Copying subarrays in PixelAudioMapper

[Ignotus-mago]

Sig[] and img[] are the same size. Subarrays can be mapped with the two LUTs, imageToSignalLUT and signalToImageLUT, when we move subarrays back and forth. This can be done with new signatures for mapImgToSig and mapSigToImg and the corresponding write methods.

[Ignotus-mago]

Slowly working my way through testing each method. Slowly. Tedious but essential.

[Ignotus-mago]

Revised pluck and plant methods, which step along the signal path. They only use signalPos as an argument for indexing, not x and y coordinates. Peel and stamp methods only use coordinates. Time now to hammer on pluck and plant methods.