engines/gig/EGADSR.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2009 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"

#include "../../common/global_private.h"

namespace LinuxSampler { namespace gig {

    EGADSR::EGADSR() {
        enterEndStage();
        Level = 0.0;
        CalculateFadeOutCoeff(CONFIG_EG_MIN_RELEASE_TIME, 44100.0); // even if the sample rate will be 192kHz it won't hurt at all
    }

    void EGADSR::CalculateFadeOutCoeff(float FadeOutTime, float SampleRate) {
        const float killSteps = FadeOutTime * SampleRate / CONFIG_DEFAULT_SUBFRAGMENT_SIZE;
        FadeOutCoeff = -1.0f / killSteps;
    }

    void EGADSR::update(event_t Event, uint SampleRate) {
        if (Event == event_hold_end) HoldAttack = false;

        switch (Stage) {
            case stage_attack:
                switch (Event) {
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_stage_end:
                        if (HoldAttack)
                            enterAttackHoldStage();
                        else
                            enterDecay1Part1Stage(SampleRate);
                        break;
                }
                break;
            case stage_attack_hold:
                switch (Event) {
                    case event_stage_end: {// just refresh time
                        const int intMax = (unsigned int) -1 >> 1;
                        StepsLeft = intMax; // we use the highest possible value
                        break;
                    }
                    case event_hold_end:
                        enterDecay1Part1Stage(SampleRate);
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                }
                break;
            case stage_decay1_part1:
                switch (Event) {
                    case event_stage_end:
                        enterDecay1Part2Stage(SampleRate);
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                }
                break;
            case stage_decay1_part2:
                switch (Event) {
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_stage_end:
                        if (Level < CONFIG_EG_BOTTOM)
                            enterEndStage();
                        else if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay2Stage(SampleRate);
                        break;
                }
                break;
            case stage_decay2:
                switch (Event) {
                    case event_stage_end:
                        enterFadeOutStage();
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_hold_end:
                        enterDecay1Part1Stage(SampleRate);
                        break;
                }
                break;
            case stage_sustain:
                switch (Event) {
                    case event_stage_end: {// just refresh time
                        const int intMax = (unsigned int) -1 >> 1;
                        StepsLeft = intMax; // we use the highest possible value
                        break;
                    }
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_hold_end:
                        enterDecay1Part1Stage(SampleRate);
                        break;
                }
                break;
            case stage_release_part1:
                switch (Event) {
                    case event_stage_end:
                        enterReleasePart2Stage();
                        break;
                    case event_cancel_release:
                        if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay2Stage(SampleRate);
                        break;
                }
                break;
            case stage_release_part2:
                switch (Event) {
                    case event_stage_end:
                        enterFadeOutStage();
                        break;
                    case event_cancel_release:
                        if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay2Stage(SampleRate);
                        break;
                }
                break;
            case stage_fadeout:
                switch (Event) {
                    case event_stage_end:
                        enterEndStage();
                        break;
                }
                break;
        }
    }

    void EGADSR::trigger(uint PreAttack, float AttackTime, bool HoldAttack, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate) {
        this->SustainLevel     = SustainLevel / 1000.0;
        this->InfiniteSustain  = InfiniteSustain;
        this->HoldAttack       = HoldAttack;

        this->Decay1Time = Decay1Time;
        this->Decay2Time = Decay2Time;

        invVolume = 1 / Volume;
        ExpOffset = (0.25 - 1 / 3.55) * invVolume;

