaimers.
      19             : 
      20             : Redistributions in binary form must reproduce the above copyright notice, 
      21             : this list of conditions and the following disclaimers in the documentation 
      22             : and/or other materials provided with the distribution.
      23             : 
      24             : Neither the names of Theoretical and Computational Biophysics Group, 
      25             : University of Illinois at Urbana-Champaign, nor the names of its contributors 
      26             : may be used to endorse or promote products derived from this Software without 
      27             : specific prior written permission.
      28             : 
      29             : THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
      30             : IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
      31             : FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL 
      32             : THE CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 
      33             : OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
      34             : ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 
      35             : OTHER DEALINGS WITH THE SOFTWARE.
      36             : +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
      37             : #ifndef __PLUMED_molfile_Gromacs_h
      38             : #define __PLUMED_molfile_Gromacs_h
      39             : /***************************************************************************
      40             :  *cr
      41             :  *cr            (C) Copyright 1995-2016 The Board of Trustees of the
      42             :  *cr                        University of Illinois
      43             :  *cr                         All Rights Reserved
      44             :  *cr
      45             :  ***************************************************************************/
      46             : /***************************************************************************
      47             :  * RCS INFORMATION:
      48             :  *      $RCSfile: Gromacs.h,v $
      49             :  *      $Author: johns $       $Locker:  $             $State: Exp $
      50             :  *      $Revision: 1.36 $       $Date: 2020/01/09 16:21:28 $
      51             :  ***************************************************************************/
      52             : 
      53             : /*
      54             :  * GROMACS file format reader for VMD
      55             :  *
      56             :  * This code provides a high level I/O library for reading
      57             :  * and writing the following file formats:
      58             :  *      gro     GROMACS format or trajectory
      59             :  *      g96     GROMOS-96 format or trajectory
      60             :  *      trj     Trajectory - x, v and f (binary, full precision)
      61             :  *      trr     Trajectory - x, v and f (binary, full precision, portable)
      62             :  *      xtc     Trajectory - x only (compressed, portable, any precision)
      63             :  *      top
      64             :  * Currently supported: gro trj trr g96 [xtc]
      65             :  *
      66             :  * TODO list
      67             :  *   o  velocities are ignored because VMD doesn't use them, but some other 
      68             :  *      program might ...
      69             :  *   o  gro_rec() assumes positions in .gro files are nanometers and
      70             :  *      converts to angstroms, whereas they really could be any unit
      71             :  */
      72             : 
      73             : #ifndef GROMACS_H
      74             : #define GROMACS_H
      75             : 
      76             : #include <math.h>
      77             : #include <stdio.h>
      78             : #include <stdlib.h>
      79             : #include <string.h>
      80             : #include <ctype.h>
      81             : 
      82             : #if defined(_AIX)
      83             : #include <strings.h>
      84             : #endif
      85             : 
      86             : #include "endianswap.h"
      87             : 
      88             : namespace PLMD{
      89             : namespace molfile{
      90             : 
      91             : #if defined(WIN32) || defined(WIN64)
      92             : #define strcasecmp stricmp
      93             : #endif
      94             : 
      95             : #ifndef M_PI_2
      96             : #define M_PI_2 1.57079632679489661922
      97             : #endif
      98             : 
      99             : // Error codes for mdio_errno
     100             : #define MDIO_SUCCESS            0
     101             : #define MDIO_BADFORMAT          1
     102             : #define MDIO_EOF                2
     103             : #define MDIO_BADPARAMS          3
     104             : #define MDIO_IOERROR            4
     105             : #define MDIO_BADPRECISION       5
     106             : #define MDIO_BADMALLOC          6
     107             : #define MDIO_CANTOPEN           7
     108             : #define MDIO_BADEXTENSION       8
     109             : #define MDIO_UNKNOWNFMT         9
     110             : #define MDIO_CANTCLOSE          10
     111             : #define MDIO_WRONGFORMAT        11
     112             : #define MDIO_SIZEERROR          12
     113             : #define MDIO_UNKNOWNERROR       1000
     114             : 
     115             : #define MDIO_READ       0
     116             : #define MDIO_WRITE      1
     117             : 
     118             : #define MDIO_MAX_ERRVAL         11
     119             : 
     120             : // Format extensions
     121             : const char *mdio_fmtexts[] = {
     122             :     "",
     123             :     ".gro",
     124             :     ".trr",
     125             :     ".g96",
     126             :     ".trj",
     127             :     ".xtc",
     128             :     NULL
     129             : };
     130             : 
     131             : 
     132             : static int mdio_errcode;        // Last error code
     133             : 
     134             : #define TRX_MAGIC       1993    // Magic number for .trX files
     135             : #define XTC_MAGIC       1995    // Magic number for .xtc files
     136             : #define MAX_GRO_LINE    500     // Maximum line length of .gro files
     137             : #define MAX_G96_LINE    500     // Maximum line length of .g96 files
     138             : #define MAX_TRX_TITLE   80      // Maximum length of a title in .trX
     139             : #define MAX_MDIO_TITLE  80      // Maximum supported title length
     140             : #define ANGS_PER_NM     10      // Unit conversion factor
     141             : #define ANGS2_PER_NM2   100     // Unit conversion factor
     142             : 
     143             : 
     144             : // All the supported file types and their respective extensions
     145             : #define MDFMT_GRO               1
     146             : #define MDFMT_TRR               2
     147             : #define MDFMT_G96               3
     148             : #define MDFMT_TRJ               4
     149             : #define MDFMT_XTC               5
     150             : 
     151             : 
     152             : // A structure to hold .trX file format header information. This
     153             : // is an optional member of the md_file structure that is used
     154             : // when .trX files are being dealt with.
     155             : typedef struct {
     156             :         int version;            // File version number
     157             :         char title[MAX_TRX_TITLE + 1];  // File title
     158             :         int ir_size;
     159             :         int e_size;
     160             :         int box_size;
     161             :         int vir_size;
     162             :         int pres_size;
     163             :         int top_size;
     164             :         int sym_size;
     165             :         int x_size;             // Positions of atoms
     166             :         int v_size;             // Velocities of atoms
     167             :         int f_size;
     168             :         int natoms;             // Number of atoms in the system
     169             :         int step;
     170             :         int nre;
     171             :         float t;
     172             :         float lambda;
     173             : } trx_hdr;
     174             : 
     175             : 
     176             : // A generic i/o structure that contains information about the
     177             : // file itself and the input/output state
     178             : typedef struct {
     179             :         FILE *  f;      // Pointer to the file
     180             :         int     fmt;    // The file format
     181             :         int     prec;   // Real number precision
     182             :         int     rev;    // Reverse endiannism?
     183             :         trx_hdr * trx;  // Trx files require a great deal more
     184             :                         // header data to be stored.
     185             : } md_file;
     186             : 
     187             : 
     188             : // A format-independent structure to hold header data from files
     189             : typedef struct {
     190             :         char title[MAX_MDIO_TITLE + 1];
     191             :         int natoms;
     192             :         float timeval;
     193             : } md_header;
     194             : 
     195             : 
     196             : // A format-independent structure to hold unit cell data
     197             : typedef struct {
     198             :   float A, B, C, alpha, beta, gamma;
     199             : } md_box;
     200             : 
     201             : 
     202             : // Timestep information
     203             : typedef struct {
     204             :         float *pos;     // Position array (3 * natoms)
     205             :         //float *vel;   // Velocity array ** (VMD doesn't use this) **
     206             :         //float *f;     // Force array ** (VMD doesn't use this) **
     207             :         //float *box;   // Computational box ** (VMD doesn't use this) **
     208             :         int natoms;     // Number of atoms
     209             :         int step;       // Simulation step
     210             :         float time;     // Time of simulation
     211             :   md_box *box;
     212             : } md_ts;
     213             : 
     214             : 
     215             : // Atom information
     216             : typedef struct {
     217             :         char resid[7];          // Residue index number
     218             :         char resname[7];        // Residue name
     219             :         int atomnum;            // Atom index number
     220             :         char atomname[7];       // Atom name
     221             :         float pos[3];           // Position array (3 * natoms)
     222             :         //float vel[3]; // Velocity array ** (VMD doesn't use this) **
     223             : } md_atom;
     224             : 
     225             : 
     226             : // Open a molecular dynamics file. The second parameter specifies
     227             : // the format of the file. If it is zero, the format is determined
     228             : // from the file extension. the third argument (if given) decides
     229             : // whether to read (==0) or to write (!= 0).
     230             : // using a default argument set to read for backward compatibility.
     231             : static md_file *mdio_open(const char *, const int, const int=MDIO_READ);
     232             : 
     233             : // Closes a molecular dynamics file.
     234             : static int mdio_close(md_file *);
     235             : 
     236             : 
     237             : // Format-independent file I/O routines
     238             : static int mdio_header(md_file *, md_header *);
     239             : static int mdio_timestep(md_file *, md_ts *);
     240             : 
     241             : 
     242             : // .gro file functions
     243             : static int gro_header(md_file *, char *, int, float *, int *, int = 1);
     244             : static int gro_rec(md_file *, md_atom *);
     245             : static int gro_timestep(md_file *, md_ts *);
     246             : 
     247             : 
     248             : // .trX file functions
     249             : static int trx_header(md_file *, int = 0);
     250             : static int trx_int(md_file *, int *);
     251             : static int trx_real(md_file *, float *);
     252             : 
     253             : static int trx_rvector(md_file *, float *);
     254             : static int trx_string(md_file *, char *, int);
     255             : static int trx_timestep(md_file *, md_ts *);
     256             : 
     257             : // .g96 file functions
     258             : static int g96_header(md_file *, char *, int, float *);
     259             : static int g96_timestep(md_file *, md_ts *);
     260             : static int g96_rec(md_file *, md_atom *);
     261             : static int g96_countatoms(md_file *);
     262             : 
     263             : 
     264             : // .xtc file functions
     265             : static int xtc_int(md_file *, int *);
     266             : static int xtc_float(md_file *, float *);
     267             : /* 
     268             : static int xtc_receivebits(int *, int);
     269             : static void xtc_receiveints(int *, int, int, const unsigned *, int *);
     270             : */
     271             : static int xtc_timestep(md_file *, md_ts *);
     272             : static int xtc_3dfcoord(md_file *, float *, int *, float *);
     273             : 
     274             : 
     275             : // Error reporting functions
     276             : static int mdio_errno(void);
     277             : static const char *mdio_errmsg(int);
     278             : static int mdio_seterror(int);
     279             : 
     280             : 
     281             : // Miscellaneous functions
     282             : static int strip_white(char *);
     283             : static int mdio_readline(md_file *, char *, int, int = 1);
     284             : static int mdio_tsfree(md_ts *, int = 0);
     285             : static int mdio_readbox(md_box *, float *, float *, float *);
     286             : 
     287             : 
     288             : 
     289             : static int xtc_receivebits(int *, int);
     290             : 
     291             : // Error descriptions for mdio_errno
     292             : static const char *mdio_errdescs[] = {
     293             :         "no error",
     294             :         "file does not match format",
     295             :         "unexpected end-of-file reached",
     296             :         "function called with bad parameters",
     297             :         "file i/o error",
     298             :         "unsupported precision",
     299             :         "out of memory",
     300             :         "cannot open file",
     301             :         "bad file extension",
     302             :         "unknown file format",
     303             :         "cannot close file",
     304             :         "wrong file format for this function",
     305             :         "binary i/o error: sizeof(int) != 4",
     306             :         NULL
     307             : };
     308             : 
     309             : /*! \fn static inline bool host_is_little_endian(void)
     310             :  * detect endiannes of host machine. returns true on little endian machines. */
     311             : static inline int host_is_little_endian(void) 
     312             : {
     313             :   const union { unsigned char c[4]; unsigned int i; } 
     314             :   fixed = { { 0x10 , 0x20 , 0x40 , 0x80 } };
     315             :   const unsigned int i = 0x80402010U;
     316             :         
     317             :   if (fixed.i == i) {
     318             :     return 1;
     319             :   }
     320             :   return 0;
     321             : }
     322             : 
     323             : 
     324             : 
     325             : // Open a molecular dynamics file. The second parameter specifies
     326             : // the format of the file. If it is zero, the format is determined
     327             : // from the file extension.
