Add GraphicEQ audio helper class, improve audio animations

[SugarCubes.git] / Audio.pde

diff --git a/Audio.pde b/Audio.pde
new file mode 100644 (file)
index 0000000..06390bc
--- /dev/null
+++ b/Audio.pde
@@ -0,0 +1,85 @@
+/**
+ * This is a reusable equalizer class that lets you get averaged
+ * bands with dB scaling and smoothing.
+ */
+public static class GraphicEQ {
+  
+  private final HeronLX lx;
+  
+  public final BasicParameter level = new BasicParameter("LVL", 0.5);
+  public final BasicParameter range = new BasicParameter("RNGE", 0.5);
+  public final BasicParameter slope = new BasicParameter("SLOP", 0.5);
+  public final BasicParameter attack = new BasicParameter("ATK", 0.5);
+  public final BasicParameter release = new BasicParameter("REL", 0.5);    
+
+  private final FFT fft;
+  private final int numBands;
+
+  private final LinearEnvelope[] bandVals;
+  
+  public final static int DEFAULT_NUM_BANDS = 16;
+
+  public GraphicEQ(HeronLX lx) {
+    this(lx, DEFAULT_NUM_BANDS);
+  }
+  
+  /**
+   * Note that the number of bands is a suggestion. Due to the FFT implementation
+   * the actual number may be slightly different.
+   */
+  public GraphicEQ(HeronLX lx, int num) {
+    this.lx = lx;
+    fft = new FFT(lx.audioInput().bufferSize(), lx.audioInput().sampleRate());
+    fft.window(FFT.HAMMING);
+    fft.logAverages(50, num/8);
+    numBands = this.fft.avgSize();
+    bandVals = new LinearEnvelope[numBands];
+    for (int i = 0; i < bandVals.length; ++i) {
+      bandVals[i] = new LinearEnvelope(0, 0, 500).trigger();
+    }
+  }
+  
+  final float logTen = log(10);
+  public float log10(float val) {
+    return log(val) / logTen;
+  }
+  
+  public float getLevel(int band) {
+    return bandVals[band].getValuef();
+  }
+  
+  public float getAverageLevel(int minBand, int numBands) {
+    float avg = 0;
+    for (int i = minBand; i < minBand + numBands; ++i) {
+      avg += bandVals[i].getValuef();
+    }
+    avg /= numBands;
+    return avg;
+  }
+  
+  public void run(int deltaMs) {
+    fft.forward(lx.audioInput().mix);
+    float zeroDBReference = pow(10, 100*(1-level.getValuef())/20.);
+    float decibelRange = 12 + range.getValuef() * 60;
+    float decibelSlope = slope.getValuef() * 60.f / numBands;
+    for (int i = 0; i < numBands; ++i) {
+      float raw = fft.getAvg(i);
+      float decibels = 20*log10(raw / zeroDBReference);
+      float positiveDecibels = decibels + decibelRange;
+      positiveDecibels += i*decibelSlope;
+      float value = constrain(positiveDecibels / decibelRange, 0, 1);
+      
+      if (value > bandVals[i].getValuef()) {
+        bandVals[i].setEndVal(value, attack.getValuef() * 20).trigger();
+      }
+    }
+    for (LinearEnvelope band : bandVals) {
+      band.run(deltaMs);
+      if (!band.isRunning() && band.getValuef() > 0) {
+        band.setEndVal(0, release.getValuef() * 1600).trigger();
+      }
+    }    
+  }
+}
+
+