engines/gig/EGADSR.h

/***************************************************************************
 *                                                                         *
 *   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                                                   *
 ***************************************************************************/

#ifndef __LS_GIG_EGADSR_H__
#define __LS_GIG_EGADSR_H__

#include "../../common/global.h"
#include "../../common/RTMath.h"

namespace LinuxSampler { namespace gig {

/**
 * ADSR Envelope Generator
 *
 * Envelope Generator with stage 'Attack', 'Attack_Hold', 'Decay_1',
 * 'Decay_2', 'Sustain' and 'Release' for modulating arbitrary synthesis
 * parameters.
 */
class EGADSR {
    public:

        /**
         * Used to define what kind of segment the envelope currently is at.
         */
        enum segment_t {
            segment_end = 0, ///< final end state of envelope reached
            segment_lin = 1, ///< envelope is currently at a linear segment
            segment_exp = 2  ///< envelope is currently at a exponental segment
        };

        /**
         * Used to inform the EG about an event.
         */
        enum event_t {
            event_stage_end,
            event_release,
            event_cancel_release,
            event_hold_end
        };

        /**
         * Constructor
         */
        EGADSR();

        /**
         * Change fade out time.
         */
        void CalculateFadeOutCoeff(float FadeOutTime, float SampleRate);

        /**
         * Will be called by the voice when the key / voice was triggered.
         *
         * @param PreAttack       - Preattack value for the envelope
         *                          (0 - 1000 permille)
         * @param AttackTime      - Attack time for the envelope
         *                          (0.000 - 60.000s)
         * @param HoldAttack      - if true, Decay1 will be postponed until the
         *                          sample reached the sample loop start.
         * @param Decay1Time      - Decay1 time of the sample amplitude EG
         *                          (0.000 - 60.000s)
         * @param Decay2Time      - only if !InfiniteSustain: 2nd decay stage
         *                          time of the sample amplitude EG
         *                          (0.000 - 60.000s)
         * @param InfiniteSustain - if true, instead of going into Decay2
         *                          stage, Decay1 level will be hold until note
         *                          will be released
         * @param SustainLevel    - Sustain level of the sample amplitude EG
         *                          (0 - 1000 permille)
         * @param ReleaseTIme     - Release time for the envelope
         *                          (0.000 - 60.000s)
         * @param Volume          - volume the sample will be played at
         *                          (0.0 - 1.0) - used when calculating the
         *                          exponential curve parameters.
         * @param SampleRate      - sample rate of used audio output driver
         */
        void trigger(uint PreAttack, float AttackTime, bool HoldAttack, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate); //FIXME: we should better use 'float' for SampleRate

        /**
         * Returns true in case envelope hasn't reached its final end state yet.
         */
        inline bool active() {
            return (bool) Segment;
        }

        /**
         * Returns what kind of segment the envelope currently is at.
         */
        inline segment_t getSegmentType() {
            return Segment;
        }

        /**
         * Advance envelope by \a SamplePoints steps.
         */
        inline void increment(int SamplePoints) {
            StepsLeft = RTMath::Max(0, StepsLeft - SamplePoints);
        }

        /**
         * Returns amount of steps until the end of current envelope stage.
         */
        inline int toStageEndLeft() {
            return StepsLeft;
        }

        /**
         * Should be called to inform the EG about an external event and
         * also whenever an envelope stage is completed. This will handle
         * the envelope's transition to the respective next stage.
         *
         * @param Event        - what happened
         */
        void update(event_t Event, uint SampleRate);

        /**
         * Calculates exactly one, the next sample point of EG
         * (linear segment). Call this if envelope is currently in a linear
         * segment.
         *
         * @returns next envelope level
         */
        inline float processLin() {
            return (Level += Coeff);
        }

        /**
         * Calculates exactly one, the next sample point of EG
         * (exponential segment). Call this if envelope is currently in an
         * exponential segment.
         *
         * @returns next envelope level
         */
        inline float processExp() {
            return (Level = Level * Coeff + Offset);
        }