     328         209 : md_file *mdio_open(const char *fn, const int fmt, const int rw) {
     329             :         md_file *mf;
     330             : 
     331         209 :         if (!fn) {
     332           0 :                 mdio_seterror(MDIO_BADPARAMS);
     333           0 :                 return NULL;
     334             :         }
     335             : 
     336             :         // Allocate memory
     337         209 :         mf = (md_file *) malloc(sizeof(md_file));
     338         209 :         if (!mf) {
     339           0 :                 mdio_seterror(MDIO_BADMALLOC);
     340           0 :                 return NULL;
     341             :         }
     342             : 
     343             :         // Zero out the structure
     344             :         memset(mf, 0, sizeof(md_file));
     345             : 
     346             :         // Determine the file type from the extension
     347         209 :         if (!fmt) {
     348             :                 char *p;
     349             :                 int n;
     350             : 
     351             :                 // Seek to the extension part of the filename
     352           0 :                 for (p = (char *) &fn[strlen(fn) - 1]; *p != '.' && p > fn; p--);
     353           0 :                 if (p == fn) {
     354           0 :                         free(mf);
     355           0 :                         mdio_seterror(MDIO_BADEXTENSION);
     356           0 :                         return NULL;
     357             :                 }
     358             : 
     359             :                 // Check the extension against known extensions
     360           0 :                 for (n = 1; mdio_fmtexts[n]; n++)
     361           0 :                         if (!strcasecmp(p, mdio_fmtexts[n])) break;
     362             : 
     363             :                 // If !mdio_fmtexts[n], we failed (unknown ext)
     364           0 :                 if (!mdio_fmtexts[n]) {
     365           0 :                         free(mf);
     366           0 :                         mdio_seterror(MDIO_UNKNOWNFMT);
     367           0 :                         return NULL;
     368             :                 }
     369             : 
     370             :                 // All set
     371           0 :                 mf->fmt = n;
     372             :         }
     373             :         else {
     374         209 :                 mf->fmt = fmt;
     375             :         }
     376             : 
     377             :         // Differentiate between binary and ascii files. Also,
     378             :         // .trX files need a header information structure allocated.
     379         209 :         switch (mf->fmt) {
     380           0 :     case MDFMT_GRO:
     381             :         case MDFMT_G96: /* fallthrough */
     382           0 :         if (rw) 
     383           0 :             mf->f = fopen(fn, "wt");
     384             :         else
     385           0 :             mf->f = fopen(fn, "rt");
     386             : 
     387             :                 break;
     388           5 :         case MDFMT_TRR:
     389             :         case MDFMT_TRJ: /* fallthrough */
     390             :                 // Allocate the trx header data struct
     391           5 :                 mf->trx = (trx_hdr *) malloc(sizeof(trx_hdr));
     392           5 :                 if (!mf->trx) {
     393           0 :                         free(mf);
     394           0 :                         mdio_seterror(MDIO_BADMALLOC);
     395           0 :                         return NULL;
     396             :                 }
     397             :                 memset(mf->trx, 0, sizeof(trx_hdr));
     398         209 :         case MDFMT_XTC:  /* fallthrough */
     399             :                 // Finally, open the file
     400         209 :         if (rw)
     401           0 :             mf->f = fopen(fn, "wb");
     402             :         else
     403         209 :             mf->f = fopen(fn, "rb");
     404             : 
     405             :                 break;
     406           0 :         default:
     407           0 :                 free(mf);
     408           0 :                 mdio_seterror(MDIO_UNKNOWNFMT);
     409           0 :                 return NULL;
     410             :         }
     411             : 
     412             :         // Check for opening error
     413         209 :         if (!mf->f) {
     414           0 :                 if (mf->trx) free(mf->trx);
     415           0 :                 free(mf);
     416           0 :                 mdio_seterror(MDIO_CANTOPEN);
     417           0 :                 return NULL;
     418             :         }
     419             : 
     420             :         // File is opened, we're all set!
     421         209 :         mdio_seterror(MDIO_SUCCESS);
     422         209 :         return mf;
     423             : }
     424             : 
     425             : 
     426             : // Closes a molecular dynamics file.
     427         209 : static int mdio_close(md_file *mf) {
     428         209 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
     429             : 
     430         209 :         if (fclose(mf->f) == EOF) return mdio_seterror(MDIO_CANTCLOSE);
     431             : 
     432             :         // Free the dynamically allocated memory
     433         209 :         if (mf->trx) free(mf->trx);
     434         209 :         free(mf);
     435         209 :         return mdio_seterror(MDIO_SUCCESS);
     436             : }
     437             : 
     438             : 
     439             : // Returns the last error code reported by any of the mdio functions
     440         209 : static int mdio_errno(void) {
     441         209 :         return mdio_errcode;
     442             : }
     443             : 
     444             : 
     445             : // Returns a textual message regarding an mdio error code
     446           0 : static const char *mdio_errmsg(int n) {
     447           0 :         if (n < 0 || n > MDIO_MAX_ERRVAL) return (char *) "unknown error";
     448           0 :         else return mdio_errdescs[n];
     449             : }
     450             : 
     451             : 
     452             : // Sets the error code and returns an appropriate return value
     453             : // for the calling function to return to its parent
     454     2378763 : static int mdio_seterror(int code) {
     455     2378763 :         mdio_errcode = code;
     456     2378763 :         return code ? -1 : 0;
     457             : }
     458             : 
     459             : 
     460             : // Reads a line from the text file, strips leading/trailing whitespace
     461             : // and newline, checks for errors, and returns the number of characters
     462             : // in the string on success or -1 on error.
     463           0 : static int mdio_readline(md_file *mf, char *buf, int n, int strip) {
     464           0 :         if (!buf || n < 1 || !mf) return mdio_seterror(MDIO_BADPARAMS);
     465             : 
     466             :         // Read the line
     467           0 :         fgets(buf, n, mf->f);
     468             : 
     469             :         // End of file reached?
     470           0 :         if (feof(mf->f)) return mdio_seterror(MDIO_EOF);
     471             : 
     472             :         // File I/O error?
     473           0 :         if (ferror(mf->f)) return mdio_seterror(MDIO_IOERROR);
     474             : 
     475             :         // comment line?
     476           0 :         if (buf[0] == '#') return mdio_readline(mf,buf,n,strip);
     477             : 
     478             :         // Strip whitespace
     479           0 :         if (strip) strip_white(buf);
     480             : 
     481           0 :         return strlen(buf);
     482             : }
     483             : 
     484             : 
     485             : // Strips leading and trailing whitespace from a string. Tabs,
     486             : // spaces, newlines and carriage returns are stripped. Example:
     487             : // "\n   hello\t \r" becomes "hello".
     488           0 : static int strip_white(char *buf) {
     489             :         int i, j, k;
     490             : 
     491             :         // Protect against NULL pointer
     492           0 :         if (!buf) return -1;
     493           0 :         if (!strlen(buf)) return -1;
     494             : 
     495             :         // Kill trailing whitespace first
     496           0 :         for (i = strlen(buf) - 1;
     497           0 :              buf[i] == ' ' || buf[i] == '\t' ||
     498           0 :              buf[i] == '\n' || buf[i] == '\r';
     499             :              i--)
     500           0 :                 buf[i] = 0;
     501             : 
     502             :         // Skip past leading whitespace
     503           0 :         for (i = 0; buf[i] == ' ' || buf[i] == '\t' ||
     504           0 :              buf[i] == '\n' || buf[i] == '\r'; i++);
     505           0 :         if (i) {
     506             :                 k = 0;
     507           0 :                 for (j = i; buf[j]; j++)
     508           0 :                         buf[k++] = buf[j];
     509           0 :                 buf[k] = 0;
     510             :         }
     511             : 
     512           0 :         return strlen(buf);
     513             : }
     514             : 
     515             : 
     516             : // Frees the memory allocated in a ts structure. The holderror
     517             : // parameter defaults to zero. Programs that are calling this
     518             : // function because of an error reported by another function should
     519             : // set holderror so that mdio_tsfree() does not overwrite the error
     520             : // code with mdio_seterror().
     521       18549 : static int mdio_tsfree(md_ts *ts, int holderror) {
     522       18549 :         if (!ts) {
     523           0 :                 if (holderror) return -1;
     524           0 :                 else return mdio_seterror(MDIO_BADPARAMS);
     525             :         }
     526             : 
     527       18549 :         if (ts->pos && ts->natoms > 0) free(ts->pos);
     528             : 
     529       18549 :   if (ts->box) free(ts->box);
     530             : 
     531       18549 :         if (holderror) return -1;
     532       18549 :         else return mdio_seterror(MDIO_SUCCESS);
     533             : }
     534             : 
     535             : 
     536             : // Converts box basis vectors to A, B, C, alpha, beta, and gamma.  
     537             : // Stores values in md_box struct, which should be allocated before calling
     538             : // this function.
