engines/gig/EGADSR.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2016 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 {

    void EGADSR::update(event_t Event, uint SampleRate) {
        if (atEnd(Event)) return;

        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;
                    default: ; // noop
                }
                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;
                    default: ; // noop
                }
                break;
            case stage_decay1_part1:
                switch (Event) {
                    case event_stage_end:
                        enterDecay1Part2Stage(SampleRate);
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    default: ; // noop
                }
                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;
                    default: ; // noop
                }
                break;
            case stage_decay2:
                switch (Event) {
                    case event_stage_end:
                        enterFadeOutStage();
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_hold_end:
                        enterDecay1Part1Stage(SampleRate);
                        break;
                    default: ; // noop
                }
                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;
                    default: ; // noop
                }
                break;
            case stage_release_part1:
                switch (Event) {
                    case event_stage_end:
                        enterReleasePart2Stage();
                        break;
                    case event_cancel_release:
                        if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay2Stage(SampleRate);
                        break;
                    default: ; // noop
                }
                break;
            case stage_release_part2:
                switch (Event) {
                    case event_stage_end:
                        enterFadeOutStage();
                        break;
                    case event_cancel_release:
                        if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay2Stage(SampleRate);
                        break;
                    default: ; // noop
                }
                break;
            case stage_fadeout:
            case stage_end:
                ; // noop
        }
    }

    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;

        enterFirstStage();
        enterAttackStage(PreAttack, AttackTime, SampleRate);
    }

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

        if (AttackTime >= 1e-8) {
            // 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 0.0316.
            StepsLeft = int(0.655f * RTMath::Max(AttackTime, 0.0316f) * 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();
    }

