3DS port

[asiekierka]

It's happening! There's a port-3ds branch for development now; it will form the basis of NitrousTracker 0.7.0.

The main omissions at this point are:

• Widgets
  • patch piano to support direct pixel drawing
  • patch typewriter to support direct pixel drawing
  • patch FX keyboard to support direct pixel drawing
  • implement microphone recording
  • patch sample display to support direct pixel drawing (reverting to the pre-OAM code on non-NDS platforms)
  • fix rendering bugs in envelope editor
• Layout
  • the sub screen is still, effectively, laid out around a 256x192 display (de-hardcoding locations/sizes encouraged for future porting work)
  • add support for swapping screens (i propose that in the swapped mode on 3DS, the pattern view screen is resized to 320x240, while the sub screen is 320x240 with black borders, to simplify things for now)
  • fix a bug where, when scrolled to the right edge of the pattern view, the scrolling is not updated when swapping to the smaller screen
• Audio
  • implement 3DS playback engine