     539       18549 : static int mdio_readbox(md_box *box, float *x, float *y, float *z) {
     540             :   float A, B, C;
     541             : 
     542       18549 :   if (!box) {
     543           0 :     return mdio_seterror(MDIO_BADPARAMS);
     544             :   }
     545             : 
     546             :   // A, B, C are the lengths of the x, y, z vectors, respectively
     547       18549 :   A = sqrt( x[0]*x[0] + x[1]*x[1] + x[2]*x[2] ) * ANGS_PER_NM;
     548       18549 :   B = sqrt( y[0]*y[0] + y[1]*y[1] + y[2]*y[2] ) * ANGS_PER_NM;
     549       18549 :   C = sqrt( z[0]*z[0] + z[1]*z[1] + z[2]*z[2] ) * ANGS_PER_NM;
     550       18549 :   if ((A<=0) || (B<=0) || (C<=0)) {
     551             :     /* Use zero-length box size and set angles to 90. */
     552           0 :     box->A = box->B = box->C = 0;
     553           0 :     box->alpha = box->beta = box->gamma = 90;
     554             :   } else {
     555       18549 :     box->A = A;
     556       18549 :     box->B = B;
     557       18549 :     box->C = C;
     558             :   
     559             :     // gamma, beta, alpha are the angles between the x & y, x & z, y & z
     560             :     // vectors, respectively
     561       18549 :     box->gamma = acos( (x[0]*y[0]+x[1]*y[1]+x[2]*y[2])*ANGS2_PER_NM2/(A*B) ) * 90.0/M_PI_2;
     562       18549 :     box->beta = acos( (x[0]*z[0]+x[1]*z[1]+x[2]*z[2])*ANGS2_PER_NM2/(A*C) ) * 90.0/M_PI_2;
     563       18549 :     box->alpha = acos( (y[0]*z[0]+y[1]*z[1]+y[2]*z[2])*ANGS2_PER_NM2/(B*C) ) * 90.0/M_PI_2; 
     564             :   }
     565       18549 :   return mdio_seterror(MDIO_SUCCESS);
     566             : }
     567             : 
     568             : 
     569             : // Reads the header of a file (format independent)
     570         209 : static int mdio_header(md_file *mf, md_header *mdh) {
     571             :         int n;
     572         209 :         if (!mf || !mdh) return mdio_seterror(MDIO_BADPARAMS);
     573         209 :         if (!mf->f) return mdio_seterror(MDIO_BADPARAMS);
     574             : 
     575         209 :         switch (mf->fmt) {
     576           0 :         case MDFMT_GRO:
     577           0 :                 if (gro_header(mf, mdh->title, MAX_MDIO_TITLE,
     578             :                 &mdh->timeval, &mdh->natoms, 1) < 0)
     579           0 :                         return -1;
     580             :                 return 0;
     581             : 
     582           5 :         case MDFMT_TRR: 
     583             :         case MDFMT_TRJ: /* fallthrough */
     584           5 :                 if (trx_header(mf, 1) < 0) return -1;
     585           5 :                 mdh->natoms = mf->trx->natoms;
     586           5 :                 mdh->timeval = (float) mf->trx->t;
     587           5 :                 strncpy(mdh->title, mf->trx->title, MAX_MDIO_TITLE);
     588           5 :                 return 0;
     589             : 
     590           0 :         case MDFMT_G96:
     591           0 :                 if (g96_header(mf, mdh->title, MAX_MDIO_TITLE,
     592             :                 &mdh->timeval) < 0) return -1;
     593           0 :                 mdh->natoms = -1;
     594           0 :                 return 0;
     595             : 
     596             :         case MDFMT_XTC:
     597             :                 memset(mdh, 0, sizeof(md_header));
     598             :                 // Check magic number
     599         204 :                 if (xtc_int(mf, &n) < 0) return -1;
     600         204 :                 if (n != XTC_MAGIC) return mdio_seterror(MDIO_BADFORMAT);
     601             : 
     602             :                 // Get number of atoms
     603         204 :                 if (xtc_int(mf, &n) < 0) return -1;
     604         204 :                 mdh->natoms = n;
     605         204 :                 rewind(mf->f);
     606             :                 return 0;
     607             : 
     608           0 :         default:
     609           0 :                 return mdio_seterror(MDIO_UNKNOWNFMT);
     610             :         }
     611             : }
     612             : 
     613             : 
     614             : // Reads in a timestep from a file (format independent)
     615       18758 : static int mdio_timestep(md_file *mf, md_ts *ts) {
     616       18758 :         if (!mf || !ts) return mdio_seterror(MDIO_BADPARAMS);
     617       18758 :         if (!mf->f) return mdio_seterror(MDIO_BADPARAMS);
     618             : 
     619       18758 :         switch (mf->fmt) {
     620           0 :         case MDFMT_GRO:
     621           0 :                 return gro_timestep(mf, ts);
     622             : 
     623         155 :         case MDFMT_TRR:
     624             :         case MDFMT_TRJ: /* fallthrough */
     625         155 :                 return trx_timestep(mf, ts);
     626             : 
     627           0 :         case MDFMT_G96:
     628           0 :                 return g96_timestep(mf, ts);
     629             : 
     630       18603 :         case MDFMT_XTC:
     631       18603 :                 return xtc_timestep(mf, ts);
     632             : 
     633           0 :         default:
     634           0 :                 return mdio_seterror(MDIO_UNKNOWNFMT);
     635             :         }
     636             : }
     637             : 
     638             : 
     639             : 
     640           0 : static int g96_header(md_file *mf, char *title, int titlelen, float *timeval) {
     641             :         char buf[MAX_G96_LINE + 1];
     642             :         char *p;
     643             : 
     644             :         // Check parameters
     645           0 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
     646             : 
     647             :         // The header consists of blocks. The title block
     648             :         // is mandatory, and a TIMESTEP block is optional.
     649             :         // Example:
     650             :         //
     651             :         // TITLE
     652             :         // Generated by trjconv :  t=  90.00000
     653             :         // more title info
     654             :         // .
     655             :         // .
     656             :         // .
     657             :         // END
     658             :         // .
     659             :         // .
     660             :         // .
     661             : 
     662           0 :         if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     663           0 :         if (strcasecmp(buf, "TITLE")) return mdio_seterror(MDIO_BADFORMAT);
     664             : 
     665             :         // Read in the title itself
     666           0 :         if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     667             : 
     668             :         // The timevalue can be included in the title string
     669             :         // after a "t=" prefix.
     670           0 :         if ((p = (char *) strstr(buf, "t="))) {
     671             :                 char *q = p;
     672           0 :                 *(q--) = 0;
     673             : 
     674             :                 // Skip the `t=' and strip whitespace from
     675             :                 // the resulting strings
     676           0 :                 p += 2;
     677           0 :                 strip_white(p);
     678           0 :                 strip_white(buf);
     679             : 
     680             :                 // Grab the timevalue from the title string
     681           0 :                 if (timeval) *timeval = (float) atof(p);
     682             :         }
     683             :         else {
     684             :                 // No timevalue - just copy the string and strip
     685             :                 // any leading/trailing whitespace
     686           0 :                 if (timeval) *timeval = 0;
     687           0 :                 strip_white(buf);
     688             :         }
     689             : 
     690             :         // Copy the title string
     691           0 :         if (title && titlelen) strncpy(title, buf, titlelen);
     692             : 
     693             :         // Now ignore subsequent title lines and get the END string
     694           0 :         while (strcasecmp(buf, "END"))
     695           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     696             : 
     697             :         // Done!
     698           0 :         return mdio_seterror(MDIO_SUCCESS);
     699             : }
     700             : 
     701             : 
     702             : // Used to determine the number of atoms in a g96 file, because
     703             : // VMD needs to know this for some reason.
     704           0 : static int g96_countatoms(md_file *mf) {
     705             :         char buf[MAX_G96_LINE + 1];
     706             :         int natoms;
     707             :         int n;
     708             :         long fpos;
     709             :         float lastf;
     710             : 
     711           0 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
     712             : 
     713           0 :         fpos = ftell(mf->f);
     714             : 
     715             :         natoms = 0;
     716             :         for (;;) {
     717           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1, 0) < 0)
     718             :                         break;
     719           0 :                 n = sscanf(buf, "%*6c%*6c%*6c%*6c %*f %*f %f", &lastf);
     720           0 :                 if (n == 1) natoms++;
     721             :                 else {
     722           0 :                         strip_white(buf);
     723           0 :                         if (!strcasecmp(buf, "END")) break;
     724             :                 }
     725             :         }
     726             : 
     727           0 :         fseek(mf->f, fpos, SEEK_SET);
     728           0 :         return natoms;
     729             : }
     730             : 
     731             : 
     732             : // Reads an atom line from the G96 file
     733           0 : static int g96_rec(md_file *mf, md_atom *ma) {
     734             :         char buf[MAX_G96_LINE + 1];
     735             :         char atomnum[7];
     736             :         int n;
     737             : 
     738             :         // Check parameters
     739           0 :         if (!mf || !ma) return mdio_seterror(MDIO_BADPARAMS);
     740             : 
     741             :         // Read in a line, assuming it is an atom line
     742             :         do {
     743           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1, 0) < 0) return -1;
     744           0 :         } while (buf[0] == '#' || strlen(buf) == 0);
     745             : 
     746           0 :         n = sscanf(buf, "%6c%6c%6c%6c %f %f %f",
     747           0 :                 ma->resid, ma->resname, ma->atomname, atomnum,
     748             :                 &ma->pos[0], &ma->pos[1], &ma->pos[2]);
     749           0 :         if (n == 7) {
     750           0 :                 atomnum[6] = 0;
     751           0 :                 ma->resid[6] = 0;
     752           0 :                 ma->resname[6] = 0;
     753           0 :                 ma->atomname[6] = 0;
     754             : 
     755           0 :                 strip_white(atomnum);
     756           0 :                 strip_white(ma->resid);
     757           0 :                 strip_white(ma->resname);
     758           0 :                 strip_white(ma->atomname);
     759             : 
     760           0 :                 ma->atomnum = atoi(atomnum);
     761             : 
     762           0 :                 ma->pos[0] *= ANGS_PER_NM;
     763           0 :                 ma->pos[1] *= ANGS_PER_NM;
     764           0 :                 ma->pos[2] *= ANGS_PER_NM;
     765             : 
     766           0 :                 return 0;
     767             :         }
     768             : 
     769           0 :         return mdio_seterror(MDIO_BADFORMAT);
     770             : }
     771             : 
     772             : 
     773             : // Reads a timestep from a G96 file and stores the data in
     774             : // the generic md_ts structure. Returns 0 on success or a
     775             : // negative number on error and sets mdio_errcode.
     776           0 : static int g96_timestep(md_file *mf, md_ts *ts) {
     777             :         char            buf[MAX_G96_LINE + 1];
     778             :         char            stripbuf[MAX_G96_LINE + 1];
     779             :         float           pos[3], x[3], y[3], z[3], *currAtom;
     780             :         long            fpos;
     781             :         int             n, i, boxItems;
     782             : 
     783             :         // Check parameters
     784           0 :         if (!mf || !ts) return mdio_seterror(MDIO_BADPARAMS);
     785             : 
     786             :   // Allocate data space for the timestep, using the number of atoms
     787             :   // determined by open_g96_read().
     788           0 :         ts->pos = (float *) malloc(sizeof(float) * 3 * ts->natoms);
     789           0 :         if (!ts->pos) {
     790           0 :                 return mdio_seterror(MDIO_BADMALLOC);
     791             :         }
     792             :   currAtom = ts->pos;
     793             : 
     794             :         // The timesteps follow the header in a fixed block
     795             :         // format:
     796             :         //
     797             :         // TIMESTEP
     798             :         //         <step number> <time value>
     799             :         // END
     800             :         // POSITIONRED
     801             :         //     <x float> <y float> <z float>
     802             :         //     .         .         .
     803             :         //     .         .         .
     804             :         //     .         .         .
     805             :         // END
     806             :         // VELOCITYRED
     807             :         //     <x float> <y float> <z float>
     808             :         //     .         .         .
     809             :         //     .         .         .
     810             :         //     .         .         .
     811             :         // END
     812             :         // BOX
     813             :         //     <x float> <y float> <z float>
     814             :         // END
     815             :         //
     816             :         // -----
     817             :         //
     818             :         // The TIMESTEP, VELOCITY and BOX blocks are optional.
     819             :         // Floats are written in 15.9 precision.
