/[svn]/linuxsampler/trunk/src/engines/gig/EGADSR.cpp
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Contents of /linuxsampler/trunk/src/engines/gig/EGADSR.cpp

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Revision 286 - (show annotations) (download)
Sat Oct 16 17:29:05 2004 UTC (19 years, 5 months ago) by schoenebeck
File size: 15142 byte(s)
just added some sanity checks for debugging

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 "EGADSR.h"
24
25 namespace LinuxSampler { namespace gig {
26
27 const float EGADSR::FadeOutCoeff(CalculateFadeOutCoeff());
28
29 float EGADSR::CalculateFadeOutCoeff() {
30 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 return -1.0f / killSteps;
33 }
34
35 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 * @param TotalSamples - total number of sample points to be rendered in this
47 * audio fragment cycle by the audio engine
48 * @param pEvents - event list with "release" and "cancel release" events
49 * @param itTriggerEvent - event that caused triggering of the voice (only if
50 * the voice was triggered in the current audio
51 * fragment, NULL otherwise)
52 * @param SamplePos - current playback position
53 * @param CurrentPitch - current pitch value for playback
54 * @param itKillEvent - (optional) event which caused this voice to be killed
55 */
56 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
60 // if the voice was killed in this fragment we only process the time before this kill event, then switch to 'stage_fadeout'
61 int Samples = (itKillEvent) ? RTMath::Min(itKillEvent->FragmentPos(), pEngine->MaxFadeOutPos) : (int) TotalSamples;
62
63 int iSample = TriggerDelay;
64
65 #if DEVMODE
66 if (TriggerDelay > TotalSamples) { // FIXME: should be removed before the final release (purpose: just a sanity check for debugging)
67 dmsg(1,("EGADSR: ERROR, TriggerDelay > Totalsamples\n"));
68 int* i = NULL;
69 (*i)++; // force a segfault
70 }
71 #endif // DEVMODE
72
73 while (iSample < TotalSamples) {
74
75 // if the voice was killed in this fragment and we already processed the time before this kill event
76 if (itKillEvent && iSample >= Samples) Stage = stage_fadeout;
77
78 switch (Stage) {
79 case stage_attack: {
80 TriggerDelay = 0;
81 int to_process = RTMath::Min(AttackStepsLeft, Samples - iSample);
82 int process_end = iSample + to_process;
83 AttackStepsLeft -= to_process;
84 while (iSample < process_end) {
85 Level += AttackCoeff;
86 pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
87 }
88 if (iSample == TotalSamples) { // postpone last transition event for the next audio fragment
89 RTList<Event>::Iterator itLastEvent = pEvents->last();
90 if (itLastEvent) ReleasePostponed = (itLastEvent->Type == Event::type_release);
91 }
92 if (!AttackStepsLeft) Stage = (ReleasePostponed) ? stage_release : (HoldAttack) ? stage_attack_hold : stage_decay1;
93 break;
94 }
95 case stage_attack_hold: {
96 if (SamplePos >= LoopStart) {
97 Stage = stage_decay1;
98 break;
99 }
100 int holdstepsleft = (int) (LoopStart - SamplePos / CurrentPitch); // FIXME: just an approximation, inaccuracy grows with higher audio fragment size, sufficient for usual fragment sizes though
101 int to_process = RTMath::Min(holdstepsleft, Samples - iSample);
102 int process_end = iSample + to_process;
103 if (itTransitionEvent && itTransitionEvent->FragmentPos() <= process_end) {
104 process_end = itTransitionEvent->FragmentPos();
105 Stage = (itTransitionEvent->Type == Event::type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
106 ++itTransitionEvent;
107 }
108 else if (to_process == holdstepsleft) Stage = stage_decay1;
109 while (iSample < process_end) {
