N163 waveforms are reversed on visualizer

[Kyuchumimo]

This does not happen in FamiTracker v0.4.6 or 0CC-FamiTracker 0.3.15.3, only in j0CC-FamiTracker 0.6.3 or Dn-FamiTracker (which is based on j0CC-Famitracker 0.6.3, so this problem has always been present in Dn-Famitracker)

Using Wine 6.0.1 on Lubuntu 21.04

[Gumball2415]

After running some crosschecking with nsfplay, Dn-FamiTracker, and my Mappy Kids cartridge, it seems that this is correct and hardware accurate behavior.

nsfplay's N163 emulation in relation to hardware (top is nsfplay, bottom is famicom hardware)

• notice the direction of the saw base matching hardware
• note that the phase of the hardware recording is globally inverted, so i had to revert it for easier comparison

Dn-FT's N163 emulation in relation to nsfplay: (top is Dn-FT, bottom is nsfplay)

test recordings used. note that famicom hardware audio phase is overall inverted, but in relation to 2a03, it's still correct.