}} // namespace LinuxSampler::gig
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	schoenebeck	3034	* Copyright (C) 2005 - 2016 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	persson	2055	void EGADSR::update(event_t Event, uint SampleRate) {
31			if (atEnd(Event)) return;
32	schoenebeck	738
33	persson	783	if (Event == event_hold_end) HoldAttack = false;
34
35	schoenebeck	738	switch (Stage) {
36			case stage_attack:
37	persson	783	switch (Event) {
38			case event_release:
39	schoenebeck	738	enterReleasePart1Stage();
40	persson	783	break;
41			case event_stage_end:
42			if (HoldAttack)
43			enterAttackHoldStage();
44			else
45			enterDecay1Part1Stage(SampleRate);
46			break;
47	schoenebeck	3034	default: ; // noop
48	schoenebeck	53	}
49	schoenebeck	738	break;
50			case stage_attack_hold:
51			switch (Event) {
52	persson	783	case event_stage_end: {// just refresh time
53			const int intMax = (unsigned int) -1 >> 1;
54			StepsLeft = intMax; // we use the highest possible value
55			break;
56			}
57			case event_hold_end:
58	schoenebeck	738	enterDecay1Part1Stage(SampleRate);
59	schoenebeck	53	break;
60	schoenebeck	738	case event_release:
61			enterReleasePart1Stage();
62			break;
63	schoenebeck	3034	default: ; // noop
64	schoenebeck	53	}
65	schoenebeck	738	break;
66			case stage_decay1_part1:
67			switch (Event) {
68	persson	768	case event_stage_end:
69			enterDecay1Part2Stage(SampleRate);
70	persson	614	break;
71	persson	1909	case event_release:
72			enterReleasePart1Stage();
73	schoenebeck	738	break;
74	schoenebeck	3034	default: ; // noop
75	persson	614	}
76	schoenebeck	738	break;
77			case stage_decay1_part2:
78			switch (Event) {
79			case event_release:
80			enterReleasePart1Stage();
81			break;
82	persson	1906	case event_stage_end:
83	persson	783	if (Level < CONFIG_EG_BOTTOM)
84			enterEndStage();
85			else if (InfiniteSustain)
86	schoenebeck	738	enterSustainStage();
87			else
88			enterDecay2Stage(SampleRate);
89			break;
90	schoenebeck	3034	default: ; // noop
91	schoenebeck	53	}
92	schoenebeck	738	break;
93			case stage_decay2:
94			switch (Event) {
95			case event_stage_end:
96			enterFadeOutStage();
97			break;
98			case event_release:
99			enterReleasePart1Stage();
100			break;
101	persson	783	case event_hold_end:
102			enterDecay1Part1Stage(SampleRate);
103			break;
104	schoenebeck	3034	default: ; // noop
105	persson	614	}
106	schoenebeck	738	break;
107			case stage_sustain:
108			switch (Event) {
109			case event_stage_end: {// just refresh time
110			const int intMax = (unsigned int) -1 >> 1;
111			StepsLeft = intMax; // we use the highest possible value
112			break;
113	schoenebeck	53	}
114	schoenebeck	738	case event_release:
115			enterReleasePart1Stage();
116			break;
117	persson	783	case event_hold_end:
118			enterDecay1Part1Stage(SampleRate);
119			break;
120	schoenebeck	3034	default: ; // noop
121	schoenebeck	53	}
122	schoenebeck	738	break;
123			case stage_release_part1:
124			switch (Event) {
125			case event_stage_end:
126			enterReleasePart2Stage();
127			break;
128			case event_cancel_release:
129			if (InfiniteSustain)
130			enterSustainStage();
131			else
132			enterDecay2Stage(SampleRate);
133			break;
134	schoenebeck	3034	default: ; // noop
135	schoenebeck	53	}
136	schoenebeck	738	break;
137			case stage_release_part2:
138			switch (Event) {
139			case event_stage_end:
140			enterFadeOutStage();
141			break;
142			case event_cancel_release:
143			if (InfiniteSustain)
144			enterSustainStage();
145			else
146			enterDecay2Stage(SampleRate);
147			break;
148	schoenebeck	3034	default: ; // noop
149	schoenebeck	53	}
150	schoenebeck	738	break;
151	schoenebeck	3034	case stage_fadeout:
152			case stage_end:
153			; // noop
154	schoenebeck	53	}
155			}
156
157	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) {
158			this->SustainLevel = SustainLevel / 1000.0;
159	schoenebeck	53	this->InfiniteSustain = InfiniteSustain;
160			this->HoldAttack = HoldAttack;
161
162	schoenebeck	738	this->Decay1Time = Decay1Time;
163			this->Decay2Time = Decay2Time;
164	persson	614
165	schoenebeck	738	invVolume = 1 / Volume;
166			ExpOffset = (0.25 - 1 / 3.55) * invVolume;
167
168			// calculate release stage parameters (lin+exp curve)
169			if (ReleaseTime < CONFIG_EG_MIN_RELEASE_TIME) ReleaseTime = CONFIG_EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
170			const float ReleaseStepsLeft = (long) (ReleaseTime * SampleRate);
171			ReleaseSlope = 1.365 * (0 - 1) / ReleaseStepsLeft;
172			ReleaseCoeff = ReleaseSlope * invVolume;
173			ReleaseSlope *= 3.55;
174			ReleaseCoeff2 = exp(ReleaseSlope);
175			ReleaseCoeff3 = ExpOffset * (1 - ReleaseCoeff2);
176			ReleaseLevel2 = 0.25 * invVolume;
