trunk/src/eg_d.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003 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 "eg_d.h"

EG_D::EG_D(ModulationSystem::destination_t ModulationDestination) {
    this->ModulationDestination = ModulationDestination;
}

/**
 * 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
 */
void EG_D::Process(uint Samples) {
    if (!DecayStepsLeft) return;

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

/**
 * 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 EG_D::Trigger(float Depth, double DecayTime, uint Delay) {
    this->TriggerDelay = Delay;
    this->Level        = Depth;

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

    dmsg(4,("Depth=%d, DecayTime=%f\n", Depth, DecayTime));
}
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003 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 "eg_d.h"
24
25	EG_D::EG_D(ModulationSystem::destination_t ModulationDestination) {
26	this->ModulationDestination = ModulationDestination;
27	}
28
29	/**
30	* Will be called by the voice for every audio fragment to let the EG
31	* queue it's modulation changes for the current audio fragment.
32	*
33	* @param Samples - total number of sample points to be rendered in this
34	* audio fragment cycle by the audio engine
35	*/
36	void EG_D::Process(uint Samples) {
37	if (!DecayStepsLeft) return;
38
39	int iSample = TriggerDelay;
40	int to_process = Min(Samples - iSample, DecayStepsLeft);
41	int process_end = iSample + to_process;
42	DecayStepsLeft -= to_process;
43	while (iSample < to_process) {
44	ModulationSystem::pDestinationParameter[ModulationDestination][iSample++] *= Level;
45	Level += DecayCoeff;
46	}
47	TriggerDelay = 0;
48	}
49
50	/**
51	* Will be called by the voice when the key / voice was triggered.
52	*
53	* @param Depth - Initial level of the envelope
54	* @param DecayTime - Decay time of the envelope (0.000 - 10.000s)
55	* @param Delay - Number of sample points triggering should be delayed.
56	*/
57	void EG_D::Trigger(float Depth, double DecayTime, uint Delay) {
58	this->TriggerDelay = Delay;
59	this->Level = Depth;
60
61	// calculate decay parameters (lin. curve)
62	DecayStepsLeft = (long) (DecayTime * ModulationSystem::SampleRate());
63	DecayCoeff = (1.0 - Depth) / DecayStepsLeft;
64
65	dmsg(4,("Depth=%d, DecayTime=%f\n", Depth, DecayTime));
66	}