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/*************************************************************************** |
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* * |
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* LinuxSampler - modular, streaming capable sampler * |
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* * |
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* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck * |
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* Copyright (C) 2005 Christian Schoenebeck * |
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* * |
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* This program is free software; you can redistribute it and/or modify * |
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* it under the terms of the GNU General Public License as published by * |
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* the Free Software Foundation; either version 2 of the License, or * |
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* (at your option) any later version. * |
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* * |
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* This program is distributed in the hope that it will be useful, * |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
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* GNU General Public License for more details. * |
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* * |
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* You should have received a copy of the GNU General Public License * |
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* along with this program; if not, write to the Free Software * |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
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* MA 02111-1307 USA * |
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***************************************************************************/ |
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|
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#ifndef __LS_GIG_EGADSR_H__ |
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#define __LS_GIG_EGADSR_H__ |
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|
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#include "../../common/global.h" |
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#include "../../common/RTMath.h" |
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|
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namespace LinuxSampler { namespace gig { |
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|
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/** |
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* ADSR Envelope Generator |
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* |
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* Envelope Generator with stage 'Attack', 'Attack_Hold', 'Decay_1', |
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* 'Decay_2', 'Sustain' and 'Release' for modulating arbitrary synthesis |
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* parameters. |
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*/ |
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class EGADSR { |
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public: |
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|
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/** |
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* Used to define what kind of segment the envelope currently is at. |
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*/ |
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enum segment_t { |
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segment_end = 0, ///< final end state of envelope reached |
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segment_lin = 1, ///< envelope is currently at a linear segment |
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segment_exp = 2 ///< envelope is currently at a exponental segment |
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}; |
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|
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/** |
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* Used to inform the EG about an event. |
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*/ |
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enum event_t { |
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event_stage_end, |
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event_release, |
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event_cancel_release, |
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event_hold_end |
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}; |
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|
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/** |
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* Constructor |
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*/ |
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EGADSR(); |
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|
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/** |
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* Change fade out time. |
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*/ |
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void CalculateFadeOutCoeff(float FadeOutTime, float SampleRate); |
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|
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/** |
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* Will be called by the voice when the key / voice was triggered. |
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* |
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* @param PreAttack - Preattack value for the envelope |
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* (0 - 1000 permille) |
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* @param AttackTime - Attack time for the envelope |
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* (0.000 - 60.000s) |
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* @param HoldAttack - if true, Decay1 will be postponed until the |
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* sample reached the sample loop start. |
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* @param Decay1Time - Decay1 time of the sample amplitude EG |
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* (0.000 - 60.000s) |
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* @param Decay2Time - only if !InfiniteSustain: 2nd decay stage |
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* time of the sample amplitude EG |
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* (0.000 - 60.000s) |
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* @param InfiniteSustain - if true, instead of going into Decay2 |
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* stage, Decay1 level will be hold until note |
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* will be released |
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* @param SustainLevel - Sustain level of the sample amplitude EG |
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* (0 - 1000 permille) |
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* @param ReleaseTIme - Release time for the envelope |
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* (0.000 - 60.000s) |
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* @param Volume - volume the sample will be played at |
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* (0.0 - 1.0) - used when calculating the |
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* exponential curve parameters. |
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* @param SampleRate - sample rate of used audio output driver |
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*/ |
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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 |
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|
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/** |
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* Returns true in case envelope hasn't reached its final end state yet. |
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*/ |
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inline bool active() { |
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return (bool) Segment; |
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} |
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|
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/** |
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* Returns what kind of segment the envelope currently is at. |
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*/ |
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inline segment_t getSegmentType() { |
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return Segment; |
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} |
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|
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/** |
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* Advance envelope by \a SamplePoints steps. |
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*/ |
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inline void increment(int SamplePoints) { |
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StepsLeft = RTMath::Max(0, StepsLeft - SamplePoints); |
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} |
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|
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/** |
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* Returns amount of steps until the end of current envelope stage. |
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*/ |
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inline int toStageEndLeft() { |
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return StepsLeft; |
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} |
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|
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/** |
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* Should be called to inform the EG about an external event and |
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* also whenever an envelope stage is completed. This will handle |
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* the envelope's transition to the respective next stage. |
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* |
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* @param Event - what happened |
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*/ |
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void update(event_t Event, uint SampleRate); |
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|
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/** |
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* Calculates exactly one, the next sample point of EG |
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* (linear segment). Call this if envelope is currently in a linear |
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* segment. |
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* |
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* @returns next envelope level |
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*/ |
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inline float processLin() { |
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return (Level += Coeff); |
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} |
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|
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/** |
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* Calculates exactly one, the next sample point of EG |
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* (exponential segment). Call this if envelope is currently in an |
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* exponential segment. |
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* |
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* @returns next envelope level |
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*/ |
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inline float processExp() { |
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return (Level = Level * Coeff + Offset); |
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} |
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|
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/** |
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* Returns current envelope level without modifying anything. This |
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* might be needed once the envelope reached its final end state, |
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* because calling processLin() or processExp() at this point will |
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* result in undesired behavior. |
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*/ |
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inline float getLevel() { |
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return Level; |
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} |
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|
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private: |
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|
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enum stage_t { |
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stage_attack, |
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stage_attack_hold, |
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stage_decay1_part1, |
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stage_decay1_part2, |
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stage_decay2, |
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stage_sustain, |
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stage_release_part1, |
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stage_release_part2, |
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stage_fadeout, |
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stage_end |
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}; |
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|
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float Level; |
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float Coeff; |
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float Offset; |
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int StepsLeft; |
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segment_t Segment; |
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stage_t Stage; |
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bool HoldAttack; |
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bool InfiniteSustain; |
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float Decay1Time; |
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float Decay1Level2; |
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float Decay1Slope; |
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float Decay2Time; |
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float SustainLevel; |
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float ReleaseCoeff; |
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float ReleaseCoeff2; |
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float ReleaseCoeff3; |
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float ReleaseLevel2; |
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float ReleaseSlope; |
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float invVolume; |
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float ExpOffset; |
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float FadeOutCoeff; ///< very fast ramp down for e.g. voice stealing |
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|
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void enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate); |
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void enterAttackHoldStage(); |
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void enterDecay1Part1Stage(const uint SampleRate); |
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void enterDecay1Part2Stage(const uint SampleRate); |
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void enterDecay2Stage(const uint SampleRate); |
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void enterSustainStage(); |
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void enterReleasePart1Stage(); |
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void enterReleasePart2Stage(); |
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void enterFadeOutStage(); |
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void enterEndStage(); |
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}; |
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|
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}} // namespace LinuxSampler::gig |
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|
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#endif // __LS_GIG_EGADSR_H__ |