From 20d28e80a5c861a9d5f449ea911ab75b4f37ad0d Mon Sep 17 00:00:00 2001 From: Jef Date: Tue, 24 Sep 2024 14:54:57 +0200 Subject: Initial community commit --- .../openmpt-trunk/soundlib/TinyFFT.h | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Src/external_dependencies/openmpt-trunk/soundlib/TinyFFT.h (limited to 'Src/external_dependencies/openmpt-trunk/soundlib/TinyFFT.h') diff --git a/Src/external_dependencies/openmpt-trunk/soundlib/TinyFFT.h b/Src/external_dependencies/openmpt-trunk/soundlib/TinyFFT.h new file mode 100644 index 00000000..5f0e8f90 --- /dev/null +++ b/Src/external_dependencies/openmpt-trunk/soundlib/TinyFFT.h @@ -0,0 +1,42 @@ +/* + * TinyFFT.h + * --------- + * Purpose: A simple FFT implementation for power-of-two FFTs + * Notes : This is a C++ adaption of Ryuhei Mori's BSD 2-clause licensed TinyFFT + * available from https://github.com/ryuhei-mori/tinyfft + * Authors: Ryuhei Mori + * OpenMPT Devs + * The OpenMPT source code is released under the BSD license. Read LICENSE for more details. + */ + + +#pragma once + +#include "openmpt/all/BuildSettings.hpp" +#include + +OPENMPT_NAMESPACE_BEGIN + +class TinyFFT +{ + static constexpr std::complex I{0.0, 1.0}; + std::vector> w; // Pre-computed twiddle factors + const uint32 k; // log2 of FFT size + + void GenerateTwiddleFactors(uint32 i, uint32 b, std::complex z); + +public: + TinyFFT(const uint32 fftSize); + + uint32 Size() const noexcept; + + // Computes in-place FFT of size 2^k of A, result is in bit-reversed order. + void FFT(std::vector> &A) const; + + // Computes in-place IFFT of size 2^k of A, input is expected to be in bit-reversed order. + void IFFT(std::vector> &A) const; + + static void Normalize(std::vector> &data); +}; + +OPENMPT_NAMESPACE_END -- cgit