engines/gig/EGADSR.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 "EGADSR.h"

namespace LinuxSampler { namespace gig {

    const float EGADSR::FadeOutCoeff(CalculateFadeOutCoeff());

    float EGADSR::CalculateFadeOutCoeff() {
        const float sampleRate = 44100.0; // even if the sample rate will be 192kHz it won't hurt at all
        const float killSteps  = EG_MIN_RELEASE_TIME * sampleRate;
        return -1.0f / killSteps;
    }

    EGADSR::EGADSR(gig::Engine* pEngine, Event::destination_t ModulationDestination) {
        this->pEngine = pEngine;
        this->ModulationDestination = ModulationDestination;
        Stage = stage_end;
        Level = 0.0;
    }

    /**
     * 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 TotalSamples  - total number of sample points to be rendered in this
     *                        audio fragment cycle by the audio engine
     * @param pEvents       - event list with "release" and "cancel release" events
     * @param itTriggerEvent - event that caused triggering of the voice (only if
     *                        the voice was triggered in the current audio
     *                        fragment, NULL otherwise)
     * @param SamplePos     - current playback position
     * @param CurrentPitch  - current pitch value for playback
     * @param itKillEvent   - (optional) event which caused this voice to be killed
     */
    void EGADSR::Process(uint TotalSamples, RTList<Event>* pEvents, RTList<Event>::Iterator itTriggerEvent, double SamplePos, double CurrentPitch, RTList<Event>::Iterator itKillEvent) {
        // skip all events which occured before this voice was triggered
        RTList<Event>::Iterator itTransitionEvent = (itTriggerEvent) ? ++itTriggerEvent : pEvents->first();

        // if the voice was killed in this fragment we only process the time before this kill event, then switch to 'stage_fadeout'
        int Samples = (itKillEvent) ? RTMath::Min(itKillEvent->FragmentPos(), pEngine->MaxFadeOutPos) : (int) TotalSamples;

        int iSample = TriggerDelay;
        while (iSample < TotalSamples) {

            // if the voice was killed in this fragment and we already processed the time before this kill event
            if (itKillEvent && iSample >= Samples) Stage = stage_fadeout;

