Revised wording in pdb2gmx.c, hopefully clearer now.

[gromacs/rigid-bodies.git] / src / gmxlib / mtop_util.c

/* -*- mode: c; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; c-file-style: "stroustrup"; -*-
 *
 * 
 * This file is part of Gromacs        Copyright (c) 1991-2008
 * David van der Spoel, Erik Lindahl, Berk Hess, University of Groningen.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * To help us fund GROMACS development, we humbly ask that you cite
 * the research papers on the package. Check out http://www.gromacs.org
 * 
 * And Hey:
 * Gnomes, ROck Monsters And Chili Sauce
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>
#include "smalloc.h"
#include "typedefs.h"
#include "mtop_util.h"
#include "topsort.h"
#include "symtab.h"
#include "gmx_fatal.h"

static int gmx_mtop_maxresnr(const gmx_mtop_t *mtop,int maxres_renum)
{
    int maxresnr,mt,r;
    const t_atoms *atoms;

    maxresnr = 0;

    for(mt=0; mt<mtop->nmoltype; mt++)
    {
        atoms = &mtop->moltype[mt].atoms;
        if (atoms->nres > maxres_renum)
        {
            for(r=0; r<atoms->nres; r++)
            {
                if (atoms->resinfo[r].nr > maxresnr)
                {
                    maxresnr = atoms->resinfo[r].nr;
                }
            }
        }
    }

    return maxresnr;
}

void gmx_mtop_finalize(gmx_mtop_t *mtop)
{
    char *env;

    mtop->maxres_renum = 1;
    
    env = getenv("GMX_MAXRESRENUM");
    if (env != NULL)
    {
        sscanf(env,"%d",&mtop->maxres_renum);
    }
    if (mtop->maxres_renum == -1)
    {
        /* -1 signals renumber residues in all molecules */
        mtop->maxres_renum = INT_MAX;
    }

    mtop->maxresnr = gmx_mtop_maxresnr(mtop,mtop->maxres_renum);
}

int ncg_mtop(const gmx_mtop_t *mtop)
{
    int ncg;
    int mb;
    
    ncg = 0;
    for(mb=0; mb<mtop->nmolblock; mb++)
    {
        ncg +=
            mtop->molblock[mb].nmol*
            mtop->moltype[mtop->molblock[mb].type].cgs.nr;
    }
    
    return ncg;
}

void gmx_mtop_atomnr_to_atom(const gmx_mtop_t *mtop,int atnr_global,
                             t_atom **atom)
{
    int mb,a_start,a_end,atnr_mol;

    if (atnr_global < 0 || atnr_global >= mtop->natoms)
    {
        gmx_fatal(FARGS,"gmx_mtop_atomnr_to_atom was called with atnr_global=%d which is not in the atom range of this system (%d-%d)",
                  atnr_global,0,mtop->natoms-1);
    }
    
    mb = -1;
    a_end = 0;
    do
    {
        mb++;
        a_start = a_end;
        a_end = a_start + mtop->molblock[mb].nmol*mtop->molblock[mb].natoms_mol;
    }
    while (atnr_global >= a_end);
    
    atnr_mol = (atnr_global - a_start) % mtop->molblock[mb].natoms_mol;

    *atom = &mtop->moltype[mtop->molblock[mb].type].atoms.atom[atnr_mol];
}

void gmx_mtop_atomnr_to_ilist(const gmx_mtop_t *mtop,int atnr_global,
                              t_ilist **ilist_mol,int *atnr_offset)
{
    int mb,a_start,a_end,atnr_local;

    if (atnr_global < 0 || atnr_global >= mtop->natoms)
    {
        gmx_fatal(FARGS,"gmx_mtop_atomnr_to_moltype was called with atnr_global=%d which is not in the atom range of this system (%d-%d)",
                  atnr_global,0,mtop->natoms-1);
    }
    
    mb = -1;
    a_end = 0;
    do
    {
        mb++;
        a_start = a_end;
        a_end = a_start + mtop->molblock[mb].nmol*mtop->molblock[mb].natoms_mol;
    }
    while (atnr_global >= a_end);

    *ilist_mol = mtop->moltype[mtop->molblock[mb].type].ilist;
    
    atnr_local = (atnr_global - a_start) % mtop->molblock[mb].natoms_mol;