        // calculate release stage parameters (lin+exp curve)
        if (ReleaseTime < CONFIG_EG_MIN_RELEASE_TIME) ReleaseTime = CONFIG_EG_MIN_RELEASE_TIME;  // to avoid click sounds at the end of the sample playback
        const float ReleaseStepsLeft = (long) (ReleaseTime * SampleRate);
        ReleaseSlope  = 1.365 * (0 - 1) / ReleaseStepsLeft;
        ReleaseCoeff  = ReleaseSlope * invVolume;
        ReleaseSlope  *= 3.55;
        ReleaseCoeff2 = exp(ReleaseSlope);
        ReleaseCoeff3 = ExpOffset * (1 - ReleaseCoeff2);
        ReleaseLevel2 = 0.25 * invVolume;

        enterAttackStage(PreAttack, AttackTime, SampleRate);
    }

    void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate) {
        Stage   = stage_attack;
        Segment = segment_lin;

        if (AttackTime >= 0.0005f) {
            // Measurements of GSt output shows that the real attack time
            // is about 65.5% of the value specified in the gig file.
            // The minimum attack value used is 0.032.
            StepsLeft = int(0.655f * RTMath::Max(AttackTime, 0.032f) * SampleRate);
            Level = (float) PreAttack / 1000.0;
            Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0
        } else { // attack is zero - immediately jump to the next stage
            Level = 1.029f; // a bit higher than max sustain
            if (HoldAttack) enterAttackHoldStage();
            else            enterDecay1Part1Stage(SampleRate);
        }
    }

    void EGADSR::enterAttackHoldStage() {
        Stage     = stage_attack_hold;
        Segment   = segment_lin;
        Coeff     = 0.0f; // don't rise anymore
        const int intMax = (unsigned int) -1 >> 1;
        StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
    }

    void EGADSR::enterDecay1Part1Stage(const uint SampleRate) {
        // The decay1 and release stage both consist of two parts,
        // first a linear curve, f, followed by an exponential curve,
        // g:
        //
        // f(x + d) = f(x) + Coeff
        // g(x + d) = Coeff2 * g(x) + Coeff3
        //
        // (where d is 1/SampleRate). The transition from f to g is
        // done when f(x) has reached Level2 = 25% of full volume.
        StepsLeft = (int) (Decay1Time * SampleRate);
        if (StepsLeft && Level > SustainLevel) {
            Stage        = stage_decay1_part1;
            Segment      = segment_lin;
            Decay1Slope = (1.347f * SustainLevel - 1.361f) / StepsLeft;
            Coeff        = Decay1Slope * invVolume;
            Decay1Level2 = 0.25 * invVolume;
            StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff);
            if (StepsLeft <= 0) enterDecay1Part2Stage(SampleRate);
        } else {
            if (InfiniteSustain) enterSustainStage();
            else                 enterDecay2Stage(SampleRate);
        }
    }

    void EGADSR::enterDecay1Part2Stage(const uint SampleRate) {
        if (SustainLevel < Decay1Level2) {
            Stage   = stage_decay1_part2;
            Segment = segment_exp;
            Decay1Slope *= 3.55;
            Coeff  = exp(Decay1Slope);
            Offset = ExpOffset * (1 - Coeff);
            StepsLeft = int(log((SustainLevel - ExpOffset) / (Level - ExpOffset)) / Decay1Slope);
            if (StepsLeft > 0) return;
        }
        if (InfiniteSustain) enterSustainStage();
        else                 enterDecay2Stage(SampleRate);
    }

    void EGADSR::enterDecay2Stage(const uint SampleRate) {
        Stage      = stage_decay2;
        Segment    = segment_lin;
        Decay2Time = RTMath::Max(Decay2Time, 0.05f);
        StepsLeft  = (int) (Decay2Time * SampleRate);
        Coeff      = (-1.03 / StepsLeft) * invVolume;
        //FIXME: do we really have to calculate 'StepsLeft' two times?
        StepsLeft  = int((CONFIG_EG_BOTTOM - Level) / Coeff);
        if (StepsLeft <= 0) enterEndStage();
    }

    void EGADSR::enterSustainStage() {
        Stage   = stage_sustain;
        Segment = segment_lin;
        Coeff   = 0.0f; // don't change the envelope level in this stage
        const int intMax = (unsigned int) -1 >> 1;
        StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
    }