            switch (Stage) {
                case stage_attack: {
                    TriggerDelay = 0;
                    int to_process   = RTMath::Min(AttackStepsLeft, Samples - iSample);
                    int process_end  = iSample + to_process;
                    AttackStepsLeft -= to_process;
                    while (iSample < process_end) {
                        Level += AttackCoeff;
                        pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
                    }
                    if (iSample == TotalSamples) { // postpone last transition event for the next audio fragment
                        RTList<Event>::Iterator itLastEvent = pEvents->last();
                        if (itLastEvent) ReleasePostponed = (itLastEvent->Type == Event::type_release);
                    }
                    if (!AttackStepsLeft) Stage = (ReleasePostponed) ? stage_release : (HoldAttack) ? stage_attack_hold : stage_decay1;
                    break;
                }
                case stage_attack_hold: {
                    if (SamplePos >= LoopStart) {
                        Stage = stage_decay1;
                        break;
                    }
                    int holdstepsleft = (int) (LoopStart - SamplePos / CurrentPitch); // FIXME: just an approximation, inaccuracy grows with higher audio fragment size, sufficient for usual fragment sizes though
                    int to_process    = RTMath::Min(holdstepsleft, Samples - iSample);
                    int process_end   = iSample + to_process;
                    if (itTransitionEvent && itTransitionEvent->FragmentPos() <= process_end) {
                        process_end       = itTransitionEvent->FragmentPos();
                        Stage             = (itTransitionEvent->Type == Event::type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
                        ++itTransitionEvent;
                    }
                    else if (to_process == holdstepsleft) Stage = stage_decay1;
                    while (iSample < process_end) {
                        pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
                    }
                    break;
                }
                case stage_decay1: {
                    int to_process   = RTMath::Min(Samples - iSample, Decay1StepsLeft);
                    int process_end  = iSample + to_process;
                    if (itTransitionEvent && itTransitionEvent->FragmentPos() <= process_end) {
                        process_end       = itTransitionEvent->FragmentPos();
                        Stage             = (itTransitionEvent->Type == Event::type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
                        ++itTransitionEvent;
                    }
                    else {
                        Decay1StepsLeft -= to_process;
                        if (!Decay1StepsLeft) Stage = (InfiniteSustain) ? stage_sustain : stage_decay2;
                    }
                    while (iSample < process_end) {
                        Level += Level * Decay1Coeff;
                        pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
                    }
                    break;
                }
                case stage_decay2: {
                    int process_end;
                    if (itTransitionEvent && itTransitionEvent->Type == Event::type_release && itTransitionEvent->FragmentPos() <= Samples) {
                        process_end       = itTransitionEvent->FragmentPos();
                        ++itTransitionEvent;
                        Stage             = stage_release; // switch to release stage soon
                    }
                    else process_end = Samples;
                    while (iSample < process_end) {
                        Level += Level * Decay2Coeff;
                        pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
                    }
                    if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_fadeout;
                    break;
                }
                case stage_sustain: {
                    int process_end;
                    if (itTransitionEvent && itTransitionEvent->Type == Event::type_release && itTransitionEvent->FragmentPos() <= Samples) {
                        process_end       = itTransitionEvent->FragmentPos();
                        ++itTransitionEvent;
                        Stage             = stage_release; // switch to release stage soon
                    }
                    else process_end = Samples;
                    while (iSample < process_end) {
                       pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
                    }
                    break;
                }
                case stage_release: {
                    int process_end;
                    if (itTransitionEvent && itTransitionEvent->Type == Event::type_cancel_release && itTransitionEvent->FragmentPos() <= Samples) {
                        process_end       = itTransitionEvent->FragmentPos();
                        ++itTransitionEvent;
                        Stage             = (InfiniteSustain) ? stage_sustain : stage_decay2; // switch back to sustain / decay2 stage soon
                    }
                    else process_end = Samples;
                    while (iSample < process_end) {
                        Level += Level * ReleaseCoeff;
                        pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
                    }
                    if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_fadeout;
                    break;
                }
                case stage_fadeout: {
                    int to_process   = RTMath::Min(int(Level / (-FadeOutCoeff)), TotalSamples - iSample);
                    int process_end  = iSample + to_process;
                    while (iSample < process_end) {
                        Level += FadeOutCoeff;
                        pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
                    }
                    Stage = stage_end;
                    if (Level > -FadeOutCoeff) dmsg(1,("EGADSR: Warning, final fade out level too high, may result in click sound!\n"));
                } //Fall through here instead of breaking otherwise we can get back into stage_fadeout and loop forever!
                case stage_end: {
                    while (iSample < TotalSamples) {
                        pEngine->pSynthesisParameters[ModulationDestination][iSample++] = 0.0f;
                    }
                    break;
                }
            }
        }

        if (itKillEvent && Stage != stage_end) {
            dmsg(1,("EGADSR: VOICE KILLING NOT COMPLETED !!!\n"));
            dmsg(1,("EGADSR: Stage=%d,iSample=%d,Samples=%d, TotalSamples=%d, MaxFadoutPos=%d\n",Stage,iSample,Samples,TotalSamples,pEngine->MaxFadeOutPos));
        }
    }

