engines/gig/EGADSR.cpp

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

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;
        FadeOutCoeff = -1.0f / killSteps;
    }

    void EGADSR::update(event_t Event, double SamplePos, float CurrentPitch, uint SampleRate) {
        switch (Stage) {
            case stage_attack:
                if (StepsLeft) {
                    PostponedEvent = Event;
                } else {
                    if (Event == event_release)
                        enterReleasePart1Stage();
                    else if (Event == event_cancel_release)
                        enterSustainStage();
                    else if (PostponedEvent == event_release)
                        enterReleasePart1Stage();
                    else if (PostponedEvent == event_cancel_release)
                        enterSustainStage();
                    else if (HoldAttack)
                        enterAttackHoldStage(SamplePos, CurrentPitch);
                    else
                        enterDecay1Part1Stage(SampleRate);
                }
                break;
            case stage_attack_hold:
                switch (Event) {
                    case event_stage_end:
                        enterDecay1Part1Stage(SampleRate);
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_cancel_release:
                        if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay1Part1Stage(SampleRate);
                        break;
                }
                break;
            case stage_decay1_part1:
                switch (Event) {
                    case event_stage_end:
                        enterDecay1Part2Stage(SampleRate);
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_cancel_release:
                        if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay2Stage(SampleRate);
                        break;
                }
                break;
            case stage_decay1_part2:
                switch (Event) {
                    case event_release:
                        enterReleasePart1Stage();
                        break;
                    case event_stage_end: // fall through
                    case event_cancel_release:
                        if (InfiniteSustain)
                            enterSustainStage();
                        else
                            enterDecay2Stage(SampleRate);
                        break;
                }
                break;
            case stage_decay2:
                switch (Event) {
                    case event_stage_end:
                        enterFadeOutStage();
                        break;
                    case event_release:
                        enterReleasePart1Stage();
                        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;
                }
                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, long LoopStart, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate) {

        if (SustainLevel) {
            this->SustainLevel = SustainLevel / 1000.0;
        } else {
            // sustain level 0 means that voice dies after decay 1
            this->SustainLevel = CONFIG_EG_BOTTOM;
            InfiniteSustain    = false;
            Decay2Time         = CONFIG_EG_MIN_RELEASE_TIME;
        }
        this->InfiniteSustain  = InfiniteSustain;
        this->HoldAttack       = HoldAttack;
        this->LoopStart        = LoopStart;

        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, 0.0, 1.0f);
    }

    void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate, const double SamplePos, const float CurrentPitch) {
        Stage   = stage_attack;
        Segment = segment_lin;
        // Measurements of GSt output shows that the real attack time
        // is about 65.5% of the value specified in the gig file.
        StepsLeft = (int) (0.655f * AttackTime * SampleRate);
        if (StepsLeft) {
            Level = (float) PreAttack / 1000.0;
            Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0
        } else { // immediately jump to the next stage
            Level = 1.0;
            if (HoldAttack) enterAttackHoldStage(SamplePos, CurrentPitch);
            else            enterDecay1Part1Stage(SampleRate);
        }
        PostponedEvent = (event_t) -1; // init with anything except release or cancel_release
    }

    void EGADSR::enterAttackHoldStage(const double SamplePos, const float CurrentPitch) {
        Stage     = stage_attack_hold;
        Segment   = segment_lin;
        Coeff     = 0.0f; // don't rise anymore
        StepsLeft = (int) (LoopStart - SamplePos / CurrentPitch); // FIXME: just an approximation, inaccuracy grows with higher audio fragment size, sufficient for usual fragment sizes though
    }

    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 && SustainLevel < 1.0) {
            Stage        = stage_decay1_part1;
            Segment      = segment_lin;
            Decay1Slope  = 1.365 * (SustainLevel - 1.0) / StepsLeft;
            Coeff        = Decay1Slope * invVolume;
            Decay1Level2 = 0.25 * invVolume;
            if (Level < Decay1Level2) enterDecay1Part2Stage(SampleRate);
            else StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff);
        } 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);
        } else {
            if (InfiniteSustain) enterSustainStage();
            else                 enterDecay2Stage(SampleRate);
        }
    }

    void EGADSR::enterDecay2Stage(const uint SampleRate) {
        Stage      = stage_decay2;
        Segment    = segment_lin;
        Decay2Time = RTMath::Max(Decay2Time, CONFIG_EG_MIN_RELEASE_TIME);
        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;
    }

