Instruments: add better synth, pitch control

14 files changed, 316 insertions, 101 deletions

diff --git a/src/com/jsyn/unitgen/Circuit.java b/src/com/jsyn/unitgen/Circuit.java
index a501600..c5a1dcf 100644
--- a/src/com/jsyn/unitgen/Circuit.java
+++ b/src/com/jsyn/unitgen/Circuit.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -17,17 +17,21 @@
 package com.jsyn.unitgen;
 
 import java.util.ArrayList;
+import java.util.LinkedHashMap;
 
 import com.jsyn.engine.SynthesisEngine;
+import com.jsyn.ports.UnitPort;
 
 /**
  * Contains a list of units that are executed together.
- * 
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public class Circuit extends UnitGenerator {
     private ArrayList<UnitGenerator> units = new ArrayList<UnitGenerator>();
 
+    private final LinkedHashMap<String, UnitPort> portAliases = new LinkedHashMap<String, UnitPort>();
+
     @Override
     public void generate(int start, int limit) {
         for (UnitGenerator unit : units) {
@@ -57,6 +61,11 @@ public class Circuit extends UnitGenerator {
         }
     }
 
+    /**
+     * @deprecated ignored, frameRate comes from the SynthesisEngine
+     * @param rate
+     */
+    @Deprecated
     @Override
     public void setFrameRate(int frameRate) {
         super.setFrameRate(frameRate);
@@ -83,4 +92,31 @@ public class Circuit extends UnitGenerator {
 
     public void usePreset(int presetIndex) {
     }
+
+
+    /**
+     * Add an alternate name for looking up a port.
+     * @param port
+     * @param alias
+     */
+    public void addPortAlias(UnitPort port, String alias) {
+        // Store in a hash table by an alternate name.
+        portAliases.put(alias.toLowerCase(), port);
+    }
+
+
+    /**
+     * Case-insensitive search for a port by its name or alias.
+     * @param portName
+     * @return matching port or null
+     */
+    @Override
+    public UnitPort getPortByName(String portName) {
+        UnitPort port = super.getPortByName(portName);
+        if (port == null) {
+            port = portAliases.get(portName.toLowerCase());
+        }
+        return port;
+    }
+
 }
diff --git a/src/com/jsyn/unitgen/EnvelopeDAHDSR.java b/src/com/jsyn/unitgen/EnvelopeDAHDSR.java
index 6acd763..c5ebe83 100644
--- a/src/com/jsyn/unitgen/EnvelopeDAHDSR.java
+++ b/src/com/jsyn/unitgen/EnvelopeDAHDSR.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -30,7 +30,7 @@ import com.jsyn.ports.UnitOutputPort;
  * exponential Release will never reach 0.0. But when it reaches -96 dB the DAHDSR just sets its
  * output to 0.0 and stops. There is an example program in the ZIP archive called HearDAHDSR. It
  * drives a DAHDSR with a square wave.
- * 
+ *
  * @author Phil Burk (C) 2010 Mobileer Inc
  * @see SegmentedEnvelope
  */
diff --git a/src/com/jsyn/unitgen/FilterFourPoles.java b/src/com/jsyn/unitgen/FilterFourPoles.java
index d4f80f4..39a47c7 100644
--- a/src/com/jsyn/unitgen/FilterFourPoles.java
+++ b/src/com/jsyn/unitgen/FilterFourPoles.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,13 +20,13 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * Resonant filter in the style of the Moog ladder filter. This implementation is loosely based on:
- * http://www.musicdsp.org/archive.php?classid=3#26 
+ * http://www.musicdsp.org/archive.php?classid=3#26
  * More interesting reading:
  * http://dafx04.na.infn.it/WebProc/Proc/P_061.pdf
  * http://www.acoustics.ed.ac.uk/wp-content/uploads/AMT_MSc_FinalProjects
  * /2012__Daly__AMT_MSc_FinalProject_MoogVCF.pdf
  * http://www.music.mcgill.ca/~ich/research/misc/papers/cr1071.pdf
- * 
+ *
  * @author Phil Burk (C) 2014 Mobileer Inc
  * @see FilterLowPass
  */
@@ -37,6 +37,14 @@ public class FilterFourPoles extends TunableFilter {
     private static final double MINIMUM_FREQUENCY = 1.0; // blows up if near 0.01
     private static final double MINIMUM_Q = 0.00001;
 
