void ProcessData()
{
double[] powerSpectrum;
ComplexSignal cs = Signal.FromArray(dataBuffer, SAMPLE_RATE).ToComplex();
cs.ForwardFourierTransform();
powerSpectrum = Tools.GetPowerSpectrum(cs.GetChannel(0));
//Convert to dB
powerSpectrum = powerSpectrum.Select((double arg, int index) => (10 * Math.Log10(arg / baselinePowerSpectrum[index]))).ToArray();
// Normalize values
double minPowerSpectrum = (powerSpectrum.Min());
double maxPowerSpectrum = (powerSpectrum.Max());
powerSpectrum = powerSpectrum.Select((double arg, int index) => (arg - minPowerSpectrum) / (maxPowerSpectrum - minPowerSpectrum)).ToArray();
//Pick the color scheme according to the peak frequency - Blue-Green if peak below alpha,
//Yellow-Red otherwise
int highestFrequency = Array.IndexOf(powerSpectrum, powerSpectrum.Max());
currentScheme = highestFrequency >= alphaCutoff ? (highestFrequency >= gammaCutoff ? COLOUR_SCHEME.YELLOW_RED : COLOUR_SCHEME.PURPLE_RED) : COLOUR_SCHEME.BLUE_GREEN;
Color[] spectrogramColours;
if (currentScheme == COLOUR_SCHEME.BLUE_GREEN)
{
spectrogramColours = powerSpectrum.Select(((double arg) => ColourUtility.HSL2BlueGreen(arg, 0.75, 0.5))).ToArray();
}
else if (currentScheme == COLOUR_SCHEME.PURPLE_RED)
{
spectrogramColours = powerSpectrum.Select(((double arg) => ColourUtility.HSL2PurpleRed(arg, 0.75, 0.5))).ToArray();
}
else
{
spectrogramColours = powerSpectrum.Select(((double arg) => ColourUtility.HSL2YellowRed(arg, 0.75, 0.5))).ToArray();
}
//Set the texture
for (int i = 0; i < numFreqs; i++)
{
texture.SetPixel(i, (currentWindow % maxTextureWidth), spectrogramColours[i]);
}
currentWindow++;
texture.Apply();
//Set the normal map
float xLeft;
float xRight;
float yUp;
float yDown;
float yDelta;
float xDelta;
for (int i = 0; i < numFreqs; i++)
{
int y = (currentWindow % maxTextureWidth);
yUp = normalMap.GetPixel(y - 1, i).grayscale;
yDown = normalMap.GetPixel(y + 1, i).grayscale;
int tempI = (int)Mathf.Clamp(i, 1, numFreqs - 2);
xLeft = (float)powerSpectrum[tempI - 1];
xRight = (float)powerSpectrum[tempI + 1];
xDelta = ((xLeft - xRight) + 1) * 0.5f;
yDelta = ((yUp - yDown) + 1) * 0.5f;
normalMap.SetPixel(i, y, new Color(xDelta, yDelta, 1.0f, yDelta));
}
normalMap.Apply();
}