engines/gig/EGADSR.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2013 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;
                }
                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;
        }
    }

    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	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* Copyright (C) 2005 - 2013 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	void EGADSR::update(event_t Event, uint SampleRate) {
31	if (atEnd(Event)) return;
32
33	if (Event == event_hold_end) HoldAttack = false;
34
35	switch (Stage) {
36	case stage_attack:
37	switch (Event) {
38	case event_release:
39	enterReleasePart1Stage();
40	break;
41	case event_stage_end:
42	if (HoldAttack)
43	enterAttackHoldStage();
44	else
45	enterDecay1Part1Stage(SampleRate);
46	break;
47	}
48	break;
49	case stage_attack_hold:
50	switch (Event) {
51	case event_stage_end: {// just refresh time
52	const int intMax = (unsigned int) -1 >> 1;
53	StepsLeft = intMax; // we use the highest possible value
54	break;
55	}
56	case event_hold_end:
57	enterDecay1Part1Stage(SampleRate);
58	break;
59	case event_release:
60	enterReleasePart1Stage();
61	break;
62	}
63	break;
64	case stage_decay1_part1:
65	switch (Event) {
66	case event_stage_end:
67	enterDecay1Part2Stage(SampleRate);
68	break;
69	case event_release:
70	enterReleasePart1Stage();
71	break;
72	}
73	break;
74	case stage_decay1_part2:
75	switch (Event) {
76	case event_release:
77	enterReleasePart1Stage();
78	break;
79	case event_stage_end:
80	if (Level < CONFIG_EG_BOTTOM)
81	enterEndStage();
82	else if (InfiniteSustain)
83	enterSustainStage();
84	else
85	enterDecay2Stage(SampleRate);
86	break;
87	}
88	break;
89	case stage_decay2:
90	switch (Event) {
91	case event_stage_end:
92	enterFadeOutStage();
93	break;
94	case event_release:
95	enterReleasePart1Stage();
96	break;
97	case event_hold_end:
98	enterDecay1Part1Stage(SampleRate);
99	break;
100	}
101	break;
102	case stage_sustain:
103	switch (Event) {
104	case event_stage_end: {// just refresh time
105	const int intMax = (unsigned int) -1 >> 1;
106	StepsLeft = intMax; // we use the highest possible value
107	break;
108	}
109	case event_release:
110	enterReleasePart1Stage();
111	break;
112	case event_hold_end:
113	enterDecay1Part1Stage(SampleRate);
114	break;
115	}
116	break;
117	case stage_release_part1:
118	switch (Event) {
119	case event_stage_end:
120	enterReleasePart2Stage();
121	break;
122	case event_cancel_release:
123	if (InfiniteSustain)
124	enterSustainStage();
125	else
126	enterDecay2Stage(SampleRate);
127	break;
128	}
129	break;
130	case stage_release_part2:
131	switch (Event) {
132	case event_stage_end:
133	enterFadeOutStage();
134	break;
135	case event_cancel_release:
136	if (InfiniteSustain)
137	enterSustainStage();
138	else
139	enterDecay2Stage(SampleRate);
140	break;
141	}
142	break;
143	}
144	}
145
146	void EGADSR::trigger(uint PreAttack, float AttackTime, bool HoldAttack, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate) {
147	this->SustainLevel = SustainLevel / 1000.0;
148	this->InfiniteSustain = InfiniteSustain;
149	this->HoldAttack = HoldAttack;
150
151	this->Decay1Time = Decay1Time;
152	this->Decay2Time = Decay2Time;
153
154	invVolume = 1 / Volume;
155	ExpOffset = (0.25 - 1 / 3.55) * invVolume;
156
157	// calculate release stage parameters (lin+exp curve)
158	if (ReleaseTime < CONFIG_EG_MIN_RELEASE_TIME) ReleaseTime = CONFIG_EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback
159	const float ReleaseStepsLeft = (long) (ReleaseTime * SampleRate);
160	ReleaseSlope = 1.365 * (0 - 1) / ReleaseStepsLeft;
161	ReleaseCoeff = ReleaseSlope * invVolume;
162	ReleaseSlope *= 3.55;
163	ReleaseCoeff2 = exp(ReleaseSlope);
164	ReleaseCoeff3 = ExpOffset * (1 - ReleaseCoeff2);
165	ReleaseLevel2 = 0.25 * invVolume;
166
167	enterFirstStage();
168	enterAttackStage(PreAttack, AttackTime, SampleRate);
169	}
170
171	void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate) {
172	Stage = stage_attack;
173	Segment = segment_lin;
174
175	if (AttackTime >= 1e-8) {
176	// Measurements of GSt output shows that the real attack time
177	// is about 65.5% of the value specified in the gig file.
