trunk/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* pReleaseTransitionEvent;
    if (pTriggerEvent) {
        pEvents->set_current(pTriggerEvent);
        pReleaseTransitionEvent = pEvents->next();
    }
    else {
        pReleaseTransitionEvent = pEvents->first();
    }

    int iSample = TriggerDelay;
    while (iSample < Samples) {
        switch (Stage) {
            case stage_attack: {
                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;
                }
                TriggerDelay = 0;
                if (!AttackStepsLeft) Stage = (HoldAttack) ? stage_attack_hold : stage_decay1;
                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);
                }
                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;
                while (iSample < process_end) {
                    ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
                }
                if (to_process == holdstepsleft) Stage = stage_decay1;
                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);
                }
                break;
            }
            case stage_decay1: {
                int to_process   = Min(Samples - iSample, Decay1StepsLeft);
                int process_end  = iSample + to_process;
                Decay1StepsLeft -= to_process;
                while (iSample < process_end) {
                    Level += Decay1Coeff;
                    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 (!Decay1StepsLeft) {
                    Stage = (ReleasePostponed) ? stage_release
                                               : (InfiniteSustain) ? stage_sustain
                                                                   : stage_decay2;
                }
                break;
            }
            case stage_decay2: {
                int process_end;
                if (pReleaseTransitionEvent && pReleaseTransitionEvent->Type == ModulationSystem::event_type_release) {
                    process_end             = pReleaseTransitionEvent->FragmentPos();
                    pReleaseTransitionEvent = 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 (pReleaseTransitionEvent && pReleaseTransitionEvent->Type == ModulationSystem::event_type_release) {
                    process_end             = pReleaseTransitionEvent->FragmentPos();
                    pReleaseTransitionEvent = 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 (pReleaseTransitionEvent && pReleaseTransitionEvent->Type == ModulationSystem::event_type_cancel_release) {
                    process_end             = pReleaseTransitionEvent->FragmentPos();
                    pReleaseTransitionEvent = 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	/***************************************************************************
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	*
34	* @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	*/
43	void EG_VCA::Process(uint Samples, RTEList<ModulationSystem::Event>* pEvents, ModulationSystem::Event* pTriggerEvent, double SamplePos, double CurrentPitch) {
44	ModulationSystem::Event* pReleaseTransitionEvent;
45	if (pTriggerEvent) {
46	pEvents->set_current(pTriggerEvent);
47	pReleaseTransitionEvent = pEvents->next();
48	}
49	else {
50	pReleaseTransitionEvent = pEvents->first();
51	}
52
53	int iSample = TriggerDelay;
54	while (iSample < Samples) {
55	switch (Stage) {
56	case stage_attack: {
57	int to_process = Min(Samples - iSample, AttackStepsLeft);
58	int process_end = iSample + to_process;
59	AttackStepsLeft -= to_process;
60	while (iSample < process_end) {
61	Level += AttackCoeff;
62	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
63	}
64	TriggerDelay = 0;
65	if (!AttackStepsLeft) Stage = (HoldAttack) ? stage_attack_hold : stage_decay1;
66	if (iSample == Samples) { // postpone last transition event for the next audio fragment
67	ModulationSystem::Event* pLastEvent = pEvents->last();
68	if (pLastEvent) ReleasePostponed = (pLastEvent->Type == ModulationSystem::event_type_release);
69	}
70	break;
71	}
72	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	int to_process = Min(Samples - iSample, holdstepsleft);
79	int process_end = iSample + to_process;
80	while (iSample < process_end) {
81	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
82	}
83	if (to_process == holdstepsleft) Stage = stage_decay1;
84	if (iSample == Samples) { // postpone last transition event for the next audio fragment
85	ModulationSystem::Event* pLastEvent = pEvents->last();
86	if (pLastEvent) ReleasePostponed = (pLastEvent->Type == ModulationSystem::event_type_release);
87	}
88	break;
89	}
90	case stage_decay1: {
91	int to_process = Min(Samples - iSample, Decay1StepsLeft);
92	int process_end = iSample + to_process;
93	Decay1StepsLeft -= to_process;
94	while (iSample < process_end) {
95	Level += Decay1Coeff;
96	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
97	}
98	if (iSample == Samples) { // postpone last transition event for the next audio fragment
99	ModulationSystem::Event* pLastEvent = pEvents->last();
100	if (pLastEvent) ReleasePostponed = (pLastEvent->Type == ModulationSystem::event_type_release);
101	}
102	if (!Decay1StepsLeft) {
103	Stage = (ReleasePostponed) ? stage_release
104	: (InfiniteSustain) ? stage_sustain
105	: stage_decay2;
106	}
107	break;
108	}
109	case stage_decay2: {
110	int process_end;
111	if (pReleaseTransitionEvent && pReleaseTransitionEvent->Type == ModulationSystem::event_type_release) {
112	process_end = pReleaseTransitionEvent->FragmentPos();
113	pReleaseTransitionEvent = pEvents->next();
114	Stage = stage_release; // switch to release stage soon
115	}
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	case stage_sustain: {
125	int process_end;
126	if (pReleaseTransitionEvent && pReleaseTransitionEvent->Type == ModulationSystem::event_type_release) {
127	process_end = pReleaseTransitionEvent->FragmentPos();
128	pReleaseTransitionEvent = pEvents->next();
129	Stage = stage_release; // switch to release stage soon
130	}
131	else process_end = Samples;
132	while (iSample < process_end) {
133	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
134	}
135	break;
136	}
137	case stage_release: {
138	int process_end;
139	if (pReleaseTransitionEvent && pReleaseTransitionEvent->Type == ModulationSystem::event_type_cancel_release) {
140	process_end = pReleaseTransitionEvent->FragmentPos();
141	pReleaseTransitionEvent = pEvents->next();
142	Stage = (InfiniteSustain) ? stage_sustain : stage_decay2; // switch back to sustain / decay2 stage soon
143	}
144	else process_end = Samples;
145	while (iSample < process_end) {
146	Level += Level * ReleaseCoeff;
147	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
148	}
149	if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_end;
150	break;
151	}
152	case stage_end: {
153	while (iSample < Samples) {
154	Level += Level * ReleaseCoeff;
155	ModulationSystem::pDestinationParameter[ModulationSystem::destination_vca][iSample++] *= Level;
156	}
157	break;
158	}
159	}
160	}
161	}
162
163	/**
164	* Will be called by the voice when the key / voice was triggered.
165	*
166	* @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	*/
177	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
186	// calculate attack stage parameters (lin. curve)
187	AttackStepsLeft = (long) (AttackTime * ModulationSystem::SampleRate());
188	if (AttackStepsLeft) {
189	Level = (float) PreAttack / 1000.0;
190	AttackCoeff = (1.0 - Level) / AttackStepsLeft;
191	}
192	else {
193	Level = 1.0;
194	AttackCoeff = 0.0;
195	}
196
197	// 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	if (ReleaseTime < EG_MIN_RELEASE_TIME) ReleaseTime = EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
211	ReleaseStepsLeft = (long) (ReleaseTime * ModulationSystem::SampleRate());
212	//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
215	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	}