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package com.pheelicks.visualizer.renderer;
import com.pheelicks.visualizer.AudioData;
import com.pheelicks.visualizer.FFTData;
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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