+    //private static final double SATURATION_COEFFICIENT = 0.1666667;
+    private static final double SATURATION_COEFFICIENT = 0.2;
+    // Inflection point where slope is zero.
+    private static final double SATURATION_UPPER_INPUT = 1.0 / Math.sqrt(3.0 * SATURATION_COEFFICIENT);
+    private static final double SATURATION_LOWER_INPUT = 0.0 - SATURATION_UPPER_INPUT;
+    private static final double SATURATION_UPPER_OUTPUT = cubicPolynomial(SATURATION_UPPER_INPUT);
+    private static final double SATURATION_LOWER_OUTPUT = cubicPolynomial(SATURATION_LOWER_INPUT);
+
     private double x1;
     private double x2;
     private double x3;
@@ -57,6 +65,7 @@ public class FilterFourPoles extends TunableFilter {
 
     public FilterFourPoles() {
         addPort(Q = new UnitInputPort("Q"));
+        frequency.setup(40.0, DEFAULT_FREQUENCY, 4000.0);
         Q.setup(0.1, 2.0, 10.0);
     }
 
@@ -111,7 +120,6 @@ public class FilterFourPoles extends TunableFilter {
                 oneSample(0.0);
             }
             oneSample(x0);
-
             outputs[i] = y4;
         }
 
@@ -143,8 +151,35 @@ public class FilterFourPoles extends TunableFilter {
         this.oversampled = oversampled;
     }
 
-    private double clip(double x) {
-        return x - (x * x * x * 0.1666667);
+    // Soft saturation. This used to blow up the filter!
+    private static double cubicPolynomial(double x) {
+        return x - (x * x * x * SATURATION_COEFFICIENT);
     }
 
+    private static double clip(double x) {
+        if (x > SATURATION_UPPER_INPUT) {
+            return SATURATION_UPPER_OUTPUT;
+        } else if (x < SATURATION_LOWER_INPUT) {
+            return SATURATION_LOWER_OUTPUT;
+        } else {
+            return cubicPolynomial(x);
+        }
+    }
+
+    public void reset() {
+        x1 = 0.0;
+        x2 = 0.0;
+        x3 = 0.0;
+        x4 = 0.0;
+        y1 = 0.0;
+        y2 = 0.0;
+        y3 = 0.0;
+        y4 = 0.0;
+
+        previousFrequency = 0.0;
+        previousQ = 0.0;
+        f = 0.0;
+        fTo4th = 0.0;
+        feedback = 0.0;
+    }
 }
diff --git a/src/com/jsyn/unitgen/LineOut.java b/src/com/jsyn/unitgen/LineOut.java
index 489033e..d58f211 100644
--- a/src/com/jsyn/unitgen/LineOut.java
+++ b/src/com/jsyn/unitgen/LineOut.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,7 +20,7 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * Input audio is sent to the external audio output device.
- * 
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public class LineOut extends UnitGenerator implements UnitSink {
diff --git a/src/com/jsyn/unitgen/LinearRamp.java b/src/com/jsyn/unitgen/LinearRamp.java
index 438adf6..cad53d5 100644
--- a/src/com/jsyn/unitgen/LinearRamp.java
+++ b/src/com/jsyn/unitgen/LinearRamp.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -26,7 +26,7 @@ import com.jsyn.ports.UnitVariablePort;
  * value toward the value of input. An internal phase value will go from 0.0 to 1.0 at a rate
  * controlled by time. When the internal phase reaches 1.0, the output will equal input.
  * <P>
- * 
+ *
  * @author (C) 1997 Phil Burk, SoftSynth.com
  * @see ExponentialRamp
  * @see AsymptoticRamp
@@ -52,33 +52,41 @@ public class LinearRamp extends UnitFilter {
     public void generate(int start, int limit) {
         double[] outputs = output.getValues();
         double currentInput = input.getValues()[0];
-        double currentTime = time.getValues()[0];
         double currentValue = current.getValue();
 
-        if (currentTime != timeHeld) {
-            rate = convertTimeToRate(currentTime);
-            timeHeld = currentTime;
-        }
-
-        /* If input has changed, start new segment */
-        if (currentInput != target) /*
-                                     * Equality check is OK because we set them exactly equal below.
-                                     */
+        // If input has changed, start new segment.
+        // Equality check is OK because we set them exactly equal below.
+        if (currentInput != target)
         {
             source = currentValue;
             phase = 0.0;
             target = currentInput;
         }
 
