void FFT::performRealOnlyForwardTransform (float* d) const noexcept
{
const size_t scratchSize = 16 + sizeof (FFT::Complex) * (size_t) size;
if (scratchSize < maxFFTScratchSpaceToAlloca)
{
performRealOnlyForwardTransform (static_cast<Complex*> (alloca (scratchSize)), d);
}
else
{
HeapBlock<char> heapSpace (scratchSize);
performRealOnlyForwardTransform (reinterpret_cast<Complex*> (heapSpace.getData()), d);
}
}
void FFT::performFrequencyOnlyForwardTransform (float* d) const noexcept
{
performRealOnlyForwardTransform (d);
const int twiceSize = size * 2;
for (int i = 0; i < twiceSize; i += 2)
{
d[i / 2] = juce_hypot (d[i], d[i + 1]);
if (i >= size)
{
d[i] = 0;
d[i + 1] = 0;
}
}
}