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

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

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

}} // 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	554	* Copyright (C) 2005 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			namespace LinuxSampler { namespace gig {
27
28	schoenebeck	738	EGADSR::EGADSR() {
29			enterEndStage();
30			Level = 0.0;
31			CalculateFadeOutCoeff(CONFIG_EG_MIN_RELEASE_TIME, 44100.0); // even if the sample rate will be 192kHz it won't hurt at all
32			}
33
34	schoenebeck	688	void EGADSR::CalculateFadeOutCoeff(float FadeOutTime, float SampleRate) {
35			const float killSteps = FadeOutTime * SampleRate;
36			FadeOutCoeff = -1.0f / killSteps;
37	schoenebeck	239	}
38
39	schoenebeck	738	void EGADSR::update(event_t Event, double SamplePos, float CurrentPitch, uint SampleRate) {
40			switch (Stage) {
41			case stage_attack:
42			if (StepsLeft) {
43			PostponedEvent = Event;
44			} else {
45			if (Event == event_release)
46			enterReleasePart1Stage();
47			else if (Event == event_cancel_release)
48			enterSustainStage();
49			else if (PostponedEvent == event_release)
50			enterReleasePart1Stage();
51			else if (PostponedEvent == event_cancel_release)
52			enterSustainStage();
53			else if (HoldAttack)
54			enterAttackHoldStage(SamplePos, CurrentPitch);
55			else
56			enterDecay1Part1Stage(SampleRate);
57	schoenebeck	53	}
58	schoenebeck	738	break;
59			case stage_attack_hold:
60			switch (Event) {
61			case event_stage_end:
62			enterDecay1Part1Stage(SampleRate);
63	schoenebeck	53	break;
64	schoenebeck	738	case event_release:
65			enterReleasePart1Stage();
66			break;
67			case event_cancel_release:
68			if (InfiniteSustain)
69			enterSustainStage();
70			else
71			enterDecay1Part1Stage(SampleRate);
72			break;
73	schoenebeck	53	}
74	schoenebeck	738	break;
75			case stage_decay1_part1:
76			switch (Event) {
77	persson	768	case event_stage_end:
78			enterDecay1Part2Stage(SampleRate);
79	persson	614	break;
80	schoenebeck	738	case event_release:
81			enterReleasePart1Stage();
82			break;
83			case event_cancel_release:
84			if (InfiniteSustain)
85			enterSustainStage();
86			else
87			enterDecay2Stage(SampleRate);
88			break;
89	persson	614	}
90	schoenebeck	738	break;
91			case stage_decay1_part2:
92			switch (Event) {
93			case event_release:
94			enterReleasePart1Stage();
95			break;
96			case event_stage_end: // fall through
97			case event_cancel_release:
98			if (InfiniteSustain)
99			enterSustainStage();
100			else
101			enterDecay2Stage(SampleRate);
102			break;
103	schoenebeck	53	}
104	schoenebeck	738	break;
105			case stage_decay2:
106			switch (Event) {
107			case event_stage_end:
108			enterFadeOutStage();
109			break;
110			case event_release:
111			enterReleasePart1Stage();
112			break;
113	persson	614	}
114	schoenebeck	738	break;
115			case stage_sustain:
116			switch (Event) {
117			case event_stage_end: {// just refresh time
118			const int intMax = (unsigned int) -1 >> 1;
119			StepsLeft = intMax; // we use the highest possible value
120			break;
121	schoenebeck	53	}
122	schoenebeck	738	case event_release:
123			enterReleasePart1Stage();
124			break;
125	schoenebeck	53	}
126	schoenebeck	738	break;
127			case stage_release_part1:
128			switch (Event) {
129			case event_stage_end:
130			enterReleasePart2Stage();
131			break;
132			case event_cancel_release:
133			if (InfiniteSustain)
134			enterSustainStage();
135			else
136			enterDecay2Stage(SampleRate);
137			break;
138	schoenebeck	53	}
139	schoenebeck	738	break;
140			case stage_release_part2:
141			switch (Event) {
142			case event_stage_end:
143			enterFadeOutStage();
144			break;
145			case event_cancel_release:
146			if (InfiniteSustain)
147			enterSustainStage();
148			else
149			enterDecay2Stage(SampleRate);
150			break;
151	schoenebeck	53	}
152	schoenebeck	738	break;
153			case stage_fadeout:
154			switch (Event) {
155			case event_stage_end:
156			enterEndStage();
157			break;
158	persson	614	}
159	schoenebeck	738	break;
160	schoenebeck	53	}
161			}
162
163	schoenebeck	738	void EGADSR::trigger(uint PreAttack, float AttackTime, bool HoldAttack, long LoopStart, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate) {
164
165	persson	614	if (SustainLevel) {
166			this->SustainLevel = SustainLevel / 1000.0;
167			} else {
168			// sustain level 0 means that voice dies after decay 1
169			this->SustainLevel = CONFIG_EG_BOTTOM;
170			InfiniteSustain = false;
171			Decay2Time = CONFIG_EG_MIN_RELEASE_TIME;
172			}
173	schoenebeck	53	this->InfiniteSustain = InfiniteSustain;
174			this->HoldAttack = HoldAttack;
175			this->LoopStart = LoopStart;
176
177	schoenebeck	738	this->Decay1Time = Decay1Time;
178			this->Decay2Time = Decay2Time;
179	persson	614
180	schoenebeck	738	invVolume = 1 / Volume;
181			ExpOffset = (0.25 - 1 / 3.55) * invVolume;
182
183			// calculate release stage parameters (lin+exp curve)
184			if (ReleaseTime < CONFIG_EG_MIN_RELEASE_TIME) ReleaseTime = CONFIG_EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
185			const float ReleaseStepsLeft = (long) (ReleaseTime * SampleRate);
186			ReleaseSlope = 1.365 * (0 - 1) / ReleaseStepsLeft;
187			ReleaseCoeff = ReleaseSlope * invVolume;
188			ReleaseSlope *= 3.55;
189			ReleaseCoeff2 = exp(ReleaseSlope);
190			ReleaseCoeff3 = ExpOffset * (1 - ReleaseCoeff2);
191			ReleaseLevel2 = 0.25 * invVolume;
192	persson	768
193			enterAttackStage(PreAttack, AttackTime, SampleRate, 0.0, 1.0f);
194	schoenebeck	738	}
195
196			void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate, const double SamplePos, const float CurrentPitch) {
197			Stage = stage_attack;
198			Segment = segment_lin;
199	persson	614	// Measurements of GSt output shows that the real attack time
200			// is about 65.5% of the value specified in the gig file.
201	schoenebeck	738	StepsLeft = (int) (0.655f * AttackTime * SampleRate);
202			if (StepsLeft) {
203			Level = (float) PreAttack / 1000.0;
204			Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0
205			} else { // immediately jump to the next stage
206	persson	768	Level = 1.0;
207	schoenebeck	738	if (HoldAttack) enterAttackHoldStage(SamplePos, CurrentPitch);
208			else enterDecay1Part1Stage(SampleRate);
209	schoenebeck	53	}
210	schoenebeck	738	PostponedEvent = (event_t) -1; // init with anything except release or cancel_release
211			}
212	schoenebeck	53
213	schoenebeck	738	void EGADSR::enterAttackHoldStage(const double SamplePos, const float CurrentPitch) {
214			Stage = stage_attack_hold;
215			Segment = segment_lin;
216			Coeff = 0.0f; // don't rise anymore
217			StepsLeft = (int) (LoopStart - SamplePos / CurrentPitch); // FIXME: just an approximation, inaccuracy grows with higher audio fragment size, sufficient for usual fragment sizes though