    /**
     * Will be called by the voice when the key / voice was triggered.
     *
     * @param PreAttack       - Preattack value for the envelope (0 - 1000 permille)
     * @param AttackTime      - Attack time for the envelope (0.000 - 60.000s)
     * @param HoldAttack      - If true, Decay1 will be postponed until the sample reached the sample loop start.
     * @param LoopStart       - Sample position where sample loop starts (if any)
     * @param Decay1Time      - Decay1 time of the sample amplitude EG (0.000 - 60.000s).
     * @param Decay2Time      - Only if !InfiniteSustain: 2nd decay stage time of the sample amplitude EG (0.000 - 60.000s).
     * @param InfiniteSustain - If true, instead of going into Decay2 phase, Decay1 level will be hold until note will be released.
     * @param SustainLevel    - Sustain level of the sample amplitude EG (0 - 1000 permille).
     * @param ReleaseTIme     - Release time for the envelope (0.000 - 60.000s)
     * @param Delay           - Number of sample points triggering should be delayed.
     */
    void EGADSR::Trigger(uint PreAttack, double AttackTime, bool HoldAttack, long LoopStart, double Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, double ReleaseTime, uint Delay) {
        this->TriggerDelay     = Delay;
        this->Stage            = stage_attack;
        this->SustainLevel     = (SustainLevel) ? (SustainLevel > EG_ENVELOPE_LIMIT) ? (float) SustainLevel / 1000.0 : EG_ENVELOPE_LIMIT : 1.0;
        this->InfiniteSustain  = InfiniteSustain;
        this->HoldAttack       = HoldAttack;
        this->LoopStart        = LoopStart;
        this->ReleasePostponed = false;

        // calculate attack stage parameters (lin. curve)
        AttackStepsLeft = (long) (AttackTime * pEngine->pAudioOutputDevice->SampleRate());
        if (AttackStepsLeft) {
            Level       = (float) PreAttack / 1000.0;
            AttackCoeff = (1.0 - Level) / AttackStepsLeft;
        }
        else {
            Level       = 1.0;
            AttackCoeff = 0.0;
        }

        // calculate decay1 stage parameters (exp. curve)
        Decay1StepsLeft = (long) (Decay1Time * pEngine->pAudioOutputDevice->SampleRate());
        Decay1Coeff     = (Decay1StepsLeft) ? exp(log(this->SustainLevel) / (double) Decay1StepsLeft) - 1.0
                                            : 0.0;

        // calculate decay2 stage parameters (exp. curve)
        if (!InfiniteSustain) {
            if (Decay2Time < EG_MIN_RELEASE_TIME) Decay2Time = EG_MIN_RELEASE_TIME;
            long Decay2Steps = (long) (Decay2Time * pEngine->pAudioOutputDevice->SampleRate());
            Decay2Coeff      = (Decay2Steps) ? exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / Decay2Steps + log(this->SustainLevel)) - this->SustainLevel
                                             : 0.0;
        }

        // calculate release stage parameters (exp. curve)
        if (ReleaseTime < EG_MIN_RELEASE_TIME) ReleaseTime = EG_MIN_RELEASE_TIME;  // to avoid click sounds at the end of the sample playback
        ReleaseStepsLeft = (long) (ReleaseTime * pEngine->pAudioOutputDevice->SampleRate());
        ReleaseCoeff     = exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / ReleaseStepsLeft + log(this->SustainLevel)) - this->SustainLevel;

        dmsg(4,("PreAttack=%d, AttackLength=%d, AttackCoeff=%f, Decay1Coeff=%f, Decay2Coeff=%f, ReleaseLength=%d, ReleaseCoeff=%f\n",
                PreAttack, AttackStepsLeft, AttackCoeff, Decay1Coeff, Decay2Coeff, ReleaseStepsLeft, ReleaseCoeff));
    }