    *atnr_offset = atnr_global - atnr_local;
}

void gmx_mtop_atomnr_to_molblock_ind(const gmx_mtop_t *mtop,int atnr_global,
                                     int *molb,int *molnr,int *atnr_mol)
{
    int mb,a_start,a_end;
    t_atoms *atoms;

    if (atnr_global < 0 || atnr_global >= mtop->natoms)
    {
        gmx_fatal(FARGS,"gmx_mtop_atomnr_to_moltype was called with atnr_global=%d which is not in the atom range of this system (%d-%d)",
                  atnr_global,0,mtop->natoms-1);
    }
    
    mb = -1;
    a_end = 0;
    do
    {
        mb++;
        a_start = a_end;
        a_end = a_start + mtop->molblock[mb].nmol*mtop->molblock[mb].natoms_mol;
    }
    while (atnr_global >= a_end);

    *molb  = mb;
    *molnr = (atnr_global - a_start) / mtop->molblock[mb].natoms_mol;
    *atnr_mol = atnr_global - a_start - (*molnr)*mtop->molblock[mb].natoms_mol;
}

void gmx_mtop_atominfo_global(const gmx_mtop_t *mtop,int atnr_global,
                              char **atomname,int *resnr,char **resname)
{
    int mb,a_start,a_end,maxresnr,at_loc;
    gmx_molblock_t *molb;
    t_atoms *atoms=NULL;
    
    if (atnr_global < 0 || atnr_global >= mtop->natoms)
    {
        gmx_fatal(FARGS,"gmx_mtop_atominfo_global was called with atnr_global=%d which is not in the atom range of this system (%d-%d)",
                  atnr_global,0,mtop->natoms-1);
    }
    
    mb = -1;
    a_end = 0;
    maxresnr = mtop->maxresnr;
    do
    {
        if (mb >= 0)
        {
            if (atoms->nres <= mtop->maxres_renum)
            {
                /* Single residue molecule, keep counting */
                maxresnr += mtop->molblock[mb].nmol*atoms->nres;
            }
        }
        mb++;
        atoms = &mtop->moltype[mtop->molblock[mb].type].atoms;
        a_start = a_end;
        a_end = a_start + mtop->molblock[mb].nmol*atoms->nr;
    }
    while (atnr_global >= a_end);

    at_loc = (atnr_global - a_start) % atoms->nr;
    *atomname = *(atoms->atomname[at_loc]);
    if (atoms->nres > mtop->maxres_renum)
    {
        *resnr = atoms->resinfo[atoms->atom[at_loc].resind].nr;
    }
    else
    {
        /* Single residue molecule, keep counting */
        *resnr = maxresnr + 1 + (atnr_global - a_start)/atoms->nr*atoms->nres + atoms->atom[at_loc].resind;
    }
    *resname  = *(atoms->resinfo[atoms->atom[at_loc].resind].name);
}

typedef struct gmx_mtop_atomloop_all
{
    const gmx_mtop_t *mtop;
    int        mblock;
    t_atoms    *atoms;
    int        mol;
    int        maxresnr;
    int        at_local;
    int        at_global;
} t_gmx_mtop_atomloop_all;

gmx_mtop_atomloop_all_t
gmx_mtop_atomloop_all_init(const gmx_mtop_t *mtop)
{
    struct gmx_mtop_atomloop_all *aloop;

    snew(aloop,1);

    aloop->mtop         = mtop;
    aloop->mblock       = 0;
    aloop->atoms        =
        &mtop->moltype[mtop->molblock[aloop->mblock].type].atoms;
    aloop->mol          = 0;
    aloop->maxresnr     = mtop->maxresnr;
    aloop->at_local     = -1;
    aloop->at_global    = -1;

    return aloop;
}

static void gmx_mtop_atomloop_all_destroy(gmx_mtop_atomloop_all_t aloop)
{
    sfree(aloop);
}

gmx_bool gmx_mtop_atomloop_all_next(gmx_mtop_atomloop_all_t aloop,
                                int *at_global,t_atom **atom)
{
    if (aloop == NULL)
    {
        gmx_incons("gmx_mtop_atomloop_all_next called without calling gmx_mtop_atomloop_all_init");
    }

    aloop->at_local++;
    aloop->at_global++;

