- Increase palette table from 256 to 1024. the 1st 256 colors are used
by FCEUmm internally and for compatibility (PS2/PSP will use the old
emphasis located in this area). New 512 colors with emphasis will be
read from offset 256 of this palette table.
- Support loading of 512 palette, this will still use the same nes.pal
filename.
- 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.