}} // namespace LinuxSampler::gig
1	schoenebeck	53	/***************************************************************************
2			* *
3			* LinuxSampler - modular, streaming capable sampler *
4			* *
5	schoenebeck	56	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	schoenebeck	53	* *
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 "EGADSR.h"
24
25			namespace LinuxSampler { namespace gig {
26
27	schoenebeck	252	const float EGADSR::FadeOutCoeff(CalculateFadeOutCoeff());
28	schoenebeck	239
29	schoenebeck	252	float EGADSR::CalculateFadeOutCoeff() {
30	schoenebeck	251	const float sampleRate = 44100.0; // even if the sample rate will be 192kHz it won't hurt at all
31			const float killSteps = EG_MIN_RELEASE_TIME * sampleRate;
32	schoenebeck	285	return -1.0f / killSteps;
33	schoenebeck	239	}
34
35	schoenebeck	53	EGADSR::EGADSR(gig::Engine* pEngine, Event::destination_t ModulationDestination) {
36			this->pEngine = pEngine;
37			this->ModulationDestination = ModulationDestination;
38			Stage = stage_end;
39			Level = 0.0;
40			}
41
42			/**
43			* Will be called by the voice for every audio fragment to let the EG
44			* queue it's modulation changes for the current audio fragment.
45			*
46	schoenebeck	239	* @param TotalSamples - total number of sample points to be rendered in this
47	schoenebeck	53	* audio fragment cycle by the audio engine
48			* @param pEvents - event list with "release" and "cancel release" events
49	schoenebeck	271	* @param itTriggerEvent - event that caused triggering of the voice (only if
50	schoenebeck	239	* the voice was triggered in the current audio
51	schoenebeck	53	* fragment, NULL otherwise)
52			* @param SamplePos - current playback position
53			* @param CurrentPitch - current pitch value for playback
54	schoenebeck	271	* @param itKillEvent - (optional) event which caused this voice to be killed
55	schoenebeck	53	*/
56	schoenebeck	271	void EGADSR::Process(uint TotalSamples, RTList<Event>* pEvents, RTList<Event>::Iterator itTriggerEvent, double SamplePos, double CurrentPitch, RTList<Event>::Iterator itKillEvent) {
57			// skip all events which occured before this voice was triggered
58			RTList<Event>::Iterator itTransitionEvent = (itTriggerEvent) ? ++itTriggerEvent : pEvents->first();
59	schoenebeck	53
60	schoenebeck	252	// if the voice was killed in this fragment we only process the time before this kill event, then switch to 'stage_fadeout'
61	schoenebeck	285	int Samples = (itKillEvent) ? RTMath::Min(itKillEvent->FragmentPos(), pEngine->MaxFadeOutPos) : (int) TotalSamples;
62	schoenebeck	239
63	schoenebeck	53	int iSample = TriggerDelay;
64	schoenebeck	239	while (iSample < TotalSamples) {
65
66			// if the voice was killed in this fragment and we already processed the time before this kill event
67	schoenebeck	271	if (itKillEvent && iSample >= Samples) Stage = stage_fadeout;
68	schoenebeck	239
69	schoenebeck	53	switch (Stage) {
70			case stage_attack: {
71			TriggerDelay = 0;
72			int to_process = RTMath::Min(AttackStepsLeft, Samples - iSample);
73			int process_end = iSample + to_process;
74			AttackStepsLeft -= to_process;
75			while (iSample < process_end) {
76			Level += AttackCoeff;
77			pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
78			}
79	schoenebeck	239	if (iSample == TotalSamples) { // postpone last transition event for the next audio fragment
80	schoenebeck	271	RTList<Event>::Iterator itLastEvent = pEvents->last();
81			if (itLastEvent) ReleasePostponed = (itLastEvent->Type == Event::type_release);
82	schoenebeck	53	}
83			if (!AttackStepsLeft) Stage = (ReleasePostponed) ? stage_release : (HoldAttack) ? stage_attack_hold : stage_decay1;
84			break;
85			}
86			case stage_attack_hold: {
87			if (SamplePos >= LoopStart) {
88			Stage = stage_decay1;
89			break;
90			}
91			int holdstepsleft = (int) (LoopStart - SamplePos / CurrentPitch); // FIXME: just an approximation, inaccuracy grows with higher audio fragment size, sufficient for usual fragment sizes though