     820             :         //
     821             :         // Reference: GROMACS 2.0 user manual
     822             :         //            http://rugmd4.chem.rug.nl/~gmx/online2.0/g96.html
     823             : 
     824             :         // First, look for an (optional) title block and skip it
     825           0 :         if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     826             : 
     827           0 :   if (!strcasecmp(buf, "TITLE")) {
     828             :     // skip over the text until we reach 'END'
     829           0 :     while (strcasecmp(buf, "END")) {
     830           0 :       if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     831             :     }
     832             : 
     833             :     // Read in the next line
     834           0 :     if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     835             :   }
     836             : 
     837             :         // Next, look for a timestep block
     838           0 :         if (!strcasecmp(buf, "TIMESTEP")) {
     839             :                 // Read in the value line
     840           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     841             : 
     842             :                 // Extract the time value and the timestep index
     843           0 :                 n = sscanf(buf, "%d %f", &ts->step, &ts->time);
     844           0 :                 if (n != 2) return mdio_seterror(MDIO_BADFORMAT);
     845             : 
     846             :                 // Read the "END" line
     847           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     848           0 :                 if (strcasecmp(buf, "END"))
     849           0 :                         return mdio_seterror(MDIO_BADFORMAT);
     850             : 
     851             :                 // Read in the next line
     852           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     853             :         }
     854             :         else {
     855             :                 // No timestep specified -- set to zero
     856           0 :                 ts->step = 0;
     857           0 :                 ts->time = 0;
     858             :         }
     859             : 
     860             :         // At this point a POSITION or POSITIONRED block
     861             :         // is REQUIRED by the format
     862           0 :         if (!strcasecmp(buf, "POSITIONRED")) {
     863             : 
     864             :     // So now we read in some atoms
     865             :     i = 0;
     866           0 :                 while (i < ts->natoms) {
     867             :                         // Read in an atom
     868           0 :                         if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0)
     869             :                                 return -1;
     870             :  
     871             :       // We shouldn't reach the end yet
     872           0 :       if (!strcasecmp(buf, "END"))
     873           0 :         return mdio_seterror(MDIO_BADFORMAT);
     874             : 
     875             :                         // Get the x,y,z coordinates
     876           0 :                         n = sscanf(buf, "%f %f %f", &pos[0], &pos[1], &pos[2]);
     877             :       
     878             :       // Ignore improperly formatted lines
     879           0 :                         if (n == 3) {
     880           0 :                                 pos[0] *= ANGS_PER_NM;
     881           0 :                                 pos[1] *= ANGS_PER_NM;
     882           0 :                                 pos[2] *= ANGS_PER_NM;
     883             : 
     884             :                                 // Copy the atom data into the array
     885             :                                 memcpy(currAtom, pos, sizeof(float) * 3);
     886           0 :         currAtom += 3;
     887           0 :         i++;
     888             :                         }
     889             :                 }
     890             :         }
     891           0 :         else if (!strcasecmp(buf, "POSITION") || !strcasecmp(buf, "REFPOSITION")) {
     892             :                 /*
     893             :                 char resnum[7];
     894             :                 char resname[7];
     895             :                 char atomname[7];
     896             :                 char atomnum[7];
     897             :                 */
     898             : 
     899             :                 // So now we read in some atoms
     900             :     i = 0;
     901           0 :                 while (i < ts->natoms) {
     902             :                         // Read in the first line
     903           0 :                         if (mdio_readline(mf, buf, MAX_G96_LINE + 1, 0) < 0)
     904             :                                 return -1;
     905             :  
     906             :       // We shouldn't reach the end yet
     907             :       strcpy(stripbuf, buf);
     908           0 :       strip_white(stripbuf); 
     909           0 :       if (!strcasecmp(stripbuf, "END"))
     910           0 :         return mdio_seterror(MDIO_BADFORMAT);
     911             : 
     912             :                         // Get the x,y,z coordinates and name data
     913           0 :                         n = sscanf(buf, "%*6c%*6c%*6c%*6c %f %f %f",
     914             :                                 &pos[0], &pos[1], &pos[2]);
     915             : 
     916             :       // Ignore improperly formatted lines
     917           0 :                         if (n == 3) {
     918           0 :                                 pos[0] *= ANGS_PER_NM;
     919           0 :                                 pos[1] *= ANGS_PER_NM;
     920           0 :                                 pos[2] *= ANGS_PER_NM;
     921             : 
     922             :                                 // Copy the atom data into the linked list item
     923             :                                 memcpy(currAtom, pos, sizeof(float) * 3);
     924           0 :                                 currAtom += 3;
     925           0 :         i++;
     926             :                         }
     927             :                 }
     928             :         }
     929             :         else {
     930           0 :                 return mdio_seterror(MDIO_BADFORMAT);
     931             :         }
     932             : 
     933             :   // Read the END keyword
     934           0 :   if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0)
     935             :     return -1;
     936           0 :   if (strcasecmp(buf, "END"))
     937           0 :     return mdio_seterror(MDIO_BADFORMAT);
     938             : 
     939             :         // ... another problem: there may or may not be a VELOCITY
     940             :         // block or a BOX block, so we need to read one line beyond
     941             :         // the POSITION block to determine this. If neither VEL. nor
     942             :         // BOX are present we've read a line too far and infringed
     943             :         // on the next timestep, so we need to keep track of the
     944             :         // position now for a possible fseek() later to backtrack.
     945           0 :         fpos = ftell(mf->f);
     946             : 
     947             :         // Now we must read in the velocities and the box, if present
     948           0 :         if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) {
     949             :     // It's okay if we end the file here; any other errors need to be
     950             :     // reported.
     951           0 :     if (mdio_errcode == MDIO_EOF) 
     952           0 :       return mdio_seterror(MDIO_SUCCESS);
     953             :     else 
     954             :       return -1;
     955             :   }
     956             : 
     957             :         // Is there a velocity block present ?
     958           0 :         if (!strcasecmp(buf, "VELOCITY") || !strcasecmp(buf, "VELOCITYRED")) {
     959             :                 // Ignore all the coordinates - VMD doesn't use them
     960             :                 for (;;) {
     961           0 :                         if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0)
     962             :                                 return -1;
     963           0 :                         if (!strcasecmp(buf, "END")) break;
     964             :                 }
     965             : 
     966             :                 // Again, record our position because we may need
     967             :                 // to fseek here later if we read too far.
     968           0 :                 fpos = ftell(mf->f);
     969             : 
     970             :                 // Go ahead and read the next line.
     971           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     972             :         }
     973             : 
     974             :         // Is there a box present ?
     975           0 :         if (!strcasecmp(buf, "BOX")) {
     976           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) return -1;
     977           0 :     boxItems = sscanf(buf, " %f %f %f %f %f %f %f %f %f", 
     978             :                &x[0], &y[1], &z[2], &x[1], &x[2], &y[0], &y[2], &z[0], &z[1]);
     979           0 :     if (boxItems == 3) {
     980           0 :       x[1] = x[2] = 0;
     981           0 :       y[0] = y[2] = 0;
     982           0 :       z[0] = z[1] = 0;
     983             :     }
     984           0 :     else if (boxItems != 9) 
     985           0 :       return mdio_seterror(MDIO_BADFORMAT);
     986             : 
     987             :     // Allocate the box and convert the vectors.
     988           0 :     ts->box = (md_box *) malloc(sizeof(md_box));
     989           0 :     if (mdio_readbox(ts->box, x, y, z) < 0) {
     990           0 :       free(ts->box);
     991           0 :       ts->box = NULL;
     992           0 :       return mdio_seterror(MDIO_BADFORMAT);
     993             :     }
     994             : 
     995           0 :                 if (mdio_readline(mf, buf, MAX_G96_LINE + 1) < 0) {
     996           0 :       free(ts->box);
     997           0 :       ts->box = NULL;
     998           0 :       return -1;
     999             :     }
    1000           0 :                 if (strcasecmp(buf, "END")) {
    1001           0 :       free(ts->box);
    1002           0 :       ts->box = NULL;
    1003           0 :                         return mdio_seterror(MDIO_BADFORMAT);
    1004             :     }
    1005             :         }
    1006             :         else {
    1007             :                 // We have read too far, so fseek back to the
    1008             :                 // last known safe position so we don't return
    1009             :                 // with the file pointer set infringing on the
    1010             :                 // next timestep data.
    1011           0 :                 fseek(mf->f, fpos, SEEK_SET);
    1012             :         }
    1013             : 
    1014             :         // We're done!
    1015           0 :         return mdio_seterror(MDIO_SUCCESS);
    1016             : }
    1017             : 
    1018             : 
    1019             : // Attempts to read header data from a GROMACS structure file
    1020             : // The GROMACS header format is as follows (fixed, 2 lines ASCII):
    1021             : // <title> [ n= <timevalue> ]
    1022             : //     <num atoms>
    1023           0 : static int gro_header(md_file *mf, char *title, int titlelen, float *timeval,
    1024             :                int *natoms, int rewind) {
    1025             :   char buf[MAX_GRO_LINE + 1];
    1026             :   long fpos;
    1027             :   char *p;
    1028             : 
    1029             :   // Check parameters
    1030           0 :   if (!mf)
    1031           0 :     return mdio_seterror(MDIO_BADPARAMS);
    1032             : 
    1033             :   // Get the current file position for rewinding later
    1034           0 :   fpos = ftell(mf->f);
    1035             : 
    1036             :   // The header consists of 2 lines - get the first line
    1037           0 :   if (mdio_readline(mf, buf, MAX_GRO_LINE + 1) < 0) return -1;
    1038             : 
    1039             :   // The timevalue can be included in the title string
    1040             :   // after a "t=" prefix.
    1041           0 :   if ((p = (char *) strstr(buf, "t="))) {
    1042             :     char *q = p;
    1043           0 :     *(q--) = 0;
    1044             : 
    1045             :     // Skip the `t=' and strip whitespace from
    1046             :     // the resulting strings
    1047           0 :     p += 2;
    1048           0 :     strip_white(p);
    1049           0 :     strip_white(buf);
    1050             : 
    1051             :     // Grab the timevalue from the title string
    1052           0 :     if (timeval) *timeval = (float) atof(p);
    1053             :   } else {
    1054             :     // No timevalue - just copy the string
    1055           0 :     if (timeval) *timeval = 0;
    1056             :   }
    1057             : 
    1058             :   // Copy the title string
    1059           0 :   if (title && titlelen) strncpy(title, buf, titlelen);
    1060             : 
    1061             :   // Get the second line and grab the number of atoms
    1062           0 :   if (mdio_readline(mf, buf, MAX_GRO_LINE + 1) < 0) return -1;
    1063             : 
    1064             :   // Store the number of atoms
    1065           0 :   if (natoms && (!(*natoms = atoi(buf))))
    1066           0 :     return mdio_seterror(MDIO_BADFORMAT);
    1067             : 
    1068             :   // Now we rewind the file so that subsequent calls to
    1069             :   // gro_timestep() will succeed. gro_timestep() requires
    1070             :   // the header to be at the current file pointer.
    1071           0 :   if (rewind)
    1072           0 :     fseek(mf->f, fpos, SEEK_SET);
    1073             : 
    1074             :   return 0; // Done!
    1075             : }
    1076             : 
    1077             : 
    1078             : // Reads one atom record from a GROMACS file. Returns GMX_SUCCESS
    1079             : // on success or a negative number on error.
    1080             : //
    1081             : // Record format (one line, fixed):
    1082             : //    rrrrrRRRRRaaaaaAAAAA <x pos> <y pos> <z pos> <x vel> <y vel> <z vel>
    1083             : //
    1084             : //    r = residue number
    1085             : //    R = residue name
    1086             : //    a = atom name
    1087             : //    A = atom number
    1088             : //
    1089           0 : static int gro_rec(md_file *mf, md_atom *ma) {
    1090             :   char buf[MAX_GRO_LINE + 1];
    1091             :   char atomnum[6];
    1092             :   char xposc[12], yposc[12], zposc[12];
    1093             :   int n;
    1094             : 
    1095           0 :   if (!mf)
    1096           0 :     return mdio_seterror(MDIO_BADPARAMS);
    1097             : 
    1098             :   do {
    1099           0 :     if (mdio_readline(mf, buf, MAX_GRO_LINE + 1, 0) < 0)
    1100             :       return -1;
    1101           0 :   } while (buf[0] == '#' || !strlen(buf));
    1102             : 
    1103             :   // Read in the fields
    1104           0 :   n = sscanf(buf, "%5c%5c%5c%5c%8c%8c%8c", 
    1105           0 :              ma->resid, ma->resname, ma->atomname, atomnum, 
    1106             :              xposc, yposc, zposc);
    1107             : 
    1108           0 :   if (n != 7)
    1109           0 :     return mdio_seterror(MDIO_BADFORMAT);
    1110             : 
    1111             :   // Null terminate the strings
    1112           0 :   ma->resname[5] = 0;
    1113           0 :   ma->atomname[5] = 0;
    1114           0 :   ma->resid[5] = 0;
    1115           0 :   atomnum[5] = 0;
    1116           0 :   xposc[8] = 0;
    1117           0 :   yposc[8] = 0;
    1118           0 :   zposc[8] = 0;
    1119             :  
    1120           0 :   if ((sscanf(xposc, "%f", &ma->pos[0]) != 1) ||
    1121           0 :       (sscanf(yposc, "%f", &ma->pos[1]) != 1) ||
    1122           0 :       (sscanf(zposc, "%f", &ma->pos[2]) != 1)) {
    1123           0 :     return mdio_seterror(MDIO_BADFORMAT);
    1124             :   }
    1125             : 
    1126             :   // Convert strings to numbers
    1127           0 :   strip_white(atomnum);
    1128           0 :   ma->atomnum = atoi(atomnum);
    1129             : 
    1130             :   // Convert nanometers to angstroms
    1131           0 :   ma->pos[0] *= ANGS_PER_NM;
    1132           0 :   ma->pos[1] *= ANGS_PER_NM;
    1133           0 :   ma->pos[2] *= ANGS_PER_NM;
    1134             : 
    1135             :   // Strip leading and trailing whitespace
    1136           0 :   strip_white(ma->atomname);
    1137           0 :   strip_white(ma->resname);
    1138           0 :   strip_white(ma->resid);
    1139             : 
    1140           0 :   return 0;
    1141             : }
    1142             : 
    1143             : 
    1144             : // Reads in a timestep from a .gro file. Ignores the data
    1145             : // not needed for a timestep, so is a little faster than
    1146             : // calling gro_rec() for each atom. Also reads in the
    1147             : // header block.
