v0_1_0/src/eg_vca.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_vca.h"

EG_VCA::EG_VCA() {
    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 Samples       - 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 pTriggerEvent - event that caused triggering of the voice (only if
 *                        the voices was triggered in the current audio
 *                        fragment, NULL otherwise)
 * @param SamplePos     - current playback position
 * @param CurrentPitch  - current pitch value for playback
 */
void EG_VCA::Process(uint Samples, RTEList<ModulationSystem::Event>* pEvents, ModulationSystem::Event* pTriggerEvent, double SamplePos, double CurrentPitch) {
    ModulationSystem::Event* pTransitionEvent;
    if (pTriggerEvent) {
        pEvents->set_current(pTriggerEvent);
        pTransitionEvent = pEvents->next();
    }
    else {
        pTransitionEvent = pEvents->first();
    }

    int iSample = TriggerDelay;
    while (iSample < Samples) {
        switch (Stage) {
            case stage_attack: {
                TriggerDelay = 0;
                int to_process   = Min(Samples - iSample, AttackStepsLeft);
                int process_end  = iSample + to_process;
                AttackStepsLeft -= to_process;
                while (iSample < process_end) {
                    Level += AttackCoeff;
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }                                
                if (iSample == Samples) { // postpone last transition event for the next audio fragment
                    ModulationSystem::Event* pLastEvent = pEvents->last();
                    if (pLastEvent) ReleasePostponed = (pLastEvent->Type == ModulationSystem::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    = Min(Samples - iSample, holdstepsleft);                                                                
                int process_end   = iSample + to_process;                
                if (pTransitionEvent && pTransitionEvent->FragmentPos() <= process_end) {
                    process_end      = pTransitionEvent->FragmentPos();                    
                    Stage            = (pTransitionEvent->Type == ModulationSystem::event_type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
                    pTransitionEvent = pEvents->next();
                }
                else if (to_process == holdstepsleft) Stage = stage_decay1;                
                while (iSample < process_end) {
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }                
                break;
            }
            case stage_decay1: {
                int to_process   = Min(Samples - iSample, Decay1StepsLeft);
                int process_end  = iSample + to_process;
                if (pTransitionEvent && pTransitionEvent->FragmentPos() <= process_end) {
                    process_end      = pTransitionEvent->FragmentPos();                    
                    Stage            = (pTransitionEvent->Type == ModulationSystem::event_type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
                    pTransitionEvent = pEvents->next();
                }
                else {
                    Decay1StepsLeft -= to_process;
                    if (!Decay1StepsLeft) Stage = (InfiniteSustain) ? stage_sustain : stage_decay2;
                }
                while (iSample < process_end) {
                    Level += Decay1Coeff;
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }                
                break;
            }
            case stage_decay2: {
                int process_end;
                if (pTransitionEvent && pTransitionEvent->Type == ModulationSystem::event_type_release) {
                    process_end      = pTransitionEvent->FragmentPos();
                    pTransitionEvent = pEvents->next();
                    Stage            = stage_release; // switch to release stage soon
                }
                else process_end = Samples;
                while (iSample < process_end) {
                    Level += Level * Decay2Coeff;
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }
                if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_end;
                break;
            }
            case stage_sustain: {
                int process_end;
                if (pTransitionEvent && pTransitionEvent->Type == ModulationSystem::event_type_release) {
                    process_end      = pTransitionEvent->FragmentPos();
                    pTransitionEvent = pEvents->next();