110 pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
111 }
112 break;
113 }
114 case stage_decay1: {
115 int to_process = RTMath::Min(Samples - iSample, Decay1StepsLeft);
116 int process_end = iSample + to_process;
117 if (itTransitionEvent && itTransitionEvent->FragmentPos() <= process_end) {
118 process_end = itTransitionEvent->FragmentPos();
119 Stage = (itTransitionEvent->Type == Event::type_release) ? stage_release : (InfiniteSustain) ? stage_sustain : stage_decay2;
120 ++itTransitionEvent;
121 }
122 else {
123 Decay1StepsLeft -= to_process;
124 if (!Decay1StepsLeft) Stage = (InfiniteSustain) ? stage_sustain : stage_decay2;
125 }
126 while (iSample < process_end) {
127 Level += Level * Decay1Coeff;
128 pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
129 }
130 break;
131 }
132 case stage_decay2: {
133 int process_end;
134 if (itTransitionEvent && itTransitionEvent->Type == Event::type_release && itTransitionEvent->FragmentPos() <= Samples) {
135 process_end = itTransitionEvent->FragmentPos();
136 ++itTransitionEvent;
137 Stage = stage_release; // switch to release stage soon
138 }
139 else process_end = Samples;
140 while (iSample < process_end) {
141 Level += Level * Decay2Coeff;
142 pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
143 }
144 if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_fadeout;
145 break;
146 }
147 case stage_sustain: {
148 int process_end;
149 if (itTransitionEvent && itTransitionEvent->Type == Event::type_release && itTransitionEvent->FragmentPos() <= Samples) {
150 process_end = itTransitionEvent->FragmentPos();
151 ++itTransitionEvent;
152 Stage = stage_release; // switch to release stage soon
153 }
154 else process_end = Samples;
155 while (iSample < process_end) {
156 pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
157 }
158 break;
159 }
160 case stage_release: {
161 int process_end;
162 if (itTransitionEvent && itTransitionEvent->Type == Event::type_cancel_release && itTransitionEvent->FragmentPos() <= Samples) {
163 process_end = itTransitionEvent->FragmentPos();
164 ++itTransitionEvent;
165 Stage = (InfiniteSustain) ? stage_sustain : stage_decay2; // switch back to sustain / decay2 stage soon
166 }
167 else process_end = Samples;
168 while (iSample < process_end) {
169 Level += Level * ReleaseCoeff;
170 pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
171 }
172 if (Level <= EG_ENVELOPE_LIMIT) Stage = stage_fadeout;
173 break;
174 }
175 case stage_fadeout: {
176 int to_process = RTMath::Min(int(Level / (-FadeOutCoeff)), TotalSamples - iSample);
177 int process_end = iSample + to_process;
178 while (iSample < process_end) {
179 Level += FadeOutCoeff;
180 pEngine->pSynthesisParameters[ModulationDestination][iSample++] *= Level;
181 }
182 Stage = stage_end;
183 if (Level > -FadeOutCoeff) dmsg(1,("EGADSR: Warning, final fade out level too high, may result in click sound!\n"));
184 } //Fall through here instead of breaking otherwise we can get back into stage_fadeout and loop forever!
185 case stage_end: {
186 while (iSample < TotalSamples) {
187 pEngine->pSynthesisParameters[ModulationDestination][iSample++] = 0.0f;
188 }
189 break;
190 }
191 }
192 }
193
194 #if DEVMODE
195 if (itKillEvent && Stage != stage_end) { // FIXME: should be removed before the final release (purpose: just a sanity check for debugging)
196 dmsg(1,("EGADSR: ERROR, voice killing not completed !!!\n"));
197 dmsg(1,("EGADSR: Stage=%d,iSample=%d,Samples=%d, TotalSamples=%d, MaxFadoutPos=%d\n",Stage,iSample,Samples,TotalSamples,pEngine->MaxFadeOutPos));
198 }
199 #endif // DEVMODE
200 }
201
202 /**
203 * Will be called by the voice when the key / voice was triggered.
