- do overscan cropping after the ntsc frame is generated. this allows
removing left and right screen artifacts when using horizontal crop like
what you would see happen in TV when adjusting horizontal size (HSIZE).
- add core option that implements NTSC scanline effects. This requires
framebuffer to double the height, so a define is added (NTSC_SCANLINES at
the top of libretro.c) to disable this on some low-memory platforms or just disable NTSC filters altogether.
- some minor cleanups
- this implementation is based on a more accurate colour emphasis from fceux.
- The raw palette + nes decoder shader was kinda incomplete since the implementation was based on
a per-frame basis which means that the emphasis bits were read once and applied to the whole frame. This
means that some games that uses a per pixel or per scanline emphasis would not appear correct. The more
accurate implementation reads emphasis bits from bits 5-7 of PPU[1] and saves this info in a separate frame.
- The same implementation is also used to fix emphasis for the ntsc filter.
- ines.c - misc cleanups
- Fix Dendy not restored when changing overrides back to auto mode
- directly apply new scanlines and additional scanlines when changing overclock settings
- (readability) change variable name overlock_state to overclock_enabled
mmc5 fix taken from fceux source code to handle correctly the register
$5130 in fceumm. Now we can play games like Legend of Link nes hack that
need this fix.
