#39 WIP polyphase channelizers. Creates test tuner and controller to

use in testing tuner and polyphase channel manager operations.

src/source/tuner/test/SampleGenerator.java

@@ -0,0 +1,147 @@
+/*******************************************************************************
+ * sdrtrunk
+ * Copyright (C) 2014-2017 Dennis Sheirer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ ******************************************************************************/
+package source.tuner.test;
+
+import dsp.mixer.LowPhaseNoiseOscillator;
+import sample.Listener;
+import sample.complex.ComplexBuffer;
+import util.ThreadPool;
+
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+
+public class SampleGenerator
+{
+    private LowPhaseNoiseOscillator mOscillator;
+    private Listener<ComplexBuffer> mListener;
+    private long mInterval;
+    private int mSamplesPerInterval;
+    private ScheduledFuture<?> mScheduledFuture;
+
+    /**
+     * Generates complex sample buffers at the specified sample rate with a unity gain tone at the specified
+     * frequency.  This generator runs via a scheduled thread pool and generates samples at the specified time
+     * interval.
+     *
+     * @param sampleRate of the complex samples
+     * @param frequency of the tone produced by the generator
+     * @param interval in milliseconds for generating samples
+     */
+    public SampleGenerator(int sampleRate, long frequency, long interval)
+    {
+        mOscillator = new LowPhaseNoiseOscillator(sampleRate, frequency);
+        mInterval = interval;
+
+        updateSamplesPerInterval();
+    }
+
+    /**
+     * Updates the number of complex samples generated per interval
+     */
+    private void updateSamplesPerInterval()
+    {
+        mSamplesPerInterval = (int)((double)mOscillator.getSampleRate() * ((double)mInterval / 1000.0) * 2.0);
+    }
+
+    /**
+     * Starts the generator producing samples
+     */
+    public void start()
+    {
+        if(mScheduledFuture == null)
+        {
+            mScheduledFuture = ThreadPool.SCHEDULED.scheduleAtFixedRate(new Generator(), 0, mInterval,
+                TimeUnit.MILLISECONDS);
+        }
+        else
+        {
+            throw new IllegalStateException("Sample generator is already started");
+        }
+    }
+
+    /**
+     * Stops the generator from producing samples
+     */
+    public void stop()
+    {
+        if(mScheduledFuture != null)
+        {
+            mScheduledFuture.cancel(true);
+            mScheduledFuture = null;
+        }
+        else
+        {
+            throw new IllegalStateException("Sample generator is already stopped");
+        }
+    }
+
+    /**
+     * Registers the listener to receive samples once the generator starts.  Note: invoke this method with null
+     * argument to de-register the listener.
+     *
+     * @param listener to receive complex sample buffers
+     */
+    public void setListener(Listener<ComplexBuffer> listener)
+    {
+        mListener = listener;
+    }
+
+    /**
+     * Updates the tone frequency for this generator
+     * @param frequency to generate
+     */
+    public void setFrequency(long frequency)
+    {
+        mOscillator.setFrequency(frequency);
+    }
+
+    /**
+     * Current tone frequency for this generator
+     */
+    public long getFrequency()
+    {
+        return mOscillator.getFrequency();
+    }
+
+    /**
+     * Updates the sample rate for this generator
+     * @param sampleRate in hertz for complex samples
+     */
+    public void setSampleRate(int sampleRate)
+    {
+        mOscillator.setSampleRate(sampleRate);
+        updateSamplesPerInterval();
+    }
+
+    /**
+     * Generates a complex sample buffer and distributes the buffer to a registered listener
+     */
+    public class Generator implements Runnable
+    {
+        @Override
+        public void run()
+        {
+            if(mListener != null)
+            {
+                float[] samples = mOscillator.generate(mSamplesPerInterval);
+                mListener.receive(new ComplexBuffer(samples));
+            }
+        }
+    }
+}