/*
 * DISTRHO PingPongPan Plugin, based on PingPongPan by Michael Gruhn
 * Copyright (C) 2007 Michael Gruhn <michael-gruhn@web.de>
 * Copyright (C) 2012-2015 Filipe Coelho <falktx@falktx.com>
 *
 * This program 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.
 *
 * 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 Lesser General Public License for more details.
 *
 * For a full copy of the license see the LICENSE file.
 */

#include "DistrhoPluginPingPongPan.hpp"

#include <cmath>

static const float k2PI = 6.283185307f;

START_NAMESPACE_DISTRHO

// -----------------------------------------------------------------------

DistrhoPluginPingPongPan::DistrhoPluginPingPongPan()
    : Plugin(paramCount, 1, 0) // 1 program, 0 states
{
    // set default values
    loadProgram(0);

    // reset
    deactivate();
}

// -----------------------------------------------------------------------
// Init

void DistrhoPluginPingPongPan::initParameter(uint32_t index, Parameter& parameter)
{
    switch (index)
    {
    case paramFreq:
        parameter.hints      = kParameterIsAutomable;
        parameter.name       = "Frequency";
        parameter.symbol     = "freq";
        parameter.ranges.def = 50.0f;
        parameter.ranges.min = 0.0f;
        parameter.ranges.max = 100.0f;
        break;

    case paramWidth:
        parameter.hints      = kParameterIsAutomable;
        parameter.name       = "Width";
        parameter.symbol     = "width";
        parameter.unit       = "%";
        parameter.ranges.def = 75.0f;
        parameter.ranges.min = 0.0f;
        parameter.ranges.max = 100.0f;
        break;
    }
}

void DistrhoPluginPingPongPan::initProgramName(uint32_t index, String& programName)
{
    if (index != 0)
        return;

    programName = "Default";
}

// -----------------------------------------------------------------------
// Internal data

float DistrhoPluginPingPongPan::getParameterValue(uint32_t index) const
{
    switch (index)
    {
    case paramFreq:
        return fFreq;
    case paramWidth:
        return fWidth;
    default:
        return 0.0f;
    }
}

void DistrhoPluginPingPongPan::setParameterValue(uint32_t index, float value)
{
    if (getSampleRate() <= 0.0)
        return;

    switch (index)
    {
    case paramFreq:
        fFreq = value;
        waveSpeed = (k2PI * fFreq / 100.0f)/(float)getSampleRate();
        break;
    case paramWidth:
        fWidth = value;
        break;
    }
}

void DistrhoPluginPingPongPan::loadProgram(uint32_t index)
{
    if (index != 0)
        return;

    // Default values
    fFreq  = 50.0f;
    fWidth = 75.0f;

    // reset filter values
    activate();
}

// -----------------------------------------------------------------------
// Process

void DistrhoPluginPingPongPan::activate()
{
    waveSpeed = (k2PI * fFreq / 100.0f)/(float)getSampleRate();
}

void DistrhoPluginPingPongPan::deactivate()
{
    wavePos = 0.0f;
}

void DistrhoPluginPingPongPan::run(const float* const* inputs, float** outputs, uint32_t frames)
{
    const float* in1  = inputs[0];
    const float* in2  = inputs[1];
    float*       out1 = outputs[0];
    float*       out2 = outputs[1];

    for (uint32_t i=0; i < frames; ++i)
    {
        pan = std::fmin(std::fmax(std::sin(wavePos) * (fWidth/100.0f), -1.0f), 1.0f);

        if ((wavePos += waveSpeed) >= k2PI)
            wavePos -= k2PI;

        out1[i] = in1[i] * (pan > 0.0f ? 1.0f-pan : 1.0f);
        out2[i] = in2[i] * (pan < 0.0f ? 1.0f+pan : 1.0f);
    }
}

// -----------------------------------------------------------------------

Plugin* createPlugin()
{
    return new DistrhoPluginPingPongPan();
}

// -----------------------------------------------------------------------

END_NAMESPACE_DISTRHO
