Use inline wrappers to clarify forward/inverse FFTs

2 files changed, 18 insertions, 5 deletions

diff --git a/common/alcomplex.cpp b/common/alcomplex.cpp
index 0af9fc98..f1d13551 100644
--- a/common/alcomplex.cpp
+++ b/common/alcomplex.cpp
@@ -51,7 +51,7 @@ void complex_fft(const al::span<std::complex<double>> buffer, const double sign)
 
 void complex_hilbert(const al::span<std::complex<double>> buffer)
 {
-    complex_fft(buffer, 1.0);
+    inverse_fft(buffer);
 
     const double inverse_size = 1.0/static_cast<double>(buffer.size());
     auto bufiter = buffer.begin();
@@ -65,5 +65,5 @@ void complex_hilbert(const al::span<std::complex<double>> buffer)
 
     std::fill(bufiter, buffer.end(), std::complex<double>{});
 
-    complex_fft(buffer, -1.0);
+    forward_fft(buffer);
 }
diff --git a/common/alcomplex.h b/common/alcomplex.h
index 12b86436..23b8114a 100644
--- a/common/alcomplex.h
+++ b/common/alcomplex.h
@@ -7,13 +7,26 @@
 
 /**
  * Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is
- * FFT and 1 is iFFT (inverse). Fills the buffer with the Discrete Fourier
- * Transform (DFT) of the time domain data stored in the buffer. The buffer is
- * an array of complex numbers, and MUST BE power of two.
+ * 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