f@0: /***************************************************/
f@0: /*! \class Envelope
f@0:     \brief STK linear line envelope class.
f@0: 
f@0:     This class implements a simple linear line envelope generator
f@0:     which is capable of ramping to an arbitrary target value by a
f@0:     specified \e rate.  It also responds to simple \e keyOn and \e
f@0:     keyOff messages, ramping to 1.0 on keyOn and to 0.0 on keyOff.
f@0: 
f@0:     by Perry R. Cook and Gary P. Scavone, 1995--2014.
f@0: */
f@0: /***************************************************/
f@0: 
f@0: #include "../include/Envelope.h"
f@0: 
f@0: namespace stk {
f@0: 
f@0: Envelope :: Envelope( void ) : Generator()
f@0: {    
f@0:   target_ = 0.0;
f@0:   value_ = 0.0;
f@0:   rate_ = 0.001;
f@0:   state_ = 0;
f@0:   Stk::addSampleRateAlert( this );
f@0: }
f@0: 
f@0: Envelope :: ~Envelope( void )
f@0: {
f@0:   Stk::removeSampleRateAlert( this );
f@0: }
f@0: 
f@0: Envelope& Envelope :: operator= ( const Envelope& e )
f@0: {
f@0:   if ( this != &e ) {
f@0:     target_ = e.target_;
f@0:     value_ = e.value_;
f@0:     rate_ = e.rate_;
f@0:     state_ = e.state_;
f@0:   }
f@0: 
f@0:   return *this;
f@0: }
f@0: 
f@0: void Envelope :: sampleRateChanged( StkFloat newRate, StkFloat oldRate )
f@0: {
f@0:   if ( !ignoreSampleRateChange_ )
f@0:     rate_ = oldRate * rate_ / newRate;
f@0: }
f@0: 
f@0: void Envelope :: setRate( StkFloat rate )
f@0: {
f@0:   if ( rate < 0.0 ) {
f@0:     oStream_ << "Envelope::setRate: argument must be >= 0.0!";
f@0:     handleError( StkError::WARNING ); return;
f@0:   }
f@0: 
f@0:   rate_ = rate;
f@0: }
f@0: 
f@0: void Envelope :: setTime( StkFloat time )
f@0: {
f@0:   if ( time <= 0.0 ) {
f@0:     oStream_ << "Envelope::setTime: argument must be > 0.0!";
f@0:     handleError( StkError::WARNING ); return;
f@0:   }
f@0: 
f@0:   rate_ = 1.0 / ( time * Stk::sampleRate() );
f@0: }
f@0: 
f@0: void Envelope :: setTarget( StkFloat target )
f@0: {
f@0:   target_ = target;
f@0:   if ( value_ != target_ ) state_ = 1;
f@0: }
f@0: 
f@0: void Envelope :: setValue( StkFloat value )
f@0: {
f@0:   state_ = 0;
f@0:   target_ = value;
f@0:   value_ = value;
f@0:   lastFrame_[0] = value_;
f@0: }
f@0: 
f@0: } // stk namespace