    if (aloop->at_local >= aloop->atoms->nr)
    {
        if (aloop->atoms->nres <= aloop->mtop->maxres_renum)
        {
            /* Single residue molecule, increase the count with one */
            aloop->maxresnr += aloop->atoms->nres;
        }
        aloop->mol++;
        aloop->at_local = 0;
        if (aloop->mol >= aloop->mtop->molblock[aloop->mblock].nmol)
        {
            aloop->mblock++;
            if (aloop->mblock >= aloop->mtop->nmolblock)
            {
                gmx_mtop_atomloop_all_destroy(aloop);
                return FALSE;
            }
            aloop->atoms = &aloop->mtop->moltype[aloop->mtop->molblock[aloop->mblock].type].atoms;
            aloop->mol = 0;
        }
    }

    *at_global = aloop->at_global;
    *atom      = &aloop->atoms->atom[aloop->at_local];

    return TRUE;
}

void gmx_mtop_atomloop_all_names(gmx_mtop_atomloop_all_t aloop,
                                 char **atomname,int *resnr,char **resname)
{
    int resind_mol;

    *atomname = *(aloop->atoms->atomname[aloop->at_local]);
    resind_mol = aloop->atoms->atom[aloop->at_local].resind;
    *resnr = aloop->atoms->resinfo[resind_mol].nr;
    if (aloop->atoms->nres <= aloop->mtop->maxres_renum)
    {
        *resnr = aloop->maxresnr + 1 + resind_mol;
    }
    *resname  = *(aloop->atoms->resinfo[resind_mol].name);
}

void gmx_mtop_atomloop_all_moltype(gmx_mtop_atomloop_all_t aloop,
                                   gmx_moltype_t **moltype,int *at_mol)
{
    *moltype = &aloop->mtop->moltype[aloop->mtop->molblock[aloop->mblock].type];
    *at_mol  = aloop->at_local;
}

typedef struct gmx_mtop_atomloop_block
{
    const gmx_mtop_t *mtop;
    int        mblock;
    t_atoms    *atoms;
    int        at_local;
} t_gmx_mtop_atomloop_block;

gmx_mtop_atomloop_block_t
gmx_mtop_atomloop_block_init(const gmx_mtop_t *mtop)
{
    struct gmx_mtop_atomloop_block *aloop;

    snew(aloop,1);

    aloop->mtop      = mtop;
    aloop->mblock    = 0;
    aloop->atoms     = &mtop->moltype[mtop->molblock[aloop->mblock].type].atoms;
    aloop->at_local  = -1;

    return aloop;
}

static void gmx_mtop_atomloop_block_destroy(gmx_mtop_atomloop_block_t aloop)
{
    sfree(aloop);
}

gmx_bool gmx_mtop_atomloop_block_next(gmx_mtop_atomloop_block_t aloop,
                                  t_atom **atom,int *nmol)
{
    if (aloop == NULL)
    {
        gmx_incons("gmx_mtop_atomloop_all_next called without calling gmx_mtop_atomloop_all_init");
    }

    aloop->at_local++;

    if (aloop->at_local >= aloop->atoms->nr)
    {
        aloop->mblock++;
        if (aloop->mblock >= aloop->mtop->nmolblock)
        {
            gmx_mtop_atomloop_block_destroy(aloop);
            return FALSE;
        }
        aloop->atoms = &aloop->mtop->moltype[aloop->mtop->molblock[aloop->mblock].type].atoms;
        aloop->at_local = 0;
    }
    
    *atom = &aloop->atoms->atom[aloop->at_local];
    *nmol = aloop->mtop->molblock[aloop->mblock].nmol;
   
    return TRUE;
}

typedef struct gmx_mtop_ilistloop
{
    const gmx_mtop_t *mtop;
    int           mblock;
} t_gmx_mtop_ilist;

gmx_mtop_ilistloop_t
gmx_mtop_ilistloop_init(const gmx_mtop_t *mtop)
{
    struct gmx_mtop_ilistloop *iloop;

    snew(iloop,1);

    iloop->mtop      = mtop;
    iloop->mblock    = -1;

    return iloop;
}

static void gmx_mtop_ilistloop_destroy(gmx_mtop_ilistloop_t iloop)
{
    sfree(iloop);
}

gmx_bool gmx_mtop_ilistloop_next(gmx_mtop_ilistloop_t iloop,
                             t_ilist **ilist_mol,int *nmol)
{
    if (iloop == NULL)
    {
        gmx_incons("gmx_mtop_ilistloop_next called without calling gmx_mtop_ilistloop_init");
    }

    iloop->mblock++;
    if (iloop->mblock == iloop->mtop->nmolblock)
    {
        gmx_mtop_ilistloop_destroy(iloop);
        return FALSE;
    }