    void EGADSR::enterReleasePart1Stage() {
        Stage     = stage_release_part1;
        Segment   = segment_lin;
        StepsLeft = int((ReleaseLevel2 - Level) / ReleaseCoeff);
        Coeff     = ReleaseCoeff;
        if (StepsLeft <= 0) enterReleasePart2Stage();
    }

    void EGADSR::enterReleasePart2Stage() {
        Stage     = stage_release_part2;
        Segment   = segment_exp;
        StepsLeft = int(log((CONFIG_EG_BOTTOM - ExpOffset) / (Level - ExpOffset)) / ReleaseSlope);
        Coeff     = ReleaseCoeff2;
        Offset    = ReleaseCoeff3;
        if (StepsLeft <= 0) enterFadeOutStage();
    }

    void EGADSR::enterFadeOutStage() {
        Stage     = stage_fadeout;
        Segment   = segment_lin;
        StepsLeft = int(Level / (-FadeOutCoeff));
        Coeff     = FadeOutCoeff;
        if (StepsLeft <= 0) enterEndStage();
    }

    void EGADSR::enterFadeOutStage(int maxFadeOutSteps) {
        Stage     = stage_fadeout;
        Segment   = segment_lin;
        StepsLeft = int(Level / (-FadeOutCoeff));
        if (StepsLeft > maxFadeOutSteps) {
            StepsLeft = maxFadeOutSteps;
            Coeff = -Level / maxFadeOutSteps;
        } else {
            Coeff = FadeOutCoeff;
        }
        if (StepsLeft <= 0) enterEndStage();
    }

    void EGADSR::enterEndStage() {
        Stage   = stage_end;
        Segment = segment_end;
        Level   = 0;
    }