    1148             : //
    1149           0 : static int gro_timestep(md_file *mf, md_ts *ts) {
    1150             :         char buf[MAX_GRO_LINE + 1];
    1151             :         long coord;
    1152             :         int i, n, boxItems;
    1153             :   float x[3], y[3], z[3];
    1154             :   char xposc[12], yposc[12], zposc[12];
    1155             : 
    1156           0 :   if (!mf || !ts) 
    1157           0 :     return mdio_seterror(MDIO_BADPARAMS);
    1158             : 
    1159           0 :   if (gro_header(mf, NULL, 0, &ts->time, &ts->natoms, 0) < 0)
    1160             :     return -1;
    1161             : 
    1162           0 :   ts->pos = (float *) malloc(3 * sizeof(float) * ts->natoms);
    1163           0 :   if (!ts->pos)
    1164           0 :     return mdio_seterror(MDIO_BADMALLOC);
    1165             : 
    1166             :   coord = 0;
    1167           0 :   for (i = 0; i < ts->natoms; i++) {
    1168           0 :     if (mdio_readline(mf, buf, MAX_GRO_LINE + 1, 0) < 0) {
    1169           0 :       free(ts->pos);
    1170           0 :       return -1;
    1171             :     }
    1172             :         
    1173           0 :     n = sscanf(buf, "%*5c%*5c%*5c%*5c%8c%8c%8c", xposc, yposc, zposc);
    1174           0 :     if (n != 3) 
    1175           0 :       return mdio_seterror(MDIO_BADFORMAT);
    1176             : 
    1177           0 :     if ((sscanf(xposc, "%f", &ts->pos[coord    ]) != 1) ||
    1178           0 :         (sscanf(yposc, "%f", &ts->pos[coord + 1]) != 1) ||
    1179           0 :         (sscanf(zposc, "%f", &ts->pos[coord + 2]) != 1)) {
    1180           0 :       return mdio_seterror(MDIO_BADFORMAT);
    1181             :     }
    1182             : 
    1183           0 :     ts->pos[coord    ] *= ANGS_PER_NM;
    1184           0 :     ts->pos[coord + 1] *= ANGS_PER_NM;
    1185           0 :     ts->pos[coord + 2] *= ANGS_PER_NM;
    1186             : 
    1187           0 :     coord += 3;
    1188             :   }
    1189             : 
    1190             :   // Read the box, stored as three vectors representing its edges
    1191           0 :   if (mdio_readline(mf, buf, MAX_GRO_LINE + 1, 0) < 0) {
    1192           0 :     free(ts->pos);
    1193           0 :     return -1;
    1194             :   }
    1195             : 
    1196           0 :   boxItems = sscanf(buf, " %f %f %f %f %f %f %f %f %f", 
    1197             :              &x[0], &y[1], &z[2], &x[1], &x[2], &y[0], &y[2], &z[0], &z[1]);
    1198             : 
    1199             :   // File may only include three scalars for the box information -- if
    1200             :   // that's the case, the box is orthoganal.
    1201           0 :   if (boxItems == 3) {
    1202           0 :     x[1] = x[2] = 0;
    1203           0 :     y[0] = y[2] = 0;
    1204           0 :     z[0] = z[1] = 0;
    1205           0 :   } else if (boxItems != 9) {
    1206           0 :     free(ts->pos);
    1207           0 :     return -1;
    1208             :   }
    1209             : 
    1210             :   // Allocate the box and convert the vectors.
    1211           0 :   ts->box = (md_box *) malloc(sizeof(md_box));
    1212           0 :   if (mdio_readbox(ts->box, x, y, z) < 0) {
    1213           0 :     free(ts->pos);
    1214           0 :     free(ts->box);
    1215           0 :     ts->box = NULL;
    1216           0 :     return -1;
    1217             :   }
    1218             : 
    1219             :   return 0;
    1220             : }
    1221             : 
    1222             : 
    1223             : // Attempts to read header data from a .trX trajectory file
    1224             : //
    1225             : // The .trX header format is as follows:
    1226             : //
    1227             : //      4 bytes         - magic number (0x07C9)
    1228             : //      ...
    1229             : //
    1230         160 : static int trx_header(md_file *mf, int rewind) {
    1231             :         int magic;
    1232             :         trx_hdr *hdr;
    1233             :         long fpos;
    1234             : 
    1235         160 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1236             : 
    1237             :         // In case we need to rewind
    1238         160 :         fpos = ftell(mf->f);
    1239             : 
    1240             :         // We need to store some data to the trX header data
    1241             :         // structure inside the md_file structure
    1242         160 :         hdr = mf->trx;
    1243         160 :         if (!mf->trx) return mdio_seterror(MDIO_BADPARAMS);
    1244             : 
    1245             :         // Read the magic number
    1246         160 :         if (trx_int(mf, &magic) < 0) return -1;
    1247         155 :         if (magic != TRX_MAGIC) {
    1248             :                 // Try reverse endianism
    1249           5 :                 swap4_aligned(&magic, 1);
    1250           5 :                 if (magic != TRX_MAGIC) return mdio_seterror(MDIO_BADFORMAT);
    1251             : 
    1252             :                 // Enable byte swapping (actually works, too!)
    1253           5 :                 mf->rev = 1;
    1254             :         }
    1255             : 
    1256             :         // Read the version number. 
    1257             :         // XXX. this is not the version number, but the storage size
    1258             :         // of the following XDR encoded string.
    1259             :         // the 'title' string is in fact the version identifier.
    1260             :         // since VMD does not use any of that, it does no harm,
    1261             :         // but is should still be fixed occasionally. AK 2005/01/08.
    1262             : 
    1263         155 :         if(mf->fmt!=MDFMT_TRJ) {
    1264             :                 // It appears that TRJ files either don't contain a version
    1265             :                 // number or don't have a length-delimiter on the string,
    1266             :                 // whereas TRR files do contain both.  Thus, with TRJ, we just
    1267             :                 // assume that the version number is the string length and 
    1268             :                 // just hope for the best. -- WLD 2006/07/09
    1269         155 :                 if (trx_int(mf, &hdr->version) < 0) return -1;
    1270             :         }
    1271             : 
    1272             :         // Read in the title string
    1273         155 :         if (trx_string(mf, hdr->title, MAX_TRX_TITLE) < 0)
    1274             :                 return -1;
    1275             : 
    1276             :         // Read in some size data
    1277         155 :         if (trx_int(mf, &hdr->ir_size) < 0) return -1;
    1278         155 :         if (trx_int(mf, &hdr->e_size) < 0) return -1;
    1279         155 :         if (trx_int(mf, &hdr->box_size) < 0) return -1;
    1280         155 :         if (trx_int(mf, &hdr->vir_size) < 0) return -1;
    1281         155 :         if (trx_int(mf, &hdr->pres_size) < 0) return -1;
    1282         155 :         if (trx_int(mf, &hdr->top_size) < 0) return -1;
    1283         155 :         if (trx_int(mf, &hdr->sym_size) < 0) return -1;
    1284         155 :         if (trx_int(mf, &hdr->x_size) < 0) return -1;
    1285         155 :         if (trx_int(mf, &hdr->v_size) < 0) return -1;
    1286         155 :         if (trx_int(mf, &hdr->f_size) < 0) return -1;
    1287         155 :         if (trx_int(mf, &hdr->natoms) < 0) return -1;
    1288         155 :         if (trx_int(mf, &hdr->step) < 0) return -1;
    1289         155 :         if (trx_int(mf, &hdr->nre) < 0) return -1;
    1290             : 
    1291             :         // Make sure there are atoms...
    1292         155 :         if (!hdr->natoms) return mdio_seterror(MDIO_BADFORMAT);
    1293             : 
    1294             :         // Try to determine precision (float? double?)
    1295         155 :         if (hdr->x_size) mf->prec = hdr->x_size / (hdr->natoms * 3);
    1296           0 :         else if (hdr->v_size) mf->prec = hdr->v_size / (hdr->natoms * 3);
    1297           0 :         else if (hdr->f_size) mf->prec = hdr->f_size / (hdr->natoms * 3);
    1298           0 :         else return mdio_seterror(MDIO_BADPRECISION);
    1299             : 
    1300         155 :         if (mf->prec != sizeof(float) && mf->prec != sizeof(double)) {
    1301             :                 // We have no data types this size! The
    1302             :                 // file must've been generated on another
    1303             :                 // platform
    1304           0 :                 return mdio_seterror(MDIO_BADPRECISION);
    1305             :         }
    1306             : 
    1307             :         // Read in timestep and lambda
    1308         155 :         if (trx_real(mf, &hdr->t) < 0) return -1;
    1309         155 :         if (trx_real(mf, &hdr->lambda) < 0) return -1;
    1310             : 
    1311             :         // Rewind if necessary
    1312         155 :         if (rewind) fseek(mf->f, fpos, SEEK_SET);
    1313             : 
    1314             :         return 0;
    1315             : }
    1316             : 
    1317             : 
    1318             : // Reads in an integer and stores it in y. Returns GMX_SUCCESS
    1319             : // on success or a negative number on error.
    1320        2485 : static int trx_int(md_file *mf, int *y) {
    1321        2485 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1322             : 
    1323             :         // sanity check.
    1324             :         if (sizeof(int) != 4) return mdio_seterror(MDIO_SIZEERROR);
    1325             : 
    1326        2485 :         if (y) {
    1327        4970 :                 if (fread(y, 4, 1, mf->f) != 1)
    1328           5 :                         return mdio_seterror(MDIO_IOERROR);
    1329        2480 :                 if (mf->rev) swap4_aligned(y, 1);
    1330             :         }
    1331           0 :         else if (fseek(mf->f, 4, SEEK_CUR) != 0)
    1332           0 :                 return mdio_seterror(MDIO_IOERROR);
    1333             : 
    1334        2480 :         return mdio_seterror(MDIO_SUCCESS);
    1335             : }
    1336             : 
    1337             : 
    1338             : // Reads in either a float or a double, depending on the
    1339             : // precision, and stores that number in y. Returns
    1340             : // GMX_SUCCESS on success or a negative number on error.