    *ilist_mol =
        iloop->mtop->moltype[iloop->mtop->molblock[iloop->mblock].type].ilist;

    *nmol = iloop->mtop->molblock[iloop->mblock].nmol;

    return TRUE;
}
typedef struct gmx_mtop_ilistloop_all
{
    const gmx_mtop_t *mtop;
    int           mblock;
    int           mol;
    int           a_offset;
} t_gmx_mtop_ilist_all;

gmx_mtop_ilistloop_all_t
gmx_mtop_ilistloop_all_init(const gmx_mtop_t *mtop)
{
    struct gmx_mtop_ilistloop_all *iloop;

    snew(iloop,1);

    iloop->mtop      = mtop;
    iloop->mblock    = 0;
    iloop->mol       = -1;
    iloop->a_offset  = 0;

    return iloop;
}

static void gmx_mtop_ilistloop_all_destroy(gmx_mtop_ilistloop_all_t iloop)
{
    sfree(iloop);
}

gmx_bool gmx_mtop_ilistloop_all_next(gmx_mtop_ilistloop_all_t iloop,
                                 t_ilist **ilist_mol,int *atnr_offset)
{
    gmx_molblock_t *molb;

    if (iloop == NULL)
    {
        gmx_incons("gmx_mtop_ilistloop_all_next called without calling gmx_mtop_ilistloop_all_init");
    }
    
    if (iloop->mol >= 0)
    {
        iloop->a_offset += iloop->mtop->molblock[iloop->mblock].natoms_mol;
    }

    iloop->mol++;

    if (iloop->mol >= iloop->mtop->molblock[iloop->mblock].nmol) {
        iloop->mblock++;
        iloop->mol = 0;
        if (iloop->mblock == iloop->mtop->nmolblock)
        {
            gmx_mtop_ilistloop_all_destroy(iloop);
            return FALSE;
        }
    }
    
    *ilist_mol =
        iloop->mtop->moltype[iloop->mtop->molblock[iloop->mblock].type].ilist;

    *atnr_offset = iloop->a_offset;

    return TRUE;
}

int gmx_mtop_ftype_count(const gmx_mtop_t *mtop,int ftype)
{
    gmx_mtop_ilistloop_t iloop;
    t_ilist *il;
    int n,nmol;

    n = 0;

    iloop = gmx_mtop_ilistloop_init(mtop);
    while (gmx_mtop_ilistloop_next(iloop,&il,&nmol))
    {
        n += nmol*il[ftype].nr/(1+NRAL(ftype));
    }

    return n;
}

t_block gmx_mtop_global_cgs(const gmx_mtop_t *mtop)
{
    t_block cgs_gl,*cgs_mol;
    int mb,mol,cg;
    gmx_molblock_t *molb;
    t_atoms *atoms;
    
    /* In most cases this is too much, but we realloc at the end */
    snew(cgs_gl.index,mtop->natoms+1);
    
    cgs_gl.nr       = 0;
    cgs_gl.index[0] = 0;
    for(mb=0; mb<mtop->nmolblock; mb++)
    {
        molb    = &mtop->molblock[mb];
        cgs_mol = &mtop->moltype[molb->type].cgs;
        for(mol=0; mol<molb->nmol; mol++)
        {
            for(cg=0; cg<cgs_mol->nr; cg++)
            {
                cgs_gl.index[cgs_gl.nr+1] =
                    cgs_gl.index[cgs_gl.nr] +
                    cgs_mol->index[cg+1] - cgs_mol->index[cg];
                cgs_gl.nr++;
            }
        }
    }
    cgs_gl.nalloc_index = cgs_gl.nr + 1;
    srenew(cgs_gl.index,cgs_gl.nalloc_index);

    return cgs_gl;
}

static void atomcat(t_atoms *dest, t_atoms *src, int copies,
                    int maxres_renum, int *maxresnr)
{
    int i,j,l,size;
    int srcnr=src->nr;
    int destnr=dest->nr;

    if (srcnr)
    {
        size=destnr+copies*srcnr;
        srenew(dest->atom,size);
        srenew(dest->atomname,size);
        srenew(dest->atomtype,size);
        srenew(dest->atomtypeB,size);
    }
    if (src->nres)
    {
        size=dest->nres+copies*src->nres;
        srenew(dest->resinfo,size);
    }
    