                    Stage            = stage_release; // switch to release stage soon
                }
                else process_end = Samples;
                while (iSample < process_end) {
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }
                break;
            }
            case stage_release: {
                int process_end;
                if (pTransitionEvent && pTransitionEvent->Type == ModulationSystem::event_type_cancel_release) {
                    process_end      = pTransitionEvent->FragmentPos();
                    pTransitionEvent = pEvents->next();
                    Stage            = (InfiniteSustain) ? stage_sustain : stage_decay2; // switch back to sustain / decay2 stage soon
                }
                else process_end = Samples;
                while (iSample < process_end) {
                    Level += Level * ReleaseCoeff;
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }
                if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_end;
                break;
            }
            case stage_end: {
                while (iSample < Samples) {
                    Level += Level * ReleaseCoeff;
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }
                break;
            }
        }
    }
}

/**
 * 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 EG_VCA::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 * ModulationSystem::SampleRate());
    if (AttackStepsLeft) {
        Level       = (float) PreAttack / 1000.0;
        AttackCoeff = (1.0 - Level) / AttackStepsLeft;
    }
    else {
        Level       = 1.0;
        AttackCoeff = 0.0;
    }

    // calculate decay1 stage parameters (lin. curve)
    Decay1StepsLeft = (long) (Decay1Time * ModulationSystem::SampleRate());
    Decay1Coeff     = (Decay1StepsLeft) ? (this->SustainLevel - 1.0) / Decay1StepsLeft : 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 * ModulationSystem::SampleRate());
        Decay2Coeff      = (Decay2Steps) ? exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / Decay2Steps + log(this->SustainLevel)) - this->SustainLevel
                                         : 0.0;
    }

    // calcuate 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 * ModulationSystem::SampleRate());
    //ReleaseCoeff     = exp(log(EG_ENVELOPE_LIMIT) / (double) ReleaseStepsLeft) - 1.0; // <- this is only accurate for a curve start level of exactly 1.0, otherwise we have to use the following calculation for the coefficient...
    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));
}
1	schoenebeck	30	/***************************************************************************
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_vca.h"
24
25			EG_VCA::EG_VCA() {
26			Stage = stage_end;
27			Level = 0.0;
28			}
29
30			/**
31			* Will be called by the voice for every audio fragment to let the EG
32			* queue it's modulation changes for the current audio fragment.
33	schoenebeck	32	*
34	schoenebeck	33	* @param Samples - total number of sample points to be rendered in this
35			* audio fragment cycle by the audio engine
36			* @param pEvents - event list with "release" and "cancel release" events
37			* @param pTriggerEvent - event that caused triggering of the voice (only if
38			* the voices was triggered in the current audio
39			* fragment, NULL otherwise)
40			* @param SamplePos - current playback position
41			* @param CurrentPitch - current pitch value for playback
42	schoenebeck	30	*/
43	schoenebeck	33	void EG_VCA::Process(uint Samples, RTEList<ModulationSystem::Event>* pEvents, ModulationSystem::Event* pTriggerEvent, double SamplePos, double CurrentPitch) {
44	schoenebeck	37	ModulationSystem::Event* pTransitionEvent;
45	schoenebeck	33	if (pTriggerEvent) {
46			pEvents->set_current(pTriggerEvent);
47	schoenebeck	37	pTransitionEvent = pEvents->next();
48	schoenebeck	33	}
49			else {
50	schoenebeck	37	pTransitionEvent = pEvents->first();
51	schoenebeck	33	}
52	schoenebeck	30
53	schoenebeck	32	int iSample = TriggerDelay;
54			while (iSample < Samples) {
55	schoenebeck	30	switch (Stage) {
56			case stage_attack: {
57	schoenebeck	37	TriggerDelay = 0;
58	schoenebeck	33	int to_process = Min(Samples - iSample, AttackStepsLeft);
59			int process_end = iSample + to_process;
60			AttackStepsLeft -= to_process;
61	schoenebeck	32	while (iSample < process_end) {
62	schoenebeck	30	Level += AttackCoeff;
63	schoenebeck	32	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
64	schoenebeck	37	}
65	schoenebeck	33	if (iSample == Samples) { // postpone last transition event for the next audio fragment
