complex FFT

[LauerViolence]

Integrated the output of complex numbers split into real and imaginairy parts into the existing FFT-function. They are output as double-values.
Also added separate IFFT-Function in double precision for resynthesis. Works for now, but buffering and inverse windowing could be improved in the future.

This makes convolution of audio-signals (f.e. for filters or reverbs) possible.

Alternatively the complex-output-FFT could be implemented as a separate function to keep the existing one (which serves mainly analysis purposes) in its state and have the complex one (which serves processing purposes) separate.

[joreg]

Please remove the following unnecessary changes from the PR:

• adding \runtims\VL.Audio - Verknüpfung.lnk
• adding \src\Backu\VL.Audio.sln
• adding UpgradeLog.htm
• the change to VL.Audio.sln is a downgrade as you seem to be working with an older VS version. if you can't update VS, simply don't commit changes to that file

[LauerViolence]

Done, I´ve also noticed that I somehow accidentially added a second set of dependencies for different version of many packages, which I reverted now. Sorry, I´m very new to this sort of thing but I hope my changes are usable now.

[tebjan]

Just saw this randomly and have some thoughts about it:

• complex FFT and IFFT should be done solely in the Audio loop, not in the main loop on update. it is virtually impossible to keep that synchronous

Following that thought:

• I would not add the outputs to the standard FFT node but make a new node that is made for the purpose of FFT resynthesis which is actually a region that has FFT data as input and FFT data as output. this way it is guaranteed that the resynthesis is correct and the user doesn't have the mental load of dealing with synchronization.

It should be relatively easy to do with the NWaves library.

The nodes doing FFF/IFFT on update like the vvvv beta nodes do no harm, but aren't that useful, unfortunately.

[LauerViolence]

good point, I´ll try doing that, for now I mainly wanted to use this for non-realtime cases (such as convoluting audiosignals with graphics data and playing back the resulting blocks on loop) so it doesn´t need to be synchronous but in general I´ll move it towards the audio-loop