January 19, 2008 at 1:28 pm
I've been tossing around a few ideas on how you could pull off a control pad for a first person action game on the iPhone. This control scheme would be implemented in a native app with the SDK, it wouldn't be possible in the browser.
The problem at hand is that I can't think of any really feasible way to have a player hold the iPhone in their hands with more digits available for touching the screen than their two thumbs. This causes an issue, because most console first person games use the two thumbs to control movement and looking, and the index fingers on shoulder buttons to control shooting and jumping. With only two thumbs available you can't really look, move, and shoot all at once.
One option is to totally discard the looking aspect. This would result in a game like Wolfenstein 3D or Doom, where you can't look up or down. I really don't think I want to do that, however, which leaves me with trying to find some sort of compromise on what two actions the player can do simultaneously.
The image above shows the control scheme that I currently favor. The two circles would emulate analog sticks. You would keep your thumbs at the center of the two circles (note how this is only possible on a multi-touch device like the iPhone). As you slide your thumbs away from the centers, your character would respond in the direction your thumb slides. For example, moving your left thumb to the top of the move circle would make your character run forward. Moving your right thumb to the left of the look circle would make your character look to the left.
The buttons arranged around the circles are positioned based off of what tradeoffs I think make sense. In order to fire, you would need to remove your thumb from the move circle and tap the fire button. This means that moving and firing are mutually exclusive actions. You could look and fire at the same time, though, and I think that tends to be a bit more important than moving and firing. Also, pulling off a quick shot involves only a small amount of time with your thumb off the movement circle. You just quickly tap fire and then put your thumb back on the movement circle.
Similar to how firing and moving are mutually exclusive, jumping and looking are mutually exclusive. So long as a game doesn't involve tricky platforming sequences, I don't think this is a big loss.
The three buttons down the middle have less importance in that they don't need to be pushed in the heat of battle, so they're smaller.
So that's the control scheme I currently favor. An alternate idea is to do something similar to how the Metroid Prime series on Gamecube works. In that control scheme, there would be one circle that controlled either moving or looking based off the state of a switch on one side of the pad. The extra visual real estate could be used for larger buttons, and a lock-on button.
Any thoughts?