    /* residue information */
    for (l=dest->nres,j=0; (j<copies); j++,l+=src->nres)
    {
        memcpy((char *) &(dest->resinfo[l]),(char *) &(src->resinfo[0]),
               (size_t)(src->nres*sizeof(src->resinfo[0])));
    }
    
    for (l=destnr,j=0; (j<copies); j++,l+=srcnr)
    {
        memcpy((char *) &(dest->atomname[l]),(char *) &(src->atomname[0]),
               (size_t)(srcnr*sizeof(src->atomname[0])));
        memcpy((char *) &(dest->atomtype[l]),(char *) &(src->atomtype[0]),
               (size_t)(srcnr*sizeof(src->atomtype[0])));
        memcpy((char *) &(dest->atomtypeB[l]),(char *) &(src->atomtypeB[0]),
               (size_t)(srcnr*sizeof(src->atomtypeB[0])));
        memcpy((char *) &(dest->atom[l]),(char *) &(src->atom[0]),
               (size_t)(srcnr*sizeof(src->atom[0])));
    }
    
    /* Increment residue indices */
    for (l=destnr,j=0; (j<copies); j++)
    {
        for (i=0; (i<srcnr); i++,l++)
        {
            dest->atom[l].resind = dest->nres+j*src->nres+src->atom[i].resind;
        }
    }    
    
    if (src->nres <= maxres_renum)
    {
        /* Single residue molecule, continue counting residues */
        for (j=0; (j<copies); j++)
        {
            for (l=0; l<src->nres; l++)
            {
                (*maxresnr)++;
                dest->resinfo[dest->nres+j*src->nres+l].nr = *maxresnr;
            }
        }
    }
    
    dest->nres += copies*src->nres;
    dest->nr   += copies*src->nr;
}

t_atoms gmx_mtop_global_atoms(const gmx_mtop_t *mtop)
{
    t_atoms atoms;
    int maxresnr,mb;
    gmx_molblock_t *molb;

    init_t_atoms(&atoms,0,FALSE);

    maxresnr = mtop->maxresnr;
    for(mb=0; mb<mtop->nmolblock; mb++)
    {
        molb = &mtop->molblock[mb];
        atomcat(&atoms,&mtop->moltype[molb->type].atoms,molb->nmol,
                mtop->maxres_renum,&maxresnr);
    }
    
    return atoms;
}

void gmx_mtop_make_atomic_charge_groups(gmx_mtop_t *mtop,
                                        gmx_bool bKeepSingleMolCG)
{
    int     mb,cg;
    t_block *cgs_mol;
    
    for(mb=0; mb<mtop->nmolblock; mb++)
    {
        cgs_mol = &mtop->moltype[mtop->molblock[mb].type].cgs;
        if (!(bKeepSingleMolCG && cgs_mol->nr == 1))
        {
            cgs_mol->nr           = mtop->molblock[mb].natoms_mol;
            cgs_mol->nalloc_index = cgs_mol->nr + 1;
            srenew(cgs_mol->index,cgs_mol->nalloc_index);
            for(cg=0; cg<cgs_mol->nr+1; cg++)
            {
                cgs_mol->index[cg] = cg;
            }
        }
    }
}

/*
 * The cat routines below are old code from src/kernel/topcat.c
 */ 

static void blockcat(t_block *dest,t_block *src,int copies, 
                     int dnum,int snum)
{
    int i,j,l,nra,size;
    
    if (src->nr)
    {
        size=(dest->nr+copies*src->nr+1);
        srenew(dest->index,size);
    }
    
    nra = dest->index[dest->nr];
    for (l=dest->nr,j=0; (j<copies); j++)
    {
        for (i=0; (i<src->nr); i++)
        {
            dest->index[l++] = nra + src->index[i];
        }
        nra += src->index[src->nr];
    }
    dest->nr += copies*src->nr;
    dest->index[dest->nr] = nra;
}

