SimpleEnvelope.cpp

/*
 *  Simple Envelope Detectors (source)
 *
 *  File        : SimpleEnvelope.cpp
 *  Library     : SimpleSource
 *  Version     : 1.12
 *  Implements  : EnvelopeDetector, AttRelEnvelope
 *
 *  2006, ChunkWare Music Software, OPEN-SOURCE
 *
 *  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.
 */
 
#include "SimpleEnvelope.h"
 
namespace chunkware_simple
{
    //-------------------------------------------------------------
    // envelope detector
    //-------------------------------------------------------------
    EnvelopeDetector::EnvelopeDetector(double ms, double sampleRate)
    {
        assert(sampleRate > 0.0);
        assert(ms > 0.0);
        sampleRate_ = sampleRate;
        ms_ = ms;
 
        // setCoef();
        // TODO: KB avoid virtual function call in ctor
        coef_ = exp(-1000.0 / (ms_ * sampleRate_));
    }
 
    //-------------------------------------------------------------
    void EnvelopeDetector::setTc(double ms)
    {
        assert(ms > 0.0);
        ms_ = ms;
        setCoef();
    }
 
    //-------------------------------------------------------------
    void EnvelopeDetector::setSampleRate(double sampleRate)
    {
        assert(sampleRate > 0.0);
        sampleRate_ = sampleRate;
        setCoef();
    }
 
    //-------------------------------------------------------------
    void EnvelopeDetector::setCoef(void)
    {
        coef_ = exp(-1000.0 / (ms_ * sampleRate_));
    }
 
    //-------------------------------------------------------------
    // attack/release envelope
    //-------------------------------------------------------------
    AttRelEnvelope::AttRelEnvelope(double att_ms, double rel_ms, double sampleRate)
        : att_(att_ms, sampleRate)
        , rel_(rel_ms, sampleRate)
    {
    }
 
    //-------------------------------------------------------------
    void AttRelEnvelope::setAttack(double ms)
    {
        att_.setTc(ms);
    }
 
    //-------------------------------------------------------------
    void AttRelEnvelope::setRelease(double ms)
    {
        rel_.setTc(ms);
    }
 
    //-------------------------------------------------------------
    void AttRelEnvelope::setSampleRate(double sampleRate)
    {
        att_.setSampleRate(sampleRate);
        rel_.setSampleRate(sampleRate);
    }
 
}   // end namespace chunkware_simple