update openal-soft

sync point: master-ac5d40e40a0155351fe1be4aab30017b6a13a859

Engine/lib/openal-soft/common/alcomplex.h

@@ -0,0 +1,38 @@
+#ifndef ALCOMPLEX_H
+#define ALCOMPLEX_H
+
+#include <complex>
+
+#include "alspan.h"
+
+/**
+ * Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is
+ * FFT and 1 is inverse FFT. Applies the Discrete Fourier Transform (DFT) to
+ * the data supplied in the buffer, which MUST BE power of two.
+ */
+void complex_fft(const al::span<std::complex<double>> buffer, const double sign);
+
+/**
+ * Calculate the frequency-domain response of the time-domain signal in the
+ * provided buffer, which MUST BE power of two.
+ */
+inline void forward_fft(const al::span<std::complex<double>> buffer)
+{ complex_fft(buffer, -1.0); }
+
+/**
+ * Calculate the time-domain signal of the frequency-domain response in the
+ * provided buffer, which MUST BE power of two.
+ */
+inline void inverse_fft(const al::span<std::complex<double>> buffer)
+{ complex_fft(buffer, 1.0); }
+
+/**
+ * Calculate the complex helical sequence (discrete-time analytical signal) of
+ * the given input using the discrete Hilbert transform (In-place algorithm).
+ * Fills the buffer with the discrete-time analytical signal stored in the
+ * buffer. The buffer is an array of complex numbers and MUST BE power of two,
+ * and the imaginary components should be cleared to 0.
+ */
+void complex_hilbert(const al::span<std::complex<double>> buffer);
+
+#endif /* ALCOMPLEX_H */