Application: gvSIG desktop

/******************************************************************************

 * $Id: nad_init.c,v 1.8 2003/03/17 18:56:01 warmerda Exp $

 *

 * Project:  PROJ.4

 * Purpose:  Load datum shift files into memory.

 * Author:   Frank Warmerdam, warmerdam@pobox.com

 *

 ******************************************************************************

 * Copyright (c) 2000, Frank Warmerdam

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included

 * in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 * DEALINGS IN THE SOFTWARE.

 ******************************************************************************

 *

 * $Log: nad_init.c,v $

 * Revision 1.8  2003/03/17 18:56:01  warmerda

 * implement delayed loading of ctable format files

 *

 * Revision 1.7  2003/03/15 06:02:02  warmerda

 * preliminary NTv2 support, major restructure of datum shifting

 *

 * Revision 1.6  2002/07/08 02:32:05  warmerda

 * ensure clean C++ builds

 *

 * Revision 1.5  2002/04/30 16:26:07  warmerda

 * trip newlines of ctable id field

 *

 * Revision 1.4  2001/08/17 17:28:37  warmerda

 * removed use of emess()

 *

 * Revision 1.3  2001/04/05 19:31:54  warmerda

 * substantially reorganized and added NTv1 support

 *

 */

#define PJ_LIB__

#include <projects.h>

#include <stdio.h>

#include <errno.h>

#include <assert.h>

#include <string.h>

/************************************************************************/

/*                          nad_ctable_load()                           */

/*                                                                      */

/*      Load the data portion of a ctable formatted grid.               */

/************************************************************************/

int nad_ctable_load( struct CTABLE *ct, FILE *fid )

{

    int  a_size;

    fseek( fid, sizeof(struct CTABLE), SEEK_SET );

    /* read all the actual shift values */

    a_size = ct->lim.lam * ct->lim.phi;

    ct->cvs = (FLP *) pj_malloc(sizeof(FLP) * a_size);

    if( ct->cvs == NULL 

        || fread(ct->cvs, sizeof(FLP), a_size, fid) != a_size )

    {

        pj_errno = -38;

        return 0;

    }

    return 1;

} 

/************************************************************************/

/*                          nad_ctable_init()                           */

/*                                                                      */

/*      Read the header portion of a "ctable" format grid.              */

/************************************************************************/

struct CTABLE *nad_ctable_init( FILE * fid )

{

    struct CTABLE *ct;

    int                id_end;

    /* read the table header */

    ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));

    if( ct == NULL 

        || fread( ct, sizeof(struct CTABLE), 1, fid ) != 1 )

    {

        pj_errno = -38;

        return NULL;

    }

    /* do some minimal validation to ensure the structure isn't corrupt */

    if( ct->lim.lam < 1 || ct->lim.lam > 100000 

        || ct->lim.phi < 1 || ct->lim.phi > 100000 )

    {

        pj_errno = -38;

        return NULL;

    }

    /* trim white space and newlines off id */

    for( id_end = strlen(ct->id)-1; id_end > 0; id_end-- )

    {

        if( ct->id[id_end] == '\n' || ct->id[id_end] == ' ' )

            ct->id[id_end] = '\0';

        else

            break;

    }

    ct->cvs = NULL;

    return ct;

}

/************************************************************************/

/*                              nad_init()                              */

/*                                                                      */

/*      Read a datum shift file in any of the supported binary formats. */

/************************************************************************/

struct CTABLE *nad_init(char *name) 

{

    char         fname[MAX_PATH_FILENAME+1];

    struct CTABLE *ct;

    FILE         *fid;

    char        header[512];

    errno = pj_errno = 0;

/* -------------------------------------------------------------------- */

/*      Open the file using the usual search rules.                     */

/* -------------------------------------------------------------------- */

    strcpy(fname, name);

    if (!(fid = pj_open_lib(fname, "rb"))) {

        pj_errno = errno;

        return 0;

    }

    ct = nad_ctable_init( fid );

    if( ct != NULL )

    {

        if( !nad_ctable_load( ct, fid ) )

        {

            nad_free( ct );

            ct = NULL;

        }

    }

    fclose(fid);

    return ct;

}

/************************************************************************/

/*                              nad_free()                              */

/*                                                                      */

/*      Free a CTABLE grid shift structure produced by nad_init().      */

/************************************************************************/

void nad_free(struct CTABLE *ct) 

{

    if (ct) {

        if( ct->cvs != NULL )

            pj_dalloc(ct->cvs);

        pj_dalloc(ct);

    }

}