waterbackground - ArcadeTV/megadrive-samples GitHub Wiki

water background

Image by Davit Masia

I came across this effect in the main menu of Konami's Double Dribble. How this works is rather simple:

  • The plane scroll mode is set to line scroll (VDP register $0B)
  • The hscroll table is pre-filled with numbers that represent a sinus style offset for each line.
  • The plane is then moved vertically by writing an incremented value to the vscroll table, while the graphics are tiled across the plane's dimension.