Multitouch Interface on a Singletouch Screen

Super Cameraman · Post by **Super Cameraman** » Sat Aug 25, 2007 1:27 pm

I'm sure everyone here knows what a multitouch screen is. The iPhone has one, Microsoft's "Surface" has one, but multitouch screens are more expensive then singletouch, and they aren't very popular on portable devices. (Except for the iPhone.)

When you touch in two places on a single touch screen, like a DS, the screen picks that up as being touched directly in between the two points you touch it. Don't believe me? Open up Pictochat, or some sort of drawing app on a handheld, and draw with two fingers. It should look like a ghost is drawing in between your fingers.

So here's my idea. Look at this diagram.

(Somehow the lines came out wavy... Oh well)

Imagine that only points 1, 2, and 3 are visible. The yellow is invisible.

When you put your stylus on the area of point one, you are pressing point one. This is the same for points 2 and 3.

Now, when you put your styli (plural stylus, I think) on points 1 and 2, the touch screen thinks you are pressing the yellow point, "point 1 + 2." This also goes for 1 + 3, and 2 + 3.

The problem with this, is that, to my knowledge, a group of three buttons in this arrangement is the only way this would work. With four buttons in a square, when pressing buttons that are diagonal to each other, the two sets would appear the same to the touch screen.

I made a Flash application of this, but I have no where to host it, or test it. I won a PocketPC on eBay (Dell Axim X30) and it should be coming in a few days, but until then, I can't test it. (Unless you know how to work DSflash for the Nintendo DS...

Would this idea work?

SCM

Post by **bicostp** » Sat Aug 25, 2007 1:59 pm

What exactly are you trying to do?

If the Flash file is small enough you can just throw it on ImageShack.

Super Cameraman · Post by **Super Cameraman** » Sat Aug 25, 2007 2:05 pm

What I'm trying to do is make an application for a portable touch screen device that can be touched in more then one place at the same time... If I had a way to test it, I'm make a video of it in action, but that's going to have to wait a few days.

It's probably small enough, but I don't know how to use Imageshack...

SCM

vskid · Post by **vskid** » Sat Aug 25, 2007 2:09 pm

bicostp wrote:What exactly are you trying to do?

Yeah, I was thinking the same thing, seems like a lot of work for something that'll leave it harder than before.

For imageshack, just upload it, then get online with your pocket pc and go to it.

tom61 · Post by **tom61** » Sat Aug 25, 2007 2:31 pm

Hmm... Interesting concept. Could be interesting if combined with an onscreen gamepad on the Nokia 770 for emulators, just calculate the offsets between the buttons and gamepad directions and have them initiate the combination of the two when touched. The 770 has poor button layout and can't handle multiple physical button presses, but the trick you posted here seems to work everytime, in the vertical plane at least.

However, I've tried multi-touching a Pocket PC's screen before (as it works as right click on some PC touch screens), and the results are inconsistent at best. On my Axim X5 I seem to recall it registering the bottom-most tap only, on my current Toshiba e350 PPC, I can only get the in-between one to register only half the time, otherwise it registers the lower tap.

Post by **Skyone** » Sat Aug 25, 2007 2:37 pm

Yes, but if you are only single touching, it will register it as a multi-touch no matter what. You'd then have to modify the LCD to receive the heat from your fingers, that's too much.

Also (as you may have stated, I don't fully understand your post), there would be no way of finding the two points from one, as there are quite a few possibilities of where the two touches could be.

I really don't understand the full use of this. It seems it would be easier to just buy a multi-touch screen overlay.

Super Cameraman · Post by **Super Cameraman** » Sat Aug 25, 2007 2:37 pm

Well whatever I try touching with two styluses, it usually uses the points in between the two... This worked so far on my old Toshiba e755 pocketpc, my DS, DS lite, and my Palm Zire 31...

Another idea, using the same layout, could be a simple drumset app. You would have a bass drum, snare, and hihat, and you can use more then one at the same time... When I get the PocketPC, I'll try that.

EDIT: Okay, I uploaded some tests. Test them out using a PocketPC or something else with a touch screen.

Number 1: Button Test
Press the circles. Try pressing more then one at the same time.

Number 2: Drums
Play a bass drum, snare, an hi hat.

tom61 · Post by **tom61** » Sat Aug 25, 2007 9:49 pm

Interesting test. I tried it on my Lifebook, inconsistent results. Most of the time it worked, but sometimes it would only register one.

I've been playing with multitouch on my 770, and it has different interaction zones. I drew a gamepad in the sketch program, and played with that. For the most part, it worked, but sometimes you had to lift both fingers off and tap at the exact same time, not the best for gamepad emulation.

For those that are wondering what this could be used for (if the effect worked 100% of the time), imagine a touch screen based machine with poor or no game controls (quite a few out there, Nokia 770, Dell Axim X30 just as examples from this thread) that don't use 4:3 screens emulating older systems. With current on-screen controller interfaces, the only way to register more than one button, or a direction and a button, is to press one in the hardware, and one on-screen. With this effect, you could put the D-Pad on one side, and a set of buttons on the other. Then when both are pressed at the same time, it registers a press in between (in an easily calculatable range, no worse than a shown button). The 770 has a wide screen, so the on-screen D-pad could be on the right, virtual gameboy screen in the middle, then buttons on the right. Then, taps registered 1/2 way between a given button and a direction (where the gameboy screen is) can trigger both the button and direction.

Hopefully that made some sense. While you can't do cool stuff like a rotatory dial, you can do interesting stuff if you limit the interface.

vskid · Post by **vskid** » Sat Aug 25, 2007 11:40 pm

I understand now, I think it only seems practical for purposes similar to what tom61 was saying, theres not really much else that I can think of that you wouldn't be able to this with easier with just one touch. But where the emulator would just have you hitting a set amount of buttons, that seems entirely possible.

Super Cameraman · Post by **Super Cameraman** » Sun Aug 26, 2007 8:50 am

Well, it's not like I was trying to change the way touch screens work forever, I just got curious, and wanted to test it out. Thanks for the help though. My PocketPC might come today, so I'll test it out, and make new tests. It's worth a shot.