htbl.c

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/*                          H T B L . C
 * BRL-CAD
 *
 * Copyright (c) 2004-2006 United States Government as represented by
 * the U.S. Army Research Laboratory.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this file; see the file named COPYING for more
 * information.
 */

/** @addtogroup librt */

/*@{*/
/** @file htbl.c
 *  Support for variable length arrays of "struct hit".
 *  Patterned after the libbu/ptbl.c idea.
 *
 *  Author -
 *      Michael John Muuss
 *
 *  Source -
 *      The U. S. Army Research Laboratory
 *      Aberdeen Proving Ground, Maryland  21005-5068  USA
 *
 */
/*@}*/

#ifndef lint
static const char librt_htbl_RCSid[] = "@(#)$Header: /cvsroot/brlcad/brlcad/src/librt/htbl.c,v 14.10 2006/09/16 02:04:25 lbutler Exp $ (ARL)";
#endif

#include "common.h"


#include <stdio.h>
#include <string.h>
#include "machine.h"
#include "bu.h"
#include "vmath.h"
#include "raytrace.h"

/*
 *                      R T _ H T B L _ I N I T
 */
void
rt_htbl_init(struct rt_htbl *b, int len, const char *str)

                                /* initial len. */

{
        if (bu_debug & BU_DEBUG_PTBL)
                bu_log("rt_htbl_init(%8x, len=%d, %s)\n", b, len, str);
        BU_LIST_INIT(&b->l);
        b->l.magic = RT_HTBL_MAGIC;
        if( len <= 0 )  len = 64;
        b->blen = len;
        b->hits = (struct hit *)bu_calloc(b->blen, sizeof(struct hit), str);
        b->end = 0;
}

/*
 *                      R T _ H T B L _ R E S E T
 *
 *  Reset the table to have no elements, but retain any existing storage.
 */
void
rt_htbl_reset(struct rt_htbl *b)
{
        RT_CK_HTBL(b);
        b->end = 0;
        if (bu_debug & BU_DEBUG_PTBL)
                bu_log("rt_htbl_reset(%8x)\n", b);
}

/*
 *                      R T _ H T B L _ F R E E
 *
 *  Deallocate dynamic hit buffer
 *  and render unusable without a subsequent rt_htbl_init().
 */
void
rt_htbl_free(struct rt_htbl *b)
{
        RT_CK_HTBL(b);

        bu_free((genptr_t)b->hits, "rt_htbl.hits[]");
        bzero((char *)b, sizeof(struct rt_htbl));       /* sanity */

        if (bu_debug & BU_DEBUG_PTBL)
                bu_log("rt_htbl_free(%8x)\n", b);
}

/*
 *                      R T _ H T B L _ G E T
 *
 *  Allocate another hit structure, extending the array if necessary.
 */
struct hit *
rt_htbl_get(struct rt_htbl *b)
{
        RT_CK_HTBL(b);

        if( b->end >= b->blen )  {
                /* Increase size of array */
                b->hits = (struct hit *)bu_realloc( (char *)b->hits,
                        sizeof(struct hit) * (b->blen *= 4),
                        "rt_htbl.hits[]" );
        }

        /* There is sufficient room */
        return &b->hits[b->end++];
}

/*
 * Local Variables:
 * mode: C
 * tab-width: 8
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 * ex: shiftwidth=4 tabstop=8
 */

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