engines/gig/EGDecay.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *                                                                         *
 *   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., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#include "EGDecay.h"

namespace LinuxSampler { namespace gig {

    EGDecay::EGDecay(gig::Engine* pEngine, Event::destination_t ModulationDestination) {
        this->ModulationDestination = ModulationDestination;
        this->pEngine = pEngine;
    }

    /**
     * Will be called by the voice for every audio fragment to let the EG
     * queue it's modulation changes for the current audio fragment.
     *
     * @param Samples - total number of sample points to be rendered in this
     *                  audio fragment cycle by the audio engine
     * @returns true if there was something to process
     */
    bool EGDecay::Process(uint Samples) {
        if (!DecayStepsLeft) return false;

        int iSample     = TriggerDelay;
        int to_process  = RTMath::Min(Samples - iSample, DecayStepsLeft);
        int process_end = iSample + to_process;
        DecayStepsLeft -= to_process;
        while (iSample < to_process) {
            pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
            Level += DecayCoeff;
        }
        TriggerDelay = 0;

        return true;
    }

    /**
     * Will be called by the voice when the key / voice was triggered.
     *
     * @param Depth     - Initial level of the envelope
     * @param DecayTime - Decay time of the envelope (0.000 - 10.000s)
     * @param Delay     - Number of sample points triggering should be delayed.
     */
    void EGDecay::Trigger(float Depth, double DecayTime, uint Delay) {
        this->TriggerDelay = Delay;
        this->Level        = Depth;

        // calculate decay parameters (lin. curve)
        DecayStepsLeft = (long) (DecayTime * pEngine->pAudioOutputDevice->SampleRate());
        DecayCoeff     = (1.0 - Depth) / DecayStepsLeft;

        dmsg(4,("Depth=%d, DecayTime=%f\n", Depth, DecayTime));
    }

}} // namespace LinuxSampler::gig
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* *
7	* This program is free software; you can redistribute it and/or modify *
8	* it under the terms of the GNU General Public License as published by *
9	* the Free Software Foundation; either version 2 of the License, or *
10	* (at your option) any later version. *
11	* *
12	* This program is distributed in the hope that it will be useful, *
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15	* GNU General Public License for more details. *
16	* *
17	* You should have received a copy of the GNU General Public License *
18	* along with this program; if not, write to the Free Software *
19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20	* MA 02111-1307 USA *
21	***************************************************************************/
22
23	#include "EGDecay.h"
24
25	namespace LinuxSampler { namespace gig {
26
27	EGDecay::EGDecay(gig::Engine* pEngine, Event::destination_t ModulationDestination) {
28	this->ModulationDestination = ModulationDestination;
29	this->pEngine = pEngine;
30	}
31
32	/**
33	* Will be called by the voice for every audio fragment to let the EG
34	* queue it's modulation changes for the current audio fragment.
35	*
36	* @param Samples - total number of sample points to be rendered in this
37	* audio fragment cycle by the audio engine
38	* @returns true if there was something to process
39	*/
40	bool EGDecay::Process(uint Samples) {
41	if (!DecayStepsLeft) return false;
42
43	int iSample = TriggerDelay;
44	int to_process = RTMath::Min(Samples - iSample, DecayStepsLeft);
45	int process_end = iSample + to_process;
46	DecayStepsLeft -= to_process;
47	while (iSample < to_process) {
48	pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
49	Level += DecayCoeff;
50	}
51	TriggerDelay = 0;
52
53	return true;
54	}
55
56	/**
57	* Will be called by the voice when the key / voice was triggered.
58	*
59	* @param Depth - Initial level of the envelope
60	* @param DecayTime - Decay time of the envelope (0.000 - 10.000s)
61	* @param Delay - Number of sample points triggering should be delayed.
62	*/
63	void EGDecay::Trigger(float Depth, double DecayTime, uint Delay) {
64	this->TriggerDelay = Delay;
65	this->Level = Depth;
66
67	// calculate decay parameters (lin. curve)
68	DecayStepsLeft = (long) (DecayTime * pEngine->pAudioOutputDevice->SampleRate());
69	DecayCoeff = (1.0 - Depth) / DecayStepsLeft;
70
71	dmsg(4,("Depth=%d, DecayTime=%f\n", Depth, DecayTime));
72	}
73
74	}} // namespace LinuxSampler::gig