        /**
         * Returns current envelope level without modifying anything. This
         * might be needed once the envelope reached its final end state,
         * because calling processLin() or processExp() at this point will
         * result in undesired behavior.
         */
        inline float getLevel() {
            return Level;
        }

        void enterFadeOutStage();

    private:

        enum stage_t {
            stage_attack,
            stage_attack_hold,
            stage_decay1_part1,
            stage_decay1_part2,
            stage_decay2,
            stage_sustain,
            stage_release_part1,
            stage_release_part2,
            stage_fadeout,
            stage_end
        };

        float     Level;
        float     Coeff;
        float     Offset;
        int       StepsLeft;
        segment_t Segment;
        stage_t   Stage;
        bool      HoldAttack;
        bool      InfiniteSustain;
        float     Decay1Time;
        float     Decay1Level2;
        float     Decay1Slope;
        float     Decay2Time;
        float     SustainLevel;
        float     ReleaseCoeff;
        float     ReleaseCoeff2;
        float     ReleaseCoeff3;
        float     ReleaseLevel2;
        float     ReleaseSlope;
        float     invVolume;
        float     ExpOffset;
        float     FadeOutCoeff; ///< very fast ramp down for e.g. voice stealing

        void enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate);
        void enterAttackHoldStage();
        void enterDecay1Part1Stage(const uint SampleRate);
        void enterDecay1Part2Stage(const uint SampleRate);
        void enterDecay2Stage(const uint SampleRate);
        void enterSustainStage();
        void enterReleasePart1Stage();
        void enterReleasePart2Stage();
        void enterEndStage();
};

