FMod C# API definition for FFT is completely wrong

FMOD Engine
1

I might just be using it wrong, but the definition of FMOD_DSP_PARAMETER_FFT in C# seems completely wrong. I can’t do anything but get it to crash.

By reading the docs I believe I’ve figured out roughly how it should actually look, which is this struct (followed by an example of how to use it):

        [StructLayout(LayoutKind.Sequential)]
        private unsafe struct ActualDspParameterFft {
            public int length;
            public int numchannels;
            // note: not float**, float[] or float[][]
            public float* spectrum;
        }

        private unsafe void FeedFModFFTOutputIntoWaveform (Span<Vector2> waveform) {
            AssertOk(FMod.FFTDsp.getParameterFloat((int)FMOD.DSP_FFT.RMS, out var rms));
            AssertOk(FMod.FFTDsp.getParameterData((int)FMOD.DSP_FFT.SPECTRUMDATA, out var pSpectrum, out var nSpectrum));
            var pFft = (ActualDspParameterFft*)pSpectrum;
            // if the fft hasn't processed enough input yet its length or channels will be 0
            if ((pFft->length <= 0) || (pFft->numchannels <= 0))
                return;
            var spectrumData = new Span<float>(pFft->spectrum, pFft->length);
            // spectrumData contains the data for the first channel
        }
2

Hi,

Thank you for bringing this to our attention.

I will pass it onto our development team to investigate further.