218			}
219	persson	614
220	schoenebeck	738	void EGADSR::enterDecay1Part1Stage(const uint SampleRate) {
221	persson	614	// The decay1 and release stage both consist of two parts,
222			// first a linear curve, f, followed by an exponential curve,
223			// g:
224			//
225			// f(x + d) = f(x) + Coeff
226			// g(x + d) = Coeff2 * g(x) + Coeff3
227			//
228			// (where d is 1/SampleRate). The transition from f to g is
229			// done when f(x) has reached Level2 = 25% of full volume.
230	schoenebeck	738	StepsLeft = (int) (Decay1Time * SampleRate);
231			if (StepsLeft && SustainLevel < 1.0) {
232			Stage = stage_decay1_part1;
233			Segment = segment_lin;
234			Decay1Slope = 1.365 * (SustainLevel - 1.0) / StepsLeft;
235			Coeff = Decay1Slope * invVolume;
236	persson	614	Decay1Level2 = 0.25 * invVolume;
237	persson	768	if (Level < Decay1Level2) enterDecay1Part2Stage(SampleRate);
238			else StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff);
239	schoenebeck	738	} else {
240			if (InfiniteSustain) enterSustainStage();
241			else enterDecay2Stage(SampleRate);
242	persson	614	}
243	schoenebeck	738	}
244	schoenebeck	53
245	persson	768	void EGADSR::enterDecay1Part2Stage(const uint SampleRate) {
246			if (SustainLevel < Decay1Level2) {
247			Stage = stage_decay1_part2;
248			Segment = segment_exp;
249			Decay1Slope *= 3.55;
250			Coeff = exp(Decay1Slope);
251			Offset = ExpOffset * (1 - Coeff);
252			StepsLeft = int(log((SustainLevel - ExpOffset) / (Level - ExpOffset)) / Decay1Slope);
253			} else {
254			if (InfiniteSustain) enterSustainStage();
255			else enterDecay2Stage(SampleRate);
256			}
257	schoenebeck	738	}
258	schoenebeck	53
259	schoenebeck	738	void EGADSR::enterDecay2Stage(const uint SampleRate) {
260			Stage = stage_decay2;
261			Segment = segment_lin;
262			Decay2Time = RTMath::Max(Decay2Time, CONFIG_EG_MIN_RELEASE_TIME);
263			StepsLeft = (int) (Decay2Time * SampleRate);
264			Coeff = (-1.03 / StepsLeft) * invVolume;
265			//FIXME: do we really have to calculate 'StepsLeft' two times?
266			StepsLeft = int((CONFIG_EG_BOTTOM - Level) / Coeff);
267	persson	768	if (StepsLeft == 0) enterEndStage();
268	schoenebeck	738	}
269	schoenebeck	53
270	schoenebeck	738	void EGADSR::enterSustainStage() {
271			Stage = stage_sustain;
272			Segment = segment_lin;
273			Coeff = 0.0f; // don't change the envelope level in this stage
274			const int intMax = (unsigned int) -1 >> 1;
275			StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
276	schoenebeck	53	}
277
278	schoenebeck	738	void EGADSR::enterReleasePart1Stage() {
279			Stage = stage_release_part1;
280			Segment = segment_lin;
281			StepsLeft = int((ReleaseLevel2 - Level) / ReleaseCoeff);
282			Coeff = ReleaseCoeff;
283			}
284
285			void EGADSR::enterReleasePart2Stage() {
286			Stage = stage_release_part2;
287			Segment = segment_exp;
288			StepsLeft = int(log((CONFIG_EG_BOTTOM - ExpOffset) / (Level - ExpOffset)) / ReleaseSlope);
289			Coeff = ReleaseCoeff2;
290			Offset = ReleaseCoeff3;
291			}
292
293			void EGADSR::enterFadeOutStage() {
294			Stage = stage_fadeout;
295			Segment = segment_lin;
296			StepsLeft = int(Level / (-FadeOutCoeff));
297			Coeff = FadeOutCoeff;
298	persson	768	if (StepsLeft == 0) enterEndStage();
299	schoenebeck	738	}
300
301			void EGADSR::enterEndStage() {
302			Stage = stage_end;
303			Segment = segment_end;
304			}
305
306	schoenebeck	53	}} // namespace LinuxSampler::gig