}} // namespace LinuxSampler::gig
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* Copyright (C) 2005 - 2009 Christian Schoenebeck *
7	* *
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	#include "../../common/global_private.h"
27
28	namespace LinuxSampler { namespace gig {
29
30	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	void EGADSR::CalculateFadeOutCoeff(float FadeOutTime, float SampleRate) {
37	const float killSteps = FadeOutTime * SampleRate / CONFIG_DEFAULT_SUBFRAGMENT_SIZE;
38	FadeOutCoeff = -1.0f / killSteps;
39	}
40
41	void EGADSR::update(event_t Event, uint SampleRate) {
42	if (Event == event_hold_end) HoldAttack = false;
43
44	switch (Stage) {
45	case stage_attack:
46	switch (Event) {
47	case event_release:
48	enterReleasePart1Stage();
49	break;
50	case event_stage_end:
51	if (HoldAttack)
52	enterAttackHoldStage();
53	else
54	enterDecay1Part1Stage(SampleRate);
55	break;
56	}
57	break;
58	case stage_attack_hold:
59	switch (Event) {
60	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	enterDecay1Part1Stage(SampleRate);
67	break;
68	case event_release:
69	enterReleasePart1Stage();
70	break;
71	}
72	break;
73	case stage_decay1_part1:
74	switch (Event) {
75	case event_stage_end:
76	enterDecay1Part2Stage(SampleRate);
77	break;
78	case event_release:
79	enterReleasePart1Stage();
80	break;
81	}
82	break;
83	case stage_decay1_part2:
84	switch (Event) {
85	case event_release:
86	enterReleasePart1Stage();
87	break;
88	case event_stage_end:
89	if (Level < CONFIG_EG_BOTTOM)
90	enterEndStage();
91	else if (InfiniteSustain)
92	enterSustainStage();
93	else
94	enterDecay2Stage(SampleRate);
95	break;
96	}
97	break;
98	case stage_decay2:
99	switch (Event) {
100	case event_stage_end:
101	enterFadeOutStage();
102	break;
103	case event_release:
104	enterReleasePart1Stage();
105	break;
106	case event_hold_end:
107	enterDecay1Part1Stage(SampleRate);
108	break;
109	}
110	break;
111	case stage_sustain:
112	switch (Event) {
113	case event_stage_end: {// just refresh time
114	const int intMax = (unsigned int) -1 >> 1;
115	StepsLeft = intMax; // we use the highest possible value
116	break;
117	}
118	case event_release:
119	enterReleasePart1Stage();
120	break;
121	case event_hold_end:
122	enterDecay1Part1Stage(SampleRate);
123	break;
124	}
125	break;
126	case stage_release_part1:
127	switch (Event) {
128	case event_stage_end:
129	enterReleasePart2Stage();
130	break;
131	case event_cancel_release:
132	if (InfiniteSustain)
133	enterSustainStage();
134	else
135	enterDecay2Stage(SampleRate);
136	break;
137	}
138	break;
139	case stage_release_part2:
140	switch (Event) {
141	case event_stage_end:
142	enterFadeOutStage();
143	break;
144	case event_cancel_release:
145	if (InfiniteSustain)
146	enterSustainStage();
147	else
148	enterDecay2Stage(SampleRate);
149	break;
150	}
151	break;
152	case stage_fadeout:
153	switch (Event) {
154	case event_stage_end:
155	enterEndStage();
156	break;
157	}
158	break;
159	}
160	}
161
162	void EGADSR::trigger(uint PreAttack, float AttackTime, bool HoldAttack, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate) {
163	this->SustainLevel = SustainLevel / 1000.0;
164	this->InfiniteSustain = InfiniteSustain;
165	this->HoldAttack = HoldAttack;
166
167	this->Decay1Time = Decay1Time;
168	this->Decay2Time = Decay2Time;
169
170	invVolume = 1 / Volume;
171	ExpOffset = (0.25 - 1 / 3.55) * invVolume;
172
173	// calculate release stage parameters (lin+exp curve)
174	if (ReleaseTime < CONFIG_EG_MIN_RELEASE_TIME) ReleaseTime = CONFIG_EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
175	const float ReleaseStepsLeft = (long) (ReleaseTime * SampleRate);
176	ReleaseSlope = 1.365 * (0 - 1) / ReleaseStepsLeft;
177	ReleaseCoeff = ReleaseSlope * invVolume;
178	ReleaseSlope *= 3.55;
179	ReleaseCoeff2 = exp(ReleaseSlope);
180	ReleaseCoeff3 = ExpOffset * (1 - ReleaseCoeff2);
181	ReleaseLevel2 = 0.25 * invVolume;
182
183	enterAttackStage(PreAttack, AttackTime, SampleRate);
184	}
185
186	void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate) {
187	Stage = stage_attack;
188	Segment = segment_lin;
189
190	if (AttackTime >= 0.0005f) {
191	// Measurements of GSt output shows that the real attack time