-        for (int i = start; i < limit; i++) {
-            if (phase < 1.0) {
-                /* Interpolate current. */
-                currentValue = source + (phase * (target - source));
-                phase += rate;
-            } else {
-                currentValue = target;
+        if (currentValue == target) {
+            // at end of ramp
+            for (int i = start; i < limit; i++) {
+                outputs[i] = currentValue;
+            }
+        } else {
+            // in middle of ramp
+            double currentTime = time.getValues()[0];
+            // Has time changed?
+            if (currentTime != timeHeld) {
+                rate = convertTimeToRate(currentTime);
+                timeHeld = currentTime;
+            }
+
+            for (int i = start; i < limit; i++) {
+                if (phase < 1.0) {
+                    /* Interpolate current. */
+                    currentValue = source + (phase * (target - source));
+                    phase += rate;
+                } else {
+                    currentValue = target;
+                }
+                outputs[i] = currentValue;
             }
-            outputs[i] = currentValue;
         }
 
         current.setValue(currentValue);
diff --git a/src/com/jsyn/unitgen/MorphingOscillatorBL.java b/src/com/jsyn/unitgen/MorphingOscillatorBL.java
new file mode 100644
index 0000000..7ca440d
--- /dev/null
+++ b/src/com/jsyn/unitgen/MorphingOscillatorBL.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2009 Phil Burk, Mobileer Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jsyn.unitgen;
+
+import com.jsyn.engine.MultiTable;
+import com.jsyn.ports.UnitInputPort;
+
+/**
+ * Oscillator that can change its shape from sine to sawtooth to pulse.
+ *
+ * @author Phil Burk (C) 2016 Mobileer Inc
+ */
+public class MorphingOscillatorBL extends PulseOscillatorBL {
+    /**
+     * Controls the shape of the waveform.
+     * The shape varies continuously from a sine wave at -1.0,
+     * to a sawtooth at 0.0 to a pulse wave at 1.0.
+     */
+    public UnitInputPort shape;
+
+    public MorphingOscillatorBL() {
+        addPort(shape = new UnitInputPort("Shape"));
+        shape.setMinimum(-1.0);
+        shape.setMaximum(1.0);
+    }
+
+    @Override
+    protected double generateBL(MultiTable multiTable, double currentPhase,
+            double positivePhaseIncrement, double flevel, int i) {
+        double[] shapes = shape.getValues();
+        double shape = shapes[i];
+
+        if (shape < 0.0) {
+            // Squeeze flevel towards the pure sine table.
+            flevel += flevel * shape;
+            return multiTable.calculateSawtooth(currentPhase, positivePhaseIncrement, flevel);
+        } else {
+            double[] widths = width.getValues();
+            double width = widths[i];
+            width = (width > 0.999) ? 0.999 : ((width < -0.999) ? -0.999 : width);
+
+            double val1 = multiTable.calculateSawtooth(currentPhase, positivePhaseIncrement, flevel);
+            // Generate second sawtooth so we can add them together.
+            double phase2 = currentPhase + 1.0 - width; // 180 degrees out of phase
+            if (phase2 >= 1.0) {
+                phase2 -= 2.0;
+            }
+            double val2 = multiTable.calculateSawtooth(phase2, positivePhaseIncrement, flevel);
+
+            /*
+             * Need to adjust amplitude based on positive phaseInc. little less than half at
+             * Nyquist/2.0!
+             */
+            double scale = 1.0 - positivePhaseIncrement;
+            return scale * (val1 - ((val2 + width) * shape)); // apply shape morphing
+        }
+    }
+}
diff --git a/src/com/jsyn/unitgen/PitchToFrequency.java b/src/com/jsyn/unitgen/PitchToFrequency.java
new file mode 100644
index 0000000..9086749
--- /dev/null
+++ b/src/com/jsyn/unitgen/PitchToFrequency.java
@@ -0,0 +1,26 @@
+package com.jsyn.unitgen;
+
+import com.softsynth.math.AudioMath;
+
+public class PitchToFrequency extends PowerOfTwo {
+
+    public PitchToFrequency() {
+        input.setup(0.0, 60.0, 127.0);
+    }
+
+    /**
+     * Convert from MIDI pitch to an octave offset from Concert A.
+     */
+    @Override
+    public double adjustInput(double in) {
+        return (in - AudioMath.CONCERT_A_PITCH) * (1.0/12.0);
+    }
+
+    /**
+     * Convert scaler to a frequency relative to Concert A.
+     */
+    @Override
+    public double adjustOutput(double out) {
+        return out * AudioMath.getConcertAFrequency();
+    }
+}
diff --git a/src/com/jsyn/unitgen/PowerOfTwo.java b/src/com/jsyn/unitgen/PowerOfTwo.java
index 5f1b4cd..5916860 100644
--- a/src/com/jsyn/unitgen/PowerOfTwo.java
+++ b/src/com/jsyn/unitgen/PowerOfTwo.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -22,18 +22,23 @@ import com.jsyn.ports.UnitOutputPort;
 /**
  * output = (2.0^input) This is useful for converting a pitch modulation value into a frequency
  * scaler. An input value of +1.0 will output 2.0 for an octave increase. An input value of -1.0
- * will output 0.5 for an octave decrease. This implementation uses a table lookup to optimize for
+ * will output 0.5 for an octave decrease.
+ *
+ * This implementation uses a table lookup to optimize for
  * speed. It is accurate enough for tuning. It also checks to see if the current input value is the
  * same as the previous input value. If so then it reuses the previous computed value.
- * 
+ *
  * @author Phil Burk (C) 2010 Mobileer Inc
  */
 public class PowerOfTwo extends UnitGenerator {
+    /**
+     * Offset in octaves.
+     */
     public UnitInputPort input;
     public UnitOutputPort output;
 