    1341     1458760 : static int trx_real(md_file *mf, float *y) {
    1342             :         double x;
    1343             : 
    1344     1458760 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1345             : 
    1346     1458760 :         switch (mf->prec) {
    1347     1458760 :                 case sizeof(float):
    1348     1458760 :                         if (!y) {
    1349           0 :                                 if (fseek(mf->f, mf->prec, SEEK_CUR) != 0)
    1350           0 :                                         return mdio_seterror(MDIO_IOERROR);
    1351             :                         } else {
    1352     2917520 :                                 if (fread(y, mf->prec, 1, mf->f) != 1)
    1353           0 :                                         return mdio_seterror(MDIO_IOERROR);
    1354     1458760 :                                 if (mf->rev) swap4_aligned(y, 1);
    1355             :                         }
    1356     1458760 :                         return mdio_seterror(MDIO_SUCCESS);
    1357             : 
    1358           0 :                 case sizeof(double):
    1359           0 :                         if (!y) {
    1360           0 :                                 if (fseek(mf->f, mf->prec, SEEK_CUR) != 0)
    1361           0 :                                         return mdio_seterror(MDIO_IOERROR);
    1362             :                         } else {
    1363           0 :                                 if (fread(&x, mf->prec, 1, mf->f) != 1)
    1364           0 :                                         return mdio_seterror(MDIO_IOERROR);
    1365           0 :                                 if (mf->rev) swap8_aligned(&x, 1);
    1366           0 :                                 *y = (float) x;
    1367             :                         }
    1368           0 :                         return mdio_seterror(MDIO_SUCCESS);
    1369             : 
    1370           0 :                 default:
    1371           0 :                         return mdio_seterror(MDIO_BADPRECISION);
    1372             :         }
    1373             : 
    1374             : }
    1375             : 
    1376             : 
    1377             : // Reads in a real-valued vector (taking precision into account).
    1378             : // Stores the vector in vec, and returns GMX_SUCCESS on success
    1379             : // or a negative number on error.
    1380      486150 : static int trx_rvector(md_file *mf, float *vec) {
    1381      486150 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1382             : 
    1383      486150 :         if (!vec) {
    1384           0 :                 if (trx_real(mf, NULL) < 0) return -1;
    1385           0 :                 if (trx_real(mf, NULL) < 0) return -1;
    1386           0 :                 if (trx_real(mf, NULL) < 0) return -1;
    1387           0 :                 return mdio_seterror(MDIO_SUCCESS);
    1388             :         } else {
    1389      486150 :                 if (trx_real(mf, &vec[0]) < 0) return -1;
    1390      486150 :                 if (trx_real(mf, &vec[1]) < 0) return -1;
    1391      486150 :                 if (trx_real(mf, &vec[2]) < 0) return -1;
    1392      486150 :                 return mdio_seterror(MDIO_SUCCESS);
    1393             :         }
    1394             : }
    1395             : 
    1396             : 
    1397             : // Reads in a string by first reading an integer containing the
    1398             : // string's length, then reading in the string itself and storing
    1399             : // it in str. If the length is greater than max, it is truncated
    1400             : // and the rest of the string is skipped in the file. Returns the
    1401             : // length of the string on success or a negative number on error.
    1402         155 : static int trx_string(md_file *mf, char *str, int max) {
    1403             :         int size;
    1404             :   size_t ssize;
    1405             : 
    1406         155 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1407             : 
    1408         155 :         if (trx_int(mf, &size) < 0) return -1;
    1409         155 :   ssize = (size_t)size;
    1410             : 
    1411         155 :         if (str && size <= max) {
    1412         310 :                 if (fread(str, 1, size, mf->f) != ssize)
    1413           0 :                         return mdio_seterror(MDIO_IOERROR);
    1414         155 :                 str[size] = 0;
    1415         155 :                 return size;
    1416           0 :         } else if (str) {
    1417           0 :                 if (fread(str, 1, max, mf->f) != ssize)
    1418           0 :                         return mdio_seterror(MDIO_IOERROR);
    1419           0 :                 if (fseek(mf->f, size - max, SEEK_CUR) != 0)
    1420           0 :                         return mdio_seterror(MDIO_IOERROR);
    1421           0 :                 str[max] = 0;
    1422           0 :                 return max;
    1423             :         } else {
    1424           0 :                 if (fseek(mf->f, size, SEEK_CUR) != 0)
    1425           0 :                         return mdio_seterror(MDIO_IOERROR);
    1426             :                 return 0;
    1427             :         }
    1428             : }
    1429             : 
    1430             : 
    1431             : // Reads in a timestep frame from the .trX file and returns the
    1432             : // data in a timestep structure. Returns NULL on error.
    1433         155 : static int trx_timestep(md_file *mf, md_ts *ts) {
    1434             :   int i;
    1435             :   float x[3], y[3], z[3];
    1436             :   trx_hdr *hdr;
    1437             : 
    1438         155 :   if (!mf || !ts) return mdio_seterror(MDIO_BADPARAMS);
    1439         155 :   if (mf->fmt != MDFMT_TRJ && mf->fmt != MDFMT_TRR)
    1440           0 :     return mdio_seterror(MDIO_WRONGFORMAT);
    1441             : 
    1442             :   // Read the header
    1443         155 :   if (trx_header(mf) < 0) return -1;
    1444             : 
    1445             :   // We need some data from the trX header
    1446         150 :   hdr = mf->trx;
    1447         150 :   if (!hdr) return mdio_seterror(MDIO_BADPARAMS);
    1448             : 
    1449         150 :   if (hdr->box_size) { // XXX need to check value of box_size!!
    1450         150 :     if (trx_rvector(mf, x) < 0) return -1;
    1451         150 :     if (trx_rvector(mf, y) < 0) return -1;
    1452         150 :     if (trx_rvector(mf, z) < 0) return -1;
    1453             : 
    1454             :     // Allocate the box and convert the vectors.
    1455         150 :     ts->box = (md_box *) malloc(sizeof(md_box));
    1456         150 :     if (mdio_readbox(ts->box, x, y, z) < 0) {
    1457           0 :       free(ts->box);
    1458           0 :       ts->box = NULL;
    1459           0 :       return -1;
    1460             :     }
    1461             :   }
    1462             : 
    1463         150 :   if (hdr->vir_size) {
    1464           0 :     if (trx_rvector(mf, NULL) < 0) return -1;
    1465           0 :     if (trx_rvector(mf, NULL) < 0) return -1;
    1466           0 :     if (trx_rvector(mf, NULL) < 0) return -1;
    1467             :   }
    1468             : 
    1469         150 :   if (hdr->pres_size) {
    1470           0 :     if (trx_rvector(mf, NULL) < 0) return -1;
    1471           0 :     if (trx_rvector(mf, NULL) < 0) return -1;
    1472           0 :     if (trx_rvector(mf, NULL) < 0) return -1;
    1473             :   }
    1474             : 
    1475         150 :   if (hdr->x_size) {
    1476         150 :     ts->pos = (float *) malloc(sizeof(float) * 3 * hdr->natoms);
    1477         150 :     if (!ts->pos) 
    1478           0 :       return mdio_seterror(MDIO_BADMALLOC);
    1479             : 
    1480         150 :     ts->natoms = hdr->natoms;
    1481      485850 :     for (i = 0; i < hdr->natoms; i++) {
    1482      485700 :       if (trx_rvector(mf, &ts->pos[i * 3]) < 0) {
    1483           0 :         mdio_tsfree(ts, 1);
    1484           0 :         return -1;
    1485             :       }
    1486             : 
    1487      485700 :       ts->pos[i * 3    ] *= ANGS_PER_NM;
    1488      485700 :       ts->pos[i * 3 + 1] *= ANGS_PER_NM;
    1489      485700 :       ts->pos[i * 3 + 2] *= ANGS_PER_NM;
    1490             :     }
    1491             :   }
    1492             : 
    1493         150 :   if (hdr->v_size) {
    1494           0 :     for (i = 0; i < hdr->natoms; i++) {
    1495           0 :       if (trx_rvector(mf, NULL) < 0) {
    1496           0 :         mdio_tsfree(ts, 1);
    1497           0 :         return -1;
    1498             :       }
    1499             :     }
    1500             :   }
    1501             : 
    1502         150 :   if (hdr->f_size) {
    1503           0 :     for (i = 0; i < hdr->natoms; i++) {
    1504           0 :       if (trx_rvector(mf, NULL) < 0) {
    1505           0 :         mdio_tsfree(ts, 1);
    1506           0 :         return -1;
    1507             :       }
    1508             :     }
    1509             :   }
    1510             : 
    1511         150 :   return mdio_seterror(MDIO_SUCCESS);
    1512             : }
    1513             : 
    1514             : 
    1515             : // writes an int in big endian. Returns GMX_SUCCESS
    1516             : // on success or a negative number on error.
    1517           0 : static int put_trx_int(md_file *mf, int y) {
    1518           0 :       if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1519             : 
    1520             :       // sanity check.
    1521             :       if (sizeof(int) != 4) return mdio_seterror(MDIO_SIZEERROR);
    1522             : 
    1523           0 :       if (mf->rev) swap4_aligned(&y, 1);
    1524           0 :       if (fwrite(&y, 4, 1, mf->f) != 1)
    1525           0 :     return mdio_seterror(MDIO_IOERROR);
    1526             : 
    1527           0 :   return mdio_seterror(MDIO_SUCCESS);
    1528             : }
    1529             : 
    1530             : // writes a real in big-endian. Returns GMX_SUCCESS
    1531             : // on success or a negative number on error.
    1532           0 : static int put_trx_real(md_file *mf, float y) {
    1533           0 :       if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1534             : 
    1535           0 :       if (mf->rev) swap4_aligned(&y, 1);
    1536           0 :       if (fwrite(&y, 4, 1, mf->f) != 1)
    1537           0 :         return mdio_seterror(MDIO_IOERROR);
    1538             : 
    1539           0 :       return mdio_seterror(MDIO_SUCCESS);
    1540             : }
    1541             : 
    1542             : 
    1543             : // writes an xdr encoded string. Returns GMX_SUCCESS
    1544             : // on success or a negative number on error.
    1545           0 : static int put_trx_string(md_file *mf, const char *s) {
    1546           0 :         if (!mf || !s) return mdio_seterror(MDIO_BADPARAMS);
    1547             :         
    1548             :         // write: size of object, string length, string data
    1549           0 :         size_t len = strlen(s);
    1550           0 :         if ( put_trx_int(mf, len+1)
    1551           0 :              || put_trx_int(mf, len)
    1552           0 :              || (fwrite(s, len, 1, mf->f) != 1))
    1553           0 :           return mdio_seterror(MDIO_IOERROR);
    1554             : 
    1555           0 :         return mdio_seterror(MDIO_SUCCESS);
    1556             : }
    1557             : 
    1558             : 
    1559             : // xtc_int() - reads an integer from an xtc file
    1560      156752 : static int xtc_int(md_file *mf, int *i) {
    1561             :         unsigned char c[4];
    1562             : 
    1563      156752 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1564             :         // sanity check.
    1565             :         if (sizeof(int) != 4) return mdio_seterror(MDIO_SIZEERROR);
    1566             : 
    1567      156752 :         if (fread(c, 1, 4, mf->f) != 4) {
    1568         204 :                 if (feof(mf->f)) return mdio_seterror(MDIO_EOF);
    1569           0 :                 else if (ferror(mf->f)) return mdio_seterror(MDIO_IOERROR);
    1570           0 :                 else return mdio_seterror(MDIO_UNKNOWNERROR);
    1571             :         }
    1572             : 
    1573      156548 :         if (i) *i = c[3] + (c[2] << 8) + (c[1] << 16) + (c[0] << 24);
    1574      156548 :         return mdio_seterror(MDIO_SUCCESS);
    1575             : }
    1576             : 
    1577             : 
    1578             : // xtc_float() - reads a float from an xtc file
    1579      218551 : static int xtc_float(md_file *mf, float *f) {
    1580             :         unsigned char c[4];
    1581             :         int i;
    1582             : 
    1583      218551 :         if (!mf) return mdio_seterror(MDIO_BADPARAMS);
    1584             : 
    1585      218551 :         if (fread(c, 1, 4, mf->f) != 4) {
    1586           0 :                 if (feof(mf->f)) return mdio_seterror(MDIO_EOF);
    1587           0 :                 else if (ferror(mf->f)) return mdio_seterror(MDIO_IOERROR);
    1588           0 :                 else return mdio_seterror(MDIO_UNKNOWNERROR);
    1589             :         }
    1590             : 
    1591      218551 :         if (f) {
    1592             :                 // By reading the number in as an integer and then
    1593             :                 // copying it to a floating point number we can
    1594             :                 // ensure proper endianness
    1595      218551 :                 i = c[3] + (c[2] << 8) + (c[1] << 16) + (c[0] << 24);
    1596             :                 memcpy(f, &i, 4);
    1597             :         }
    1598      218551 :         return mdio_seterror(MDIO_SUCCESS);
    1599             : }
    1600             : 
    1601             : 
    1602             : // xtc_data() - reads a specific amount of data from an xtc
    1603             : // file using the xdr format.
