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

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Revision 1906 - (hide annotations) (download)
Sat May 16 12:14:27 2009 UTC (14 years, 11 months ago) by persson
File size: 13220 byte(s)
* bugfix: sometimes, when playing a note twice fast, the second note
  was silent

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 persson 1906 * Copyright (C) 2005 - 2009 Christian Schoenebeck *
7 schoenebeck 53 * *
8     * This program is free software; you can redistribute it and/or modify *
9     * it under the terms of the GNU General Public License as published by *
10     * the Free Software Foundation; either version 2 of the License, or *
11     * (at your option) any later version. *
12     * *
13     * This program is distributed in the hope that it will be useful, *
14     * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16     * GNU General Public License for more details. *
17     * *
18     * You should have received a copy of the GNU General Public License *
19     * along with this program; if not, write to the Free Software *
20     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21     * MA 02111-1307 USA *
22     ***************************************************************************/
23    
24     #include "EGADSR.h"
25    
26 schoenebeck 1424 #include "../../common/global_private.h"
27    
28 schoenebeck 53 namespace LinuxSampler { namespace gig {
29    
30 schoenebeck 738 EGADSR::EGADSR() {
31     enterEndStage();
32     Level = 0.0;
33     CalculateFadeOutCoeff(CONFIG_EG_MIN_RELEASE_TIME, 44100.0); // even if the sample rate will be 192kHz it won't hurt at all
34     }
35    
36 schoenebeck 688 void EGADSR::CalculateFadeOutCoeff(float FadeOutTime, float SampleRate) {
37 persson 796 const float killSteps = FadeOutTime * SampleRate / CONFIG_DEFAULT_SUBFRAGMENT_SIZE;
38 schoenebeck 688 FadeOutCoeff = -1.0f / killSteps;
39 schoenebeck 239 }
40    
41 persson 783 void EGADSR::update(event_t Event, uint SampleRate) {
42     if (Event == event_hold_end) HoldAttack = false;
43    
44 schoenebeck 738 switch (Stage) {
45     case stage_attack:
46 persson 783 switch (Event) {
47     case event_release:
48 schoenebeck 738 enterReleasePart1Stage();
49 persson 783 break;
50     case event_stage_end:
51     if (HoldAttack)
52     enterAttackHoldStage();
53     else
54     enterDecay1Part1Stage(SampleRate);
55     break;
56 schoenebeck 53 }
57 schoenebeck 738 break;
58     case stage_attack_hold:
59     switch (Event) {
60 persson 783 case event_stage_end: {// just refresh time
61     const int intMax = (unsigned int) -1 >> 1;
62     StepsLeft = intMax; // we use the highest possible value
63     break;
64     }
65     case event_hold_end:
66 schoenebeck 738 enterDecay1Part1Stage(SampleRate);
67 schoenebeck 53 break;
68 schoenebeck 738 case event_release:
69     enterReleasePart1Stage();
70     break;
71 schoenebeck 53 }
72 schoenebeck 738 break;
73     case stage_decay1_part1:
74     switch (Event) {
75 persson 768 case event_stage_end:
76     enterDecay1Part2Stage(SampleRate);
77 persson 614 break;
78 schoenebeck 738 case event_cancel_release:
79     if (InfiniteSustain)
80     enterSustainStage();
81     else
82     enterDecay2Stage(SampleRate);
83     break;
84 persson 614 }
85 schoenebeck 738 break;
86     case stage_decay1_part2:
87     switch (Event) {
88     case event_release:
89     enterReleasePart1Stage();
90     break;
91 persson 1906 case event_stage_end:
92 persson 783 if (Level < CONFIG_EG_BOTTOM)
93     enterEndStage();
94     else if (InfiniteSustain)
95 schoenebeck 738 enterSustainStage();
96     else
97     enterDecay2Stage(SampleRate);
98     break;
99 schoenebeck 53 }
100 schoenebeck 738 break;
101     case stage_decay2:
102     switch (Event) {
103     case event_stage_end:
104     enterFadeOutStage();
105     break;
106     case event_release:
107     enterReleasePart1Stage();
108     break;
109 persson 783 case event_hold_end:
110     enterDecay1Part1Stage(SampleRate);
111     break;
112 persson 614 }
113 schoenebeck 738 break;
114     case stage_sustain:
115     switch (Event) {
116     case event_stage_end: {// just refresh time
