Initial commit.

src/dk/itu/mario/engine/sonar/sample/SampleLoader.java

@@ -0,0 +1,114 @@
+package dk.itu.mario.engine.sonar.sample;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+import javax.sound.sampled.AudioFormat;
+import javax.sound.sampled.AudioInputStream;
+import javax.sound.sampled.AudioSystem;
+import javax.sound.sampled.UnsupportedAudioFileException;
+
+public class SampleLoader
+{
+    /**
+     * Loads a sample from an url
+     */
+    public static SonarSample loadSample(String resourceName) throws UnsupportedAudioFileException, IOException
+    {
+        // Hack to prevent "mark/reset not supported" on some systems
+        InputStream in=SampleLoader.class.getResourceAsStream(resourceName);
+        byte[] d = rip(in);
+        AudioInputStream ais = AudioSystem.getAudioInputStream(new ByteArrayInputStream(d));
+        return buildSample(rip(ais), ais.getFormat());
+    }
+
+    /**
+     * Rips the entire contents of an inputstream into a byte array
+     */
+    private static byte[] rip(InputStream in) throws IOException
+    {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        byte[] b = new byte[4096];
+
+        int read = 0;
+        while ((read = in.read(b)) > 0)
+        {
+            bos.write(b, 0, read);
+        }
+
+        bos.close();
+        return bos.toByteArray();
+    }
+
+    /**
+     * Reorganizes audio sample data into the intenal sonar format
+     */
+    private static SonarSample buildSample(byte[] b, AudioFormat af) throws UnsupportedAudioFileException
+    {
+        // Rip audioformat data
+        int channels = af.getChannels();
+        int sampleSize = af.getSampleSizeInBits();
+        float rate = af.getFrameRate();
+        boolean signed = af.getEncoding() == AudioFormat.Encoding.PCM_SIGNED;
+
+        // Sanity checking
+        if (channels != 1) throw new UnsupportedAudioFileException("Only mono samples are supported");
+        if (!(sampleSize == 8 || sampleSize == 16 || sampleSize == 32)) throw new UnsupportedAudioFileException("Unsupported sample size");
+        if (!(af.getEncoding() == AudioFormat.Encoding.PCM_UNSIGNED || af.getEncoding() == AudioFormat.Encoding.PCM_SIGNED)) throw new UnsupportedAudioFileException("Unsupported encoding");
+
+        // Wrap the data into a bytebuffer, and set up the byte order
+        ByteBuffer bb = ByteBuffer.wrap(b);
+        bb.order(af.isBigEndian() ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
+
+        int s = b.length / (sampleSize / 8);
+        float[] buf = new float[s];
+        // Six different cases for reordering the data. Can this be improved without slowing it down?
+        if (sampleSize == 8)
+        {
+            if (signed)
+            {
+                for (int i = 0; i < s; i++)
+                    buf[i] = bb.get() / (float)0x80;
+            }
+            else
+            {
+                for (int i = 0; i < s; i++)
+                    buf[i] = ((bb.get()&0xFF)-0x80) / (float)0x80;
+            }
+        }
+        else if (sampleSize == 16)
+        {
+            if (signed)
+            {
+                for (int i = 0; i < s; i++)
+                    buf[i] = bb.getShort() / (float)0x8000;
+            }
+            else
+            {
+                for (int i = 0; i < s; i++)
+                    buf[i] = ((bb.getShort()&0xFFFF)-0x8000) / (float)0x8000;
+            }
+        }
+        else if (sampleSize == 32)
+        {
+            if (signed)
+            {
+                for (int i = 0; i < s; i++)
+                    buf[i] = bb.getInt() / (float)0x80000000;
+            }
+            else
+            {
+                // Nasty.. check this.
+                for (int i = 0; i < s; i++)
+                    buf[i] = ((bb.getInt()&0xFFFFFFFFl)-0x80000000l) / (float)0x80000000;
+            }
+        }
+
+        // Return the completed sample
+        return new SonarSample(buf, rate);
+    }
+}