66			ModulationSystem::Event* pLastEvent = pEvents->last();
67			if (pLastEvent) ReleasePostponed = (pLastEvent->Type == ModulationSystem::event_type_release);
68			}
69	schoenebeck	37	if (!AttackStepsLeft) Stage = (ReleasePostponed) ? stage_release : (HoldAttack) ? stage_attack_hold : stage_decay1;
70	schoenebeck	30	break;
71			}
72	schoenebeck	33	case stage_attack_hold: {
73			if (SamplePos >= LoopStart) {
74			Stage = stage_decay1;
75			break;
76			}
77			int holdstepsleft = (int) (LoopStart - SamplePos / CurrentPitch); // FIXME: just an approximation, inaccuracy grows with higher audio fragment size, sufficient for usual fragment sizes though
78	schoenebeck	37	int to_process = Min(Samples - iSample, holdstepsleft);
79			int process_end = iSample + to_process;
80			if (pTransitionEvent && pTransitionEvent->FragmentPos() <= process_end) {
81			process_end = pTransitionEvent->FragmentPos();
82			Stage = (pTransitionEvent->Type == ModulationSystem::event_type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
83			pTransitionEvent = pEvents->next();
84			}
85			else if (to_process == holdstepsleft) Stage = stage_decay1;
86	schoenebeck	33	while (iSample < process_end) {
87			ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
88	schoenebeck	37	}
89	schoenebeck	33	break;
90			}
91			case stage_decay1: {
92			int to_process = Min(Samples - iSample, Decay1StepsLeft);
93			int process_end = iSample + to_process;
94	schoenebeck	37	if (pTransitionEvent && pTransitionEvent->FragmentPos() <= process_end) {
95			process_end = pTransitionEvent->FragmentPos();
96			Stage = (pTransitionEvent->Type == ModulationSystem::event_type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
97			pTransitionEvent = pEvents->next();
98			}
99			else {
100			Decay1StepsLeft -= to_process;
101			if (!Decay1StepsLeft) Stage = (InfiniteSustain) ? stage_sustain : stage_decay2;
102			}
103	schoenebeck	33	while (iSample < process_end) {
104			Level += Decay1Coeff;
105			ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
106	schoenebeck	37	}
107	schoenebeck	33	break;
108			}
109			case stage_decay2: {
110			int process_end;
111	schoenebeck	37	if (pTransitionEvent && pTransitionEvent->Type == ModulationSystem::event_type_release) {
112			process_end = pTransitionEvent->FragmentPos();
113			pTransitionEvent = pEvents->next();
114			Stage = stage_release; // switch to release stage soon
115	schoenebeck	33	}
116			else process_end = Samples;
117			while (iSample < process_end) {
118			Level += Level * Decay2Coeff;
119			ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
120			}
121			if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_end;
122			break;
123			}
124	schoenebeck	30	case stage_sustain: {
125	schoenebeck	33	int process_end;
126	schoenebeck	37	if (pTransitionEvent && pTransitionEvent->Type == ModulationSystem::event_type_release) {
127			process_end = pTransitionEvent->FragmentPos();
128			pTransitionEvent = pEvents->next();
129			Stage = stage_release; // switch to release stage soon
130	schoenebeck	33	}
131			else process_end = Samples;
132			while (iSample < process_end) {
133			ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
134			}
135	schoenebeck	32	break;
136	schoenebeck	30	}
137			case stage_release: {
138	schoenebeck	33	int process_end;
139	schoenebeck	37	if (pTransitionEvent && pTransitionEvent->Type == ModulationSystem::event_type_cancel_release) {
140			process_end = pTransitionEvent->FragmentPos();
141			pTransitionEvent = pEvents->next();
142			Stage = (InfiniteSustain) ? stage_sustain : stage_decay2; // switch back to sustain / decay2 stage soon
143	schoenebeck	33	}
144			else process_end = Samples;
145			while (iSample < process_end) {
146			Level += Level * ReleaseCoeff;
147	schoenebeck	32	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
148	schoenebeck	30	}
149			if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_end;
150	schoenebeck	33	break;
151	schoenebeck	30	}
152			case stage_end: {
153	schoenebeck	32	while (iSample < Samples) {
154	schoenebeck	33	Level += Level * ReleaseCoeff;
155	schoenebeck	32	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
156	schoenebeck	30	}
157	schoenebeck	33	break;
158	schoenebeck	30	}
159			}
160			}
161			}
162
163			/**
164			* Will be called by the voice when the key / voice was triggered.
165			*
166	schoenebeck	33	* @param PreAttack - Preattack value for the envelope (0 - 1000 permille)
167			* @param AttackTime - Attack time for the envelope (0.000 - 60.000s)
168			* @param HoldAttack - If true, Decay1 will be postponed until the sample reached the sample loop start.