117     const int intMax = (unsigned int) -1 >> 1;
118     StepsLeft = intMax; // we use the highest possible value
119     break;
120 schoenebeck 53 }
121 schoenebeck 738 case event_release:
122     enterReleasePart1Stage();
123     break;
124 persson 783 case event_hold_end:
125     enterDecay1Part1Stage(SampleRate);
126     break;
127 schoenebeck 53 }
128 schoenebeck 738 break;
129     case stage_release_part1:
130     switch (Event) {
131     case event_stage_end:
132     enterReleasePart2Stage();
133     break;
134     case event_cancel_release:
135     if (InfiniteSustain)
136     enterSustainStage();
137     else
138     enterDecay2Stage(SampleRate);
139     break;
140 schoenebeck 53 }
141 schoenebeck 738 break;
142     case stage_release_part2:
143     switch (Event) {
144     case event_stage_end:
145     enterFadeOutStage();
146     break;
147     case event_cancel_release:
148     if (InfiniteSustain)
149     enterSustainStage();
150     else
151     enterDecay2Stage(SampleRate);
152     break;
153 schoenebeck 53 }
154 schoenebeck 738 break;
155     case stage_fadeout:
156     switch (Event) {
157     case event_stage_end:
158     enterEndStage();
159     break;
160 persson 614 }
161 schoenebeck 738 break;
162 schoenebeck 53 }
163     }
164    
165 persson 783 void EGADSR::trigger(uint PreAttack, float AttackTime, bool HoldAttack, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate) {
166     this->SustainLevel = SustainLevel / 1000.0;
167 schoenebeck 53 this->InfiniteSustain = InfiniteSustain;
168     this->HoldAttack = HoldAttack;
169    
170 schoenebeck 738 this->Decay1Time = Decay1Time;
171     this->Decay2Time = Decay2Time;
172 persson 614
173 schoenebeck 738 invVolume = 1 / Volume;
174     ExpOffset = (0.25 - 1 / 3.55) * invVolume;
175    
176     // calculate release stage parameters (lin+exp curve)
177     if (ReleaseTime < CONFIG_EG_MIN_RELEASE_TIME) ReleaseTime = CONFIG_EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
178     const float ReleaseStepsLeft = (long) (ReleaseTime * SampleRate);
179     ReleaseSlope = 1.365 * (0 - 1) / ReleaseStepsLeft;
180     ReleaseCoeff = ReleaseSlope * invVolume;
181     ReleaseSlope *= 3.55;
182     ReleaseCoeff2 = exp(ReleaseSlope);
183     ReleaseCoeff3 = ExpOffset * (1 - ReleaseCoeff2);
184     ReleaseLevel2 = 0.25 * invVolume;
185 persson 768
186 persson 783 enterAttackStage(PreAttack, AttackTime, SampleRate);
187 schoenebeck 738 }
188    
189 persson 783 void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate) {
190 schoenebeck 738 Stage = stage_attack;
191     Segment = segment_lin;
192 persson 797
193     if (AttackTime >= 0.0005f) {
194     // Measurements of GSt output shows that the real attack time
195     // is about 65.5% of the value specified in the gig file.
196     // The minimum attack value used is 0.032.
197     StepsLeft = int(0.655f * RTMath::Max(AttackTime, 0.032f) * SampleRate);
198 schoenebeck 738 Level = (float) PreAttack / 1000.0;
199     Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0
200 persson 797 } else { // attack is zero - immediately jump to the next stage
201 persson 1046 Level = 1.029f; // a bit higher than max sustain
202 persson 783 if (HoldAttack) enterAttackHoldStage();
203 schoenebeck 738 else enterDecay1Part1Stage(SampleRate);
204 schoenebeck 53 }
205 schoenebeck 738 }
206 schoenebeck 53
207 persson 783 void EGADSR::enterAttackHoldStage() {
208 schoenebeck 738 Stage = stage_attack_hold;
209     Segment = segment_lin;
210     Coeff = 0.0f; // don't rise anymore
211 persson 783 const int intMax = (unsigned int) -1 >> 1;
212     StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
213 schoenebeck 738 }
214 persson 614
215 schoenebeck 738 void EGADSR::enterDecay1Part1Stage(const uint SampleRate) {
216 persson 614 // The decay1 and release stage both consist of two parts,
217     // first a linear curve, f, followed by an exponential curve,
218     // g:
219     //
220     // f(x + d) = f(x) + Coeff
221     // g(x + d) = Coeff2 * g(x) + Coeff3
222     //
223     // (where d is 1/SampleRate). The transition from f to g is
224     // done when f(x) has reached Level2 = 25% of full volume.
