[idea] using kissfft for general OF fft, all players.

[dimitre]

so it can serve as a placeholder until proper per platforms options are developed (if)
It is not hard to build Kiss for all platforms. I'm already building it in ofLibs
https://github.com/ofWorks/ofLibs/releases

soundPlayers can have an ofSoundFFT object inside

sketch: ofSoundFFT.h

#pragma once

#include <kissfft/kiss_fft.h>
#include <kissfft/kiss_fftr.h>
#include <vector>

class ofSoundFFT {
public:
	ofSoundFFT();
	~ofSoundFFT();

	void setup(int bands);
	void process(const float* input, int size);
	const std::vector<float>& getSpectrum() const { return spectrum; }
	
	static std::vector<float> createWindow(int size, int type = 0);
	static void applyWindow(std::vector<float> &signal, const std::vector<float> &window);

private:
	kiss_fftr_cfg fftCfg = nullptr;
	int fftSize = 0;
	std::vector<float> windowedSignal;
	std::vector<kiss_fft_cpx> cx_out;
	std::vector<float> spectrum;
	std::vector<float> window;
	float windowSum = 0.0f;
	
	float computeWindowSum(const std::vector<float>& window);
};

[dimitre]

related: https://forum.openframeworks.cc/t/ofsoundgetspectrum-not-implemented-on-this-platform-on-osx/45398/2

[dimitre]

I've implemented today in macOS using LLMs help. it seems to be working OK.
it uses KissFFT now but there are faster alternatives out there. maybe they can be plugged directly in ofSoundFFT later.