92			int to_process = RTMath::Min(holdstepsleft, Samples - iSample);
93			int process_end = iSample + to_process;
94	schoenebeck	271	if (itTransitionEvent && itTransitionEvent->FragmentPos() <= process_end) {
95			process_end = itTransitionEvent->FragmentPos();
96			Stage = (itTransitionEvent->Type == Event::type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
97			++itTransitionEvent;
98	schoenebeck	53	}
99			else if (to_process == holdstepsleft) Stage = stage_decay1;
100			while (iSample < process_end) {
101			pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
102			}
103			break;
104			}
105			case stage_decay1: {
106			int to_process = RTMath::Min(Samples - iSample, Decay1StepsLeft);
107			int process_end = iSample + to_process;
108	schoenebeck	271	if (itTransitionEvent && itTransitionEvent->FragmentPos() <= process_end) {
109			process_end = itTransitionEvent->FragmentPos();
110			Stage = (itTransitionEvent->Type == Event::type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
111			++itTransitionEvent;
112	schoenebeck	53	}
113			else {
114			Decay1StepsLeft -= to_process;
115			if (!Decay1StepsLeft) Stage = (InfiniteSustain) ? stage_sustain : stage_decay2;
116			}
117			while (iSample < process_end) {
118			Level += Level * Decay1Coeff;
119			pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
120			}
121			break;
122			}
123			case stage_decay2: {
124			int process_end;
125	schoenebeck	271	if (itTransitionEvent && itTransitionEvent->Type == Event::type_release && itTransitionEvent->FragmentPos() <= Samples) {
126			process_end = itTransitionEvent->FragmentPos();
127			++itTransitionEvent;
128			Stage = stage_release; // switch to release stage soon
129	schoenebeck	53	}
130			else process_end = Samples;
131			while (iSample < process_end) {
132			Level += Level * Decay2Coeff;
133			pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
134			}
135	schoenebeck	252	if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_fadeout;
136	schoenebeck	53	break;
137			}
138			case stage_sustain: {
139			int process_end;
140	schoenebeck	271	if (itTransitionEvent && itTransitionEvent->Type == Event::type_release && itTransitionEvent->FragmentPos() <= Samples) {
141			process_end = itTransitionEvent->FragmentPos();
142			++itTransitionEvent;
143			Stage = stage_release; // switch to release stage soon
144	schoenebeck	53	}
145			else process_end = Samples;
146			while (iSample < process_end) {
147			pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
148			}
149			break;
150			}
151			case stage_release: {
152			int process_end;
153	schoenebeck	271	if (itTransitionEvent && itTransitionEvent->Type == Event::type_cancel_release && itTransitionEvent->FragmentPos() <= Samples) {
154			process_end = itTransitionEvent->FragmentPos();
155			++itTransitionEvent;
156			Stage = (InfiniteSustain) ? stage_sustain : stage_decay2; // switch back to sustain / decay2 stage soon
157	schoenebeck	53	}
158			else process_end = Samples;
159			while (iSample < process_end) {
160			Level += Level * ReleaseCoeff;
161			pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
162			}
163	schoenebeck	252	if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_fadeout;
164	schoenebeck	53	break;
165			}
166	schoenebeck	252	case stage_fadeout: {
167			int to_process = RTMath::Min(int(Level / (-FadeOutCoeff)), TotalSamples - iSample);
168	schoenebeck	251	int process_end = iSample + to_process;
169			while (iSample < process_end) {
170	schoenebeck	252	Level += FadeOutCoeff;
171	schoenebeck	53	pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
172			}
173	schoenebeck	285	Stage = stage_end;
174			if (Level > -FadeOutCoeff) dmsg(1,("EGADSR: Warning, final fade out level too high, may result in click sound!\n"));
175	senkov	259	} //Fall through here instead of breaking otherwise we can get back into stage_fadeout and loop forever!