     private static double[] table;
-    private static final int NUM_VALUES = 1024;
+    private static final int NUM_VALUES = 2048;
     // Cached computation.
     private double lastInput = 0.0;
     private double lastOutput = 1.0;
@@ -61,39 +66,43 @@ public class PowerOfTwo extends UnitGenerator {
         double[] inputs = input.getValues();
         double[] outputs = output.getValues();
 
-        if (true) {
-            for (int i = start; i < limit; i++) {
-                double in = inputs[i];
-                // Can we reuse a previously computed value?
-                if (in == lastInput) {
-                    outputs[i] = lastOutput;
-                } else {
-                    int octave = (int) Math.floor(in);
-                    double normal = in - octave;
-                    // Do table lookup.
-                    double findex = normal * NUM_VALUES;
-                    int index = (int) findex;
-                    double fraction = findex - index;
-                    double value = table[index] + (fraction * (table[index + 1] - table[index]));
+        for (int i = start; i < limit; i++) {
+            double in = inputs[i];
+            // Can we reuse a previously computed value?
+            if (in == lastInput) {
+                outputs[i] = lastOutput;
+            } else {
+                lastInput = in;
+                double adjustedInput = adjustInput(in);
+                int octave = (int) Math.floor(adjustedInput);
+                double normal = adjustedInput - octave;
+                // Do table lookup.
+                double findex = normal * NUM_VALUES;
+                int index = (int) findex;
+                double fraction = findex - index;
+                double value = table[index] + (fraction * (table[index + 1] - table[index]));
 
-                    // Adjust for octave.
-                    while (octave > 0) {
-                        octave -= 1;
-                        value *= 2.0;
-                    }
-                    while (octave < 0) {
-                        octave += 1;
-                        value *= 0.5;
-                    }
-                    outputs[i] = value;
-                    lastInput = in;
-                    lastOutput = value;
+                // Adjust for octave.
+                while (octave > 0) {
+                    octave -= 1;
+                    value *= 2.0;
                 }
-            }
-        } else {
-            for (int i = start; i < limit; i++) {
-                outputs[i] = Math.pow(2.0, inputs[i]);
+                while (octave < 0) {
+                    octave += 1;
+                    value *= 0.5;
+                }
+                double adjustedOutput = adjustOutput(value);
+                outputs[i] = adjustedOutput;
+                lastOutput = adjustedOutput;
             }
         }
     }
+
+    public double adjustInput(double in) {
+        return in;
+    }
+
+    public double adjustOutput(double out) {
+        return out;
+    }
 }
diff --git a/src/com/jsyn/unitgen/PulseOscillatorBL.java b/src/com/jsyn/unitgen/PulseOscillatorBL.java
index 43fe27b..c0e234c 100644
--- a/src/com/jsyn/unitgen/PulseOscillatorBL.java
+++ b/src/com/jsyn/unitgen/PulseOscillatorBL.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,11 +20,15 @@ import com.jsyn.engine.MultiTable;
 import com.jsyn.ports.UnitInputPort;
 