169			* @param LoopStart - Sample position where sample loop starts (if any)
170			* @param Decay1Time - Decay1 time of the sample amplitude EG (0.000 - 60.000s).
171			* @param Decay2Time - Only if !InfiniteSustain: 2nd decay stage time of the sample amplitude EG (0.000 - 60.000s).
172			* @param InfiniteSustain - If true, instead of going into Decay2 phase, Decay1 level will be hold until note will be released.
173			* @param SustainLevel - Sustain level of the sample amplitude EG (0 - 1000 permille).
174			* @param ReleaseTIme - Release time for the envelope (0.000 - 60.000s)
175			* @param Delay - Number of sample points triggering should be delayed.
176	schoenebeck	30	*/
177	schoenebeck	33	void EG_VCA::Trigger(uint PreAttack, double AttackTime, bool HoldAttack, long LoopStart, double Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, double ReleaseTime, uint Delay) {
178			this->TriggerDelay = Delay;
179			this->Stage = stage_attack;
180			this->SustainLevel = (SustainLevel) ? (SustainLevel > EG_ENVELOPE_LIMIT) ? (float) SustainLevel / 1000.0 : EG_ENVELOPE_LIMIT : 1.0;
181			this->InfiniteSustain = InfiniteSustain;
182			this->HoldAttack = HoldAttack;
183			this->LoopStart = LoopStart;
184			this->ReleasePostponed = false;
185	schoenebeck	30
186	schoenebeck	33	// calculate attack stage parameters (lin. curve)
187	schoenebeck	32	AttackStepsLeft = (long) (AttackTime * ModulationSystem::SampleRate());
188	schoenebeck	30	if (AttackStepsLeft) {
189	schoenebeck	33	Level = (float) PreAttack / 1000.0;
190			AttackCoeff = (1.0 - Level) / AttackStepsLeft;
191	schoenebeck	30	}
192			else {
193			Level = 1.0;
194			AttackCoeff = 0.0;
195			}
196
197	schoenebeck	33	// calculate decay1 stage parameters (lin. curve)
198			Decay1StepsLeft = (long) (Decay1Time * ModulationSystem::SampleRate());
199			Decay1Coeff = (Decay1StepsLeft) ? (this->SustainLevel - 1.0) / Decay1StepsLeft : 0.0;
200
201			// calculate decay2 stage parameters (exp. curve)
202			if (!InfiniteSustain) {
203			if (Decay2Time < EG_MIN_RELEASE_TIME) Decay2Time = EG_MIN_RELEASE_TIME;
204			long Decay2Steps = (long) (Decay2Time * ModulationSystem::SampleRate());
205			Decay2Coeff = (Decay2Steps) ? exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / Decay2Steps + log(this->SustainLevel)) - this->SustainLevel
206			: 0.0;
207			}
208
209			// calcuate release stage parameters (exp. curve)
210	schoenebeck	30	if (ReleaseTime < EG_MIN_RELEASE_TIME) ReleaseTime = EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
211	schoenebeck	32	ReleaseStepsLeft = (long) (ReleaseTime * ModulationSystem::SampleRate());
212	schoenebeck	33	//ReleaseCoeff = exp(log(EG_ENVELOPE_LIMIT) / (double) ReleaseStepsLeft) - 1.0; // <- this is only accurate for a curve start level of exactly 1.0, otherwise we have to use the following calculation for the coefficient...
213			ReleaseCoeff = exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / ReleaseStepsLeft + log(this->SustainLevel)) - this->SustainLevel;
214	schoenebeck	30
215	schoenebeck	33	dmsg(4,("PreAttack=%d, AttackLength=%d, AttackCoeff=%f, Decay1Coeff=%f, Decay2Coeff=%f, ReleaseLength=%d, ReleaseCoeff=%f\n",
216			PreAttack, AttackStepsLeft, AttackCoeff, Decay1Coeff, Decay2Coeff, ReleaseStepsLeft, ReleaseCoeff));
217	schoenebeck	30	}