1 files changed, 59 insertions, 0 deletions
diff --git a/src/com/jsyn/unitgen/TriangleOscillator.java b/src/com/jsyn/unitgen/TriangleOscillator.java
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+++ b/src/com/jsyn/unitgen/TriangleOscillator.java
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+/*
+ * 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;
+
+/**
+ * Simple triangle wave oscillator.
+ * 
+ * @author Phil Burk (C) 2009 Mobileer Inc
+ */
+public class TriangleOscillator extends UnitOscillator {
+    int frame;
+
+    public TriangleOscillator() {
+        super();
+        phase.setValue(-0.5);
+    }
+
+    @Override
+    public void generate(int start, int limit) {
+
+        double[] frequencies = frequency.getValues();
+        double[] amplitudes = amplitude.getValues();
+        double[] outputs = output.getValues();
+
+        // Variables have a single value.
+        double currentPhase = phase.getValue();
+
+        for (int i = start; i < limit; i++) {
+            /* Generate sawtooth phasor to provide phase for triangle generation. */
+            double phaseIncrement = convertFrequencyToPhaseIncrement(frequencies[i]);
+            currentPhase = incrementWrapPhase(currentPhase, phaseIncrement);
+
+            /* Map phase to triangle waveform. */
+            /* 0 - 0.999 => 0.5-p => +0.5 - -0.5 */
+            /* -1.0 - 0.0 => 0.5+p => -0.5 - +0.5 */
+            double triangle = (currentPhase >= 0.0) ? (0.5 - currentPhase) : (0.5 + currentPhase);
+
+            outputs[i] = triangle * 2.0 * amplitudes[i];
+        }
+
+        // Value needs to be saved for next time.
+        phase.setValue(currentPhase);
+    }
+
+}