 /**
- * Pulse oscillator that uses two band limited sawtooth oscillators.
- * 
+ * Pulse oscillator that uses two band limited sawtooth waveforms.
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public class PulseOscillatorBL extends SawtoothOscillatorBL {
+    /** Controls the duty cycle of the pulse waveform.
+     * The width varies from -1.0 to +1.0.
+     * When width is zero the output is a square wave.
+     */
     public UnitInputPort width;
 
     public PulseOscillatorBL() {
@@ -48,7 +52,7 @@ public class PulseOscillatorBL extends SawtoothOscillatorBL {
         double val2 = multiTable.calculateSawtooth(phase2, positivePhaseIncrement, flevel);
 
         /*
-         * Need to adjust amplitude based on positive phaseInc. little less than half at
+         * Need to adjust amplitude based on positive phaseInc and width. little less than half at
          * Nyquist/2.0!
          */
         double scale = 1.0 - positivePhaseIncrement;
diff --git a/src/com/jsyn/unitgen/SawtoothOscillatorDPW.java b/src/com/jsyn/unitgen/SawtoothOscillatorDPW.java
index 6868c15..27d0c5a 100644
--- a/src/com/jsyn/unitgen/SawtoothOscillatorDPW.java
+++ b/src/com/jsyn/unitgen/SawtoothOscillatorDPW.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,7 +20,7 @@ package com.jsyn.unitgen;
  * Sawtooth DPW oscillator (a sawtooth with reduced aliasing).
  * Based on a paper by Antti Huovilainen and Vesa Valimaki:
  * http://www.scribd.com/doc/33863143/New-Approaches-to-Digital-Subtractive-Synthesis
- * 
+ *
  * @author Phil Burk and Lisa Tolentino (C) 2009 Mobileer Inc
  */
 public class SawtoothOscillatorDPW extends UnitOscillator {
diff --git a/src/com/jsyn/unitgen/SquareOscillatorBL.java b/src/com/jsyn/unitgen/SquareOscillatorBL.java
index cfe8541..cb9e141 100644
--- a/src/com/jsyn/unitgen/SquareOscillatorBL.java
+++ b/src/com/jsyn/unitgen/SquareOscillatorBL.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -21,7 +21,7 @@ import com.jsyn.engine.MultiTable;
 /**
  * Band-limited square wave oscillator. This requires more CPU than a SquareOscillator but is less
  * noisy at high frequencies.
- * 
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public class SquareOscillatorBL extends SawtoothOscillatorBL {
@@ -32,8 +32,9 @@ public class SquareOscillatorBL extends SawtoothOscillatorBL {
 
         /* Generate second sawtooth so we can add them together. */
         double phase2 = currentPhase + 1.0; /* 180 degrees out of phase. */
-        if (phase2 >= 1.0)
+        if (phase2 >= 1.0) {
             phase2 -= 2.0;
+        }
         double val2 = multiTable.calculateSawtooth(phase2, positivePhaseIncrement, flevel);
 
         /*
diff --git a/src/com/jsyn/unitgen/TunableFilter.java b/src/com/jsyn/unitgen/TunableFilter.java
index 1724ec1..31f6631 100644
--- a/src/com/jsyn/unitgen/TunableFilter.java
+++ b/src/com/jsyn/unitgen/TunableFilter.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -15,7 +15,7 @@
  */
 /**
  * Aug 26, 2009
- * com.jsyn.engine.units.TunableFilter.java 
+ * com.jsyn.engine.units.TunableFilter.java
  */
 
 package com.jsyn.unitgen;
@@ -24,13 +24,13 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * A UnitFilter with a frequency port.
- * 
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc Translated from 'C' to Java by Lisa
  *         Tolenti.
  */
 public abstract class TunableFilter extends UnitFilter {
 
-    private static final double DEFAULT_FREQUENCY = 400;
+    static final double DEFAULT_FREQUENCY = 400;
     public UnitInputPort frequency;
 