204 *
205 * @param PreAttack - Preattack value for the envelope (0 - 1000 permille)
206 * @param AttackTime - Attack time for the envelope (0.000 - 60.000s)
207 * @param HoldAttack - If true, Decay1 will be postponed until the sample reached the sample loop start.
208 * @param LoopStart - Sample position where sample loop starts (if any)
209 * @param Decay1Time - Decay1 time of the sample amplitude EG (0.000 - 60.000s).
210 * @param Decay2Time - Only if !InfiniteSustain: 2nd decay stage time of the sample amplitude EG (0.000 - 60.000s).
211 * @param InfiniteSustain - If true, instead of going into Decay2 phase, Decay1 level will be hold until note will be released.
212 * @param SustainLevel - Sustain level of the sample amplitude EG (0 - 1000 permille).
213 * @param ReleaseTIme - Release time for the envelope (0.000 - 60.000s)
214 * @param Delay - Number of sample points triggering should be delayed.
215 */
216 void EGADSR::Trigger(uint PreAttack, double AttackTime, bool HoldAttack, long LoopStart, double Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, double ReleaseTime, uint Delay) {
217 this->TriggerDelay = Delay;
218 this->Stage = stage_attack;
219 this->SustainLevel = (SustainLevel) ? (SustainLevel > EG_ENVELOPE_LIMIT) ? (float) SustainLevel / 1000.0 : EG_ENVELOPE_LIMIT : 1.0;
220 this->InfiniteSustain = InfiniteSustain;
221 this->HoldAttack = HoldAttack;
222 this->LoopStart = LoopStart;
223 this->ReleasePostponed = false;
224
225 // calculate attack stage parameters (lin. curve)
226 AttackStepsLeft = (long) (AttackTime * pEngine->pAudioOutputDevice->SampleRate());
227 if (AttackStepsLeft) {
228 Level = (float) PreAttack / 1000.0;
229 AttackCoeff = (1.0 - Level) / AttackStepsLeft;
230 }
231 else {
232 Level = 1.0;
233 AttackCoeff = 0.0;
234 }
235
236 // calculate decay1 stage parameters (exp. curve)
237 Decay1StepsLeft = (long) (Decay1Time * pEngine->pAudioOutputDevice->SampleRate());
238 Decay1Coeff = (Decay1StepsLeft) ? exp(log(this->SustainLevel) / (double) Decay1StepsLeft) - 1.0
239 : 0.0;
240
241 // calculate decay2 stage parameters (exp. curve)
242 if (!InfiniteSustain) {
243 if (Decay2Time < EG_MIN_RELEASE_TIME) Decay2Time = EG_MIN_RELEASE_TIME;
244 long Decay2Steps = (long) (Decay2Time * pEngine->pAudioOutputDevice->SampleRate());
245 Decay2Coeff = (Decay2Steps) ? exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / Decay2Steps + log(this->SustainLevel)) - this->SustainLevel
246 : 0.0;
247 }
248
249 // calculate release stage parameters (exp. curve)
250 if (ReleaseTime < EG_MIN_RELEASE_TIME) ReleaseTime = EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
251 ReleaseStepsLeft = (long) (ReleaseTime * pEngine->pAudioOutputDevice->SampleRate());
252 ReleaseCoeff = exp((log(EG_ENVELOPE_LIMIT) - log(this->SustainLevel)) / ReleaseStepsLeft + log(this->SustainLevel)) - this->SustainLevel;
253
254 dmsg(4,("PreAttack=%d, AttackLength=%d, AttackCoeff=%f, Decay1Coeff=%f, Decay2Coeff=%f, ReleaseLength=%d, ReleaseCoeff=%f\n",
255 PreAttack, AttackStepsLeft, AttackCoeff, Decay1Coeff, Decay2Coeff, ReleaseStepsLeft, ReleaseCoeff));
256 }
257
258 }} // namespace LinuxSampler::gig

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