/*  shift.c

This file is part of a program that implements a Software-Defined Radio.

Copyright (C) 2013 Warren Pratt, NR0V
Copyright (C) 2024 Edouard Griffiths, F4EXB Adapted to SDRangel

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.

The author can be reached by email at

warren@wpratt.com

*/

#include "comm.hpp"
#include "shift.hpp"
#include "RXA.hpp"

namespace WDSP {

void SHIFT::calc_shift (SHIFT *a)
{
    a->delta = TWOPI * a->shift / a->rate;
    a->cos_delta = cos (a->delta);
    a->sin_delta = sin (a->delta);
}

SHIFT* SHIFT::create_shift (int run, int size, float* in, float* out, int rate, double fshift)
{
    SHIFT *a = new SHIFT;
    a->run = run;
    a->size = size;
    a->in = in;
    a->out = out;
    a->rate = (double) rate;
    a->shift = fshift;
    a->phase = 0.0;
    calc_shift (a);
    return a;
}

void SHIFT::destroy_shift (SHIFT *a)
{
    delete (a);
}

void SHIFT::flush_shift (SHIFT *a)
{
    a->phase = 0.0;
}

void SHIFT::xshift (SHIFT *a)
{
    if (a->run)
    {
        int i;
        double I1, Q1, t1, t2;
        double cos_phase = cos (a->phase);
        double sin_phase = sin (a->phase);

        for (i = 0; i < a->size; i++)
        {
            I1 = a->in[2 * i + 0];
            Q1 = a->in[2 * i + 1];
            a->out[2 * i + 0] = I1 * cos_phase - Q1 * sin_phase;
            a->out[2 * i + 1] = I1 * sin_phase + Q1 * cos_phase;
            t1 = cos_phase;
            t2 = sin_phase;
            cos_phase = t1 * a->cos_delta - t2 * a->sin_delta;
            sin_phase = t1 * a->sin_delta + t2 * a->cos_delta;
            a->phase += a->delta;

            if (a->phase >= TWOPI)
                a->phase -= TWOPI;

            if (a->phase <   0.0 )
                a->phase += TWOPI;
        }
    }
    else if (a->in != a->out)
    {
        std::copy( a->in,  a->in + a->size * 2, a->out);
    }
}

void SHIFT::setBuffers_shift(SHIFT *a, float* in, float* out)
{
    a->in = in;
    a->out = out;
}

void SHIFT::setSamplerate_shift (SHIFT *a, int rate)
{
    a->rate = rate;
    a->phase = 0.0;
    calc_shift(a);
}

void SHIFT::setSize_shift (SHIFT *a, int size)
{
    a->size = size;
    flush_shift (a);
}

/********************************************************************************************************
*                                                                                                       *
*                                           RXA Properties                                              *
*                                                                                                       *
********************************************************************************************************/

void SHIFT::SetShiftRun (RXA& rxa, int run)
{
    rxa.shift->run = run;
}

void SHIFT::SetShiftFreq (RXA& rxa, double fshift)
{
    rxa.shift->shift = fshift;
    calc_shift (rxa.shift);
}

} // namespace WDSP