     public TunableFilter() {
diff --git a/src/com/jsyn/unitgen/UnitGenerator.java b/src/com/jsyn/unitgen/UnitGenerator.java
index a9a7459..f8278ae 100644
--- a/src/com/jsyn/unitgen/UnitGenerator.java
+++ b/src/com/jsyn/unitgen/UnitGenerator.java
@@ -36,6 +36,20 @@ import com.softsynth.shared.time.TimeStamp;
  */
 public abstract class UnitGenerator {
     protected static final double VERY_SMALL_FLOAT = 1.0e-26;
+
+    // Some common port names.
+    public static final String PORT_NAME_INPUT = "Input";
+    public static final String PORT_NAME_OUTPUT = "Output";
+    public static final String PORT_NAME_PHASE = "Phase";
+    public static final String PORT_NAME_FREQUENCY = "Frequency";
+    public static final String PORT_NAME_FREQUENCY_SCALER = "FreqScaler";
+    public static final String PORT_NAME_AMPLITUDE = "Amplitude";
+    public static final String PORT_NAME_PAN = "Pan";
+    public static final String PORT_NAME_TIME = "Time";
+    public static final String PORT_NAME_CUTOFF = "Cutoff";
+    public static final String PORT_NAME_PRESSURE = "Pressure";
+    public static final String PORT_NAME_TIMBRE = "Timbre";
+
     public static final double FALSE = 0.0;
     public static final double TRUE = 1.0;
     protected SynthesisEngine synthesisEngine;
@@ -75,6 +89,11 @@ public abstract class UnitGenerator {
         addPort(port);
     }
 
+    /**
+     * Case-insensitive search for a port by name.
+     * @param portName
+     * @return matching port or null
+     */
     public UnitPort getPortByName(String portName) {
         return ports.get(portName.toLowerCase());
     }
@@ -141,8 +160,7 @@ public abstract class UnitGenerator {
         if (halfLife < (2.0 * getFramePeriod())) {
             return 1.0;
         } else {
-            // Strangely enough, this code is valid for both PeakFollower
-            // and AsymptoticRamp.
+            // Oddly enough, this code is valid for both PeakFollower and AsymptoticRamp.
             return 1.0 - Math.pow(0.5, 1.0 / (halfLife * getSynthesisEngine().getFrameRate()));
         }
     }
@@ -150,10 +168,11 @@ public abstract class UnitGenerator {
     protected double incrementWrapPhase(double currentPhase, double phaseIncrement) {
         currentPhase += phaseIncrement;
 
-        if (currentPhase >= 1.0)
+        if (currentPhase >= 1.0) {
             currentPhase -= 2.0;
-        else if (currentPhase < -1.0)
+        } else if (currentPhase < -1.0) {
             currentPhase += 2.0;
+        }
         return currentPhase;
     }
 
@@ -285,6 +304,11 @@ public abstract class UnitGenerator {
         getSynthesisEngine().stopUnit(this, timeStamp);
     }
 
+    /**
+     * @deprecated ignored, frameRate comes from the SynthesisEngine
+     * @param rate
+     */
+    @Deprecated
     public void setFrameRate(int rate) {
         this.frameRate = rate;
         this.framePeriod = 1.0 / rate;
diff --git a/src/com/jsyn/unitgen/UnitOscillator.java b/src/com/jsyn/unitgen/UnitOscillator.java
index 4c02f09..5d4c6fa 100644
--- a/src/com/jsyn/unitgen/UnitOscillator.java
+++ b/src/com/jsyn/unitgen/UnitOscillator.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -23,7 +23,7 @@ import com.softsynth.shared.time.TimeStamp;
 
 /**
  * Base class for all oscillators.
- * 
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public abstract class UnitOscillator extends UnitGenerator implements UnitVoice {
@@ -34,15 +34,15 @@ public abstract class UnitOscillator extends UnitGenerator implements UnitVoice
     public UnitOutputPort output;
 
     public static final double DEFAULT_FREQUENCY = 440.0;
-    public static final double DEFAULT_AMPLITUDE = 0x7FFF / (double) 0x8000;
+    public static final double DEFAULT_AMPLITUDE = 1.0;
 
     /* Define Unit Ports used by connect() and set(). */
     public UnitOscillator() {
-        addPort(frequency = new UnitInputPort("Frequency"));
+        addPort(frequency = new UnitInputPort(PORT_NAME_FREQUENCY));
         frequency.setup(40.0, DEFAULT_FREQUENCY, 8000.0);
-        addPort(amplitude = new UnitInputPort("Amplitude", DEFAULT_AMPLITUDE));
-        addPort(phase = new UnitVariablePort("Phase"));
-        addPort(output = new UnitOutputPort("Output"));
+        addPort(amplitude = new UnitInputPort(PORT_NAME_AMPLITUDE, DEFAULT_AMPLITUDE));
+        addPort(phase = new UnitVariablePort(PORT_NAME_PHASE));
+        addPort(output = new UnitOutputPort(PORT_NAME_OUTPUT));
     }
 
     /**