177	persson	768
178	persson	2055	enterFirstStage();
179	persson	783	enterAttackStage(PreAttack, AttackTime, SampleRate);
180	schoenebeck	738	}
181
182	persson	783	void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate) {
183	schoenebeck	738	Stage = stage_attack;
184			Segment = segment_lin;
185	persson	797
186	persson	2408	if (AttackTime >= 1e-8) {
187	persson	797	// Measurements of GSt output shows that the real attack time
188			// is about 65.5% of the value specified in the gig file.
189	persson	2408	// The minimum attack value used is 0.0316.
190			StepsLeft = int(0.655f * RTMath::Max(AttackTime, 0.0316f) * SampleRate);
191	schoenebeck	738	Level = (float) PreAttack / 1000.0;
192			Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0
193	persson	797	} else { // attack is zero - immediately jump to the next stage
194	persson	1046	Level = 1.029f; // a bit higher than max sustain
195	persson	783	if (HoldAttack) enterAttackHoldStage();
196	schoenebeck	738	else enterDecay1Part1Stage(SampleRate);
197	schoenebeck	53	}
198	schoenebeck	738	}
199	schoenebeck	53
200	persson	783	void EGADSR::enterAttackHoldStage() {
201	schoenebeck	738	Stage = stage_attack_hold;
202			Segment = segment_lin;
203			Coeff = 0.0f; // don't rise anymore
204	persson	783	const int intMax = (unsigned int) -1 >> 1;
205			StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
206	schoenebeck	738	}
207	persson	614
208	schoenebeck	738	void EGADSR::enterDecay1Part1Stage(const uint SampleRate) {
209	persson	614	// The decay1 and release stage both consist of two parts,
210			// first a linear curve, f, followed by an exponential curve,
211			// g:
212			//
213			// f(x + d) = f(x) + Coeff
214			// g(x + d) = Coeff2 * g(x) + Coeff3
215			//
216			// (where d is 1/SampleRate). The transition from f to g is
217			// done when f(x) has reached Level2 = 25% of full volume.
218	schoenebeck	738	StepsLeft = (int) (Decay1Time * SampleRate);
219	persson	1046	if (StepsLeft && Level > SustainLevel) {
220	schoenebeck	738	Stage = stage_decay1_part1;
221			Segment = segment_lin;
222	persson	1046	Decay1Slope = (1.347f * SustainLevel - 1.361f) / StepsLeft;
223	schoenebeck	738	Coeff = Decay1Slope * invVolume;
224	persson	614	Decay1Level2 = 0.25 * invVolume;
225	persson	1147	StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff);
226			if (StepsLeft <= 0) enterDecay1Part2Stage(SampleRate);
227	schoenebeck	738	} else {
228			if (InfiniteSustain) enterSustainStage();
229			else enterDecay2Stage(SampleRate);
230	persson	614	}
231	schoenebeck	738	}
232	schoenebeck	53
233	persson	768	void EGADSR::enterDecay1Part2Stage(const uint SampleRate) {
234			if (SustainLevel < Decay1Level2) {
235			Stage = stage_decay1_part2;
236			Segment = segment_exp;
237			Decay1Slope *= 3.55;
238			Coeff = exp(Decay1Slope);
239			Offset = ExpOffset * (1 - Coeff);
240			StepsLeft = int(log((SustainLevel - ExpOffset) / (Level - ExpOffset)) / Decay1Slope);
241	persson	1147	if (StepsLeft > 0) return;
242	persson	768	}
243	persson	1147	if (InfiniteSustain) enterSustainStage();
244			else enterDecay2Stage(SampleRate);
245	schoenebeck	738	}
246	schoenebeck	53
247	schoenebeck	738	void EGADSR::enterDecay2Stage(const uint SampleRate) {
248			Stage = stage_decay2;
249			Segment = segment_lin;
250	persson	1046	Decay2Time = RTMath::Max(Decay2Time, 0.05f);
251	schoenebeck	738	StepsLeft = (int) (Decay2Time * SampleRate);
252			Coeff = (-1.03 / StepsLeft) * invVolume;
253			//FIXME: do we really have to calculate 'StepsLeft' two times?
254			StepsLeft = int((CONFIG_EG_BOTTOM - Level) / Coeff);
255	persson	1147	if (StepsLeft <= 0) enterEndStage();
256	schoenebeck	738	}
257	schoenebeck	53
258	schoenebeck	738	void EGADSR::enterSustainStage() {
259			Stage = stage_sustain;
260			Segment = segment_lin;
261			Coeff = 0.0f; // don't change the envelope level in this stage
262			const int intMax = (unsigned int) -1 >> 1;
263			StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
264	schoenebeck	53	}
265
266	schoenebeck	738	void EGADSR::enterReleasePart1Stage() {
267			Stage = stage_release_part1;
268			Segment = segment_lin;
269			StepsLeft = int((ReleaseLevel2 - Level) / ReleaseCoeff);
270			Coeff = ReleaseCoeff;
271	persson	1147	if (StepsLeft <= 0) enterReleasePart2Stage();
272	schoenebeck	738	}
273
274			void EGADSR::enterReleasePart2Stage() {
275			Stage = stage_release_part2;
276			Segment = segment_exp;
277			StepsLeft = int(log((CONFIG_EG_BOTTOM - ExpOffset) / (Level - ExpOffset)) / ReleaseSlope);
278			Coeff = ReleaseCoeff2;
279			Offset = ReleaseCoeff3;
280	persson	1147	if (StepsLeft <= 0) enterFadeOutStage();
281	schoenebeck	738	}
282
283	schoenebeck	53	}} // namespace LinuxSampler::gig