From 6fa6928b1e07f0004b05a5aed1634b0e43096054 Mon Sep 17 00:00:00 2001
From: Felix Palmer <felix.palmer@metaswitch.com>
Date: Fri, 2 Dec 2011 17:10:51 -0800
Subject: Recfactor FFT rendering into separate class

---
 src/com/pheelicks/visualizer/BarGraphRenderer.java | 62 ++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 src/com/pheelicks/visualizer/BarGraphRenderer.java

(limited to 'src/com/pheelicks/visualizer/BarGraphRenderer.java')

diff --git a/src/com/pheelicks/visualizer/BarGraphRenderer.java b/src/com/pheelicks/visualizer/BarGraphRenderer.java
new file mode 100644
index 0000000..f1531e9
--- /dev/null
+++ b/src/com/pheelicks/visualizer/BarGraphRenderer.java
@@ -0,0 +1,62 @@
+package com.pheelicks.visualizer;
+
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Rect;
+
+public class BarGraphRenderer extends Renderer
+{
+  private int mDivisions;
+  private Paint mPaint;
+  private boolean mTop;
+
+  /**
+   * Renders the FFT data as a series of lines, in histogram form
+   * @param canvas
+   * @param divisions - must be a power of 2. Controls how many lines to draw
+   * @param paint - Paint to draw lines with
+   * @param top - whether to draw the lines at the top of the canvas, or the bottom
+   */
+  public BarGraphRenderer(Canvas canvas,
+                          int divisions,
+                          Paint paint,
+                          boolean top)
+  {
+    super(canvas);
+    mDivisions = divisions;
+    mPaint = paint;
+    mTop = top;
+  }
+
+  @Override
+  public void onRender(AudioData data, Rect rect)
+  {
+    // Do nothing, we only display FFT data
+  }
+
+  @Override
+  public void onRender(FFTData data, Rect rect)
+  {
+    for (int i = 0; i < data.bytes.length / mDivisions; i++) {
+      mFFTPoints[i * 4] = i * 4 * mDivisions;
+      mFFTPoints[i * 4 + 2] = i * 4 * mDivisions;
+      byte rfk = data.bytes[mDivisions * i];
+      byte ifk = data.bytes[mDivisions * i + 1];
+      float magnitude = (rfk * rfk + ifk * ifk);
+      int dbValue = (int) (10 * Math.log10(magnitude));
+
+      if(mTop)
+      {
+        mFFTPoints[i * 4 + 1] = 0;
+        mFFTPoints[i * 4 + 3] = (dbValue * 2 - 10);
+      }
+      else
+      {
+        mFFTPoints[i * 4 + 1] = rect.height();
+        mFFTPoints[i * 4 + 3] = rect.height() - (dbValue * 2 - 10);
+      }
+    }
+
+    mCanvas.drawLines(mFFTPoints, mPaint);
+  }
+}
-- 
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