#include <Nsound/EnvelopeAdsr.h>

Public Member Functions
	EnvelopeAdsr (const float64 &sample_rate, const float64 &attack_time, const float64 &delay_time, const float64 &sustain_amplitude, const float64 &release_time)
	Constructor. More...

void	reset ()

void	setAttackTime (const float64 &time)

void	setDelayTime (const float64 &time)

void	setSustainAmplitude (const float64 &amp)

void	setReleaseTime (const float64 &time)

AudioStream	shape (const AudioStream &as)
	Shapes the AudioStream inplace. More...

Buffer	shape (const Buffer &buf)
	Shapes the Buffer inplace. More...

float64	shape (float64 sample, bool key_on)
	Realtime interface. More...

bool	is_done () const

Protected Types
enum	Mode { attacking, delaying, sustaining, releasing, done }

Protected Attributes
float64	sample_rate_

float64	attack_slope_

float64	attack_time_

float64	delay_slope_

float64	delay_time_

float64	sustain_amp_

float64	release_slope_

float64	release_time_

float64	scale_

Mode	mode_

Detailed Description

Definition at line 69 of file EnvelopeAdsr.h.

Member Enumeration Documentation

enum Nsound::EnvelopeAdsr::Mode

protected

Enumerator
attacking
delaying
sustaining
releasing
done

Definition at line 110 of file EnvelopeAdsr.h.

110 { attacking, delaying, sustaining, releasing, done };

Nsound::EnvelopeAdsr::sustaining

Definition: EnvelopeAdsr.h:110

Nsound::EnvelopeAdsr::done

Definition: EnvelopeAdsr.h:110

Nsound::EnvelopeAdsr::releasing

Definition: EnvelopeAdsr.h:110

Nsound::EnvelopeAdsr::attacking

Definition: EnvelopeAdsr.h:110

Nsound::EnvelopeAdsr::delaying

Definition: EnvelopeAdsr.h:110

Constructor & Destructor Documentation

EnvelopeAdsr::EnvelopeAdsr	(	const float64 &	sample_rate,
		const float64 &	attack_time,
		const float64 &	delay_time,
		const float64 &	sustain_amplitude,
		const float64 &	release_time
	)

Constructor.

Definition at line 39 of file EnvelopeAdsr.cc.

References M_ASSERT_VALUE, setAttackTime(), setDelayTime(), and setReleaseTime().

     :
     sample_rate_(sample_rate),
     attack_slope_(0.0),
     attack_time_(attack_time),
     delay_slope_(0.0),
     delay_time_(delay_time),
     sustain_amp_(sustain_amplitude),
     release_slope_(0.0),
     release_time_(release_time),
     scale_(0.0),
     mode_(attacking)
 {
     M_ASSERT_VALUE(sample_rate, >, 0.0);
     M_ASSERT_VALUE(attack_time, >=, 0.0);
     M_ASSERT_VALUE(delay_time, >=, 0.0);
     M_ASSERT_VALUE(sustain_amplitude, >, 0.0);
     M_ASSERT_VALUE(sustain_amplitude, <=, 1.0);
     M_ASSERT_VALUE(release_time, >=, 0.0);
 
     M_ASSERT_VALUE(attack_time + delay_time + release_time, >, 0.0);
 
     setAttackTime(attack_time);
     setDelayTime(delay_time);
     setReleaseTime(release_time);
 }

Member Function Documentation

void EnvelopeAdsr::reset ( )

Definition at line 73 of file EnvelopeAdsr.cc.

References attacking, mode_, and scale_.

 {
     mode_ = attacking;
     scale_ = 0.0;
 }

void EnvelopeAdsr::setAttackTime ( const float64 & time )

Definition at line 81 of file EnvelopeAdsr.cc.

References attack_slope_, attack_time_, M_ASSERT_VALUE, and sample_rate_.

Referenced by EnvelopeAdsr().

 {
     M_ASSERT_VALUE(time, >=, 0.0);
 
     uint32 n_samples = static_cast<uint32>(time * sample_rate_ + 0.5);
 
     n_samples -= 1;
 
     M_ASSERT_VALUE(n_samples, >, 0);
 
     attack_slope_ = 1.0 / static_cast<float64>(n_samples);
     attack_time_ = time;
 }

void EnvelopeAdsr::setDelayTime ( const float64 & time )

Definition at line 97 of file EnvelopeAdsr.cc.

References delay_slope_, delay_time_, M_ASSERT_VALUE, and sample_rate_.

Referenced by EnvelopeAdsr().