225 schoenebeck 738 StepsLeft = (int) (Decay1Time * SampleRate);
226 persson 1046 if (StepsLeft && Level > SustainLevel) {
227 schoenebeck 738 Stage = stage_decay1_part1;
228     Segment = segment_lin;
229 persson 1046 Decay1Slope = (1.347f * SustainLevel - 1.361f) / StepsLeft;
230 schoenebeck 738 Coeff = Decay1Slope * invVolume;
231 persson 614 Decay1Level2 = 0.25 * invVolume;
232 persson 1147 StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff);
233     if (StepsLeft <= 0) enterDecay1Part2Stage(SampleRate);
234 schoenebeck 738 } else {
235     if (InfiniteSustain) enterSustainStage();
236     else enterDecay2Stage(SampleRate);
237 persson 614 }
238 schoenebeck 738 }
239 schoenebeck 53
240 persson 768 void EGADSR::enterDecay1Part2Stage(const uint SampleRate) {
241     if (SustainLevel < Decay1Level2) {
242     Stage = stage_decay1_part2;
243     Segment = segment_exp;
244     Decay1Slope *= 3.55;
245     Coeff = exp(Decay1Slope);
246     Offset = ExpOffset * (1 - Coeff);
247     StepsLeft = int(log((SustainLevel - ExpOffset) / (Level - ExpOffset)) / Decay1Slope);
248 persson 1147 if (StepsLeft > 0) return;
249 persson 768 }
250 persson 1147 if (InfiniteSustain) enterSustainStage();
251     else enterDecay2Stage(SampleRate);
252 schoenebeck 738 }
253 schoenebeck 53
254 schoenebeck 738 void EGADSR::enterDecay2Stage(const uint SampleRate) {
255     Stage = stage_decay2;
256     Segment = segment_lin;
257 persson 1046 Decay2Time = RTMath::Max(Decay2Time, 0.05f);
258 schoenebeck 738 StepsLeft = (int) (Decay2Time * SampleRate);
259     Coeff = (-1.03 / StepsLeft) * invVolume;
260     //FIXME: do we really have to calculate 'StepsLeft' two times?
261     StepsLeft = int((CONFIG_EG_BOTTOM - Level) / Coeff);
262 persson 1147 if (StepsLeft <= 0) enterEndStage();
263 schoenebeck 738 }
264 schoenebeck 53
265 schoenebeck 738 void EGADSR::enterSustainStage() {
266     Stage = stage_sustain;
267     Segment = segment_lin;
268     Coeff = 0.0f; // don't change the envelope level in this stage
269     const int intMax = (unsigned int) -1 >> 1;
270     StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
271 schoenebeck 53 }
272    
273 schoenebeck 738 void EGADSR::enterReleasePart1Stage() {
274     Stage = stage_release_part1;
275     Segment = segment_lin;
276     StepsLeft = int((ReleaseLevel2 - Level) / ReleaseCoeff);
277     Coeff = ReleaseCoeff;
278 persson 1147 if (StepsLeft <= 0) enterReleasePart2Stage();
279 schoenebeck 738 }
280    
281     void EGADSR::enterReleasePart2Stage() {
282     Stage = stage_release_part2;
283     Segment = segment_exp;
284     StepsLeft = int(log((CONFIG_EG_BOTTOM - ExpOffset) / (Level - ExpOffset)) / ReleaseSlope);
285     Coeff = ReleaseCoeff2;
286     Offset = ReleaseCoeff3;
287 persson 1147 if (StepsLeft <= 0) enterFadeOutStage();
288 schoenebeck 738 }
289    
290     void EGADSR::enterFadeOutStage() {
291     Stage = stage_fadeout;
292     Segment = segment_lin;
293     StepsLeft = int(Level / (-FadeOutCoeff));
294     Coeff = FadeOutCoeff;
295 persson 1147 if (StepsLeft <= 0) enterEndStage();
296 schoenebeck 738 }
297    
298 persson 1748 void EGADSR::enterFadeOutStage(int maxFadeOutSteps) {
299     Stage = stage_fadeout;
300     Segment = segment_lin;
301     StepsLeft = int(Level / (-FadeOutCoeff));
302     if (StepsLeft > maxFadeOutSteps) {
303     StepsLeft = maxFadeOutSteps;
304     Coeff = -Level / maxFadeOutSteps;
305     } else {
306     Coeff = FadeOutCoeff;
307     }
308     if (StepsLeft <= 0) enterEndStage();
309     }
310    
311 schoenebeck 738 void EGADSR::enterEndStage() {
312     Stage = stage_end;
313     Segment = segment_end;
314 persson 830 Level = 0;
315 schoenebeck 738 }
316    
317 schoenebeck 53 }} // namespace LinuxSampler::gig

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