1 files changed, 125 insertions, 0 deletions
diff --git a/nyqstk/src/Envelope.cpp b/nyqstk/src/Envelope.cpp
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+/***************************************************/
+/*! \class Envelope
+    \brief STK envelope base class.
+
+    This class implements a simple envelope
+    generator which is capable of ramping to
+    a target value by a specified \e rate.
+    It also responds to simple \e keyOn and
+    \e keyOff messages, ramping to 1.0 on
+    keyOn and to 0.0 on keyOff.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
+*/
+/***************************************************/
+
+#include "Envelope.h"
+
+using namespace Nyq;
+
+Envelope :: Envelope(void) : Generator()
+{    
+  target_ = 0.0;
+  value_ = 0.0;
+  rate_ = 0.001;
+  state_ = 0;
+}
+
+Envelope :: Envelope ( const Envelope& e )
+{
+  target_ = 0.0;
+  value_ = 0.0;
+  rate_ = 0.001;
+  state_ = 0;
+}
+
+Envelope :: ~Envelope(void)
+{
+}
+
+Envelope& Envelope :: operator= ( const Envelope& e )
+{
+  if ( this != &e ) {
+    target_ = e.target_;
+    value_ = e.value_;
+    rate_ = e.rate_;
+    state_ = e.state_;
+  }
+
+  return *this;
+}
+
+void Envelope :: keyOn(void)
+{
+  target_ = 1.0;
+  if (value_ != target_) state_ = 1;
+}
+
+void Envelope :: keyOff(void)
+{
+  target_ = 0.0;
+  if (value_ != target_) state_ = 1;
+}
+
+void Envelope :: setRate(StkFloat rate)
+{
+  if (rate < 0.0) {
+    errorString_ << "Envelope::setRate: negative rates not allowed ... correcting!";
+    handleError( StkError::WARNING );
+    rate_ = -rate;
+  }
+  else
+    rate_ = rate;
+}
+
+void Envelope :: setTime(StkFloat time)
+{
+  if (time < 0.0) {
+    errorString_ << "Envelope::setTime: negative times not allowed ... correcting!";
+    handleError( StkError::WARNING );
+    rate_ = 1.0 / (-time * Stk::sampleRate());
+  }
+  else
+    rate_ = 1.0 / (time * Stk::sampleRate());
+}
+
+void Envelope :: setTarget(StkFloat target)
+{
+  target_ = target;
+  if (value_ != target_) state_ = 1;
+}
+
+void Envelope :: setValue(StkFloat value)
+{
+  state_ = 0;
+  target_ = value;
+  value_ = value;
+}
+
+int Envelope :: getState(void) const
+{
+  return state_;
+}
+
+StkFloat Envelope :: computeSample(void )
+{
+  if (state_) {
+    if (target_ > value_) {
+      value_ += rate_;
+      if (value_ >= target_) {
+        value_ = target_;
+        state_ = 0;
+      }
+    }
+    else {
+      value_ -= rate_;
+      if (value_ <= target_) {
+        value_ = target_;
+        state_ = 0;
+      }
+    }
+  }
+
+  lastOutput_ = value_;
+  return value_;
+}