}} // namespace LinuxSampler::gig

#endif // __LS_GIG_EGADSR_H__
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			#ifndef __LS_GIG_EGADSR_H__
25			#define __LS_GIG_EGADSR_H__
26
27			#include "../../common/global.h"
28			#include "../../common/RTMath.h"
29
30			namespace LinuxSampler { namespace gig {
31
32			/**
33			* ADSR Envelope Generator
34			*
35			* Envelope Generator with stage 'Attack', 'Attack_Hold', 'Decay_1',
36			* 'Decay_2', 'Sustain' and 'Release' for modulating arbitrary synthesis
37			* parameters.
38			*/
39			class EGADSR {
40			public:
41	schoenebeck	738
42			/**
43			* Used to define what kind of segment the envelope currently is at.
44			*/
45			enum segment_t {
46			segment_end = 0, ///< final end state of envelope reached
47			segment_lin = 1, ///< envelope is currently at a linear segment
48			segment_exp = 2 ///< envelope is currently at a exponental segment
49			};
50
51			/**
52			* Used to inform the EG about an event.
53			*/
54			enum event_t {
55			event_stage_end,
56			event_release,
57	persson	783	event_cancel_release,
58			event_hold_end
59	schoenebeck	738	};
60
61			/**
62			* Constructor
63			*/
64			EGADSR();
65
66			/**
67			* Change fade out time.
68			*/
69			void CalculateFadeOutCoeff(float FadeOutTime, float SampleRate);
70
71			/**
72			* Will be called by the voice when the key / voice was triggered.
73			*
74			* @param PreAttack - Preattack value for the envelope
75			* (0 - 1000 permille)
76			* @param AttackTime - Attack time for the envelope
77			* (0.000 - 60.000s)
78			* @param HoldAttack - if true, Decay1 will be postponed until the
79			* sample reached the sample loop start.
80			* @param Decay1Time - Decay1 time of the sample amplitude EG
81			* (0.000 - 60.000s)
82			* @param Decay2Time - only if !InfiniteSustain: 2nd decay stage
83			* time of the sample amplitude EG
84			* (0.000 - 60.000s)
85			* @param InfiniteSustain - if true, instead of going into Decay2
86			* stage, Decay1 level will be hold until note
87			* will be released
88			* @param SustainLevel - Sustain level of the sample amplitude EG
89			* (0 - 1000 permille)
90			* @param ReleaseTIme - Release time for the envelope
91			* (0.000 - 60.000s)
92			* @param Volume - volume the sample will be played at
93			* (0.0 - 1.0) - used when calculating the
94			* exponential curve parameters.
95			* @param SampleRate - sample rate of used audio output driver
96			*/
97	persson	783	void trigger(uint PreAttack, float AttackTime, bool HoldAttack, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate); //FIXME: we should better use 'float' for SampleRate
98	schoenebeck	738
99			/**
100			* Returns true in case envelope hasn't reached its final end state yet.
101			*/
102			inline bool active() {
103			return (bool) Segment;
104			}
105
106			/**
107			* Returns what kind of segment the envelope currently is at.
108			*/
109			inline segment_t getSegmentType() {
110			return Segment;
111			}
112
113			/**
114			* Advance envelope by \a SamplePoints steps.
115			*/
116			inline void increment(int SamplePoints) {
117			StepsLeft = RTMath::Max(0, StepsLeft - SamplePoints);
118			}
119
120			/**
121			* Returns amount of steps until the end of current envelope stage.
122			*/
123			inline int toStageEndLeft() {
124			return StepsLeft;
125			}
126
127			/**
128			* Should be called to inform the EG about an external event and
129			* also whenever an envelope stage is completed. This will handle
130			* the envelope's transition to the respective next stage.
131			*
132			* @param Event - what happened
133			*/
134	persson	783	void update(event_t Event, uint SampleRate);
135	schoenebeck	738
136			/**
137			* Calculates exactly one, the next sample point of EG
138			* (linear segment). Call this if envelope is currently in a linear
139			* segment.
140			*
141			* @returns next envelope level
142			*/
143			inline float processLin() {
144			return (Level += Coeff);
145			}
146
147			/**
148			* Calculates exactly one, the next sample point of EG
149			* (exponential segment). Call this if envelope is currently in an
150			* exponential segment.
151			*
152			* @returns next envelope level
153			*/
154			inline float processExp() {
155			return (Level = Level * Coeff + Offset);
156			}
157
158			/**
159			* Returns current envelope level without modifying anything. This
160			* might be needed once the envelope reached its final end state,
161			* because calling processLin() or processExp() at this point will
162			* result in undesired behavior.
163			*/
164			inline float getLevel() {
165			return Level;
166			}
167
168	persson	796	void enterFadeOutStage();
169
170	schoenebeck	738	private:
171
172	schoenebeck	53	enum stage_t {
173			stage_attack,
174			stage_attack_hold,
175	schoenebeck	738	stage_decay1_part1,
176	persson	614	stage_decay1_part2,
177	schoenebeck	53	stage_decay2,
178			stage_sustain,
179	schoenebeck	738	stage_release_part1,
180	persson	614	stage_release_part2,
181	schoenebeck	252	stage_fadeout,
182	schoenebeck	53	stage_end
183			};
184
185	schoenebeck	738	float Level;
186			float Coeff;
187			float Offset;
188			int StepsLeft;
189			segment_t Segment;
190			stage_t Stage;
191			bool HoldAttack;
192			bool InfiniteSustain;
193			float Decay1Time;
194			float Decay1Level2;
195			float Decay1Slope;
196			float Decay2Time;
197			float SustainLevel;
198			float ReleaseCoeff;
199			float ReleaseCoeff2;
200			float ReleaseCoeff3;
201			float ReleaseLevel2;
202			float ReleaseSlope;
203			float invVolume;
204			float ExpOffset;
205			float FadeOutCoeff; ///< very fast ramp down for e.g. voice stealing
206
207	persson	783	void enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate);
208			void enterAttackHoldStage();
209	schoenebeck	738	void enterDecay1Part1Stage(const uint SampleRate);
210	persson	768	void enterDecay1Part2Stage(const uint SampleRate);
211	schoenebeck	738	void enterDecay2Stage(const uint SampleRate);
212			void enterSustainStage();
213			void enterReleasePart1Stage();
214			void enterReleasePart2Stage();
215			void enterEndStage();
216	schoenebeck	53	};
217
218			}} // namespace LinuxSampler::gig
219
220			#endif // __LS_GIG_EGADSR_H__