gbadev.org forum archive

This is a read-only mirror of the content originally found on forum.gbadev.org (now offline), salvaged from Wayback machine copies. A new forum can be found here.

DS development > Multipoint touchscreen input?

#175802 - brave_orakio - Wed Feb 09, 2011 6:28 am

Hi guys, I was wondering about this. As far as I know, according to the specs the NDS can only detect one input point on the touchscreen.

But there was a game, in particular Hotel Dusk 215, that required you use two fingers to pull down two levers at the same time. I couldn't solve this puzzle cause I thought that it wasn't possible for multipoint touchscreen input for NDS. I just thought I was missing something and I finally gave up and checked a guide about the game and I saw that you can use two fingers for input.

So then, anybody know how this was accomplished? This question is more out of curiosity really. Heh.
_________________
help me

#175803 - TwentySeven - Wed Feb 09, 2011 7:07 am

Typically, if you touch two points at the same time, the input is read as coming from the average of those two points.

eg: the game was looking for input in between the two levers.

#175804 - sverx - Wed Feb 09, 2011 10:34 am

The resulting pressure point will be on the line connecting the 2 pressure points, the position on the line depending on how much pressure you do on the points. If you're pressing both with the same strength the you can assume the resulting value it's in between :)

#175807 - brave_orakio - Thu Feb 10, 2011 1:17 am

Ah I see! Thanks! I should probably try that when I play hotel dusk again. I'll try to slide my stylus across the middle of the two levers see if it works!

Again thank you!
_________________
help me