    1604       10318 : static int xtc_data(md_file *mf, char *buf, int len) {
    1605       10318 :         if (!mf || len < 1) return mdio_seterror(MDIO_BADPARAMS);
    1606       10318 :   size_t slen = (size_t)len;
    1607       10318 :         if (buf) {
    1608       20636 :                 if (fread(buf, 1, slen, mf->f) != slen) {
    1609           0 :                         if (feof(mf->f)) return mdio_seterror(MDIO_EOF);
    1610           0 :                         if (ferror(mf->f)) return mdio_seterror(MDIO_IOERROR);
    1611           0 :                         else return mdio_seterror(MDIO_UNKNOWNERROR);
    1612             :                 }
    1613       10318 :                 if (len % 4) {
    1614        7966 :                         if (fseek(mf->f, 4 - (len % 4), SEEK_CUR)) {
    1615           0 :                                 if (feof(mf->f)) return mdio_seterror(MDIO_EOF);
    1616           0 :                                 if (ferror(mf->f)) return mdio_seterror(MDIO_IOERROR);
    1617           0 :                                 else return mdio_seterror(MDIO_UNKNOWNERROR);
    1618             :                         }
    1619             :                 }
    1620             :         }
    1621             :         else {
    1622             :                 int newlen;
    1623             :                 newlen = len;
    1624           0 :                 if (len % 4) newlen += (4 - (len % 4));
    1625           0 :                 if (fseek(mf->f, newlen, SEEK_CUR)) {
    1626           0 :                         if (feof(mf->f)) return mdio_seterror(MDIO_EOF);
    1627           0 :                         if (ferror(mf->f)) return mdio_seterror(MDIO_IOERROR);
    1628           0 :                         else return mdio_seterror(MDIO_UNKNOWNERROR);
    1629             :                 }
    1630             :         }
    1631             :         return len;
    1632             : }
    1633             : 
    1634             : 
    1635             : // xtc_timestep() - reads a timestep from an .xtc file.
    1636       18603 : static int xtc_timestep(md_file *mf, md_ts *ts) {
    1637             :         int n;
    1638             :         float f, x[3], y[3], z[3];
    1639             : 
    1640       18603 :         int size = 0; // explicitly initialized to zero.
    1641             :         float precision;
    1642             : 
    1643       18603 :         if (!mf || !ts) return mdio_seterror(MDIO_BADPARAMS);
    1644       18603 :         if (!mf->f) return mdio_seterror(MDIO_BADPARAMS);
    1645       18603 :         if (mf->fmt != MDFMT_XTC) return mdio_seterror(MDIO_WRONGFORMAT);
    1646             : 
    1647             :         // Check magic number
    1648       18603 :         if (xtc_int(mf, &n) < 0) return -1;
    1649       18399 :         if (n != XTC_MAGIC) return mdio_seterror(MDIO_BADFORMAT);
    1650             : 
    1651             :         // Get number of atoms
    1652       18399 :         if (xtc_int(mf, &n) < 0) return -1;
    1653       18399 :         ts->natoms = n;
    1654             : 
    1655             :         // Get the simulation step
    1656       18399 :         if (xtc_int(mf, &n) < 0) return -1;
    1657       18399 :         ts->step = n;
    1658             : 
    1659             :         // Get the time value
    1660       18399 :         if (xtc_float(mf, &f) < 0) return -1;
    1661       18399 :         ts->time = f;
    1662             : 
    1663             :         // Read the basis vectors of the box
    1664       36798 :   if ( (xtc_float(mf, &x[0]) < 0) ||
    1665       36798 :        (xtc_float(mf, &x[1]) < 0) ||
    1666       36798 :        (xtc_float(mf, &x[2]) < 0) ||
    1667       36798 :        (xtc_float(mf, &y[0]) < 0) ||
    1668       36798 :        (xtc_float(mf, &y[1]) < 0) ||
    1669       36798 :        (xtc_float(mf, &y[2]) < 0) ||
    1670       36798 :        (xtc_float(mf, &z[0]) < 0) ||
    1671       55197 :        (xtc_float(mf, &z[1]) < 0) ||
    1672       18399 :        (xtc_float(mf, &z[2]) < 0) )
    1673           0 :     return -1;
    1674             :   // Allocate the box and convert the vectors.
    1675       18399 :   ts->box = (md_box *) malloc(sizeof(md_box));
    1676       18399 :   if (mdio_readbox(ts->box, x, y, z) < 0) {
    1677           0 :     free(ts->box);
    1678           0 :     ts->box = NULL;
    1679           0 :     return -1;
    1680             :   }
    1681             : 
    1682       18399 :         ts->pos = (float *) malloc(sizeof(float) * 3 * ts->natoms);
    1683       18399 :         if (!ts->pos) return mdio_seterror(MDIO_BADMALLOC);
    1684       18399 :         n = xtc_3dfcoord(mf, ts->pos, &size, &precision);
    1685       18399 :         if (n < 0) return -1;
    1686             : 
    1687             :         /* Now we're left with the job of scaling... */
    1688    12353424 :         for (n = 0; n < ts->natoms * 3; n++)
    1689    12335025 :                 ts->pos[n] *= ANGS_PER_NM;
    1690             : 
    1691       18399 :         return mdio_seterror(MDIO_SUCCESS);
    1692             : }
    1693             : 
    1694             : 
    1695             : ///////////////////////////////////////////////////////////////////////
    1696             : // This algorithm is an implementation of the 3dfcoord algorithm
    1697             : // written by Frans van Hoesel (hoesel@chem.rug.nl) as part of the
    1698             : // Europort project in 1995.
    1699             : ///////////////////////////////////////////////////////////////////////
    1700             : 
    1701             : // integer table used in decompression
    1702             : static int xtc_magicints[] = {
    1703             :         0, 0, 0, 0, 0, 0, 0, 0, 0,8, 10, 12, 16, 20, 25, 32, 40, 50, 64,
    1704             :         80, 101, 128, 161, 203, 256, 322, 406, 512, 645, 812, 1024, 1290,
    1705             :         1625, 2048, 2580, 3250, 4096, 5060, 6501, 8192, 10321, 13003, 16384,
    1706             :         20642, 26007, 32768, 41285, 52015, 65536, 82570, 104031, 131072,
    1707             :         165140, 208063, 262144, 330280, 416127, 524287, 660561, 832255,
    1708             :         1048576, 1321122, 1664510, 2097152, 2642245, 3329021, 4194304,
    1709             :         5284491, 6658042, 8388607, 10568983, 13316085, 16777216 };
    1710             : 
    1711             : #define FIRSTIDX 9
    1712             : /* note that magicints[FIRSTIDX-1] == 0 */
    1713             : #define LASTIDX (sizeof(xtc_magicints) / sizeof(*xtc_magicints))
    1714             : 
    1715             : 
    1716             : // returns the number of bits in the binary expansion of
    1717             : // the given integer.
    1718           0 : static int xtc_sizeofint(int size) {
    1719             :         unsigned int num = 1;
    1720           0 :   unsigned int ssize = (unsigned int)size;
    1721             :         int nbits = 0;
    1722             : 
    1723           0 :         while (ssize >= num && nbits < 32) {
    1724           0 :                 nbits++;
    1725           0 :                 num <<= 1;
    1726             :         }
    1727           0 :         return nbits;
    1728             : }
    1729             : 
    1730             : // calculates the number of bits a set of integers, when compressed,
    1731             : // will take up.
    1732       10318 : static int xtc_sizeofints(int nints, unsigned int *sizes) {
    1733             :         int i;
    1734             :   unsigned int num;
    1735             :         unsigned int nbytes, nbits, bytes[32], bytecnt, tmp;
    1736             :         nbytes = 1;
    1737       10318 :         bytes[0] = 1;
    1738             :         nbits = 0;
    1739       41272 :         for (i=0; i < nints; i++) {  
    1740             :                 tmp = 0;
    1741       93160 :                 for (bytecnt = 0; bytecnt < nbytes; bytecnt++) {
    1742       62206 :                         tmp = bytes[bytecnt] * sizes[i] + tmp;
    1743       62206 :                         bytes[bytecnt] = tmp & 0xff;
    1744       62206 :                         tmp >>= 8;
    1745             :                 }
    1746       64952 :                 while (tmp != 0) {
    1747       33998 :                         bytes[bytecnt++] = tmp & 0xff;
    1748       33998 :                         tmp >>= 8;
    1749             :                 }
    1750             :                 nbytes = bytecnt;
    1751             :         }
    1752             :         num = 1;
    1753       10318 :         nbytes--;
    1754       46625 :         while (bytes[nbytes] >= num) {
    1755       36307 :                 nbits++;
    1756       36307 :                 num *= 2;
    1757             :         }
    1758       10318 :         return nbits + nbytes * 8;
    1759             : }
    1760             : 
    1761             : // reads bits from a buffer.    