static void blockacat(t_blocka *dest,t_blocka *src,int copies, 
                      int dnum,int snum)
{
    int i,j,l,size;
    int destnr  = dest->nr;
    int destnra = dest->nra;
    
    if (src->nr)
    {
        size=(dest->nr+copies*src->nr+1);
        srenew(dest->index,size);
    }
    if (src->nra)
    {
        size=(dest->nra+copies*src->nra);
        srenew(dest->a,size);
    }
    
    for (l=destnr,j=0; (j<copies); j++)
    {
        for (i=0; (i<src->nr); i++)
        {
            dest->index[l++] = dest->nra+src->index[i];
        }
        dest->nra += src->nra;
    }
    for (l=destnra,j=0; (j<copies); j++)
    {
        for (i=0; (i<src->nra); i++)
        {
            dest->a[l++] = dnum+src->a[i];
        }
        dnum+=snum;
        dest->nr += src->nr;
    }
    dest->index[dest->nr] = dest->nra;
}

static void ilistcat(int ftype,t_ilist *dest,t_ilist *src,int copies, 
                     int dnum,int snum)
{
    int nral,c,i,a;

    nral = NRAL(ftype);

    dest->nalloc = dest->nr + copies*src->nr;
    srenew(dest->iatoms,dest->nalloc);

    for(c=0; c<copies; c++)
    {
        for(i=0; i<src->nr; )
        {
            dest->iatoms[dest->nr++] = src->iatoms[i++];
            for(a=0; a<nral; a++)
            {
                dest->iatoms[dest->nr++] = dnum + src->iatoms[i++];
            }
        }
        dnum += snum;
    }
}

static void set_posres_params(t_idef *idef,gmx_molblock_t *molb,
                              int i0,int a_offset)
{
    t_ilist *il;
    int i1,i,a_molb;
    t_iparams *ip;

    il = &idef->il[F_POSRES];
    i1 = il->nr/2;
    idef->iparams_posres_nalloc = i1;
    srenew(idef->iparams_posres,idef->iparams_posres_nalloc);
    for(i=i0; i<i1; i++)
    {
        ip = &idef->iparams_posres[i];
        /* Copy the force constants */
        *ip    = idef->iparams[il->iatoms[i*2]];
        a_molb = il->iatoms[i*2+1] - a_offset;
        if (molb->nposres_xA == 0)
        {
            gmx_incons("Position restraint coordinates are missing");
        }
        ip->posres.pos0A[XX] = molb->posres_xA[a_molb][XX];
        ip->posres.pos0A[YY] = molb->posres_xA[a_molb][YY];
        ip->posres.pos0A[ZZ] = molb->posres_xA[a_molb][ZZ];
        if (molb->nposres_xB > 0)
        {
            ip->posres.pos0B[XX] = molb->posres_xB[a_molb][XX];
            ip->posres.pos0B[YY] = molb->posres_xB[a_molb][YY];
            ip->posres.pos0B[ZZ] = molb->posres_xB[a_molb][ZZ];
        }
        else
        {
            ip->posres.pos0B[XX] = ip->posres.pos0A[XX];
            ip->posres.pos0B[YY] = ip->posres.pos0A[YY];
            ip->posres.pos0B[ZZ] = ip->posres.pos0A[ZZ];
        }
        /* Set the parameter index for idef->iparams_posre */
        il->iatoms[i*2] = i;
    }
}

static void gen_local_top(const gmx_mtop_t *mtop,const t_inputrec *ir,
                          gmx_bool bMergeConstr,
                          gmx_localtop_t *top)
{
    int mb,srcnr,destnr,ftype,ftype_dest,mt,natoms,mol,nposre_old;
    gmx_molblock_t *molb;
    gmx_moltype_t *molt;
    const gmx_ffparams_t *ffp;
    t_idef *idef;
    real   *qA,*qB;
    gmx_mtop_atomloop_all_t aloop;
    int    ag;
    t_atom *atom;

    top->atomtypes = mtop->atomtypes;
    
    ffp = &mtop->ffparams;
    
    idef = &top->idef;
    idef->ntypes   = ffp->ntypes;
    idef->atnr     = ffp->atnr;
    idef->functype = ffp->functype;
    idef->iparams  = ffp->iparams;
    idef->iparams_posres = NULL;
    idef->iparams_posres_nalloc = 0;
    idef->fudgeQQ  = ffp->fudgeQQ;
    idef->cmap_grid = ffp->cmap_grid;
    idef->ilsort   = ilsortUNKNOWN;

