Version 0.99

ADSR.cpp

@@ -0,0 +1,173 @@
+/*******************************************/
+/*  ADSR Subclass of the Envelope Class,   */
+/*  by Perry R. Cook, 1995-96              */ 
+/*  This is the traditional ADSR (Attack   */
+/*  Decay, Sustain, Release) ADSR.         */
+/*  It responds to simple KeyOn and KeyOff */
+/*  messages, keeping track of it's state. */         
+/*  There are two tick (update value)      */
+/*  methods, one returns the value, and    */
+/*  other returns the state (0 = A, 1 = D, */
+/*  2 = S, 3 = R)                          */
+/*******************************************/
+
+#include "ADSR.h"    
+
+ADSR :: ADSR() : Envelope()
+{    
+    target = 0.0;
+    value = 0.0;
+    attackRate = 0.001;
+    decayRate = 0.001;
+    sustainLevel = 0.5;
+    releaseRate = 0.01;
+    state = 0;
+}
+
+ADSR :: ~ADSR()
+{    
+    /* Nothing to do here */
+}
+
+void ADSR :: keyOn()
+{
+    target = 1.0;
+    rate = attackRate;
+    state = 0;
+}
+
+void ADSR :: keyOff()
+{
+    target = 0.0;
+    rate = releaseRate;
+    state = 3;
+}
+
+void ADSR :: setAttackRate(MY_FLOAT aRate)
+{
+    if (aRate < 0.0) {
+        printf("negative rates not allowed!!, correcting\n");
+        attackRate = -aRate;
+    }
+    else attackRate = aRate;
+    attackRate = attackRate * RATE_NORM;  /*  SEE Object.h  */
+}
+
+void ADSR :: setDecayRate(MY_FLOAT aRate)
+{
+    if (aRate < 0.0) {
+        printf("negative rates not allowed!!, correcting\n");
+        decayRate = -aRate;
+    }
+    else decayRate = aRate;
+    decayRate = decayRate * RATE_NORM;	/*  SEE Object.h  */
+}
+
+void ADSR :: setSustainLevel(MY_FLOAT aLevel)
+{
+    if (aLevel < 0.0 ) {
+        printf("Sustain level out of range!!, correcting\n");
+        sustainLevel = 0.0;
+    }
+    else sustainLevel = aLevel;
+}
+
+void ADSR :: setReleaseRate(MY_FLOAT aRate)
+{
+    if (aRate < 0.0) {
+        printf("negative rates not allowed!!, correcting\n");
+        releaseRate = -aRate;
+    }
+    else releaseRate = aRate;
+    releaseRate = releaseRate * RATE_NORM;	/*  SEE Object.h  */
+}
+
+void ADSR :: setAll(MY_FLOAT attRate, MY_FLOAT decRate, MY_FLOAT susLevel, MY_FLOAT relRate)
+{
+    this->setAttackRate(attRate);
+    this->setDecayRate(decRate);
+    this->setSustainLevel(susLevel);
+    this->setReleaseRate(relRate);
+}
+
+void ADSR :: setTarget(MY_FLOAT aTarget)
+{
+    target = aTarget;
+    if (value < target) {
+	state = ATTACK;
+	this->setSustainLevel(target);
+	rate = attackRate;
+    }
+    if (value > target) {
+	this->setSustainLevel(target);
+	state = DECAY;
+	rate = decayRate;
+    }
+}
+
+void ADSR :: setValue(MY_FLOAT aValue)
+{
+    state = SUSTAIN;
+    target = aValue;
+    value = aValue;
+    this->setSustainLevel(aValue);
+    rate = 0.0;
+}
+
+MY_FLOAT ADSR :: tick()
+{
+    if (state==ATTACK)  {
+        value += rate;
+	if (value >= target)    {
+            value = target;
+            rate = decayRate;
+            target = sustainLevel;
+	    state = DECAY;
+        }
+    }    
+    else if (state==DECAY)  {
+        value -= decayRate;
+        if (value <= sustainLevel)    {
+            value = sustainLevel;
+            rate = 0.0;
+            state = SUSTAIN;
+        }
+    }
+    else if (state==RELEASE)  {
+        value -= releaseRate;
+        if (value <= 0.0)       {
+            value = 0.0;
+            state = 4;
+        }
+    }
+    return value;
+}
+
+int ADSR :: informTick()
+{
+    this->tick();
+    return state;
+}
+
+MY_FLOAT ADSR :: lastOut()
+{
+    return value;
+}
+
+/************  Test Main  ************************/
+/*
+void main()
+{
+    long i;
+    ADSR test;
+    
+    test.setAttackRate(0.15);
+    test.keyOn();
+    while(test.informTick()==ATTACK) printf("%lf\n",test.tick());
+    test.setDecayRate(0.1);
+    while (test.informTick()==DECAY) printf("%lf\n",test.lastOut());
+    test.setReleaseRate(0.05);
+    test.keyOff();
+    while(test.informTick()==RELEASE) printf("%lf\n",test.lastOut());
+}
+*/