176	schoenebeck	252	case stage_end: {
177	schoenebeck	251	while (iSample < TotalSamples) {
178			pEngine->pSynthesisParameters[ModulationDestination][iSample++] = 0.0f;
179			}
180	schoenebeck	53	break;
181			}
182			}
183			}
184	schoenebeck	285
185			if (itKillEvent && Stage != stage_end) {
186			dmsg(1,("EGADSR: VOICE KILLING NOT COMPLETED !!!\n"));
187			dmsg(1,("EGADSR: Stage=%d,iSample=%d,Samples=%d, TotalSamples=%d, MaxFadoutPos=%d\n",Stage,iSample,Samples,TotalSamples,pEngine->MaxFadeOutPos));
188			}
189	schoenebeck	53	}
190
191			/**
192			* Will be called by the voice when the key / voice was triggered.
193			*
194			* @param PreAttack - Preattack value for the envelope (0 - 1000 permille)
195			* @param AttackTime - Attack time for the envelope (0.000 - 60.000s)
196			* @param HoldAttack - If true, Decay1 will be postponed until the sample reached the sample loop start.
197			* @param LoopStart - Sample position where sample loop starts (if any)
198			* @param Decay1Time - Decay1 time of the sample amplitude EG (0.000 - 60.000s).
199			* @param Decay2Time - Only if !InfiniteSustain: 2nd decay stage time of the sample amplitude EG (0.000 - 60.000s).
200			* @param InfiniteSustain - If true, instead of going into Decay2 phase, Decay1 level will be hold until note will be released.
201			* @param SustainLevel - Sustain level of the sample amplitude EG (0 - 1000 permille).
202			* @param ReleaseTIme - Release time for the envelope (0.000 - 60.000s)
203			* @param Delay - Number of sample points triggering should be delayed.
204			*/
205			void EGADSR::Trigger(uint PreAttack, double AttackTime, bool HoldAttack, long LoopStart, double Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, double ReleaseTime, uint Delay) {
206			this->TriggerDelay = Delay;
207			this->Stage = stage_attack;
208			this->SustainLevel = (SustainLevel) ? (SustainLevel > EG_ENVELOPE_LIMIT) ? (float) SustainLevel / 1000.0 : EG_ENVELOPE_LIMIT : 1.0;
209			this->InfiniteSustain = InfiniteSustain;
210			this->HoldAttack = HoldAttack;
211			this->LoopStart = LoopStart;
212			this->ReleasePostponed = false;
213
214			// calculate attack stage parameters (lin. curve)
215			AttackStepsLeft = (long) (AttackTime * pEngine->pAudioOutputDevice->SampleRate());
216			if (AttackStepsLeft) {
217			Level = (float) PreAttack / 1000.0;
218			AttackCoeff = (1.0 - Level) / AttackStepsLeft;
219			}
220			else {
221			Level = 1.0;
222			AttackCoeff = 0.0;
223			}
224
225			// calculate decay1 stage parameters (exp. curve)
226			Decay1StepsLeft = (long) (Decay1Time * pEngine->pAudioOutputDevice->SampleRate());
227			Decay1Coeff = (Decay1StepsLeft) ? exp(log(this->SustainLevel) / (double) Decay1StepsLeft) - 1.0
228			: 0.0;
229
230			// calculate decay2 stage parameters (exp. curve)
231			if (!InfiniteSustain) {
232			if (Decay2Time < EG_MIN_RELEASE_TIME) Decay2Time = EG_MIN_RELEASE_TIME;
233			long Decay2Steps = (long) (Decay2Time * pEngine->pAudioOutputDevice->SampleRate());
234			Decay2Coeff = (Decay2Steps) ? exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / Decay2Steps + log(this->SustainLevel)) - this->SustainLevel
235	schoenebeck	239	: 0.0;
236	schoenebeck	53	}
237
238	schoenebeck	239	// calculate release stage parameters (exp. curve)
239	schoenebeck	53	if (ReleaseTime < EG_MIN_RELEASE_TIME) ReleaseTime = EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
240			ReleaseStepsLeft = (long) (ReleaseTime * pEngine->pAudioOutputDevice->SampleRate());
241			ReleaseCoeff = exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / ReleaseStepsLeft + log(this->SustainLevel)) - this->SustainLevel;
242
243			dmsg(4,("PreAttack=%d, AttackLength=%d, AttackCoeff=%f, Decay1Coeff=%f, Decay2Coeff=%f, ReleaseLength=%d, ReleaseCoeff=%f\n",
244			PreAttack, AttackStepsLeft, AttackCoeff, Decay1Coeff, Decay2Coeff, ReleaseStepsLeft, ReleaseCoeff));
245			}
246
247			}} // namespace LinuxSampler::gig