178	// The minimum attack value used is 0.0316.
179	StepsLeft = int(0.655f * RTMath::Max(AttackTime, 0.0316f) * SampleRate);
180	Level = (float) PreAttack / 1000.0;
181	Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0
182	} else { // attack is zero - immediately jump to the next stage
183	Level = 1.029f; // a bit higher than max sustain
184	if (HoldAttack) enterAttackHoldStage();
185	else enterDecay1Part1Stage(SampleRate);
186	}
187	}
188
189	void EGADSR::enterAttackHoldStage() {
190	Stage = stage_attack_hold;
191	Segment = segment_lin;
192	Coeff = 0.0f; // don't rise anymore
193	const int intMax = (unsigned int) -1 >> 1;
194	StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
195	}
196
197	void EGADSR::enterDecay1Part1Stage(const uint SampleRate) {
198	// The decay1 and release stage both consist of two parts,
199	// first a linear curve, f, followed by an exponential curve,
200	// g:
201	//
202	// f(x + d) = f(x) + Coeff
203	// g(x + d) = Coeff2 * g(x) + Coeff3
204	//
205	// (where d is 1/SampleRate). The transition from f to g is
206	// done when f(x) has reached Level2 = 25% of full volume.
207	StepsLeft = (int) (Decay1Time * SampleRate);
208	if (StepsLeft && Level > SustainLevel) {
209	Stage = stage_decay1_part1;
210	Segment = segment_lin;
211	Decay1Slope = (1.347f * SustainLevel - 1.361f) / StepsLeft;
212	Coeff = Decay1Slope * invVolume;
213	Decay1Level2 = 0.25 * invVolume;
214	StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff);
215	if (StepsLeft <= 0) enterDecay1Part2Stage(SampleRate);
216	} else {
217	if (InfiniteSustain) enterSustainStage();
218	else enterDecay2Stage(SampleRate);
219	}
220	}
221
222	void EGADSR::enterDecay1Part2Stage(const uint SampleRate) {
223	if (SustainLevel < Decay1Level2) {
224	Stage = stage_decay1_part2;
225	Segment = segment_exp;
226	Decay1Slope *= 3.55;
227	Coeff = exp(Decay1Slope);
228	Offset = ExpOffset * (1 - Coeff);
229	StepsLeft = int(log((SustainLevel - ExpOffset) / (Level - ExpOffset)) / Decay1Slope);
230	if (StepsLeft > 0) return;
231	}
232	if (InfiniteSustain) enterSustainStage();
233	else enterDecay2Stage(SampleRate);
234	}
235
236	void EGADSR::enterDecay2Stage(const uint SampleRate) {
237	Stage = stage_decay2;
238	Segment = segment_lin;
239	Decay2Time = RTMath::Max(Decay2Time, 0.05f);
240	StepsLeft = (int) (Decay2Time * SampleRate);
241	Coeff = (-1.03 / StepsLeft) * invVolume;
242	//FIXME: do we really have to calculate 'StepsLeft' two times?
243	StepsLeft = int((CONFIG_EG_BOTTOM - Level) / Coeff);
244	if (StepsLeft <= 0) enterEndStage();
245	}
246
247	void EGADSR::enterSustainStage() {
248	Stage = stage_sustain;
249	Segment = segment_lin;
250	Coeff = 0.0f; // don't change the envelope level in this stage
251	const int intMax = (unsigned int) -1 >> 1;
252	StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case)
253	}
254
255	void EGADSR::enterReleasePart1Stage() {
256	Stage = stage_release_part1;
257	Segment = segment_lin;
258	StepsLeft = int((ReleaseLevel2 - Level) / ReleaseCoeff);
259	Coeff = ReleaseCoeff;
260	if (StepsLeft <= 0) enterReleasePart2Stage();
261	}
262
263	void EGADSR::enterReleasePart2Stage() {
264	Stage = stage_release_part2;
265	Segment = segment_exp;
266	StepsLeft = int(log((CONFIG_EG_BOTTOM - ExpOffset) / (Level - ExpOffset)) / ReleaseSlope);
267	Coeff = ReleaseCoeff2;
268	Offset = ReleaseCoeff3;
269	if (StepsLeft <= 0) enterFadeOutStage();
270	}
271
272	}} // namespace LinuxSampler::gig