Provide Nintendo DS screen layout modes
Since Nintendo DS has two screens, and vertical layout isn't well suited for horizontal screens, Games should provide screen some layout modes.
Modes available in DeSmuME libretro core are:
- Top/bottom (default)
- Bottom/top
- Left/right
- Right/left
- Top only
- Bottom only
- Quick switch (top/bottom)
- Quick switch (bottom/top)
- Hybrid/top
- Hybrid/bottom
Hybrid modes also need desmume_hybrid_layout_scale
option neing set to 3
for the player to be able to see anything on smaller screen.
Other possible modes (require retro-gtk cooperation, so that's for later):