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
        };

        /**
         * 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 LoopStart       - sample position where sample loop starts
         *                          (if any)
         * @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, long LoopStart, 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
         * @param SamplePos    - current sample playback position
         * @param CurrentPitch - current frequency alternation quotient
         */
        void update(event_t Event, double SamplePos, float CurrentPitch, 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;
        }

    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;
        event_t   PostponedEvent; ///< only used in Attack stage to postpone transition events until attack time is reached
        bool      HoldAttack;
        bool      InfiniteSustain;
        long      LoopStart;
        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, const double SamplePos, const float CurrentPitch);
        void enterAttackHoldStage(const double SamplePos, const float CurrentPitch);
        void enterDecay1Part1Stage(const uint SampleRate);
        void enterDecay1Part2Stage();
        void enterDecay2Stage(const uint SampleRate);
        void enterSustainStage();
        void enterReleasePart1Stage();
        void enterReleasePart2Stage();
        void enterFadeOutStage();
        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			event_cancel_release
58			};
59
60			/**
61			* Constructor
62			*/
63			EGADSR();
64
65			/**
66			* Change fade out time.
67			*/
68			void CalculateFadeOutCoeff(float FadeOutTime, float SampleRate);
69
70			/**
71			* Will be called by the voice when the key / voice was triggered.
72			*
73			* @param PreAttack - Preattack value for the envelope
74			* (0 - 1000 permille)
75			* @param AttackTime - Attack time for the envelope
76			* (0.000 - 60.000s)
77			* @param HoldAttack - if true, Decay1 will be postponed until the
78			* sample reached the sample loop start.
79			* @param LoopStart - sample position where sample loop starts
80			* (if any)
81			* @param Decay1Time - Decay1 time of the sample amplitude EG
82			* (0.000 - 60.000s)
83			* @param Decay2Time - only if !InfiniteSustain: 2nd decay stage
84			* time of the sample amplitude EG
85			* (0.000 - 60.000s)
86			* @param InfiniteSustain - if true, instead of going into Decay2
87			* stage, Decay1 level will be hold until note
88			* will be released
89			* @param SustainLevel - Sustain level of the sample amplitude EG
90			* (0 - 1000 permille)
91			* @param ReleaseTIme - Release time for the envelope
92			* (0.000 - 60.000s)
93			* @param Volume - volume the sample will be played at
94			* (0.0 - 1.0) - used when calculating the
95			* exponential curve parameters.
96			* @param SampleRate - sample rate of used audio output driver
97			*/
98			void trigger(uint PreAttack, float AttackTime, bool HoldAttack, long LoopStart, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate); //FIXME: we should better use 'float' for SampleRate
99
100			/**
101			* Returns true in case envelope hasn't reached its final end state yet.
102			*/
103			inline bool active() {
104			return (bool) Segment;
105			}
106
107			/**
108			* Returns what kind of segment the envelope currently is at.
109			*/
110			inline segment_t getSegmentType() {
111			return Segment;
112			}
113
114			/**
115			* Advance envelope by \a SamplePoints steps.
116			*/
117			inline void increment(int SamplePoints) {
118			StepsLeft = RTMath::Max(0, StepsLeft - SamplePoints);
119			}
120
121			/**
122			* Returns amount of steps until the end of current envelope stage.
123			*/
124			inline int toStageEndLeft() {
125			return StepsLeft;
126			}
127
128			/**
129			* Should be called to inform the EG about an external event and
130			* also whenever an envelope stage is completed. This will handle
131			* the envelope's transition to the respective next stage.
132			*
133			* @param Event - what happened
134			* @param SamplePos - current sample playback position
135			* @param CurrentPitch - current frequency alternation quotient
136			*/
137			void update(event_t Event, double SamplePos, float CurrentPitch, uint SampleRate);
138
139			/**
140			* Calculates exactly one, the next sample point of EG
141			* (linear segment). Call this if envelope is currently in a linear
142			* segment.
143			*
144			* @returns next envelope level
145			*/
146			inline float processLin() {
147			return (Level += Coeff);
148			}
149
150			/**
151			* Calculates exactly one, the next sample point of EG
152			* (exponential segment). Call this if envelope is currently in an
153			* exponential segment.
154			*
155			* @returns next envelope level
156			*/
157			inline float processExp() {
158			return (Level = Level * Coeff + Offset);
159			}
160
161			/**
162			* Returns current envelope level without modifying anything. This
163			* might be needed once the envelope reached its final end state,
164			* because calling processLin() or processExp() at this point will
165			* result in undesired behavior.
166			*/
167			inline float getLevel() {
168			return Level;
169			}
170
171			private:
172
173	schoenebeck	53	enum stage_t {
174			stage_attack,
175			stage_attack_hold,
176	schoenebeck	738	stage_decay1_part1,
177	persson	614	stage_decay1_part2,
178	schoenebeck	53	stage_decay2,
179			stage_sustain,
180	schoenebeck	738	stage_release_part1,
181	persson	614	stage_release_part2,
182	schoenebeck	252	stage_fadeout,
183	schoenebeck	53	stage_end
184			};
185
186	schoenebeck	738	float Level;
187			float Coeff;
188			float Offset;
189			int StepsLeft;
190			segment_t Segment;
191			stage_t Stage;
192			event_t PostponedEvent; ///< only used in Attack stage to postpone transition events until attack time is reached
193			bool HoldAttack;
194			bool InfiniteSustain;
195			long LoopStart;
196			float Decay1Time;
197			float Decay1Level2;
198			float Decay1Slope;
199			float Decay2Time;
200			float SustainLevel;
201			float ReleaseCoeff;
202			float ReleaseCoeff2;
203			float ReleaseCoeff3;
204			float ReleaseLevel2;
205			float ReleaseSlope;
206			float invVolume;
207			float ExpOffset;
208			float FadeOutCoeff; ///< very fast ramp down for e.g. voice stealing
209
210			void enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate, const double SamplePos, const float CurrentPitch);
211			void enterAttackHoldStage(const double SamplePos, const float CurrentPitch);
212			void enterDecay1Part1Stage(const uint SampleRate);
213			void enterDecay1Part2Stage();
214			void enterDecay2Stage(const uint SampleRate);
215			void enterSustainStage();
216			void enterReleasePart1Stage();
217			void enterReleasePart2Stage();
218			void enterFadeOutStage();
219			void enterEndStage();
220	schoenebeck	53	};
221
222			}} // namespace LinuxSampler::gig
223
224			#endif // __LS_GIG_EGADSR_H__