ofxFft

To install ofxFft, move the ofxFft folder into your of/addons/ directory.

If you are using openFrameworks version 0.9.0 or later, the OF Project Generator will automatically add the required compiler search paths if you configure the project to include ofxFft.

mv ofxFft of/addons/

By default, ofxFft uses KISS FFT (included with OF). To use FFTW instead, follow these steps:

1. Download the precompiled libraries.
2. Define OFX_FFT_USE_FFTW in your compiler flags/preprocessor settings.
3. If on Windows, add the FFTW include path and link the specific DLL.
4. Update your code to use the FFTW flag in the ofxFft::create call.

The project files for the included examples (like example-basic or example-eq) are not included in the repository. You must generate them using the openFrameworks ProjectGenerator:

1. Point the ProjectGenerator to addons/ofxFft.
2. Change the project name to the exact name of the example you want to generate (e.g., example-basic).
3. Ensure ofxFft is selected from the addons list.
4. Click "Generate".

To explicitly use the FFTW backend in your code (e.g., in inApp.cpp), modify the ofxFft::create call to include the OF_FFT_FFTW flag.

// Standard KISS FFT usage:
// fft = ofxFft::create(bufferSize, OF_FFT_WINDOW_HAMMING);

// FFTW usage:
fft = ofxFft::create(bufferSize, OF_FFT_WINDOW_HAMMING, OF_FFT_FFTW);

If you are using FFTW on Windows, you must also perform these additional steps:

1. Add the include directory: of/addons/ofxFft/libs/fftw/include
2. Link with the library: of/addons/ofxFft/libs/fftw/lib/win32/libfftw3f-3.dll

Include path: of/addons/ofxFft/libs/fftw/include
Link with: of/addons/ofxFft/libs/fftw/lib/win32/libfftw3f-3.dll

To enable FFTW support, you must add the OFX_FFT_USE_FFTW definition to your project settings based on your development environment:

### Xcode
Select Project -> Build Settings -> Other C++ Flags
Add: `-DOFX_FFT_USE_FFTW`

### Linux (Makefiles & Codeblocks)
Edit `config.make` in your project folder and add to the `USER_CFLAGS` line:
`-DOFX_FFT_USE_FFTW`

### Codeblocks (Windows)
Right-click project -> "Build options..." -> Select project name (not release/debug) -> "Compiler settings" tab -> "#defines" tab -> Add: `OFX_FFT_USE_FFTW`

### Visual Studio
Right-click project -> Properties -> Set Configuration to "All Configurations" -> Configuration Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions -> Add: `OFX_FFT_USE_FFTW`

The ProcessFFT class provides several methods to extract processed audio data:

Frequency Bands:

• getSuperLowVal()
• getLowVal()
• getMidVal()
• getHighVal()
• getLoudBand(): Returns the index of the loudest frequency band for the current frame.

Audio Metrics:

• getLoudBand(): Returns the loudness of the loudest band.
• getUnscaledLoudestValue(): Returns the raw loudest value.
• getSmoothedUnscaledLoudestValue(): Returns a smoothed version of the raw loudest value.
• getDelta(): Returns the change in loudness.
• getIntensityAtFrequency(float _freq): Returns the intensity at a specific frequency.
• getSpectrum(): Returns a vector<float> containing the full spectrum amplitudes.
• getFFTpercentage(): Returns the current percentage of the FFT being used.

The ProcessFFT class provides a high-level interface for performing Fast Fourier Transforms (FFT) on audio data within an openFrameworks project. It simplifies frequency analysis by providing pre-calculated values for specific frequency bands (SuperLow, Low, Mid, High) and various audio metrics like loudness and spectral intensity.

To use it, you typically call setup() during your application's initialization and update() within your main update loop to process the incoming audio buffer.

ProcessFFT fftProcessor;

// In setup()
fftProcessor.setup();

// In update()
fftProcessor.update();

// In draw()
float lowVal = fftProcessor.getLowVal();

For debugging and visualization, ProcessFFT includes built-in drawing methods:

• drawBars(): Renders visual bars representing the FFT.
• drawDebug(): Renders debug information.
• drawHistoryGraph(ofPoint pt, fftRangeType drawType): Draws a history graph at the specified position for a specific frequency range. Valid fftRangeType values are:
  • SUPERLOW
  • LOW
  • MID
  • HIGH
  • MAXSOUND

fftProcessor.drawBars();
fftProcessor.drawHistoryGraph(ofPoint(100, 100), LOW);

The fftRangeType enum is used by drawHistoryGraph to specify which frequency band's history should be visualized.

enum fftRangeType {
    SUPERLOW,
    LOW,
    MID,
    HIGH,
    MAXSOUND
};