    1762    18314661 : static int xtc_receivebits(int *buf, int nbits) {
    1763             :         int cnt, num; 
    1764             :         unsigned int lastbits, lastbyte;
    1765             :         unsigned char * cbuf;
    1766    18314661 :         int mask = (1 << nbits) -1;
    1767             : 
    1768    18314661 :         cbuf = ((unsigned char *)buf) + 3 * sizeof(*buf);
    1769    18314661 :         cnt = buf[0];
    1770    18314661 :         lastbits = (unsigned int) buf[1];
    1771    18314661 :         lastbyte = (unsigned int) buf[2];
    1772             : 
    1773             :         num = 0;
    1774    31213307 :         while (nbits >= 8) {
    1775    12898646 :                 lastbyte = ( lastbyte << 8 ) | cbuf[cnt++];
    1776    12898646 :                 num |=  (lastbyte >> lastbits) << (nbits - 8);
    1777             :                 nbits -=8;
    1778             :         }
    1779    18314661 :         if (nbits > 0) {
    1780     5416015 :                 if (lastbits < (unsigned int)nbits) {
    1781     2556122 :                         lastbits += 8;
    1782     2556122 :                         lastbyte = (lastbyte << 8) | cbuf[cnt++];
    1783             :                 }
    1784     5416015 :                 lastbits -= nbits;
    1785     5416015 :                 num |= (lastbyte >> lastbits) & ((1 << nbits) -1);
    1786             :         }
    1787    18314661 :         num &= mask;
    1788    18314661 :         buf[0] = cnt;
    1789    18314661 :         buf[1] = lastbits;
    1790    18314661 :         buf[2] = lastbyte;
    1791    18314661 :         return num; 
    1792             : }
    1793             : 
    1794             : // decompresses small integers from the buffer
    1795             : // sizes parameter has to be non-zero to prevent divide-by-zero
    1796     4103594 : static void xtc_receiveints(int *buf, const int nints, int nbits,
    1797             :                         unsigned int *sizes, int *nums) {
    1798             :         int bytes[32];
    1799             :         int i, j, nbytes, p, num;
    1800             : 
    1801     4103594 :         bytes[1] = bytes[2] = bytes[3] = 0;
    1802             :         nbytes = 0;
    1803    16633932 :         while (nbits > 8) {
    1804    12530338 :                 bytes[nbytes++] = xtc_receivebits(buf, 8);
    1805    12530338 :                 nbits -= 8;
    1806             :         }
    1807     4103594 :         if (nbits > 0) {
    1808     4103594 :                 bytes[nbytes++] = xtc_receivebits(buf, nbits);
    1809             :         }
    1810    12310782 :         for (i = nints-1; i > 0; i--) {
    1811             :                 num = 0;
    1812    41475052 :                 for (j = nbytes-1; j >=0; j--) {
    1813    33267864 :                         num = (num << 8) | bytes[j];
    1814    33267864 :                         p = num / sizes[i];
    1815    33267864 :                         bytes[j] = p;
    1816    33267864 :                         num = num - p * sizes[i];
    1817             :                 }
    1818     8207188 :                 nums[i] = num;
    1819             :         }
    1820     4103594 :         nums[0] = bytes[0] | (bytes[1] << 8) | (bytes[2] << 16) | (bytes[3] << 24);
    1821     4103594 : }
    1822             : 
    1823             : // function that actually reads and writes compressed coordinates    
    1824       18399 : static int xtc_3dfcoord(md_file *mf, float *fp, int *size, float *precision) {
    1825             :         static int *ip = NULL;
    1826             :         static int oldsize;
    1827             :         static int *buf;
    1828             : 
    1829             :         int minint[3], maxint[3], *lip;
    1830             :         int smallidx;
    1831             :         unsigned sizeint[3], sizesmall[3], bitsizeint[3], size3;
    1832             :         int flag, k;
    1833             :         int small, smaller, i, is_smaller, run;
    1834             :         float *lfp;
    1835             :         int tmp, *thiscoord,  prevcoord[3];
    1836             : 
    1837             :         int bufsize, lsize;
    1838             :         unsigned int bitsize;
    1839             :         float inv_precision;
    1840             : 
    1841             :         /* avoid uninitialized data compiler warnings */
    1842             :         bitsizeint[0] = 0;
    1843             :         bitsizeint[1] = 0;
    1844             :         bitsizeint[2] = 0;
    1845             : 
    1846       18399 :         if (xtc_int(mf, &lsize) < 0) return -1;
    1847             : 
    1848       18399 :         if (*size != 0 && lsize != *size) return mdio_seterror(MDIO_BADFORMAT);
    1849             : 
    1850       18399 :         *size = lsize;
    1851       18399 :         size3 = *size * 3;
    1852       18399 :         if (*size <= 9) {
    1853       16162 :                 for (i = 0; i < *size; i++) {
    1854        8081 :                         if (xtc_float(mf, fp + (3 * i)) < 0) return -1;
    1855        8081 :                         if (xtc_float(mf, fp + (3 * i) + 1) < 0) return -1;
    1856        8081 :                         if (xtc_float(mf, fp + (3 * i) + 2) < 0) return -1;
    1857             :                 }
    1858             :                 return *size;
    1859             :         }
    1860       10318 :         xtc_float(mf, precision);
    1861       10318 :         if (ip == NULL) {
    1862         123 :                 ip = (int *)malloc(size3 * sizeof(*ip));
    1863         123 :                 if (ip == NULL) return mdio_seterror(MDIO_BADMALLOC);
    1864         123 :                 bufsize = (int) (size3 * 1.2);
    1865         123 :                 buf = (int *)malloc(bufsize * sizeof(*buf));
    1866         123 :                 if (buf == NULL) return mdio_seterror(MDIO_BADMALLOC);
    1867         123 :                 oldsize = *size;
    1868       10195 :         } else if (*size > oldsize) {
    1869           0 :                 ip = (int *)realloc(ip, size3 * sizeof(*ip));
    1870           0 :                 if (ip == NULL) return mdio_seterror(MDIO_BADMALLOC);
    1871           0 :                 bufsize = (int) (size3 * 1.2);
    1872           0 :                 buf = (int *)realloc(buf, bufsize * sizeof(*buf));
    1873           0 :                 if (buf == NULL) return mdio_seterror(MDIO_BADMALLOC);
    1874           0 :                 oldsize = *size;
    1875             :         }
    1876       10318 :         buf[0] = buf[1] = buf[2] = 0;
    1877             : 
    1878       10318 :         xtc_int(mf, &(minint[0]));
    1879       10318 :         xtc_int(mf, &(minint[1]));
    1880       10318 :         xtc_int(mf, &(minint[2]));
    1881             : 
    1882       10318 :         xtc_int(mf, &(maxint[0]));
    1883       10318 :         xtc_int(mf, &(maxint[1]));
    1884       10318 :         xtc_int(mf, &(maxint[2]));
    1885             :                 
    1886       10318 :         sizeint[0] = maxint[0] - minint[0]+1;
    1887       10318 :         sizeint[1] = maxint[1] - minint[1]+1;
    1888       10318 :         sizeint[2] = maxint[2] - minint[2]+1;
    1889             :         
    1890             :         /* check if one of the sizes is to big to be multiplied */
    1891       10318 :         if ((sizeint[0] | sizeint[1] | sizeint[2] ) > 0xffffff) {
    1892           0 :                 bitsizeint[0] = xtc_sizeofint(sizeint[0]);
    1893           0 :                 bitsizeint[1] = xtc_sizeofint(sizeint[1]);
    1894           0 :                 bitsizeint[2] = xtc_sizeofint(sizeint[2]);
    1895             :                 bitsize = 0; /* flag the use of large sizes */
    1896             :         } else {
    1897       10318 :                 bitsize = xtc_sizeofints(3, sizeint);
    1898             :         }
    1899             : 
    1900       10318 :         xtc_int(mf, &smallidx);
    1901       10318 :         smaller = xtc_magicints[FIRSTIDX > smallidx - 1 ? FIRSTIDX : smallidx - 1] / 2;
    1902       10318 :         small = xtc_magicints[smallidx] / 2;
    1903       10318 :         sizesmall[0] = sizesmall[1] = sizesmall[2] = xtc_magicints[smallidx];
    1904             : 
    1905             :         /* check for zero values that would yield corrupted data */
    1906       10318 :         if ( !sizesmall[0] || !sizesmall[1] || !sizesmall[2] ) {
    1907             :                 printf("XTC corrupted, sizesmall==0 (case 1)\n");
    1908           0 :                 return -1;
    1909             :         }
    1910             : 
    1911             : 
    1912             :         /* buf[0] holds the length in bytes */
    1913       10318 :         if (xtc_int(mf, &(buf[0])) < 0) return -1;
    1914             : 
    1915       10318 :         if (xtc_data(mf, (char *) &buf[3], (int) buf[0]) < 0) return -1;
    1916             : 
    1917       10318 :         buf[0] = buf[1] = buf[2] = 0;
    1918             : 
    1919             :         lfp = fp;
    1920       10318 :         inv_precision = 1.0f / (*precision);
    1921             :         run = 0;
    1922             :         i = 0;
    1923       10318 :         lip = ip;
    1924     1317465 :         while (i < lsize) {
    1925     1307147 :                 thiscoord = (int *)(lip) + i * 3;
    1926             : 
    1927     1307147 :                 if (bitsize == 0) {
    1928           0 :                         thiscoord[0] = xtc_receivebits(buf, bitsizeint[0]);
    1929           0 :                         thiscoord[1] = xtc_receivebits(buf, bitsizeint[1]);
    1930           0 :                         thiscoord[2] = xtc_receivebits(buf, bitsizeint[2]);
    1931             :                 } else {
    1932     1307147 :                         xtc_receiveints(buf, 3, bitsize, sizeint, thiscoord);
    1933             :                 }
    1934             : 
    1935     1307147 :                 i++;
    1936     1307147 :                 thiscoord[0] += minint[0];
    1937     1307147 :                 thiscoord[1] += minint[1];
    1938     1307147 :                 thiscoord[2] += minint[2];
    1939             : 
    1940             :                 prevcoord[0] = thiscoord[0];
    1941             :                 prevcoord[1] = thiscoord[1];
    1942             :                 prevcoord[2] = thiscoord[2];
    1943             :  
    1944             : 
    1945     1307147 :                 flag = xtc_receivebits(buf, 1);
    1946             :                 is_smaller = 0;
    1947     1307147 :                 if (flag == 1) {
    1948      373582 :                         run = xtc_receivebits(buf, 5);
    1949      373582 :                         is_smaller = run % 3;
    1950      373582 :                         run -= is_smaller;
    1951      373582 :                         is_smaller--;
    1952             :                 }
    1953     1307147 :                 if (run > 0) {
    1954      785944 :                         thiscoord += 3;
    1955     3582391 :                         for (k = 0; k < run; k+=3) {
    1956     2796447 :                                 xtc_receiveints(buf, 3, smallidx, sizesmall, thiscoord);
    1957     2796447 :                                 i++;
    1958     2796447 :                                 thiscoord[0] += prevcoord[0] - small;
    1959     2796447 :                                 thiscoord[1] += prevcoord[1] - small;
    1960     2796447 :                                 thiscoord[2] += prevcoord[2] - small;
    1961     2796447 :                                 if (k == 0) {
    1962             :                                         /* interchange first with second atom for better
    1963             :                                          * compression of water molecules
    1964             :                                          */
    1965      785944 :                                         tmp = thiscoord[0]; thiscoord[0] = prevcoord[0];
    1966             :                                         prevcoord[0] = tmp;
    1967      785944 :                                         tmp = thiscoord[1]; thiscoord[1] = prevcoord[1];
    1968             :                                         prevcoord[1] = tmp;
    1969      785944 :                                         tmp = thiscoord[2]; thiscoord[2] = prevcoord[2];
    1970             :                                         prevcoord[2] = tmp;
    1971      785944 :                                         *lfp++ = prevcoord[0] * inv_precision;
    1972      785944 :                                         *lfp++ = prevcoord[1] * inv_precision;
    1973      785944 :                                         *lfp++ = prevcoord[2] * inv_precision;
    1974             : 
    1975      785944 :                                         if ( !sizesmall[0] || !sizesmall[1] || !sizesmall[2] ) {
    1976             :                                                 printf("XTC corrupted, sizesmall==0 (case 2)\n");
    1977           0 :                                                 return -1;
    1978             :                                         }
    1979             : 
    1980             :                                 } else {
    1981             :                                         prevcoord[0] = thiscoord[0];
    1982             :                                         prevcoord[1] = thiscoord[1];
    1983             :                                         prevcoord[2] = thiscoord[2];
    1984             :                                 }
    1985     2796447 :                                 *lfp++ = thiscoord[0] * inv_precision;
    1986     2796447 :                                 *lfp++ = thiscoord[1] * inv_precision;
    1987     2796447 :                                 *lfp++ = thiscoord[2] * inv_precision;
    1988             :                         }
    1989             :                 } else {
    1990      521203 :                         *lfp++ = thiscoord[0] * inv_precision;
    1991      521203 :                         *lfp++ = thiscoord[1] * inv_precision;
    1992      521203 :                         *lfp++ = thiscoord[2] * inv_precision;          
    1993             :                 }
    1994     1307147 :                 smallidx += is_smaller;
    1995     1307147 :                 if (is_smaller < 0) {
    1996             :                         small = smaller;
    1997       81903 :                         if (smallidx > FIRSTIDX) {
    1998       81903 :                                 smaller = xtc_magicints[smallidx - 1] /2;
    1999             :                         } else {
    2000             :                                 smaller = 0;
    2001             :                         }
    2002     1225244 :                 } else if (is_smaller > 0) {
    2003             :                         smaller = small;
    2004      149084 :                         small = xtc_magicints[smallidx] / 2;
    2005             :                 }
    2006     1307147 :                 sizesmall[0] = sizesmall[1] = sizesmall[2] = xtc_magicints[smallidx] ;
    2007             :         }
    2008             :         return 1;
    2009             : }
    2010             : }
    2011             : }
    2012             : #endif
    2013             : #endif

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