Instruments: add better synth, pitch control

1 files changed, 72 insertions, 0 deletions

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
+        }
+    }
+}