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77 lines
2.1 KiB
77 lines
2.1 KiB
#pragma once
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#ifndef DSY_ADSR_H
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#define DSY_ADSR_H
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#include <stdint.h>
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#ifdef __cplusplus
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namespace daisysp
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{
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/** Distinct stages that the phase of the envelope can be located in.
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- IDLE = located at phase location 0, and not currently running
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- ATTACK = First segment of envelope where phase moves from 0 to 1
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- DECAY = Second segment of envelope where phase moves from 1 to SUSTAIN value
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- SUSTAIN = Third segment of envelope, stays at SUSTAIN level until GATE is released
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- RELEASE = Fourth segment of envelop where phase moves from SUSTAIN to 0
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- LAST = Last segment, aka release
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*/
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enum
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{
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ADSR_SEG_IDLE,
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ADSR_SEG_ATTACK,
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ADSR_SEG_DECAY,
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ADSR_SEG_SUSTAIN,
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ADSR_SEG_RELEASE,
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ADSR_SEG_LAST,
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};
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/** adsr envelope module
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Original author(s) : Paul Batchelor
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Ported from Soundpipe by Ben Sergentanis, May 2020
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*/
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class Adsr
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{
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public:
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Adsr() {}
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~Adsr() {}
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/** Initializes the Adsr module.
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\param sample_rate - The sample rate of the audio engine being run.
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*/
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void Init(float sample_rate);
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/** Processes one sample through the filter and returns one sample.
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\param gate - trigger the envelope, hold it to sustain
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*/
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float Process(bool gate);
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/** Sets time
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Set time per segment in seconds
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*/
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inline void SetTime(int seg, float time) { seg_time_[seg] = time; }
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/** Sustain level
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\param sus_level - sets sustain level
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*/
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inline void SetSustainLevel(float sus_level) { sus_ = sus_level; }
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/** get the current envelope segment
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\return the segment of the envelope that the phase is currently located in.
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*/
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inline uint8_t GetCurrentSegment() { return mode_; }
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/** Tells whether envelope is active
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\return true if the envelope is currently in any stage apart from idle.
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*/
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inline bool IsRunning() const { return mode_ != ADSR_SEG_IDLE; }
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private:
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float sus_, seg_time_[ADSR_SEG_LAST], a_, b_, y_, x_, prev_, atk_time_;
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int sample_rate_;
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uint8_t mode_;
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float Tau2Pole(float tau);
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float AdsrFilter();
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};
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} // namespace daisysp
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#endif
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#endif
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