    init_block(&top->cgs);
    init_blocka(&top->excls);
    for(ftype=0; ftype<F_NRE; ftype++)
    {
        idef->il[ftype].nr     = 0;
        idef->il[ftype].nalloc = 0;
        idef->il[ftype].iatoms = NULL;
    }

    natoms = 0;
    for(mb=0; mb<mtop->nmolblock; mb++)
    {
        molb = &mtop->molblock[mb];
        molt = &mtop->moltype[molb->type];
        
        srcnr  = molt->atoms.nr;
        destnr = natoms;
        
        blockcat(&top->cgs,&molt->cgs,molb->nmol,destnr,srcnr);

        blockacat(&top->excls,&molt->excls,molb->nmol,destnr,srcnr);

        nposre_old = idef->il[F_POSRES].nr;
        for(ftype=0; ftype<F_NRE; ftype++)
        {
            if (bMergeConstr &&
                ftype == F_CONSTR && molt->ilist[F_CONSTRNC].nr > 0)
            {
                /* Merge all constrains into one ilist.
                 * This simplifies the constraint code.
                 */
                for(mol=0; mol<molb->nmol; mol++) {
                    ilistcat(ftype,&idef->il[F_CONSTR],&molt->ilist[F_CONSTR],
                             1,destnr+mol*srcnr,srcnr);
                    ilistcat(ftype,&idef->il[F_CONSTR],&molt->ilist[F_CONSTRNC],
                             1,destnr+mol*srcnr,srcnr);
                }
            }
            else if (!(bMergeConstr && ftype == F_CONSTRNC))
            {
                ilistcat(ftype,&idef->il[ftype],&molt->ilist[ftype],
                         molb->nmol,destnr,srcnr);
            }
        }
        if (idef->il[F_POSRES].nr > nposre_old)
        {
            set_posres_params(idef,molb,nposre_old/2,natoms);
        }

        natoms += molb->nmol*srcnr;
    }

    if (ir == NULL)
    {
        top->idef.ilsort = ilsortUNKNOWN;
    }
    else
    {
        if (ir->efep != efepNO && gmx_mtop_bondeds_free_energy(mtop))
        {
            snew(qA,mtop->natoms);
            snew(qB,mtop->natoms);
            aloop = gmx_mtop_atomloop_all_init(mtop);
            while (gmx_mtop_atomloop_all_next(aloop,&ag,&atom))
            {
                qA[ag] = atom->q;
                qB[ag] = atom->qB;
            }
            gmx_sort_ilist_fe(&top->idef,qA,qB);
            sfree(qA);
            sfree(qB);
        }
        else
        {
            top->idef.ilsort = ilsortNO_FE;
        }
    }
}

gmx_localtop_t *gmx_mtop_generate_local_top(const gmx_mtop_t *mtop,
                                            const t_inputrec *ir)
{
    gmx_localtop_t *top;

    snew(top,1);

    gen_local_top(mtop,ir,TRUE,top);

    return top;
}

t_topology gmx_mtop_t_to_t_topology(gmx_mtop_t *mtop)
{
    int mt,mb;
    gmx_localtop_t ltop;
    t_topology top;

    gen_local_top(mtop,NULL,FALSE,&ltop);

    top.name      = mtop->name;
    top.idef      = ltop.idef;
    top.atomtypes = ltop.atomtypes;
    top.cgs       = ltop.cgs;
    top.excls     = ltop.excls;
    top.atoms     = gmx_mtop_global_atoms(mtop);
    top.mols      = mtop->mols;
    top.symtab    = mtop->symtab;

    /* We only need to free the moltype and molblock data,
     * all other pointers have been copied to top.
     *
     * Well, except for the group data, but we can't free those, because they
     * are used somewhere even after a call to this function.
     */
    for(mt=0; mt<mtop->nmoltype; mt++)
    {
        done_moltype(&mtop->moltype[mt]);
    }
    sfree(mtop->moltype);

    for(mb=0; mb<mtop->nmolblock; mb++)
    {
        done_molblock(&mtop->molblock[mb]);
    }
    sfree(mtop->molblock);

    return top;
}