/*  Scicos
*
*  Copyright (C) INRIA - METALAU Project <scicos@inria.fr>
*
* 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.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* See the file ./license.txt
*/
/*--------------------------------------------------------------------------*/
#include <math.h>
#include "MALLOC.h"
#include "scicos_block.h"
#include "dynlib_scicos_blocks.h"
#include "scicos_free.h"
#include "scicos_malloc.h"
/*--------------------------------------------------------------------------*/
SCICOS_BLOCKS_IMPEXP void ratelimiter(scicos_block *block, int flag)
{
    /*  rpar[0]=rising rate limit, rpar[1]=falling rate limit */
    double* pw = NULL;
    double rate = 0. , t = 0.;

    double** work = (double**) block->work;

    if (flag == 4)
    {
        /* the workspace is used to store previous values */
        if ((*work = (double*) scicos_malloc(sizeof(double) * 4)) == NULL )
        {
            set_block_error(-16);
            return;
        }
        pw = *work;
        pw[0] = 0.0;
        pw[1] = 0.0;
        pw[2] = 0.0;
        pw[3] = 0.0;
    }
    else  if (flag == 5)
    {
        scicos_free(*work);
    }
    else if (flag == 1)
    {
        if (get_phase_simulation() == 1)
        {
            do_cold_restart();
        }
        pw = *work;
        t = get_scicos_time();
        if (t > pw[2])
        {
            pw[0] = pw[2];
            pw[1] = pw[3];
            rate = (block->inptr[0][0] - pw[1]) / (t - pw[0]);
        }
        else if (t <= pw[2])
        {
            if (t > pw[0])
            {
                rate = (block->inptr[0][0] - pw[1]) / (t - pw[0]);
            }
            else
            {
                rate = 0.0;
            }
        }

        if (rate > block->rpar[0])
        {
            block->outptr[0][0] = (t - pw[0]) * block->rpar[0] + pw[1];
        }
        else if (rate < block->rpar[1])
        {
            block->outptr[0][0] = (t - pw[0]) * block->rpar[1] + pw[1];
        }
        else
        {
            block->outptr[0][0] = block->inptr[0][0];
        }
        pw[2] = t;
        pw[3] = block->outptr[0][0];
    }
}
/*--------------------------------------------------------------------------*/