192	// is about 65.5% of the value specified in the gig file.
193	// The minimum attack value used is 0.032.
194	StepsLeft = int(0.655f * RTMath::Max(AttackTime, 0.032f) * SampleRate);
195	Level = (float) PreAttack / 1000.0;
196	Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0
197	} else { // attack is zero - immediately jump to the next stage
198	Level = 1.029f; // a bit higher than max sustain
199	if (HoldAttack) enterAttackHoldStage();
200	else enterDecay1Part1Stage(SampleRate);
201	}
202	}
203
204	void EGADSR::enterAttackHoldStage() {
205	Stage = stage_attack_hold;
206	Segment = segment_lin;
207	Coeff = 0.0f; // don't rise anymore
208	const int intMax = (unsigned int) -1 >> 1;
209	StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
210	}
211
212	void EGADSR::enterDecay1Part1Stage(const uint SampleRate) {
213	// The decay1 and release stage both consist of two parts,
214	// first a linear curve, f, followed by an exponential curve,
215	// g:
216	//
217	// f(x + d) = f(x) + Coeff
218	// g(x + d) = Coeff2 * g(x) + Coeff3
219	//
220	// (where d is 1/SampleRate). The transition from f to g is
221	// done when f(x) has reached Level2 = 25% of full volume.
222	StepsLeft = (int) (Decay1Time * SampleRate);
223	if (StepsLeft && Level > SustainLevel) {
224	Stage = stage_decay1_part1;
225	Segment = segment_lin;
226	Decay1Slope = (1.347f * SustainLevel - 1.361f) / StepsLeft;
227	Coeff = Decay1Slope * invVolume;
228	Decay1Level2 = 0.25 * invVolume;
229	StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff);
230	if (StepsLeft <= 0) enterDecay1Part2Stage(SampleRate);
231	} else {
232	if (InfiniteSustain) enterSustainStage();
233	else enterDecay2Stage(SampleRate);
234	}
235	}
236
237	void EGADSR::enterDecay1Part2Stage(const uint SampleRate) {
238	if (SustainLevel < Decay1Level2) {
239	Stage = stage_decay1_part2;
240	Segment = segment_exp;
241	Decay1Slope *= 3.55;
242	Coeff = exp(Decay1Slope);
243	Offset = ExpOffset * (1 - Coeff);
244	StepsLeft = int(log((SustainLevel - ExpOffset) / (Level - ExpOffset)) / Decay1Slope);
245	if (StepsLeft > 0) return;
246	}
247	if (InfiniteSustain) enterSustainStage();
248	else enterDecay2Stage(SampleRate);
249	}
250
251	void EGADSR::enterDecay2Stage(const uint SampleRate) {
252	Stage = stage_decay2;
253	Segment = segment_lin;
254	Decay2Time = RTMath::Max(Decay2Time, 0.05f);
255	StepsLeft = (int) (Decay2Time * SampleRate);
256	Coeff = (-1.03 / StepsLeft) * invVolume;
257	//FIXME: do we really have to calculate 'StepsLeft' two times?
258	StepsLeft = int((CONFIG_EG_BOTTOM - Level) / Coeff);
259	if (StepsLeft <= 0) enterEndStage();
260	}
261
262	void EGADSR::enterSustainStage() {
263	Stage = stage_sustain;
264	Segment = segment_lin;
265	Coeff = 0.0f; // don't change the envelope level in this stage
266	const int intMax = (unsigned int) -1 >> 1;
267	StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
268	}
269
270	void EGADSR::enterReleasePart1Stage() {
271	Stage = stage_release_part1;
272	Segment = segment_lin;
273	StepsLeft = int((ReleaseLevel2 - Level) / ReleaseCoeff);
274	Coeff = ReleaseCoeff;
275	if (StepsLeft <= 0) enterReleasePart2Stage();
276	}
277
278	void EGADSR::enterReleasePart2Stage() {
279	Stage = stage_release_part2;
280	Segment = segment_exp;
281	StepsLeft = int(log((CONFIG_EG_BOTTOM - ExpOffset) / (Level - ExpOffset)) / ReleaseSlope);
282	Coeff = ReleaseCoeff2;
283	Offset = ReleaseCoeff3;
284	if (StepsLeft <= 0) enterFadeOutStage();
285	}
286
287	void EGADSR::enterFadeOutStage() {
288	Stage = stage_fadeout;
289	Segment = segment_lin;
290	StepsLeft = int(Level / (-FadeOutCoeff));
291	Coeff = FadeOutCoeff;
292	if (StepsLeft <= 0) enterEndStage();
293	}
294
295	void EGADSR::enterFadeOutStage(int maxFadeOutSteps) {
296	Stage = stage_fadeout;
297	Segment = segment_lin;
298	StepsLeft = int(Level / (-FadeOutCoeff));
299	if (StepsLeft > maxFadeOutSteps) {
300	StepsLeft = maxFadeOutSteps;
301	Coeff = -Level / maxFadeOutSteps;
302	} else {
303	Coeff = FadeOutCoeff;
304	}
305	if (StepsLeft <= 0) enterEndStage();
306	}
307
308	void EGADSR::enterEndStage() {
309	Stage = stage_end;
310	Segment = segment_end;
311	Level = 0;
312	}
313
314	}} // namespace LinuxSampler::gig