 {
     M_ASSERT_VALUE(time, >=, 0.0);
 
     uint32 n_samples = static_cast<uint32>(time * sample_rate_ + 0.5);
 
     n_samples -= 1;
 
     M_ASSERT_VALUE(n_samples, >, 0);
 
     delay_slope_ = -1.0 / static_cast<float64>(n_samples);
     delay_time_ = time;
 }

void EnvelopeAdsr::setSustainAmplitude ( const float64 & amp )

Definition at line 113 of file EnvelopeAdsr.cc.

References M_ASSERT_VALUE, and sustain_amp_.

 {
     M_ASSERT_VALUE(amp, >, 0.0);
 
     sustain_amp_ = amp;
 }

void EnvelopeAdsr::setReleaseTime ( const float64 & time )

Definition at line 122 of file EnvelopeAdsr.cc.

References M_ASSERT_VALUE, release_slope_, release_time_, and sample_rate_.

Referenced by EnvelopeAdsr().

 {
     M_ASSERT_VALUE(time, >=, 0.0);
 
     uint32 n_samples = static_cast<uint32>(time * sample_rate_ + 0.5);
 
     n_samples -= 1;
 
     M_ASSERT_VALUE(n_samples, >, 0);
 
     release_slope_ = -1.0 / static_cast<float64>(n_samples);
     release_time_ = time;
 }

AudioStream EnvelopeAdsr::shape ( const AudioStream & as )

Shapes the AudioStream inplace.

Definition at line 138 of file EnvelopeAdsr.cc.

References Nsound::AudioStream::getNChannels(), and Nsound::AudioStream::getSampleRate().

Referenced by shape().

 {
     AudioStream out(as.getSampleRate(), as.getNChannels());
 
     for(uint32 i = 0; i < as.getNChannels(); ++i)
     {
         out[i] = shape(as[i]);
     }
 
     return out;
 }

Buffer EnvelopeAdsr::shape ( const Buffer & buf )

Shapes the Buffer inplace.

Definition at line 152 of file EnvelopeAdsr.cc.

References attack_time_, attacking, Nsound::Buffer::begin(), delay_time_, Nsound::Buffer::end(), Nsound::Buffer::getLength(), is_done(), mode_, release_time_, sample_rate_, shape(), and sustaining.

 {
     float64 duration = static_cast<float64>(buf.getLength()) / sample_rate_;
 
     float64 sustain_time =
         duration - attack_time_ - delay_time_ - release_time_;
 
     if(sustain_time < 0) sustain_time = 0;
 
     uint32 sustain_samples = static_cast<uint32>(sustain_time * sample_rate_);
 
     mode_ = attacking;
 
     Buffer::const_iterator itor = buf.begin();
     Buffer::const_iterator end = buf.end();
 
     Buffer out;
 
     // Attack
 
     while(mode_ != sustaining && itor != end)
     {
         out << shape(*itor, true);
         ++itor;
     }
 
     // Sustain
 
     uint32 count = 0;
 
     while(count < sustain_samples && itor != end)
     {
         out << shape(*itor, true);
         ++itor;
         ++count;
     }
 
     // Relase
 
     while(!is_done() && itor != end)
     {
         out << shape(*itor, false);
         ++itor;
     }
 
     return out;
 }

float64 EnvelopeAdsr::shape	(	float64	sample,
		bool	key_on
	)

Realtime interface.

Definition at line 202 of file EnvelopeAdsr.cc.

References attack_slope_, attacking, delay_slope_, delaying, done, M_ASSERT_VALUE, mode_, release_slope_, releasing, scale_, sustain_amp_, and sustaining.

 {
     switch(mode_)
     {
         case attacking:
         {
             scale_ += attack_slope_;
             if(scale_ >= 1.0)
             {
                 scale_ = 0.999;
                 mode_ = delaying;
             }
             if(!key_on) mode_ = releasing;
 
             break;
         }
 
         case delaying:
         {
             scale_ += delay_slope_;
             if(scale_ <= sustain_amp_) mode_ = sustaining;
             if(!key_on) mode_ = releasing;
 
             break;
         }
 
         case sustaining:
         {
             scale_ = sustain_amp_;
             if(!key_on) mode_ = releasing;
 
             break;
         }
 
         case releasing:
         {
             scale_ += release_slope_;
 
             if(scale_ <= 0.0)
             {
                 scale_ = 0.0;
                 mode_ = done;
             }
 
             break;
         }
 
         case done:
         {
             scale_ = 0.0;
         }
     }
 
     M_ASSERT_VALUE(scale_, <, 1.0);
 
     return sample * scale_;
 }